mirror of
https://gitlab.winehq.org/wine/wine-gecko.git
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3839 lines
156 KiB
C++
3839 lines
156 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* vim: set ts=2 et sw=2 tw=80: */
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/* This Source Code is subject to the terms of the Mozilla Public License
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* version 2.0 (the "License"). You can obtain a copy of the License at
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* http://mozilla.org/MPL/2.0/. */
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/* rendering object for CSS "display: flex" */
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#include "nsFlexContainerFrame.h"
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#include "nsContentUtils.h"
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#include "nsCSSAnonBoxes.h"
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#include "nsDisplayList.h"
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#include "nsIFrameInlines.h"
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#include "nsLayoutUtils.h"
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#include "nsPlaceholderFrame.h"
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#include "nsPresContext.h"
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#include "nsRenderingContext.h"
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#include "nsStyleContext.h"
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#include "nsStyleUtil.h"
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#include "prlog.h"
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#include <algorithm>
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#include "mozilla/LinkedList.h"
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#include "mozilla/FloatingPoint.h"
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using namespace mozilla;
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using namespace mozilla::layout;
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// Convenience typedefs for helper classes that we forward-declare in .h file
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// (so that nsFlexContainerFrame methods can use them as parameters):
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typedef nsFlexContainerFrame::FlexItem FlexItem;
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typedef nsFlexContainerFrame::FlexLine FlexLine;
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typedef nsFlexContainerFrame::FlexboxAxisTracker FlexboxAxisTracker;
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typedef nsFlexContainerFrame::StrutInfo StrutInfo;
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#ifdef PR_LOGGING
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static PRLogModuleInfo*
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GetFlexContainerLog()
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{
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static PRLogModuleInfo *sLog;
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if (!sLog)
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sLog = PR_NewLogModule("nsFlexContainerFrame");
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return sLog;
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}
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#endif /* PR_LOGGING */
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// XXXdholbert Some of this helper-stuff should be separated out into a general
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// "LogicalAxisUtils.h" helper. Should that be a class, or a namespace (under
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// what super-namespace?), or what?
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// Helper enums
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// ============
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// Represents a physical orientation for an axis.
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// The directional suffix indicates the direction in which the axis *grows*.
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// So e.g. eAxis_LR means a horizontal left-to-right axis, whereas eAxis_BT
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// means a vertical bottom-to-top axis.
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// NOTE: The order here is important -- these values are used as indices into
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// the static array 'kAxisOrientationToSidesMap', defined below.
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enum AxisOrientationType {
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eAxis_LR,
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eAxis_RL,
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eAxis_TB,
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eAxis_BT,
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eNumAxisOrientationTypes // For sizing arrays that use these values as indices
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};
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// Represents one or the other extreme of an axis (e.g. for the main axis, the
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// main-start vs. main-end edge.
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// NOTE: The order here is important -- these values are used as indices into
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// the sub-arrays in 'kAxisOrientationToSidesMap', defined below.
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enum AxisEdgeType {
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eAxisEdge_Start,
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eAxisEdge_End,
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eNumAxisEdges // For sizing arrays that use these values as indices
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};
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// This array maps each axis orientation to a pair of corresponding
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// [start, end] physical mozilla::Side values.
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static const mozilla::Side
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kAxisOrientationToSidesMap[eNumAxisOrientationTypes][eNumAxisEdges] = {
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{ eSideLeft, eSideRight }, // eAxis_LR
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{ eSideRight, eSideLeft }, // eAxis_RL
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{ eSideTop, eSideBottom }, // eAxis_TB
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{ eSideBottom, eSideTop } // eAxis_BT
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};
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// Helper structs / classes / methods
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// ==================================
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// Indicates whether advancing along the given axis is equivalent to
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// increasing our X or Y position (as opposed to decreasing it).
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static inline bool
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AxisGrowsInPositiveDirection(AxisOrientationType aAxis)
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{
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return eAxis_LR == aAxis || eAxis_TB == aAxis;
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}
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// Indicates whether the given axis is horizontal.
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static inline bool
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IsAxisHorizontal(AxisOrientationType aAxis)
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{
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return eAxis_LR == aAxis || eAxis_RL == aAxis;
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}
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// Given an AxisOrientationType, returns the "reverse" AxisOrientationType
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// (in the same dimension, but the opposite direction)
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static inline AxisOrientationType
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GetReverseAxis(AxisOrientationType aAxis)
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{
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AxisOrientationType reversedAxis;
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if (aAxis % 2 == 0) {
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// even enum value. Add 1 to reverse.
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reversedAxis = AxisOrientationType(aAxis + 1);
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} else {
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// odd enum value. Subtract 1 to reverse.
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reversedAxis = AxisOrientationType(aAxis - 1);
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}
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// Check that we're still in the enum's valid range
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MOZ_ASSERT(reversedAxis >= eAxis_LR &&
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reversedAxis <= eAxis_BT);
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return reversedAxis;
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}
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// Returns aFrame's computed value for 'height' or 'width' -- whichever is in
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// the same dimension as aAxis.
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static inline const nsStyleCoord&
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GetSizePropertyForAxis(const nsIFrame* aFrame, AxisOrientationType aAxis)
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{
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const nsStylePosition* stylePos = aFrame->StylePosition();
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return IsAxisHorizontal(aAxis) ?
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stylePos->mWidth :
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stylePos->mHeight;
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}
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/**
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* Converts a logical position in a given axis into a position in the
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* corresponding physical (x or y) axis. If the logical axis already maps
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* directly onto one of our physical axes (i.e. LTR or TTB), then the logical
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* and physical positions are equal; otherwise, we subtract the logical
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* position from the container-size in that axis, to flip the polarity.
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* (so e.g. a logical position of 2px in a RTL 20px-wide container
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* would correspond to a physical position of 18px.)
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*/
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static nscoord
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PhysicalPosFromLogicalPos(nscoord aLogicalPosn,
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nscoord aLogicalContainerSize,
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AxisOrientationType aAxis) {
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if (AxisGrowsInPositiveDirection(aAxis)) {
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return aLogicalPosn;
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}
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return aLogicalContainerSize - aLogicalPosn;
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}
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// Helper-macro to let us pick one of two expressions to evaluate
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// (a width expression vs. a height expression), to get a main-axis or
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// cross-axis component.
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// For code that has e.g. a nsSize object, FlexboxAxisTracker::GetMainComponent
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// and GetCrossComponent are cleaner; but in cases where we simply have
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// two separate expressions for width and height (which may be expensive to
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// evaluate), these macros will ensure that only the expression for the correct
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// axis gets evaluated.
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#define GET_MAIN_COMPONENT(axisTracker_, width_, height_) \
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IsAxisHorizontal((axisTracker_).GetMainAxis()) ? (width_) : (height_)
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#define GET_CROSS_COMPONENT(axisTracker_, width_, height_) \
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IsAxisHorizontal((axisTracker_).GetCrossAxis()) ? (width_) : (height_)
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// Encapsulates our flex container's main & cross axes.
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class MOZ_STACK_CLASS nsFlexContainerFrame::FlexboxAxisTracker {
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public:
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explicit FlexboxAxisTracker(nsFlexContainerFrame* aFlexContainerFrame);
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// Accessors:
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AxisOrientationType GetMainAxis() const { return mMainAxis; }
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AxisOrientationType GetCrossAxis() const { return mCrossAxis; }
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nscoord GetMainComponent(const nsSize& aSize) const {
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return GET_MAIN_COMPONENT(*this, aSize.width, aSize.height);
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}
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int32_t GetMainComponent(const nsIntSize& aIntSize) const {
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return GET_MAIN_COMPONENT(*this, aIntSize.width, aIntSize.height);
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}
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nscoord GetCrossComponent(const nsSize& aSize) const {
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return GET_CROSS_COMPONENT(*this, aSize.width, aSize.height);
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}
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int32_t GetCrossComponent(const nsIntSize& aIntSize) const {
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return GET_CROSS_COMPONENT(*this, aIntSize.width, aIntSize.height);
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}
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nscoord GetMarginSizeInMainAxis(const nsMargin& aMargin) const {
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return IsAxisHorizontal(mMainAxis) ?
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aMargin.LeftRight() :
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aMargin.TopBottom();
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}
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nscoord GetMarginSizeInCrossAxis(const nsMargin& aMargin) const {
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return IsAxisHorizontal(mCrossAxis) ?
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aMargin.LeftRight() :
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aMargin.TopBottom();
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}
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/**
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* Converts a logical point into a "physical" x,y point.
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*
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* In the simplest case where the main-axis is left-to-right and the
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* cross-axis is top-to-bottom, this just returns
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* nsPoint(aMainPosn, aCrossPosn).
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*
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* @arg aMainPosn The main-axis position -- i.e an offset from the
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* main-start edge of the container's content box.
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* @arg aCrossPosn The cross-axis position -- i.e an offset from the
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* cross-start edge of the container's content box.
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* @return A nsPoint representing the same position (in coordinates
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* relative to the container's content box).
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*/
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nsPoint PhysicalPointFromLogicalPoint(nscoord aMainPosn,
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nscoord aCrossPosn,
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nscoord aContainerMainSize,
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nscoord aContainerCrossSize) const {
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nscoord physicalPosnInMainAxis =
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PhysicalPosFromLogicalPos(aMainPosn, aContainerMainSize, mMainAxis);
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nscoord physicalPosnInCrossAxis =
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PhysicalPosFromLogicalPos(aCrossPosn, aContainerCrossSize, mCrossAxis);
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return IsAxisHorizontal(mMainAxis) ?
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nsPoint(physicalPosnInMainAxis, physicalPosnInCrossAxis) :
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nsPoint(physicalPosnInCrossAxis, physicalPosnInMainAxis);
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}
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nsSize PhysicalSizeFromLogicalSizes(nscoord aMainSize,
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nscoord aCrossSize) const {
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return IsAxisHorizontal(mMainAxis) ?
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nsSize(aMainSize, aCrossSize) :
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nsSize(aCrossSize, aMainSize);
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}
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// Are my axes reversed with respect to what the author asked for?
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// (We may reverse the axes in the FlexboxAxisTracker constructor and set
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// this flag, to avoid reflowing our children in bottom-to-top order.)
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bool AreAxesInternallyReversed() const
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{
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return mAreAxesInternallyReversed;
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}
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private:
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AxisOrientationType mMainAxis;
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AxisOrientationType mCrossAxis;
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bool mAreAxesInternallyReversed;
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};
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/**
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* Represents a flex item.
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* Includes the various pieces of input that the Flexbox Layout Algorithm uses
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* to resolve a flexible width.
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*/
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class nsFlexContainerFrame::FlexItem : public LinkedListElement<FlexItem>
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{
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public:
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// Normal constructor:
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FlexItem(nsHTMLReflowState& aFlexItemReflowState,
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float aFlexGrow, float aFlexShrink, nscoord aMainBaseSize,
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nscoord aMainMinSize, nscoord aMainMaxSize,
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nscoord aCrossMinSize, nscoord aCrossMaxSize,
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const FlexboxAxisTracker& aAxisTracker);
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// Simplified constructor, to be used only for generating "struts":
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FlexItem(nsIFrame* aChildFrame, nscoord aCrossSize);
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// Accessors
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nsIFrame* Frame() const { return mFrame; }
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nscoord GetFlexBaseSize() const { return mFlexBaseSize; }
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nscoord GetMainMinSize() const {
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MOZ_ASSERT(!mNeedsMinSizeAutoResolution,
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"Someone's using an unresolved 'auto' main min-size");
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return mMainMinSize;
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}
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nscoord GetMainMaxSize() const { return mMainMaxSize; }
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// Note: These return the main-axis position and size of our *content box*.
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nscoord GetMainSize() const { return mMainSize; }
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nscoord GetMainPosition() const { return mMainPosn; }
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nscoord GetCrossMinSize() const { return mCrossMinSize; }
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nscoord GetCrossMaxSize() const { return mCrossMaxSize; }
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// Note: These return the cross-axis position and size of our *content box*.
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nscoord GetCrossSize() const { return mCrossSize; }
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nscoord GetCrossPosition() const { return mCrossPosn; }
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// Convenience methods to compute the main & cross size of our *margin-box*.
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// The caller is responsible for telling us the right axis, so that we can
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// pull out the appropriate components of our margin/border/padding structs.
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nscoord GetOuterMainSize(AxisOrientationType aMainAxis) const
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{
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return mMainSize + GetMarginBorderPaddingSizeInAxis(aMainAxis);
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}
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nscoord GetOuterCrossSize(AxisOrientationType aCrossAxis) const
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{
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return mCrossSize + GetMarginBorderPaddingSizeInAxis(aCrossAxis);
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}
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// Returns the distance between this FlexItem's baseline and the cross-start
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// edge of its margin-box. Used in baseline alignment.
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// (This function needs to be told what cross axis is & which edge we're
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// measuring the baseline from, so that it can look up the appropriate
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// components from mMargin.)
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nscoord GetBaselineOffsetFromOuterCrossEdge(AxisOrientationType aCrossAxis,
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AxisEdgeType aEdge) const;
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float GetShareOfWeightSoFar() const { return mShareOfWeightSoFar; }
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bool IsFrozen() const { return mIsFrozen; }
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bool HadMinViolation() const { return mHadMinViolation; }
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bool HadMaxViolation() const { return mHadMaxViolation; }
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// Indicates whether this item received a preliminary "measuring" reflow
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// before its actual reflow.
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bool HadMeasuringReflow() const { return mHadMeasuringReflow; }
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// Indicates whether this item's cross-size has been stretched (from having
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// "align-self: stretch" with an auto cross-size and no auto margins in the
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// cross axis).
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bool IsStretched() const { return mIsStretched; }
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// Indicates whether we need to resolve an 'auto' value for the main-axis
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// min-[width|height] property.
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bool NeedsMinSizeAutoResolution() const
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{ return mNeedsMinSizeAutoResolution; }
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// Indicates whether this item is a "strut" left behind by an element with
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// visibility:collapse.
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bool IsStrut() const { return mIsStrut; }
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||
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uint8_t GetAlignSelf() const { return mAlignSelf; }
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||
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// Returns the flex factor (flex-grow or flex-shrink), depending on
|
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// 'aIsUsingFlexGrow'.
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//
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// Asserts fatally if called on a frozen item (since frozen items are not
|
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// flexible).
|
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float GetFlexFactor(bool aIsUsingFlexGrow)
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{
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MOZ_ASSERT(!IsFrozen(), "shouldn't need flex factor after item is frozen");
|
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return aIsUsingFlexGrow ? mFlexGrow : mFlexShrink;
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}
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|
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// Returns the weight that we should use in the "resolving flexible lengths"
|
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// algorithm. If we're using the flex grow factor, we just return that;
|
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// otherwise, we return the "scaled flex shrink factor" (scaled by our flex
|
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// base size, so that when both large and small items are shrinking, the large
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// items shrink more).
|
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//
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// I'm calling this a "weight" instead of a "[scaled] flex-[grow|shrink]
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// factor", to more clearly distinguish it from the actual flex-grow &
|
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// flex-shrink factors.
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//
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// Asserts fatally if called on a frozen item (since frozen items are not
|
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// flexible).
|
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float GetWeight(bool aIsUsingFlexGrow)
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{
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MOZ_ASSERT(!IsFrozen(), "shouldn't need weight after item is frozen");
|
||
|
||
if (aIsUsingFlexGrow) {
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return mFlexGrow;
|
||
}
|
||
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// We're using flex-shrink --> return mFlexShrink * mFlexBaseSize
|
||
if (mFlexBaseSize == 0) {
|
||
// Special-case for mFlexBaseSize == 0 -- we have no room to shrink, so
|
||
// regardless of mFlexShrink, we should just return 0.
|
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// (This is really a special-case for when mFlexShrink is infinity, to
|
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// avoid performing mFlexShrink * mFlexBaseSize = inf * 0 = undefined.)
|
||
return 0.0f;
|
||
}
|
||
return mFlexShrink * mFlexBaseSize;
|
||
}
|
||
|
||
// Getters for margin:
|
||
// ===================
|
||
const nsMargin& GetMargin() const { return mMargin; }
|
||
|
||
// Returns the margin component for a given mozilla::Side
|
||
nscoord GetMarginComponentForSide(mozilla::Side aSide) const
|
||
{ return mMargin.Side(aSide); }
|
||
|
||
// Returns the total space occupied by this item's margins in the given axis
|
||
nscoord GetMarginSizeInAxis(AxisOrientationType aAxis) const
|
||
{
|
||
mozilla::Side startSide = kAxisOrientationToSidesMap[aAxis][eAxisEdge_Start];
|
||
mozilla::Side endSide = kAxisOrientationToSidesMap[aAxis][eAxisEdge_End];
|
||
return GetMarginComponentForSide(startSide) +
|
||
GetMarginComponentForSide(endSide);
|
||
}
|
||
|
||
// Getters for border/padding
|
||
// ==========================
|
||
const nsMargin& GetBorderPadding() const { return mBorderPadding; }
|
||
|
||
// Returns the border+padding component for a given mozilla::Side
|
||
nscoord GetBorderPaddingComponentForSide(mozilla::Side aSide) const
|
||
{ return mBorderPadding.Side(aSide); }
|
||
|
||
// Returns the total space occupied by this item's borders and padding in
|
||
// the given axis
|
||
nscoord GetBorderPaddingSizeInAxis(AxisOrientationType aAxis) const
|
||
{
|
||
mozilla::Side startSide = kAxisOrientationToSidesMap[aAxis][eAxisEdge_Start];
|
||
mozilla::Side endSide = kAxisOrientationToSidesMap[aAxis][eAxisEdge_End];
|
||
return GetBorderPaddingComponentForSide(startSide) +
|
||
GetBorderPaddingComponentForSide(endSide);
|
||
}
|
||
|
||
// Getter for combined margin/border/padding
|
||
// =========================================
|
||
// Returns the total space occupied by this item's margins, borders and
|
||
// padding in the given axis
|
||
nscoord GetMarginBorderPaddingSizeInAxis(AxisOrientationType aAxis) const
|
||
{
|
||
return GetMarginSizeInAxis(aAxis) + GetBorderPaddingSizeInAxis(aAxis);
|
||
}
|
||
|
||
// Setters
|
||
// =======
|
||
// Helper to set the resolved value of min-[width|height]:auto for the main
|
||
// axis. (Should only be used if NeedsMinSizeAutoResolution() returns true.)
|
||
void UpdateMainMinSize(nscoord aNewMinSize)
|
||
{
|
||
NS_ASSERTION(aNewMinSize >= 0,
|
||
"How did we end up with a negative min-size?");
|
||
MOZ_ASSERT(mMainMaxSize >= aNewMinSize,
|
||
"Should only use this function for resolving min-size:auto, "
|
||
"and main max-size should be an upper-bound for resolved val");
|
||
MOZ_ASSERT(mNeedsMinSizeAutoResolution &&
|
||
(mMainMinSize == 0 || mFrame->IsThemed(mFrame->StyleDisplay())),
|
||
"Should only use this function for resolving min-size:auto, "
|
||
"so we shouldn't already have a nonzero min-size established "
|
||
"(unless it's a themed-widget-imposed minimum size)");
|
||
|
||
if (aNewMinSize > mMainMinSize) {
|
||
mMainMinSize = aNewMinSize;
|
||
// Also clamp main-size to be >= new min-size:
|
||
mMainSize = std::max(mMainSize, aNewMinSize);
|
||
}
|
||
mNeedsMinSizeAutoResolution = false;
|
||
}
|
||
|
||
// This sets our flex base size, and then sets our main size to the
|
||
// resulting "hypothetical main size" (the base size clamped to our
|
||
// main-axis [min,max] sizing constraints).
|
||
void SetFlexBaseSizeAndMainSize(nscoord aNewFlexBaseSize)
|
||
{
|
||
MOZ_ASSERT(!mIsFrozen || mFlexBaseSize == NS_INTRINSICSIZE,
|
||
"flex base size shouldn't change after we're frozen "
|
||
"(unless we're just resolving an intrinsic size)");
|
||
mFlexBaseSize = aNewFlexBaseSize;
|
||
|
||
// Before we've resolved flexible lengths, we keep mMainSize set to
|
||
// the 'hypothetical main size', which is the flex base size, clamped
|
||
// to the [min,max] range:
|
||
mMainSize = NS_CSS_MINMAX(mFlexBaseSize, mMainMinSize, mMainMaxSize);
|
||
}
|
||
|
||
// Setters used while we're resolving flexible lengths
|
||
// ---------------------------------------------------
|
||
|
||
// Sets the main-size of our flex item's content-box.
|
||
void SetMainSize(nscoord aNewMainSize)
|
||
{
|
||
MOZ_ASSERT(!mIsFrozen, "main size shouldn't change after we're frozen");
|
||
mMainSize = aNewMainSize;
|
||
}
|
||
|
||
void SetShareOfWeightSoFar(float aNewShare)
|
||
{
|
||
MOZ_ASSERT(!mIsFrozen || aNewShare == 0.0f,
|
||
"shouldn't be giving this item any share of the weight "
|
||
"after it's frozen");
|
||
mShareOfWeightSoFar = aNewShare;
|
||
}
|
||
|
||
void Freeze() { mIsFrozen = true; }
|
||
|
||
void SetHadMinViolation()
|
||
{
|
||
MOZ_ASSERT(!mIsFrozen,
|
||
"shouldn't be changing main size & having violations "
|
||
"after we're frozen");
|
||
mHadMinViolation = true;
|
||
}
|
||
void SetHadMaxViolation()
|
||
{
|
||
MOZ_ASSERT(!mIsFrozen,
|
||
"shouldn't be changing main size & having violations "
|
||
"after we're frozen");
|
||
mHadMaxViolation = true;
|
||
}
|
||
void ClearViolationFlags()
|
||
{ mHadMinViolation = mHadMaxViolation = false; }
|
||
|
||
// Setters for values that are determined after we've resolved our main size
|
||
// -------------------------------------------------------------------------
|
||
|
||
// Sets the main-axis position of our flex item's content-box.
|
||
// (This is the distance between the main-start edge of the flex container
|
||
// and the main-start edge of the flex item's content-box.)
|
||
void SetMainPosition(nscoord aPosn) {
|
||
MOZ_ASSERT(mIsFrozen, "main size should be resolved before this");
|
||
mMainPosn = aPosn;
|
||
}
|
||
|
||
// Sets the cross-size of our flex item's content-box.
|
||
void SetCrossSize(nscoord aCrossSize) {
|
||
MOZ_ASSERT(!mIsStretched,
|
||
"Cross size shouldn't be modified after it's been stretched");
|
||
mCrossSize = aCrossSize;
|
||
}
|
||
|
||
// Sets the cross-axis position of our flex item's content-box.
|
||
// (This is the distance between the cross-start edge of the flex container
|
||
// and the cross-start edge of the flex item.)
|
||
void SetCrossPosition(nscoord aPosn) {
|
||
MOZ_ASSERT(mIsFrozen, "main size should be resolved before this");
|
||
mCrossPosn = aPosn;
|
||
}
|
||
|
||
void SetAscent(nscoord aAscent) {
|
||
mAscent = aAscent;
|
||
}
|
||
|
||
void SetHadMeasuringReflow() {
|
||
mHadMeasuringReflow = true;
|
||
}
|
||
|
||
void SetIsStretched() {
|
||
MOZ_ASSERT(mIsFrozen, "main size should be resolved before this");
|
||
mIsStretched = true;
|
||
}
|
||
|
||
// Setter for margin components (for resolving "auto" margins)
|
||
void SetMarginComponentForSide(mozilla::Side aSide, nscoord aLength)
|
||
{
|
||
MOZ_ASSERT(mIsFrozen, "main size should be resolved before this");
|
||
mMargin.Side(aSide) = aLength;
|
||
}
|
||
|
||
void ResolveStretchedCrossSize(nscoord aLineCrossSize,
|
||
const FlexboxAxisTracker& aAxisTracker);
|
||
|
||
uint32_t GetNumAutoMarginsInAxis(AxisOrientationType aAxis) const;
|
||
|
||
protected:
|
||
// Helper called by the constructor, to set mNeedsMinSizeAutoResolution:
|
||
void CheckForMinSizeAuto(const nsHTMLReflowState& aFlexItemReflowState,
|
||
const FlexboxAxisTracker& aAxisTracker);
|
||
|
||
// Our frame:
|
||
nsIFrame* const mFrame;
|
||
|
||
// Values that we already know in constructor: (and are hence mostly 'const')
|
||
const float mFlexGrow;
|
||
const float mFlexShrink;
|
||
|
||
const nsMargin mBorderPadding;
|
||
nsMargin mMargin; // non-const because we need to resolve auto margins
|
||
|
||
// These are non-const so that we can lazily update them with the item's
|
||
// intrinsic size (obtained via a "measuring" reflow), when necessary.
|
||
// (e.g. if we have a vertical flex item with "flex-basis:auto",
|
||
// "flex-basis:main-size;height:auto", or "min-height:auto")
|
||
nscoord mFlexBaseSize;
|
||
nscoord mMainMinSize;
|
||
nscoord mMainMaxSize;
|
||
|
||
const nscoord mCrossMinSize;
|
||
const nscoord mCrossMaxSize;
|
||
|
||
// Values that we compute after constructor:
|
||
nscoord mMainSize;
|
||
nscoord mMainPosn;
|
||
nscoord mCrossSize;
|
||
nscoord mCrossPosn;
|
||
nscoord mAscent;
|
||
|
||
// Temporary state, while we're resolving flexible widths (for our main size)
|
||
// XXXdholbert To save space, we could use a union to make these variables
|
||
// overlay the same memory as some other member vars that aren't touched
|
||
// until after main-size has been resolved. In particular, these could share
|
||
// memory with mMainPosn through mAscent, and mIsStretched.
|
||
float mShareOfWeightSoFar;
|
||
bool mIsFrozen;
|
||
bool mHadMinViolation;
|
||
bool mHadMaxViolation;
|
||
|
||
// Misc:
|
||
bool mHadMeasuringReflow; // Did this item get a preliminary reflow,
|
||
// to measure its desired height?
|
||
bool mIsStretched; // See IsStretched() documentation
|
||
bool mIsStrut; // Is this item a "strut" left behind by an element
|
||
// with visibility:collapse?
|
||
|
||
// Does this item need to resolve a min-[width|height]:auto (in main-axis).
|
||
bool mNeedsMinSizeAutoResolution;
|
||
|
||
uint8_t mAlignSelf; // My "align-self" computed value (with "auto"
|
||
// swapped out for parent"s "align-items" value,
|
||
// in our constructor).
|
||
};
|
||
|
||
/**
|
||
* Represents a single flex line in a flex container.
|
||
* Manages a linked list of the FlexItems that are in the line.
|
||
*/
|
||
class nsFlexContainerFrame::FlexLine : public LinkedListElement<FlexLine>
|
||
{
|
||
public:
|
||
FlexLine()
|
||
: mNumItems(0),
|
||
mNumFrozenItems(0),
|
||
mTotalInnerHypotheticalMainSize(0),
|
||
mTotalOuterHypotheticalMainSize(0),
|
||
mLineCrossSize(0),
|
||
mBaselineOffset(nscoord_MIN)
|
||
{}
|
||
|
||
// Returns the sum of our FlexItems' outer hypothetical main sizes.
|
||
// ("outer" = margin-box, and "hypothetical" = before flexing)
|
||
nscoord GetTotalOuterHypotheticalMainSize() const {
|
||
return mTotalOuterHypotheticalMainSize;
|
||
}
|
||
|
||
// Accessors for our FlexItems & information about them:
|
||
FlexItem* GetFirstItem()
|
||
{
|
||
MOZ_ASSERT(mItems.isEmpty() == (mNumItems == 0),
|
||
"mNumItems bookkeeping is off");
|
||
return mItems.getFirst();
|
||
}
|
||
|
||
const FlexItem* GetFirstItem() const
|
||
{
|
||
MOZ_ASSERT(mItems.isEmpty() == (mNumItems == 0),
|
||
"mNumItems bookkeeping is off");
|
||
return mItems.getFirst();
|
||
}
|
||
|
||
bool IsEmpty() const
|
||
{
|
||
MOZ_ASSERT(mItems.isEmpty() == (mNumItems == 0),
|
||
"mNumItems bookkeeping is off");
|
||
return mItems.isEmpty();
|
||
}
|
||
|
||
uint32_t NumItems() const
|
||
{
|
||
MOZ_ASSERT(mItems.isEmpty() == (mNumItems == 0),
|
||
"mNumItems bookkeeping is off");
|
||
return mNumItems;
|
||
}
|
||
|
||
// Adds the given FlexItem to our list of items (at the front or back
|
||
// depending on aShouldInsertAtFront), and adds its hypothetical
|
||
// outer & inner main sizes to our totals. Use this method instead of
|
||
// directly modifying the item list, so that our bookkeeping remains correct.
|
||
void AddItem(FlexItem* aItem,
|
||
bool aShouldInsertAtFront,
|
||
nscoord aItemInnerHypotheticalMainSize,
|
||
nscoord aItemOuterHypotheticalMainSize)
|
||
{
|
||
if (aShouldInsertAtFront) {
|
||
mItems.insertFront(aItem);
|
||
} else {
|
||
mItems.insertBack(aItem);
|
||
}
|
||
|
||
// Update our various bookkeeping member-vars:
|
||
mNumItems++;
|
||
if (aItem->IsFrozen()) {
|
||
mNumFrozenItems++;
|
||
}
|
||
mTotalInnerHypotheticalMainSize += aItemInnerHypotheticalMainSize;
|
||
mTotalOuterHypotheticalMainSize += aItemOuterHypotheticalMainSize;
|
||
}
|
||
|
||
// Computes the cross-size and baseline position of this FlexLine, based on
|
||
// its FlexItems.
|
||
void ComputeCrossSizeAndBaseline(const FlexboxAxisTracker& aAxisTracker);
|
||
|
||
// Returns the cross-size of this line.
|
||
nscoord GetLineCrossSize() const { return mLineCrossSize; }
|
||
|
||
// Setter for line cross-size -- needed for cases where the flex container
|
||
// imposes a cross-size on the line. (e.g. for single-line flexbox, or for
|
||
// multi-line flexbox with 'align-content: stretch')
|
||
void SetLineCrossSize(nscoord aLineCrossSize) {
|
||
mLineCrossSize = aLineCrossSize;
|
||
}
|
||
|
||
/**
|
||
* Returns the offset within this line where any baseline-aligned FlexItems
|
||
* should place their baseline. Usually, this represents a distance from the
|
||
* line's cross-start edge, but if we're internally reversing the axes (see
|
||
* AreAxesInternallyReversed()), this instead represents the distance from
|
||
* its cross-end edge.
|
||
*
|
||
* If there are no baseline-aligned FlexItems, returns nscoord_MIN.
|
||
*/
|
||
nscoord GetBaselineOffset() const {
|
||
return mBaselineOffset;
|
||
}
|
||
|
||
// Runs the "Resolving Flexible Lengths" algorithm from section 9.7 of the
|
||
// CSS flexbox spec to distribute aFlexContainerMainSize among our flex items.
|
||
void ResolveFlexibleLengths(nscoord aFlexContainerMainSize);
|
||
|
||
void PositionItemsInMainAxis(uint8_t aJustifyContent,
|
||
nscoord aContentBoxMainSize,
|
||
const FlexboxAxisTracker& aAxisTracker);
|
||
|
||
void PositionItemsInCrossAxis(nscoord aLineStartPosition,
|
||
const FlexboxAxisTracker& aAxisTracker);
|
||
|
||
friend class AutoFlexLineListClearer; // (needs access to mItems)
|
||
|
||
private:
|
||
// Helpers for ResolveFlexibleLengths():
|
||
void FreezeItemsEarly(bool aIsUsingFlexGrow);
|
||
|
||
void FreezeOrRestoreEachFlexibleSize(const nscoord aTotalViolation,
|
||
bool aIsFinalIteration);
|
||
|
||
LinkedList<FlexItem> mItems; // Linked list of this line's flex items.
|
||
|
||
uint32_t mNumItems; // Number of FlexItems in this line (in |mItems|).
|
||
// (Shouldn't change after GenerateFlexLines finishes
|
||
// with this line -- at least, not until we add support
|
||
// for splitting lines across continuations. Then we can
|
||
// update this count carefully.)
|
||
|
||
// Number of *frozen* FlexItems in this line, based on FlexItem::IsFrozen().
|
||
// Mostly used for optimization purposes, e.g. to bail out early from loops
|
||
// when we can tell they have nothing left to do.
|
||
uint32_t mNumFrozenItems;
|
||
|
||
nscoord mTotalInnerHypotheticalMainSize;
|
||
nscoord mTotalOuterHypotheticalMainSize;
|
||
nscoord mLineCrossSize;
|
||
nscoord mBaselineOffset;
|
||
};
|
||
|
||
// Information about a strut left behind by a FlexItem that's been collapsed
|
||
// using "visibility:collapse".
|
||
struct nsFlexContainerFrame::StrutInfo {
|
||
StrutInfo(uint32_t aItemIdx, nscoord aStrutCrossSize)
|
||
: mItemIdx(aItemIdx),
|
||
mStrutCrossSize(aStrutCrossSize)
|
||
{
|
||
}
|
||
|
||
uint32_t mItemIdx; // Index in the child list.
|
||
nscoord mStrutCrossSize; // The cross-size of this strut.
|
||
};
|
||
|
||
static void
|
||
BuildStrutInfoFromCollapsedItems(const FlexLine* aFirstLine,
|
||
nsTArray<StrutInfo>& aStruts)
|
||
{
|
||
MOZ_ASSERT(aFirstLine, "null first line pointer");
|
||
MOZ_ASSERT(aStruts.IsEmpty(),
|
||
"We should only build up StrutInfo once per reflow, so "
|
||
"aStruts should be empty when this is called");
|
||
|
||
uint32_t itemIdxInContainer = 0;
|
||
for (const FlexLine* line = aFirstLine; line; line = line->getNext()) {
|
||
for (const FlexItem* item = line->GetFirstItem(); item;
|
||
item = item->getNext()) {
|
||
if (NS_STYLE_VISIBILITY_COLLAPSE ==
|
||
item->Frame()->StyleVisibility()->mVisible) {
|
||
// Note the cross size of the line as the item's strut size.
|
||
aStruts.AppendElement(StrutInfo(itemIdxInContainer,
|
||
line->GetLineCrossSize()));
|
||
}
|
||
itemIdxInContainer++;
|
||
}
|
||
}
|
||
}
|
||
|
||
// Helper-function to find the first non-anonymous-box descendent of aFrame.
|
||
static nsIFrame*
|
||
GetFirstNonAnonBoxDescendant(nsIFrame* aFrame)
|
||
{
|
||
while (aFrame) {
|
||
nsIAtom* pseudoTag = aFrame->StyleContext()->GetPseudo();
|
||
|
||
// If aFrame isn't an anonymous container, then it'll do.
|
||
if (!pseudoTag || // No pseudotag.
|
||
!nsCSSAnonBoxes::IsAnonBox(pseudoTag) || // Pseudotag isn't anon.
|
||
pseudoTag == nsCSSAnonBoxes::mozNonElement) { // Text, not a container.
|
||
break;
|
||
}
|
||
|
||
// Otherwise, descend to its first child and repeat.
|
||
|
||
// SPECIAL CASE: if we're dealing with an anonymous table, then it might
|
||
// be wrapping something non-anonymous in its caption or col-group lists
|
||
// (instead of its principal child list), so we have to look there.
|
||
// (Note: For anonymous tables that have a non-anon cell *and* a non-anon
|
||
// column, we'll always return the column. This is fine; we're really just
|
||
// looking for a handle to *anything* with a meaningful content node inside
|
||
// the table, for use in DOM comparisons to things outside of the table.)
|
||
if (MOZ_UNLIKELY(aFrame->GetType() == nsGkAtoms::tableOuterFrame)) {
|
||
nsIFrame* captionDescendant =
|
||
GetFirstNonAnonBoxDescendant(aFrame->GetFirstChild(kCaptionList));
|
||
if (captionDescendant) {
|
||
return captionDescendant;
|
||
}
|
||
} else if (MOZ_UNLIKELY(aFrame->GetType() == nsGkAtoms::tableFrame)) {
|
||
nsIFrame* colgroupDescendant =
|
||
GetFirstNonAnonBoxDescendant(aFrame->GetFirstChild(kColGroupList));
|
||
if (colgroupDescendant) {
|
||
return colgroupDescendant;
|
||
}
|
||
}
|
||
|
||
// USUAL CASE: Descend to the first child in principal list.
|
||
aFrame = aFrame->GetFirstPrincipalChild();
|
||
}
|
||
return aFrame;
|
||
}
|
||
|
||
/**
|
||
* Sorting helper-function that compares two frames' "order" property-values,
|
||
* and if they're equal, compares the DOM positions of their corresponding
|
||
* content nodes. Returns true if aFrame1 is "less than or equal to" aFrame2
|
||
* according to this comparison.
|
||
*
|
||
* Note: This can't be a static function, because we need to pass it as a
|
||
* template argument. (Only functions with external linkage can be passed as
|
||
* template arguments.)
|
||
*
|
||
* @return true if the computed "order" property of aFrame1 is less than that
|
||
* of aFrame2, or if the computed "order" values are equal and aFrame1's
|
||
* corresponding DOM node is earlier than aFrame2's in the DOM tree.
|
||
* Otherwise, returns false.
|
||
*/
|
||
bool
|
||
IsOrderLEQWithDOMFallback(nsIFrame* aFrame1,
|
||
nsIFrame* aFrame2)
|
||
{
|
||
MOZ_ASSERT(aFrame1->IsFlexItem() && aFrame2->IsFlexItem(),
|
||
"this method only intended for comparing flex items");
|
||
|
||
if (aFrame1 == aFrame2) {
|
||
// Anything is trivially LEQ itself, so we return "true" here... but it's
|
||
// probably bad if we end up actually needing this, so let's assert.
|
||
NS_ERROR("Why are we checking if a frame is LEQ itself?");
|
||
return true;
|
||
}
|
||
|
||
// If we've got a placeholder frame, use its out-of-flow frame's 'order' val.
|
||
{
|
||
nsIFrame* aRealFrame1 = nsPlaceholderFrame::GetRealFrameFor(aFrame1);
|
||
nsIFrame* aRealFrame2 = nsPlaceholderFrame::GetRealFrameFor(aFrame2);
|
||
|
||
int32_t order1 = aRealFrame1->StylePosition()->mOrder;
|
||
int32_t order2 = aRealFrame2->StylePosition()->mOrder;
|
||
|
||
if (order1 != order2) {
|
||
return order1 < order2;
|
||
}
|
||
}
|
||
|
||
// The "order" values are equal, so we need to fall back on DOM comparison.
|
||
// For that, we need to dig through any anonymous box wrapper frames to find
|
||
// the actual frame that corresponds to our child content.
|
||
aFrame1 = GetFirstNonAnonBoxDescendant(aFrame1);
|
||
aFrame2 = GetFirstNonAnonBoxDescendant(aFrame2);
|
||
MOZ_ASSERT(aFrame1 && aFrame2,
|
||
"why do we have an anonymous box without any "
|
||
"non-anonymous descendants?");
|
||
|
||
|
||
// Special case:
|
||
// If either frame is for generated content from ::before or ::after, then
|
||
// we can't use nsContentUtils::PositionIsBefore(), since that method won't
|
||
// recognize generated content as being an actual sibling of other nodes.
|
||
// We know where ::before and ::after nodes *effectively* insert in the DOM
|
||
// tree, though (at the beginning & end), so we can just special-case them.
|
||
nsIAtom* pseudo1 = aFrame1->StyleContext()->GetPseudo();
|
||
nsIAtom* pseudo2 = aFrame2->StyleContext()->GetPseudo();
|
||
if (pseudo1 == nsCSSPseudoElements::before ||
|
||
pseudo2 == nsCSSPseudoElements::after) {
|
||
// frame1 is ::before and/or frame2 is ::after => frame1 is LEQ frame2.
|
||
return true;
|
||
}
|
||
if (pseudo1 == nsCSSPseudoElements::after ||
|
||
pseudo2 == nsCSSPseudoElements::before) {
|
||
// frame1 is ::after and/or frame2 is ::before => frame1 is not LEQ frame2.
|
||
return false;
|
||
}
|
||
|
||
// Usual case: Compare DOM position.
|
||
nsIContent* content1 = aFrame1->GetContent();
|
||
nsIContent* content2 = aFrame2->GetContent();
|
||
MOZ_ASSERT(content1 != content2,
|
||
"Two different flex items are using the same nsIContent node for "
|
||
"comparison, so we may be sorting them in an arbitrary order");
|
||
|
||
return nsContentUtils::PositionIsBefore(content1, content2);
|
||
}
|
||
|
||
/**
|
||
* Sorting helper-function that compares two frames' "order" property-values.
|
||
* Returns true if aFrame1 is "less than or equal to" aFrame2 according to this
|
||
* comparison.
|
||
*
|
||
* Note: This can't be a static function, because we need to pass it as a
|
||
* template argument. (Only functions with external linkage can be passed as
|
||
* template arguments.)
|
||
*
|
||
* @return true if the computed "order" property of aFrame1 is less than or
|
||
* equal to that of aFrame2. Otherwise, returns false.
|
||
*/
|
||
bool
|
||
IsOrderLEQ(nsIFrame* aFrame1,
|
||
nsIFrame* aFrame2)
|
||
{
|
||
MOZ_ASSERT(aFrame1->IsFlexItem() && aFrame2->IsFlexItem(),
|
||
"this method only intended for comparing flex items");
|
||
|
||
// If we've got a placeholder frame, use its out-of-flow frame's 'order' val.
|
||
nsIFrame* aRealFrame1 = nsPlaceholderFrame::GetRealFrameFor(aFrame1);
|
||
nsIFrame* aRealFrame2 = nsPlaceholderFrame::GetRealFrameFor(aFrame2);
|
||
|
||
int32_t order1 = aRealFrame1->StylePosition()->mOrder;
|
||
int32_t order2 = aRealFrame2->StylePosition()->mOrder;
|
||
|
||
return order1 <= order2;
|
||
}
|
||
|
||
bool
|
||
nsFlexContainerFrame::IsHorizontal()
|
||
{
|
||
const FlexboxAxisTracker axisTracker(this);
|
||
return IsAxisHorizontal(axisTracker.GetMainAxis());
|
||
}
|
||
|
||
FlexItem*
|
||
nsFlexContainerFrame::GenerateFlexItemForChild(
|
||
nsPresContext* aPresContext,
|
||
nsIFrame* aChildFrame,
|
||
const nsHTMLReflowState& aParentReflowState,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
// Create temporary reflow state just for sizing -- to get hypothetical
|
||
// main-size and the computed values of min / max main-size property.
|
||
// (This reflow state will _not_ be used for reflow.)
|
||
nsHTMLReflowState
|
||
childRS(aPresContext, aParentReflowState, aChildFrame,
|
||
aParentReflowState.ComputedSize(aChildFrame->GetWritingMode()));
|
||
|
||
// FLEX GROW & SHRINK WEIGHTS
|
||
// --------------------------
|
||
const nsStylePosition* stylePos = aChildFrame->StylePosition();
|
||
float flexGrow = stylePos->mFlexGrow;
|
||
float flexShrink = stylePos->mFlexShrink;
|
||
|
||
// MAIN SIZES (flex base size, min/max size)
|
||
// -----------------------------------------
|
||
nscoord flexBaseSize = GET_MAIN_COMPONENT(aAxisTracker,
|
||
childRS.ComputedWidth(),
|
||
childRS.ComputedHeight());
|
||
nscoord mainMinSize = GET_MAIN_COMPONENT(aAxisTracker,
|
||
childRS.ComputedMinWidth(),
|
||
childRS.ComputedMinHeight());
|
||
nscoord mainMaxSize = GET_MAIN_COMPONENT(aAxisTracker,
|
||
childRS.ComputedMaxWidth(),
|
||
childRS.ComputedMaxHeight());
|
||
// This is enforced by the nsHTMLReflowState where these values come from:
|
||
MOZ_ASSERT(mainMinSize <= mainMaxSize, "min size is larger than max size");
|
||
|
||
// CROSS MIN/MAX SIZE
|
||
// ------------------
|
||
|
||
nscoord crossMinSize = GET_CROSS_COMPONENT(aAxisTracker,
|
||
childRS.ComputedMinWidth(),
|
||
childRS.ComputedMinHeight());
|
||
nscoord crossMaxSize = GET_CROSS_COMPONENT(aAxisTracker,
|
||
childRS.ComputedMaxWidth(),
|
||
childRS.ComputedMaxHeight());
|
||
|
||
// SPECIAL-CASE FOR WIDGET-IMPOSED SIZES
|
||
// Check if we're a themed widget, in which case we might have a minimum
|
||
// main & cross size imposed by our widget (which we can't go below), or
|
||
// (more severe) our widget might have only a single valid size.
|
||
bool isFixedSizeWidget = false;
|
||
const nsStyleDisplay* disp = aChildFrame->StyleDisplay();
|
||
if (aChildFrame->IsThemed(disp)) {
|
||
nsIntSize widgetMinSize(0, 0);
|
||
bool canOverride = true;
|
||
aPresContext->GetTheme()->
|
||
GetMinimumWidgetSize(aPresContext, aChildFrame,
|
||
disp->mAppearance,
|
||
&widgetMinSize, &canOverride);
|
||
|
||
nscoord widgetMainMinSize =
|
||
aPresContext->DevPixelsToAppUnits(
|
||
aAxisTracker.GetMainComponent(widgetMinSize));
|
||
nscoord widgetCrossMinSize =
|
||
aPresContext->DevPixelsToAppUnits(
|
||
aAxisTracker.GetCrossComponent(widgetMinSize));
|
||
|
||
// GMWS() returns border-box. We need content-box, so subtract
|
||
// borderPadding (but don't let that push our min sizes below 0).
|
||
nsMargin& bp = childRS.ComputedPhysicalBorderPadding();
|
||
widgetMainMinSize = std::max(widgetMainMinSize -
|
||
aAxisTracker.GetMarginSizeInMainAxis(bp), 0);
|
||
widgetCrossMinSize = std::max(widgetCrossMinSize -
|
||
aAxisTracker.GetMarginSizeInCrossAxis(bp), 0);
|
||
|
||
if (!canOverride) {
|
||
// Fixed-size widget: freeze our main-size at the widget's mandated size.
|
||
// (Set min and max main-sizes to that size, too, to keep us from
|
||
// clamping to any other size later on.)
|
||
flexBaseSize = mainMinSize = mainMaxSize = widgetMainMinSize;
|
||
crossMinSize = crossMaxSize = widgetCrossMinSize;
|
||
isFixedSizeWidget = true;
|
||
} else {
|
||
// Variable-size widget: ensure our min/max sizes are at least as large
|
||
// as the widget's mandated minimum size, so we don't flex below that.
|
||
mainMinSize = std::max(mainMinSize, widgetMainMinSize);
|
||
mainMaxSize = std::max(mainMaxSize, widgetMainMinSize);
|
||
|
||
crossMinSize = std::max(crossMinSize, widgetCrossMinSize);
|
||
crossMaxSize = std::max(crossMaxSize, widgetCrossMinSize);
|
||
}
|
||
}
|
||
|
||
// Construct the flex item!
|
||
FlexItem* item = new FlexItem(childRS,
|
||
flexGrow, flexShrink, flexBaseSize,
|
||
mainMinSize, mainMaxSize,
|
||
crossMinSize, crossMaxSize,
|
||
aAxisTracker);
|
||
|
||
// If we're inflexible, we can just freeze to our hypothetical main-size
|
||
// up-front. Similarly, if we're a fixed-size widget, we only have one
|
||
// valid size, so we freeze to keep ourselves from flexing.
|
||
if (isFixedSizeWidget || (flexGrow == 0.0f && flexShrink == 0.0f)) {
|
||
item->Freeze();
|
||
}
|
||
|
||
// Resolve "flex-basis:auto" and/or "min-[width|height]:auto" (which might
|
||
// require us to reflow the item to measure content height)
|
||
ResolveAutoFlexBasisAndMinSize(aPresContext, *item,
|
||
childRS, aAxisTracker);
|
||
return item;
|
||
}
|
||
|
||
// Static helper-functions for ResolveAutoFlexBasisAndMinSize():
|
||
// -------------------------------------------------------------
|
||
// Indicates whether the cross-size property is set to something definite.
|
||
// The logic here should be similar to the logic for isAutoWidth/isAutoHeight
|
||
// in nsLayoutUtils::ComputeSizeWithIntrinsicDimensions().
|
||
static bool
|
||
IsCrossSizeDefinite(const nsHTMLReflowState& aItemReflowState,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
const nsStylePosition* pos = aItemReflowState.mStylePosition;
|
||
if (IsAxisHorizontal(aAxisTracker.GetCrossAxis())) {
|
||
return pos->mWidth.GetUnit() != eStyleUnit_Auto;
|
||
}
|
||
// else, vertical. (We need to use IsAutoHeight() to catch e.g. %-height
|
||
// applied to indefinite-height containing block, which counts as auto.)
|
||
nscoord cbHeight = aItemReflowState.mCBReflowState->ComputedHeight();
|
||
return !nsLayoutUtils::IsAutoHeight(pos->mHeight, cbHeight);
|
||
}
|
||
|
||
// If aFlexItem has a definite cross size, this function returns it, for usage
|
||
// (in combination with an intrinsic ratio) for resolving the item's main size
|
||
// or main min-size.
|
||
//
|
||
// The parameter "aMinSizeFallback" indicates whether we should fall back to
|
||
// returning the cross min-size, when the cross size is indefinite. (This param
|
||
// should be set IFF the caller intends to resolve the main min-size.) If this
|
||
// param is true, then this function is guaranteed to return a definite value
|
||
// (i.e. not NS_AUTOHEIGHT, excluding cases where huge sizes are involved).
|
||
//
|
||
// XXXdholbert the min-size behavior here is based on my understanding in
|
||
// http://lists.w3.org/Archives/Public/www-style/2014Jul/0053.html
|
||
// If my understanding there ends up being wrong, we'll need to update this.
|
||
static nscoord
|
||
CrossSizeToUseWithRatio(const FlexItem& aFlexItem,
|
||
const nsHTMLReflowState& aItemReflowState,
|
||
bool aMinSizeFallback,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
if (aFlexItem.IsStretched()) {
|
||
// Definite cross-size, imposed via 'align-self:stretch' & flex container.
|
||
return aFlexItem.GetCrossSize();
|
||
}
|
||
|
||
if (IsCrossSizeDefinite(aItemReflowState, aAxisTracker)) {
|
||
// Definite cross size.
|
||
return GET_CROSS_COMPONENT(aAxisTracker,
|
||
aItemReflowState.ComputedWidth(),
|
||
aItemReflowState.ComputedHeight());
|
||
}
|
||
|
||
if (aMinSizeFallback) {
|
||
// Indefinite cross-size, and we're resolving main min-size, so we'll fall
|
||
// back to ussing the cross min-size (which should be definite).
|
||
return GET_CROSS_COMPONENT(aAxisTracker,
|
||
aItemReflowState.ComputedMinWidth(),
|
||
aItemReflowState.ComputedMinHeight());
|
||
}
|
||
|
||
// Indefinite cross-size.
|
||
return NS_AUTOHEIGHT;
|
||
}
|
||
|
||
// Convenience function; returns a main-size, given a cross-size and an
|
||
// intrinsic ratio. The intrinsic ratio must not have 0 in its cross-axis
|
||
// component (or else we'll divide by 0).
|
||
static nscoord
|
||
MainSizeFromAspectRatio(nscoord aCrossSize,
|
||
const nsSize& aIntrinsicRatio,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
MOZ_ASSERT(aAxisTracker.GetCrossComponent(aIntrinsicRatio) != 0,
|
||
"Invalid ratio; will divide by 0! Caller should've checked...");
|
||
|
||
if (IsAxisHorizontal(aAxisTracker.GetCrossAxis())) {
|
||
// cross axis horiz --> aCrossSize is a width. Converting to height.
|
||
return NSCoordMulDiv(aCrossSize, aIntrinsicRatio.height, aIntrinsicRatio.width);
|
||
}
|
||
// cross axis vert --> aCrossSize is a height. Converting to width.
|
||
return NSCoordMulDiv(aCrossSize, aIntrinsicRatio.width, aIntrinsicRatio.height);
|
||
}
|
||
|
||
// Partially resolves "min-[width|height]:auto" and returns the resulting value.
|
||
// By "partially", I mean we don't consider the min-content size (but we do
|
||
// consider flex-basis, main max-size, and the intrinsic aspect ratio).
|
||
// The caller is responsible for computing & considering the min-content size
|
||
// in combination with the partially-resolved value that this function returns.
|
||
//
|
||
// Spec reference: http://dev.w3.org/csswg/css-flexbox/#min-size-auto
|
||
static nscoord
|
||
PartiallyResolveAutoMinSize(const FlexItem& aFlexItem,
|
||
const nsHTMLReflowState& aItemReflowState,
|
||
const nsSize& aIntrinsicRatio,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
MOZ_ASSERT(aFlexItem.NeedsMinSizeAutoResolution(),
|
||
"only call for FlexItems that need min-size auto resolution");
|
||
|
||
nscoord minMainSize = nscoord_MAX; // Intentionally huge; we'll shrink it
|
||
// from here, w/ std::min().
|
||
|
||
// We need the smallest of:
|
||
// * the used flex-basis, if the computed flex-basis was 'main-size':
|
||
const nsStyleCoord& flexBasis = aItemReflowState.mStylePosition->mFlexBasis;
|
||
const bool isHorizontal = IsAxisHorizontal(aAxisTracker.GetMainAxis());
|
||
if (nsStyleUtil::IsFlexBasisMainSize(flexBasis, isHorizontal) &&
|
||
aFlexItem.GetFlexBaseSize() != NS_AUTOHEIGHT) {
|
||
// NOTE: We skip this if the flex base size depends on content & isn't yet
|
||
// resolved. This is OK, because the caller is responsible for computing
|
||
// the min-content height and min()'ing it with the value we return, which
|
||
// is equivalent to what would happen if we min()'d that at this point.
|
||
minMainSize = std::min(minMainSize, aFlexItem.GetFlexBaseSize());
|
||
}
|
||
|
||
// * the computed max-width (max-height), if that value is definite:
|
||
nscoord maxSize =
|
||
GET_MAIN_COMPONENT(aAxisTracker,
|
||
aItemReflowState.ComputedMaxWidth(),
|
||
aItemReflowState.ComputedMaxHeight());
|
||
if (maxSize != NS_UNCONSTRAINEDSIZE) {
|
||
minMainSize = std::min(minMainSize, maxSize);
|
||
}
|
||
|
||
// * if the item has no intrinsic aspect ratio, its min-content size:
|
||
// --- SKIPPING THIS IN THIS FUNCTION --- caller's responsibility.
|
||
|
||
// * if the item has an intrinsic aspect ratio, the width (height) calculated
|
||
// from the aspect ratio and any definite size constraints in the opposite
|
||
// dimension.
|
||
if (aAxisTracker.GetCrossComponent(aIntrinsicRatio) != 0) {
|
||
// We have a usable aspect ratio. (not going to divide by 0)
|
||
const bool useMinSizeIfCrossSizeIsIndefinite = true;
|
||
nscoord crossSizeToUseWithRatio =
|
||
CrossSizeToUseWithRatio(aFlexItem, aItemReflowState,
|
||
useMinSizeIfCrossSizeIsIndefinite,
|
||
aAxisTracker);
|
||
nscoord minMainSizeFromRatio =
|
||
MainSizeFromAspectRatio(crossSizeToUseWithRatio,
|
||
aIntrinsicRatio, aAxisTracker);
|
||
minMainSize = std::min(minMainSize, minMainSizeFromRatio);
|
||
}
|
||
|
||
return minMainSize;
|
||
}
|
||
|
||
// Resolves flex-basis:auto, using the given intrinsic ratio and the flex
|
||
// item's cross size. On success, updates the flex item with its resolved
|
||
// flex-basis and returns true. On failure (e.g. if the ratio is invalid or
|
||
// the cross-size is indefinite), returns false.
|
||
static bool
|
||
ResolveAutoFlexBasisFromRatio(FlexItem& aFlexItem,
|
||
const nsHTMLReflowState& aItemReflowState,
|
||
const nsSize& aIntrinsicRatio,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
MOZ_ASSERT(NS_AUTOHEIGHT == aFlexItem.GetFlexBaseSize(),
|
||
"Should only be called to resolve an 'auto' flex-basis");
|
||
// If the flex item has ...
|
||
// - an intrinsic aspect ratio,
|
||
// - a [used] flex-basis of 'main-size' [We have this, if we're here.]
|
||
// - a definite cross size
|
||
// then the flex base size is calculated from its inner cross size and the
|
||
// flex item’s intrinsic aspect ratio.
|
||
if (aAxisTracker.GetCrossComponent(aIntrinsicRatio) != 0) {
|
||
// We have a usable aspect ratio. (not going to divide by 0)
|
||
const bool useMinSizeIfCrossSizeIsIndefinite = false;
|
||
nscoord crossSizeToUseWithRatio =
|
||
CrossSizeToUseWithRatio(aFlexItem, aItemReflowState,
|
||
useMinSizeIfCrossSizeIsIndefinite,
|
||
aAxisTracker);
|
||
if (crossSizeToUseWithRatio != NS_AUTOHEIGHT) {
|
||
// We have a definite cross-size
|
||
nscoord mainSizeFromRatio =
|
||
MainSizeFromAspectRatio(crossSizeToUseWithRatio,
|
||
aIntrinsicRatio, aAxisTracker);
|
||
aFlexItem.SetFlexBaseSizeAndMainSize(mainSizeFromRatio);
|
||
return true;
|
||
}
|
||
}
|
||
return false;
|
||
}
|
||
|
||
// Note: If & when we handle "min-height: min-content" for flex items,
|
||
// we may want to resolve that in this function, too.
|
||
void
|
||
nsFlexContainerFrame::
|
||
ResolveAutoFlexBasisAndMinSize(nsPresContext* aPresContext,
|
||
FlexItem& aFlexItem,
|
||
const nsHTMLReflowState& aItemReflowState,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
// (Note: We should never have a used flex-basis of "auto" if our main axis
|
||
// is horizontal; width values should always be resolvable without reflow.)
|
||
const bool isMainSizeAuto = (!IsAxisHorizontal(aAxisTracker.GetMainAxis()) &&
|
||
NS_AUTOHEIGHT == aFlexItem.GetFlexBaseSize());
|
||
|
||
const bool isMainMinSizeAuto = aFlexItem.NeedsMinSizeAutoResolution();
|
||
|
||
if (!isMainSizeAuto && !isMainMinSizeAuto) {
|
||
// Nothing to do; this function is only needed for flex items
|
||
// with a used flex-basis of "auto" or a min-main-size of "auto".
|
||
return;
|
||
}
|
||
|
||
// We may be about to do computations based on our item's cross-size
|
||
// (e.g. using it as a contstraint when measuring our content in the
|
||
// main axis, or using it with the intrinsic ratio to obtain a main size).
|
||
// BEFORE WE DO THAT, we need let the item "pre-stretch" its cross size (if
|
||
// it's got 'align-self:stretch'), for a certain case where the spec says
|
||
// the stretched cross size is considered "definite". That case is if we
|
||
// have a single-line (nowrap) flex container which itself has a definite
|
||
// cross-size. Otherwise, we'll wait to do stretching, since (in other
|
||
// cases) we don't know how much the item should stretch yet.
|
||
const nsHTMLReflowState* flexContainerRS = aItemReflowState.parentReflowState;
|
||
MOZ_ASSERT(flexContainerRS,
|
||
"flex item's reflow state should have ptr to container's state");
|
||
if (NS_STYLE_FLEX_WRAP_NOWRAP == flexContainerRS->mStylePosition->mFlexWrap) {
|
||
// XXXdholbert Maybe this should share logic with ComputeCrossSize()...
|
||
// Alternately, maybe tentative container cross size should be passed down.
|
||
nscoord containerCrossSize =
|
||
GET_CROSS_COMPONENT(aAxisTracker,
|
||
flexContainerRS->ComputedWidth(),
|
||
flexContainerRS->ComputedHeight());
|
||
// Is container's cross size "definite"?
|
||
// (Container's cross size is definite if cross-axis is horizontal, or if
|
||
// cross-axis is vertical and the cross-size is not NS_AUTOHEIGHT.)
|
||
if (IsAxisHorizontal(aAxisTracker.GetCrossAxis()) ||
|
||
containerCrossSize != NS_AUTOHEIGHT) {
|
||
aFlexItem.ResolveStretchedCrossSize(containerCrossSize, aAxisTracker);
|
||
}
|
||
}
|
||
|
||
// We'll need the intrinsic ratio (if there is one), regardless of whether
|
||
// we're resolving min-[width|height]:auto or flex-basis:auto.
|
||
const nsSize ratio = aFlexItem.Frame()->GetIntrinsicRatio();
|
||
|
||
nscoord resolvedMinSize; // (only set/used if isMainMinSizeAuto==true)
|
||
bool minSizeNeedsToMeasureContent = false; // assume the best
|
||
if (isMainMinSizeAuto) {
|
||
// Resolve the min-size, except for considering the min-content size.
|
||
// (We'll consider that later, if we need to.)
|
||
resolvedMinSize = PartiallyResolveAutoMinSize(aFlexItem, aItemReflowState,
|
||
ratio, aAxisTracker);
|
||
if (resolvedMinSize > 0 &&
|
||
aAxisTracker.GetCrossComponent(ratio) == 0) {
|
||
// We don't have a usable aspect ratio, so we need to consider our
|
||
// min-content size as another candidate min-size, which we'll have to
|
||
// min() with the current resolvedMinSize.
|
||
// (If resolvedMinSize were already at 0, we could skip this measurement
|
||
// because it can't go any lower. But it's not 0, so we need it.)
|
||
minSizeNeedsToMeasureContent = true;
|
||
}
|
||
}
|
||
|
||
bool flexBasisNeedsToMeasureContent = false; // assume the best
|
||
if (isMainSizeAuto) {
|
||
if (!ResolveAutoFlexBasisFromRatio(aFlexItem, aItemReflowState,
|
||
ratio, aAxisTracker)) {
|
||
flexBasisNeedsToMeasureContent = true;
|
||
}
|
||
}
|
||
|
||
// Measure content, if needed (w/ intrinsic-width method or a reflow)
|
||
if (minSizeNeedsToMeasureContent || flexBasisNeedsToMeasureContent) {
|
||
if (IsAxisHorizontal(aAxisTracker.GetMainAxis())) {
|
||
nsRefPtr<nsRenderingContext> rctx =
|
||
aPresContext->PresShell()->CreateReferenceRenderingContext();
|
||
if (minSizeNeedsToMeasureContent) {
|
||
resolvedMinSize = std::min(resolvedMinSize, aFlexItem.Frame()->GetMinISize(rctx));
|
||
}
|
||
NS_ASSERTION(!flexBasisNeedsToMeasureContent,
|
||
"flex-basis:auto should have been resolved in the "
|
||
"reflow state, for horizontal flexbox. It shouldn't need "
|
||
"special handling here");
|
||
} else {
|
||
// If this item is flexible (vertically), or if we're measuring the
|
||
// 'auto' min-height and our main-size is something else, then we assume
|
||
// that the computed-height we're reflowing with now could be different
|
||
// from the one we'll use for this flex item's "actual" reflow later on.
|
||
// In that case, we need to be sure the flex item treats this as a
|
||
// vertical resize, even though none of its ancestors are necessarily
|
||
// being vertically resized.
|
||
// (Note: We don't have to do this for width, because InitResizeFlags
|
||
// will always turn on mHResize on when it sees that the computed width
|
||
// is different from current width, and that's all we need.)
|
||
bool forceVerticalResizeForMeasuringReflow =
|
||
!aFlexItem.IsFrozen() || // Is the item flexible?
|
||
!flexBasisNeedsToMeasureContent; // Are we *only* measuring it for
|
||
// 'min-height:auto'?
|
||
|
||
nscoord contentHeight =
|
||
MeasureFlexItemContentHeight(aPresContext, aFlexItem,
|
||
forceVerticalResizeForMeasuringReflow,
|
||
*flexContainerRS);
|
||
if (minSizeNeedsToMeasureContent) {
|
||
resolvedMinSize = std::min(resolvedMinSize, contentHeight);
|
||
}
|
||
if (flexBasisNeedsToMeasureContent) {
|
||
aFlexItem.SetFlexBaseSizeAndMainSize(contentHeight);
|
||
}
|
||
}
|
||
}
|
||
|
||
if (isMainMinSizeAuto) {
|
||
aFlexItem.UpdateMainMinSize(resolvedMinSize);
|
||
}
|
||
}
|
||
|
||
nscoord
|
||
nsFlexContainerFrame::
|
||
MeasureFlexItemContentHeight(nsPresContext* aPresContext,
|
||
FlexItem& aFlexItem,
|
||
bool aForceVerticalResizeForMeasuringReflow,
|
||
const nsHTMLReflowState& aParentReflowState)
|
||
{
|
||
// Set up a reflow state for measuring the flex item's auto-height:
|
||
WritingMode wm = aFlexItem.Frame()->GetWritingMode();
|
||
LogicalSize availSize = aParentReflowState.ComputedSize(wm);
|
||
availSize.BSize(wm) = NS_UNCONSTRAINEDSIZE;
|
||
nsHTMLReflowState
|
||
childRSForMeasuringHeight(aPresContext, aParentReflowState,
|
||
aFlexItem.Frame(), availSize,
|
||
-1, -1, nsHTMLReflowState::CALLER_WILL_INIT);
|
||
childRSForMeasuringHeight.mFlags.mIsFlexContainerMeasuringHeight = true;
|
||
childRSForMeasuringHeight.Init(aPresContext);
|
||
|
||
if (aFlexItem.IsStretched()) {
|
||
childRSForMeasuringHeight.SetComputedWidth(aFlexItem.GetCrossSize());
|
||
childRSForMeasuringHeight.mFlags.mHResize = true;
|
||
}
|
||
|
||
if (aForceVerticalResizeForMeasuringReflow) {
|
||
childRSForMeasuringHeight.mFlags.mVResize = true;
|
||
}
|
||
|
||
nsHTMLReflowMetrics childDesiredSize(childRSForMeasuringHeight);
|
||
nsReflowStatus childReflowStatus;
|
||
const uint32_t flags = NS_FRAME_NO_MOVE_FRAME;
|
||
ReflowChild(aFlexItem.Frame(), aPresContext,
|
||
childDesiredSize, childRSForMeasuringHeight,
|
||
0, 0, flags, childReflowStatus);
|
||
|
||
MOZ_ASSERT(NS_FRAME_IS_COMPLETE(childReflowStatus),
|
||
"We gave flex item unconstrained available height, so it "
|
||
"should be complete");
|
||
|
||
FinishReflowChild(aFlexItem.Frame(), aPresContext,
|
||
childDesiredSize, &childRSForMeasuringHeight,
|
||
0, 0, flags);
|
||
|
||
aFlexItem.SetHadMeasuringReflow();
|
||
|
||
// Subtract border/padding in vertical axis, to get _just_
|
||
// the effective computed value of the "height" property.
|
||
nscoord childDesiredHeight = childDesiredSize.Height() -
|
||
childRSForMeasuringHeight.ComputedPhysicalBorderPadding().TopBottom();
|
||
|
||
return std::max(0, childDesiredHeight);
|
||
}
|
||
|
||
FlexItem::FlexItem(nsHTMLReflowState& aFlexItemReflowState,
|
||
float aFlexGrow, float aFlexShrink, nscoord aFlexBaseSize,
|
||
nscoord aMainMinSize, nscoord aMainMaxSize,
|
||
nscoord aCrossMinSize, nscoord aCrossMaxSize,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
: mFrame(aFlexItemReflowState.frame),
|
||
mFlexGrow(aFlexGrow),
|
||
mFlexShrink(aFlexShrink),
|
||
mBorderPadding(aFlexItemReflowState.ComputedPhysicalBorderPadding()),
|
||
mMargin(aFlexItemReflowState.ComputedPhysicalMargin()),
|
||
mMainMinSize(aMainMinSize),
|
||
mMainMaxSize(aMainMaxSize),
|
||
mCrossMinSize(aCrossMinSize),
|
||
mCrossMaxSize(aCrossMaxSize),
|
||
mMainPosn(0),
|
||
mCrossSize(0),
|
||
mCrossPosn(0),
|
||
mAscent(0),
|
||
mShareOfWeightSoFar(0.0f),
|
||
mIsFrozen(false),
|
||
mHadMinViolation(false),
|
||
mHadMaxViolation(false),
|
||
mHadMeasuringReflow(false),
|
||
mIsStretched(false),
|
||
mIsStrut(false),
|
||
// mNeedsMinSizeAutoResolution is initialized in CheckForMinSizeAuto()
|
||
mAlignSelf(aFlexItemReflowState.mStylePosition->mAlignSelf)
|
||
{
|
||
MOZ_ASSERT(mFrame, "expecting a non-null child frame");
|
||
MOZ_ASSERT(mFrame->GetType() != nsGkAtoms::placeholderFrame,
|
||
"placeholder frames should not be treated as flex items");
|
||
MOZ_ASSERT(!(mFrame->GetStateBits() & NS_FRAME_OUT_OF_FLOW),
|
||
"out-of-flow frames should not be treated as flex items");
|
||
|
||
SetFlexBaseSizeAndMainSize(aFlexBaseSize);
|
||
CheckForMinSizeAuto(aFlexItemReflowState, aAxisTracker);
|
||
|
||
// Assert that any "auto" margin components are set to 0.
|
||
// (We'll resolve them later; until then, we want to treat them as 0-sized.)
|
||
#ifdef DEBUG
|
||
{
|
||
const nsStyleSides& styleMargin =
|
||
aFlexItemReflowState.mStyleMargin->mMargin;
|
||
NS_FOR_CSS_SIDES(side) {
|
||
if (styleMargin.GetUnit(side) == eStyleUnit_Auto) {
|
||
MOZ_ASSERT(GetMarginComponentForSide(side) == 0,
|
||
"Someone else tried to resolve our auto margin");
|
||
}
|
||
}
|
||
}
|
||
#endif // DEBUG
|
||
|
||
// Resolve "align-self: auto" to parent's "align-items" value.
|
||
if (mAlignSelf == NS_STYLE_ALIGN_SELF_AUTO) {
|
||
mAlignSelf =
|
||
mFrame->StyleContext()->GetParent()->StylePosition()->mAlignItems;
|
||
}
|
||
|
||
// If the flex item's inline axis is the same as the cross axis, then
|
||
// 'align-self:baseline' is identical to 'flex-start'. If that's the case, we
|
||
// just directly convert our align-self value here, so that we don't have to
|
||
// handle this with special cases elsewhere.
|
||
// Moreover: for the time being (until we support writing-modes),
|
||
// all inline axes are horizontal -- so we can just check if the cross axis
|
||
// is horizontal.
|
||
// FIXME: Once we support writing-mode (vertical text), this IsAxisHorizontal
|
||
// check won't be sufficient anymore -- we'll actually need to compare our
|
||
// inline axis vs. the cross axis.
|
||
if (mAlignSelf == NS_STYLE_ALIGN_ITEMS_BASELINE &&
|
||
IsAxisHorizontal(aAxisTracker.GetCrossAxis())) {
|
||
mAlignSelf = NS_STYLE_ALIGN_ITEMS_FLEX_START;
|
||
}
|
||
}
|
||
|
||
// Simplified constructor for creating a special "strut" FlexItem, for a child
|
||
// with visibility:collapse. The strut has 0 main-size, and it only exists to
|
||
// impose a minimum cross size on whichever FlexLine it ends up in.
|
||
FlexItem::FlexItem(nsIFrame* aChildFrame, nscoord aCrossSize)
|
||
: mFrame(aChildFrame),
|
||
mFlexGrow(0.0f),
|
||
mFlexShrink(0.0f),
|
||
// mBorderPadding uses default constructor,
|
||
// mMargin uses default constructor,
|
||
mFlexBaseSize(0),
|
||
mMainMinSize(0),
|
||
mMainMaxSize(0),
|
||
mCrossMinSize(0),
|
||
mCrossMaxSize(0),
|
||
mMainSize(0),
|
||
mMainPosn(0),
|
||
mCrossSize(aCrossSize),
|
||
mCrossPosn(0),
|
||
mAscent(0),
|
||
mShareOfWeightSoFar(0.0f),
|
||
mIsFrozen(true),
|
||
mHadMinViolation(false),
|
||
mHadMaxViolation(false),
|
||
mHadMeasuringReflow(false),
|
||
mIsStretched(false),
|
||
mIsStrut(true), // (this is the constructor for making struts, after all)
|
||
mNeedsMinSizeAutoResolution(false),
|
||
mAlignSelf(NS_STYLE_ALIGN_ITEMS_FLEX_START)
|
||
{
|
||
MOZ_ASSERT(mFrame, "expecting a non-null child frame");
|
||
MOZ_ASSERT(NS_STYLE_VISIBILITY_COLLAPSE ==
|
||
mFrame->StyleVisibility()->mVisible,
|
||
"Should only make struts for children with 'visibility:collapse'");
|
||
MOZ_ASSERT(mFrame->GetType() != nsGkAtoms::placeholderFrame,
|
||
"placeholder frames should not be treated as flex items");
|
||
MOZ_ASSERT(!(mFrame->GetStateBits() & NS_FRAME_OUT_OF_FLOW),
|
||
"out-of-flow frames should not be treated as flex items");
|
||
}
|
||
|
||
void
|
||
FlexItem::CheckForMinSizeAuto(const nsHTMLReflowState& aFlexItemReflowState,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
const nsStylePosition* pos = aFlexItemReflowState.mStylePosition;
|
||
const nsStyleDisplay* disp = aFlexItemReflowState.mStyleDisplay;
|
||
|
||
// We'll need special behavior for "min-[width|height]:auto" (whichever is in
|
||
// the main axis) iff:
|
||
// (a) its computed value is "auto"
|
||
// (b) the "overflow" sub-property in the same axis (the main axis) has a
|
||
// computed value of "visible"
|
||
const nsStyleCoord& minSize = GET_MAIN_COMPONENT(aAxisTracker,
|
||
pos->mMinWidth,
|
||
pos->mMinHeight);
|
||
|
||
const uint8_t overflowVal = GET_MAIN_COMPONENT(aAxisTracker,
|
||
disp->mOverflowX,
|
||
disp->mOverflowY);
|
||
|
||
mNeedsMinSizeAutoResolution = (minSize.GetUnit() == eStyleUnit_Auto &&
|
||
overflowVal == NS_STYLE_OVERFLOW_VISIBLE);
|
||
}
|
||
|
||
nscoord
|
||
FlexItem::GetBaselineOffsetFromOuterCrossEdge(AxisOrientationType aCrossAxis,
|
||
AxisEdgeType aEdge) const
|
||
{
|
||
// NOTE: Currently, 'mAscent' (taken from reflow) is an inherently vertical
|
||
// measurement -- it's the distance from the border-top edge of this FlexItem
|
||
// to its baseline. So, we can really only do baseline alignment when the
|
||
// cross axis is vertical. (The FlexItem constructor enforces this when
|
||
// resolving the item's "mAlignSelf" value).
|
||
MOZ_ASSERT(!IsAxisHorizontal(aCrossAxis),
|
||
"Only expecting to be doing baseline computations when the "
|
||
"cross axis is vertical");
|
||
|
||
mozilla::Side sideToMeasureFrom = kAxisOrientationToSidesMap[aCrossAxis][aEdge];
|
||
|
||
nscoord marginTopToBaseline = mAscent + mMargin.top;
|
||
|
||
if (sideToMeasureFrom == eSideTop) {
|
||
// Measuring from top (normal case): the distance from the margin-box top
|
||
// edge to the baseline is just ascent + margin-top.
|
||
return marginTopToBaseline;
|
||
}
|
||
|
||
MOZ_ASSERT(sideToMeasureFrom == eSideBottom,
|
||
"We already checked that we're dealing with a vertical axis, and "
|
||
"we're not using the top side, so that only leaves the bottom...");
|
||
|
||
// Measuring from bottom: The distance from the margin-box bottom edge to the
|
||
// baseline is just the margin-box cross size (i.e. outer cross size), minus
|
||
// the already-computed distance from margin-top to baseline.
|
||
return GetOuterCrossSize(aCrossAxis) - marginTopToBaseline;
|
||
}
|
||
|
||
uint32_t
|
||
FlexItem::GetNumAutoMarginsInAxis(AxisOrientationType aAxis) const
|
||
{
|
||
uint32_t numAutoMargins = 0;
|
||
const nsStyleSides& styleMargin = mFrame->StyleMargin()->mMargin;
|
||
for (uint32_t i = 0; i < eNumAxisEdges; i++) {
|
||
mozilla::Side side = kAxisOrientationToSidesMap[aAxis][i];
|
||
if (styleMargin.GetUnit(side) == eStyleUnit_Auto) {
|
||
numAutoMargins++;
|
||
}
|
||
}
|
||
|
||
// Mostly for clarity:
|
||
MOZ_ASSERT(numAutoMargins <= 2,
|
||
"We're just looking at one item along one dimension, so we "
|
||
"should only have examined 2 margins");
|
||
|
||
return numAutoMargins;
|
||
}
|
||
|
||
// Keeps track of our position along a particular axis (where a '0' position
|
||
// corresponds to the 'start' edge of that axis).
|
||
// This class shouldn't be instantiated directly -- rather, it should only be
|
||
// instantiated via its subclasses defined below.
|
||
class MOZ_STACK_CLASS PositionTracker {
|
||
public:
|
||
// Accessor for the current value of the position that we're tracking.
|
||
inline nscoord GetPosition() const { return mPosition; }
|
||
inline AxisOrientationType GetAxis() const { return mAxis; }
|
||
|
||
// Advances our position across the start edge of the given margin, in the
|
||
// axis we're tracking.
|
||
void EnterMargin(const nsMargin& aMargin)
|
||
{
|
||
mozilla::Side side = kAxisOrientationToSidesMap[mAxis][eAxisEdge_Start];
|
||
mPosition += aMargin.Side(side);
|
||
}
|
||
|
||
// Advances our position across the end edge of the given margin, in the axis
|
||
// we're tracking.
|
||
void ExitMargin(const nsMargin& aMargin)
|
||
{
|
||
mozilla::Side side = kAxisOrientationToSidesMap[mAxis][eAxisEdge_End];
|
||
mPosition += aMargin.Side(side);
|
||
}
|
||
|
||
// Advances our current position from the start side of a child frame's
|
||
// border-box to the frame's upper or left edge (depending on our axis).
|
||
// (Note that this is a no-op if our axis grows in positive direction.)
|
||
void EnterChildFrame(nscoord aChildFrameSize)
|
||
{
|
||
if (!AxisGrowsInPositiveDirection(mAxis))
|
||
mPosition += aChildFrameSize;
|
||
}
|
||
|
||
// Advances our current position from a frame's upper or left border-box edge
|
||
// (whichever is in the axis we're tracking) to the 'end' side of the frame
|
||
// in the axis that we're tracking. (Note that this is a no-op if our axis
|
||
// grows in the negative direction.)
|
||
void ExitChildFrame(nscoord aChildFrameSize)
|
||
{
|
||
if (AxisGrowsInPositiveDirection(mAxis))
|
||
mPosition += aChildFrameSize;
|
||
}
|
||
|
||
protected:
|
||
// Protected constructor, to be sure we're only instantiated via a subclass.
|
||
explicit PositionTracker(AxisOrientationType aAxis)
|
||
: mPosition(0),
|
||
mAxis(aAxis)
|
||
{}
|
||
|
||
private:
|
||
// Private copy-constructor, since we don't want any instances of our
|
||
// subclasses to be accidentally copied.
|
||
PositionTracker(const PositionTracker& aOther)
|
||
: mPosition(aOther.mPosition),
|
||
mAxis(aOther.mAxis)
|
||
{}
|
||
|
||
protected:
|
||
// Member data:
|
||
nscoord mPosition; // The position we're tracking
|
||
const AxisOrientationType mAxis; // The axis along which we're moving
|
||
};
|
||
|
||
// Tracks our position in the main axis, when we're laying out flex items.
|
||
// The "0" position represents the main-start edge of the flex container's
|
||
// content-box.
|
||
class MOZ_STACK_CLASS MainAxisPositionTracker : public PositionTracker {
|
||
public:
|
||
MainAxisPositionTracker(const FlexboxAxisTracker& aAxisTracker,
|
||
const FlexLine* aLine,
|
||
uint8_t aJustifyContent,
|
||
nscoord aContentBoxMainSize);
|
||
|
||
~MainAxisPositionTracker() {
|
||
MOZ_ASSERT(mNumPackingSpacesRemaining == 0,
|
||
"miscounted the number of packing spaces");
|
||
MOZ_ASSERT(mNumAutoMarginsInMainAxis == 0,
|
||
"miscounted the number of auto margins");
|
||
}
|
||
|
||
// Advances past the packing space (if any) between two flex items
|
||
void TraversePackingSpace();
|
||
|
||
// If aItem has any 'auto' margins in the main axis, this method updates the
|
||
// corresponding values in its margin.
|
||
void ResolveAutoMarginsInMainAxis(FlexItem& aItem);
|
||
|
||
private:
|
||
nscoord mPackingSpaceRemaining;
|
||
uint32_t mNumAutoMarginsInMainAxis;
|
||
uint32_t mNumPackingSpacesRemaining;
|
||
uint8_t mJustifyContent;
|
||
};
|
||
|
||
// Utility class for managing our position along the cross axis along
|
||
// the whole flex container (at a higher level than a single line).
|
||
// The "0" position represents the cross-start edge of the flex container's
|
||
// content-box.
|
||
class MOZ_STACK_CLASS CrossAxisPositionTracker : public PositionTracker {
|
||
public:
|
||
CrossAxisPositionTracker(FlexLine* aFirstLine,
|
||
uint8_t aAlignContent,
|
||
nscoord aContentBoxCrossSize,
|
||
bool aIsCrossSizeDefinite,
|
||
const FlexboxAxisTracker& aAxisTracker);
|
||
|
||
// Advances past the packing space (if any) between two flex lines
|
||
void TraversePackingSpace();
|
||
|
||
// Advances past the given FlexLine
|
||
void TraverseLine(FlexLine& aLine) { mPosition += aLine.GetLineCrossSize(); }
|
||
|
||
private:
|
||
// Redeclare the frame-related methods from PositionTracker as private with
|
||
// MOZ_DELETE, to be sure (at compile time) that no client code can invoke
|
||
// them. (Unlike the other PositionTracker derived classes, this class here
|
||
// deals with FlexLines, not with individual FlexItems or frames.)
|
||
void EnterMargin(const nsMargin& aMargin) MOZ_DELETE;
|
||
void ExitMargin(const nsMargin& aMargin) MOZ_DELETE;
|
||
void EnterChildFrame(nscoord aChildFrameSize) MOZ_DELETE;
|
||
void ExitChildFrame(nscoord aChildFrameSize) MOZ_DELETE;
|
||
|
||
nscoord mPackingSpaceRemaining;
|
||
uint32_t mNumPackingSpacesRemaining;
|
||
uint8_t mAlignContent;
|
||
};
|
||
|
||
// Utility class for managing our position along the cross axis, *within* a
|
||
// single flex line.
|
||
class MOZ_STACK_CLASS SingleLineCrossAxisPositionTracker : public PositionTracker {
|
||
public:
|
||
explicit SingleLineCrossAxisPositionTracker(const FlexboxAxisTracker& aAxisTracker);
|
||
|
||
void ResolveAutoMarginsInCrossAxis(const FlexLine& aLine,
|
||
FlexItem& aItem);
|
||
|
||
void EnterAlignPackingSpace(const FlexLine& aLine,
|
||
const FlexItem& aItem,
|
||
const FlexboxAxisTracker& aAxisTracker);
|
||
|
||
// Resets our position to the cross-start edge of this line.
|
||
inline void ResetPosition() { mPosition = 0; }
|
||
};
|
||
|
||
//----------------------------------------------------------------------
|
||
|
||
// Frame class boilerplate
|
||
// =======================
|
||
|
||
NS_QUERYFRAME_HEAD(nsFlexContainerFrame)
|
||
NS_QUERYFRAME_ENTRY(nsFlexContainerFrame)
|
||
NS_QUERYFRAME_TAIL_INHERITING(nsFlexContainerFrameSuper)
|
||
|
||
NS_IMPL_FRAMEARENA_HELPERS(nsFlexContainerFrame)
|
||
|
||
nsContainerFrame*
|
||
NS_NewFlexContainerFrame(nsIPresShell* aPresShell,
|
||
nsStyleContext* aContext)
|
||
{
|
||
return new (aPresShell) nsFlexContainerFrame(aContext);
|
||
}
|
||
|
||
//----------------------------------------------------------------------
|
||
|
||
// nsFlexContainerFrame Method Implementations
|
||
// ===========================================
|
||
|
||
/* virtual */
|
||
nsFlexContainerFrame::~nsFlexContainerFrame()
|
||
{
|
||
}
|
||
|
||
template<bool IsLessThanOrEqual(nsIFrame*, nsIFrame*)>
|
||
/* static */ bool
|
||
nsFlexContainerFrame::SortChildrenIfNeeded()
|
||
{
|
||
if (nsIFrame::IsFrameListSorted<IsLessThanOrEqual>(mFrames)) {
|
||
return false;
|
||
}
|
||
|
||
nsIFrame::SortFrameList<IsLessThanOrEqual>(mFrames);
|
||
return true;
|
||
}
|
||
|
||
/* virtual */
|
||
nsIAtom*
|
||
nsFlexContainerFrame::GetType() const
|
||
{
|
||
return nsGkAtoms::flexContainerFrame;
|
||
}
|
||
|
||
#ifdef DEBUG_FRAME_DUMP
|
||
nsresult
|
||
nsFlexContainerFrame::GetFrameName(nsAString& aResult) const
|
||
{
|
||
return MakeFrameName(NS_LITERAL_STRING("FlexContainer"), aResult);
|
||
}
|
||
#endif
|
||
|
||
// Helper for BuildDisplayList, to implement this special-case for flex items
|
||
// from the spec:
|
||
// Flex items paint exactly the same as block-level elements in the
|
||
// normal flow, except that 'z-index' values other than 'auto' create
|
||
// a stacking context even if 'position' is 'static'.
|
||
// http://www.w3.org/TR/2012/CR-css3-flexbox-20120918/#painting
|
||
uint32_t
|
||
GetDisplayFlagsForFlexItem(nsIFrame* aFrame)
|
||
{
|
||
MOZ_ASSERT(aFrame->IsFlexItem(), "Should only be called on flex items");
|
||
|
||
const nsStylePosition* pos = aFrame->StylePosition();
|
||
if (pos->mZIndex.GetUnit() == eStyleUnit_Integer) {
|
||
return nsIFrame::DISPLAY_CHILD_FORCE_STACKING_CONTEXT;
|
||
}
|
||
return nsIFrame::DISPLAY_CHILD_FORCE_PSEUDO_STACKING_CONTEXT;
|
||
}
|
||
|
||
void
|
||
nsFlexContainerFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
|
||
const nsRect& aDirtyRect,
|
||
const nsDisplayListSet& aLists)
|
||
{
|
||
// XXXdholbert hacky temporary band-aid for bug 1059138: Trivially pass this
|
||
// assertion (skip it, basically) if the first child is part of a shadow DOM.
|
||
// (IsOrderLEQWithDOMFallback doesn't know how to compare tree-position of a
|
||
// shadow-DOM element vs. a non-shadow-DOM element.)
|
||
NS_ASSERTION(
|
||
(!mFrames.IsEmpty() &&
|
||
mFrames.FirstChild()->GetContent()->GetContainingShadow()) ||
|
||
nsIFrame::IsFrameListSorted<IsOrderLEQWithDOMFallback>(mFrames),
|
||
"Child frames aren't sorted correctly");
|
||
|
||
DisplayBorderBackgroundOutline(aBuilder, aLists);
|
||
|
||
// Our children are all block-level, so their borders/backgrounds all go on
|
||
// the BlockBorderBackgrounds list.
|
||
nsDisplayListSet childLists(aLists, aLists.BlockBorderBackgrounds());
|
||
for (nsFrameList::Enumerator e(mFrames); !e.AtEnd(); e.Next()) {
|
||
BuildDisplayListForChild(aBuilder, e.get(), aDirtyRect, childLists,
|
||
GetDisplayFlagsForFlexItem(e.get()));
|
||
}
|
||
}
|
||
|
||
#ifdef DEBUG
|
||
// helper for the debugging method below
|
||
bool
|
||
FrameWantsToBeInAnonymousFlexItem(nsIFrame* aFrame)
|
||
{
|
||
// Note: This needs to match the logic in
|
||
// nsCSSFrameConstructor::FrameConstructionItem::NeedsAnonFlexOrGridItem()
|
||
return (aFrame->IsFrameOfType(nsIFrame::eLineParticipant) ||
|
||
nsGkAtoms::placeholderFrame == aFrame->GetType());
|
||
}
|
||
|
||
// Debugging method, to let us assert that our anonymous flex items are
|
||
// set up correctly -- in particular, we assert:
|
||
// (1) we don't have any inline non-replaced children
|
||
// (2) we don't have any consecutive anonymous flex items
|
||
// (3) we don't have any empty anonymous flex items
|
||
//
|
||
// XXXdholbert This matches what nsCSSFrameConstructor currently does, and what
|
||
// the spec used to say. However, the spec has now changed regarding what
|
||
// types of content get wrapped in an anonymous flexbox item. The patch that
|
||
// implements those changes (in nsCSSFrameConstructor) will need to change
|
||
// this method as well.
|
||
void
|
||
nsFlexContainerFrame::SanityCheckAnonymousFlexItems() const
|
||
{
|
||
bool prevChildWasAnonFlexItem = false;
|
||
for (nsIFrame* child = mFrames.FirstChild(); child;
|
||
child = child->GetNextSibling()) {
|
||
MOZ_ASSERT(!FrameWantsToBeInAnonymousFlexItem(child),
|
||
"frame wants to be inside an anonymous flex item, "
|
||
"but it isn't");
|
||
if (child->StyleContext()->GetPseudo() ==
|
||
nsCSSAnonBoxes::anonymousFlexItem) {
|
||
MOZ_ASSERT(!prevChildWasAnonFlexItem ||
|
||
HasAnyStateBits(NS_STATE_FLEX_CHILDREN_REORDERED),
|
||
"two anon flex items in a row (shouldn't happen, unless our "
|
||
"children have been reordered with the 'order' property)");
|
||
|
||
nsIFrame* firstWrappedChild = child->GetFirstPrincipalChild();
|
||
MOZ_ASSERT(firstWrappedChild,
|
||
"anonymous flex item is empty (shouldn't happen)");
|
||
prevChildWasAnonFlexItem = true;
|
||
} else {
|
||
prevChildWasAnonFlexItem = false;
|
||
}
|
||
}
|
||
}
|
||
#endif // DEBUG
|
||
|
||
void
|
||
FlexLine::FreezeItemsEarly(bool aIsUsingFlexGrow)
|
||
{
|
||
// After we've established the type of flexing we're doing (growing vs.
|
||
// shrinking), and before we try to flex any items, we freeze items that
|
||
// obviously *can't* flex.
|
||
//
|
||
// Quoting the spec:
|
||
// # Freeze, setting its target main size to its hypothetical main size...
|
||
// # - any item that has a flex factor of zero
|
||
// # - if using the flex grow factor: any item that has a flex base size
|
||
// # greater than its hypothetical main size
|
||
// # - if using the flex shrink factor: any item that has a flex base size
|
||
// # smaller than its hypothetical main size
|
||
// http://dev.w3.org/csswg/css-flexbox/#resolve-flexible-lengths-flex-factors
|
||
//
|
||
// (NOTE: At this point, item->GetMainSize() *is* the item's hypothetical
|
||
// main size, since SetFlexBaseSizeAndMainSize() sets it up that way, and the
|
||
// item hasn't had a chance to flex away from that yet.)
|
||
|
||
// Since this loop only operates on unfrozen flex items, we can break as
|
||
// soon as we have seen all of them.
|
||
uint32_t numUnfrozenItemsToBeSeen = mNumItems - mNumFrozenItems;
|
||
for (FlexItem* item = mItems.getFirst();
|
||
numUnfrozenItemsToBeSeen > 0; item = item->getNext()) {
|
||
MOZ_ASSERT(item, "numUnfrozenItemsToBeSeen says items remain to be seen");
|
||
|
||
if (!item->IsFrozen()) {
|
||
numUnfrozenItemsToBeSeen--;
|
||
bool shouldFreeze = (0.0f == item->GetFlexFactor(aIsUsingFlexGrow));
|
||
if (!shouldFreeze) {
|
||
if (aIsUsingFlexGrow) {
|
||
if (item->GetFlexBaseSize() > item->GetMainSize()) {
|
||
shouldFreeze = true;
|
||
}
|
||
} else { // using flex-shrink
|
||
if (item->GetFlexBaseSize() < item->GetMainSize()) {
|
||
shouldFreeze = true;
|
||
}
|
||
}
|
||
}
|
||
if (shouldFreeze) {
|
||
// Freeze item! (at its hypothetical main size)
|
||
item->Freeze();
|
||
mNumFrozenItems++;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
// Based on the sign of aTotalViolation, this function freezes a subset of our
|
||
// flexible sizes, and restores the remaining ones to their initial pref sizes.
|
||
void
|
||
FlexLine::FreezeOrRestoreEachFlexibleSize(const nscoord aTotalViolation,
|
||
bool aIsFinalIteration)
|
||
{
|
||
enum FreezeType {
|
||
eFreezeEverything,
|
||
eFreezeMinViolations,
|
||
eFreezeMaxViolations
|
||
};
|
||
|
||
FreezeType freezeType;
|
||
if (aTotalViolation == 0) {
|
||
freezeType = eFreezeEverything;
|
||
} else if (aTotalViolation > 0) {
|
||
freezeType = eFreezeMinViolations;
|
||
} else { // aTotalViolation < 0
|
||
freezeType = eFreezeMaxViolations;
|
||
}
|
||
|
||
// Since this loop only operates on unfrozen flex items, we can break as
|
||
// soon as we have seen all of them.
|
||
uint32_t numUnfrozenItemsToBeSeen = mNumItems - mNumFrozenItems;
|
||
for (FlexItem* item = mItems.getFirst();
|
||
numUnfrozenItemsToBeSeen > 0; item = item->getNext()) {
|
||
MOZ_ASSERT(item, "numUnfrozenItemsToBeSeen says items remain to be seen");
|
||
if (!item->IsFrozen()) {
|
||
numUnfrozenItemsToBeSeen--;
|
||
|
||
MOZ_ASSERT(!item->HadMinViolation() || !item->HadMaxViolation(),
|
||
"Can have either min or max violation, but not both");
|
||
|
||
if (eFreezeEverything == freezeType ||
|
||
(eFreezeMinViolations == freezeType && item->HadMinViolation()) ||
|
||
(eFreezeMaxViolations == freezeType && item->HadMaxViolation())) {
|
||
|
||
MOZ_ASSERT(item->GetMainSize() >= item->GetMainMinSize(),
|
||
"Freezing item at a size below its minimum");
|
||
MOZ_ASSERT(item->GetMainSize() <= item->GetMainMaxSize(),
|
||
"Freezing item at a size above its maximum");
|
||
|
||
item->Freeze();
|
||
mNumFrozenItems++;
|
||
} else if (MOZ_UNLIKELY(aIsFinalIteration)) {
|
||
// XXXdholbert If & when bug 765861 is fixed, we should upgrade this
|
||
// assertion to be fatal except in documents with enormous lengths.
|
||
NS_ERROR("Final iteration still has unfrozen items, this shouldn't"
|
||
" happen unless there was nscoord under/overflow.");
|
||
item->Freeze();
|
||
mNumFrozenItems++;
|
||
} // else, we'll reset this item's main size to its flex base size on the
|
||
// next iteration of this algorithm.
|
||
|
||
// Clear this item's violation(s), now that we've dealt with them
|
||
item->ClearViolationFlags();
|
||
}
|
||
}
|
||
}
|
||
|
||
void
|
||
FlexLine::ResolveFlexibleLengths(nscoord aFlexContainerMainSize)
|
||
{
|
||
PR_LOG(GetFlexContainerLog(), PR_LOG_DEBUG, ("ResolveFlexibleLengths\n"));
|
||
|
||
// Determine whether we're going to be growing or shrinking items.
|
||
const bool isUsingFlexGrow =
|
||
(mTotalOuterHypotheticalMainSize < aFlexContainerMainSize);
|
||
|
||
// Do an "early freeze" for flex items that obviously can't flex in the
|
||
// direction we've chosen:
|
||
FreezeItemsEarly(isUsingFlexGrow);
|
||
|
||
if (mNumFrozenItems == mNumItems) {
|
||
// All our items are frozen, so we have no flexible lengths to resolve.
|
||
return;
|
||
}
|
||
MOZ_ASSERT(!IsEmpty(), "empty lines should take the early-return above");
|
||
|
||
// Subtract space occupied by our items' margins/borders/padding, so we can
|
||
// just be dealing with the space available for our flex items' content
|
||
// boxes.
|
||
nscoord spaceReservedForMarginBorderPadding =
|
||
mTotalOuterHypotheticalMainSize - mTotalInnerHypotheticalMainSize;
|
||
|
||
nscoord spaceAvailableForFlexItemsContentBoxes =
|
||
aFlexContainerMainSize - spaceReservedForMarginBorderPadding;
|
||
|
||
nscoord origAvailableFreeSpace;
|
||
bool isOrigAvailFreeSpaceInitialized = false;
|
||
|
||
// NOTE: I claim that this chunk of the algorithm (the looping part) needs to
|
||
// run the loop at MOST mNumItems times. This claim should hold up
|
||
// because we'll freeze at least one item on each loop iteration, and once
|
||
// we've run out of items to freeze, there's nothing left to do. However,
|
||
// in most cases, we'll break out of this loop long before we hit that many
|
||
// iterations.
|
||
for (uint32_t iterationCounter = 0;
|
||
iterationCounter < mNumItems; iterationCounter++) {
|
||
// Set every not-yet-frozen item's used main size to its
|
||
// flex base size, and subtract all the used main sizes from our
|
||
// total amount of space to determine the 'available free space'
|
||
// (positive or negative) to be distributed among our flexible items.
|
||
nscoord availableFreeSpace = spaceAvailableForFlexItemsContentBoxes;
|
||
for (FlexItem* item = mItems.getFirst(); item; item = item->getNext()) {
|
||
if (!item->IsFrozen()) {
|
||
item->SetMainSize(item->GetFlexBaseSize());
|
||
}
|
||
availableFreeSpace -= item->GetMainSize();
|
||
}
|
||
|
||
PR_LOG(GetFlexContainerLog(), PR_LOG_DEBUG,
|
||
(" available free space = %d\n", availableFreeSpace));
|
||
|
||
|
||
// The sign of our free space should agree with the type of flexing
|
||
// (grow/shrink) that we're doing (except if we've had integer overflow;
|
||
// then, all bets are off). Any disagreement should've made us use the
|
||
// other type of flexing, or should've been resolved in FreezeItemsEarly.
|
||
// XXXdholbert If & when bug 765861 is fixed, we should upgrade this
|
||
// assertion to be fatal except in documents with enormous lengths.
|
||
NS_ASSERTION((isUsingFlexGrow && availableFreeSpace >= 0) ||
|
||
(!isUsingFlexGrow && availableFreeSpace <= 0),
|
||
"availableFreeSpace's sign should match isUsingFlexGrow");
|
||
|
||
// If we have any free space available, give each flexible item a portion
|
||
// of availableFreeSpace.
|
||
if (availableFreeSpace != 0) {
|
||
// The first time we do this, we initialize origAvailableFreeSpace.
|
||
if (!isOrigAvailFreeSpaceInitialized) {
|
||
origAvailableFreeSpace = availableFreeSpace;
|
||
isOrigAvailFreeSpaceInitialized = true;
|
||
}
|
||
|
||
// STRATEGY: On each item, we compute & store its "share" of the total
|
||
// weight that we've seen so far:
|
||
// curWeight / weightSum
|
||
//
|
||
// Then, when we go to actually distribute the space (in the next loop),
|
||
// we can simply walk backwards through the elements and give each item
|
||
// its "share" multiplied by the remaining available space.
|
||
//
|
||
// SPECIAL CASE: If the sum of the weights is larger than the
|
||
// maximum representable float (overflowing to infinity), then we can't
|
||
// sensibly divide out proportional shares anymore. In that case, we
|
||
// simply treat the flex item(s) with the largest weights as if
|
||
// their weights were infinite (dwarfing all the others), and we
|
||
// distribute all of the available space among them.
|
||
float weightSum = 0.0f;
|
||
float flexFactorSum = 0.0f;
|
||
float largestWeight = 0.0f;
|
||
uint32_t numItemsWithLargestWeight = 0;
|
||
|
||
// Since this loop only operates on unfrozen flex items, we can break as
|
||
// soon as we have seen all of them.
|
||
uint32_t numUnfrozenItemsToBeSeen = mNumItems - mNumFrozenItems;
|
||
for (FlexItem* item = mItems.getFirst();
|
||
numUnfrozenItemsToBeSeen > 0; item = item->getNext()) {
|
||
MOZ_ASSERT(item,
|
||
"numUnfrozenItemsToBeSeen says items remain to be seen");
|
||
if (!item->IsFrozen()) {
|
||
numUnfrozenItemsToBeSeen--;
|
||
|
||
float curWeight = item->GetWeight(isUsingFlexGrow);
|
||
float curFlexFactor = item->GetFlexFactor(isUsingFlexGrow);
|
||
MOZ_ASSERT(curWeight >= 0.0f, "weights are non-negative");
|
||
MOZ_ASSERT(curFlexFactor >= 0.0f, "flex factors are non-negative");
|
||
|
||
weightSum += curWeight;
|
||
flexFactorSum += curFlexFactor;
|
||
|
||
if (IsFinite(weightSum)) {
|
||
if (curWeight == 0.0f) {
|
||
item->SetShareOfWeightSoFar(0.0f);
|
||
} else {
|
||
item->SetShareOfWeightSoFar(curWeight / weightSum);
|
||
}
|
||
} // else, the sum of weights overflows to infinity, in which
|
||
// case we don't bother with "SetShareOfWeightSoFar" since
|
||
// we know we won't use it. (instead, we'll just give every
|
||
// item with the largest weight an equal share of space.)
|
||
|
||
// Update our largest-weight tracking vars
|
||
if (curWeight > largestWeight) {
|
||
largestWeight = curWeight;
|
||
numItemsWithLargestWeight = 1;
|
||
} else if (curWeight == largestWeight) {
|
||
numItemsWithLargestWeight++;
|
||
}
|
||
}
|
||
}
|
||
|
||
if (weightSum != 0.0f) {
|
||
MOZ_ASSERT(flexFactorSum != 0.0f,
|
||
"flex factor sum can't be 0, if a weighted sum "
|
||
"of its components (weightSum) is nonzero");
|
||
if (flexFactorSum < 1.0f) {
|
||
// Our unfrozen flex items don't want all of the original free space!
|
||
// (Their flex factors add up to something less than 1.)
|
||
// Hence, make sure we don't distribute any more than the portion of
|
||
// our original free space that these items actually want.
|
||
nscoord totalDesiredPortionOfOrigFreeSpace =
|
||
NSToCoordRound(origAvailableFreeSpace * flexFactorSum);
|
||
|
||
// Clamp availableFreeSpace to be no larger than that ^^.
|
||
// (using min or max, depending on sign).
|
||
// This should not change the sign of availableFreeSpace (except
|
||
// possibly by setting it to 0), as enforced by this assertion:
|
||
MOZ_ASSERT(totalDesiredPortionOfOrigFreeSpace == 0 ||
|
||
((totalDesiredPortionOfOrigFreeSpace > 0) ==
|
||
(availableFreeSpace > 0)),
|
||
"When we reduce available free space for flex factors < 1,"
|
||
"we shouldn't change the sign of the free space...");
|
||
|
||
if (availableFreeSpace > 0) {
|
||
availableFreeSpace = std::min(availableFreeSpace,
|
||
totalDesiredPortionOfOrigFreeSpace);
|
||
} else {
|
||
availableFreeSpace = std::max(availableFreeSpace,
|
||
totalDesiredPortionOfOrigFreeSpace);
|
||
}
|
||
}
|
||
|
||
PR_LOG(GetFlexContainerLog(), PR_LOG_DEBUG,
|
||
(" Distributing available space:"));
|
||
// Since this loop only operates on unfrozen flex items, we can break as
|
||
// soon as we have seen all of them.
|
||
numUnfrozenItemsToBeSeen = mNumItems - mNumFrozenItems;
|
||
|
||
// NOTE: It's important that we traverse our items in *reverse* order
|
||
// here, for correct width distribution according to the items'
|
||
// "ShareOfWeightSoFar" progressively-calculated values.
|
||
for (FlexItem* item = mItems.getLast();
|
||
numUnfrozenItemsToBeSeen > 0; item = item->getPrevious()) {
|
||
MOZ_ASSERT(item,
|
||
"numUnfrozenItemsToBeSeen says items remain to be seen");
|
||
if (!item->IsFrozen()) {
|
||
numUnfrozenItemsToBeSeen--;
|
||
|
||
// To avoid rounding issues, we compute the change in size for this
|
||
// item, and then subtract it from the remaining available space.
|
||
nscoord sizeDelta = 0;
|
||
if (IsFinite(weightSum)) {
|
||
float myShareOfRemainingSpace =
|
||
item->GetShareOfWeightSoFar();
|
||
|
||
MOZ_ASSERT(myShareOfRemainingSpace >= 0.0f &&
|
||
myShareOfRemainingSpace <= 1.0f,
|
||
"my share should be nonnegative fractional amount");
|
||
|
||
if (myShareOfRemainingSpace == 1.0f) {
|
||
// (We special-case 1.0f to avoid float error from converting
|
||
// availableFreeSpace from integer*1.0f --> float --> integer)
|
||
sizeDelta = availableFreeSpace;
|
||
} else if (myShareOfRemainingSpace > 0.0f) {
|
||
sizeDelta = NSToCoordRound(availableFreeSpace *
|
||
myShareOfRemainingSpace);
|
||
}
|
||
} else if (item->GetWeight(isUsingFlexGrow) == largestWeight) {
|
||
// Total flexibility is infinite, so we're just distributing
|
||
// the available space equally among the items that are tied for
|
||
// having the largest weight (and this is one of those items).
|
||
sizeDelta =
|
||
NSToCoordRound(availableFreeSpace /
|
||
float(numItemsWithLargestWeight));
|
||
numItemsWithLargestWeight--;
|
||
}
|
||
|
||
availableFreeSpace -= sizeDelta;
|
||
|
||
item->SetMainSize(item->GetMainSize() + sizeDelta);
|
||
PR_LOG(GetFlexContainerLog(), PR_LOG_DEBUG,
|
||
(" child %p receives %d, for a total of %d\n",
|
||
item, sizeDelta, item->GetMainSize()));
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
// Fix min/max violations:
|
||
nscoord totalViolation = 0; // keeps track of adjustments for min/max
|
||
PR_LOG(GetFlexContainerLog(), PR_LOG_DEBUG,
|
||
(" Checking for violations:"));
|
||
|
||
// Since this loop only operates on unfrozen flex items, we can break as
|
||
// soon as we have seen all of them.
|
||
uint32_t numUnfrozenItemsToBeSeen = mNumItems - mNumFrozenItems;
|
||
for (FlexItem* item = mItems.getFirst();
|
||
numUnfrozenItemsToBeSeen > 0; item = item->getNext()) {
|
||
MOZ_ASSERT(item, "numUnfrozenItemsToBeSeen says items remain to be seen");
|
||
if (!item->IsFrozen()) {
|
||
numUnfrozenItemsToBeSeen--;
|
||
|
||
if (item->GetMainSize() < item->GetMainMinSize()) {
|
||
// min violation
|
||
totalViolation += item->GetMainMinSize() - item->GetMainSize();
|
||
item->SetMainSize(item->GetMainMinSize());
|
||
item->SetHadMinViolation();
|
||
} else if (item->GetMainSize() > item->GetMainMaxSize()) {
|
||
// max violation
|
||
totalViolation += item->GetMainMaxSize() - item->GetMainSize();
|
||
item->SetMainSize(item->GetMainMaxSize());
|
||
item->SetHadMaxViolation();
|
||
}
|
||
}
|
||
}
|
||
|
||
FreezeOrRestoreEachFlexibleSize(totalViolation,
|
||
iterationCounter + 1 == mNumItems);
|
||
|
||
PR_LOG(GetFlexContainerLog(), PR_LOG_DEBUG,
|
||
(" Total violation: %d\n", totalViolation));
|
||
|
||
if (mNumFrozenItems == mNumItems) {
|
||
break;
|
||
}
|
||
|
||
MOZ_ASSERT(totalViolation != 0,
|
||
"Zero violation should've made us freeze all items & break");
|
||
}
|
||
|
||
#ifdef DEBUG
|
||
// Post-condition: all items should've been frozen.
|
||
// Make sure the counts match:
|
||
MOZ_ASSERT(mNumFrozenItems == mNumItems, "All items should be frozen");
|
||
|
||
// For good measure, check each item directly, in case our counts are busted:
|
||
for (const FlexItem* item = mItems.getFirst(); item; item = item->getNext()) {
|
||
MOZ_ASSERT(item->IsFrozen(), "All items should be frozen");
|
||
}
|
||
#endif // DEBUG
|
||
}
|
||
|
||
MainAxisPositionTracker::
|
||
MainAxisPositionTracker(const FlexboxAxisTracker& aAxisTracker,
|
||
const FlexLine* aLine,
|
||
uint8_t aJustifyContent,
|
||
nscoord aContentBoxMainSize)
|
||
: PositionTracker(aAxisTracker.GetMainAxis()),
|
||
mPackingSpaceRemaining(aContentBoxMainSize), // we chip away at this below
|
||
mNumAutoMarginsInMainAxis(0),
|
||
mNumPackingSpacesRemaining(0),
|
||
mJustifyContent(aJustifyContent)
|
||
{
|
||
// mPackingSpaceRemaining is initialized to the container's main size. Now
|
||
// we'll subtract out the main sizes of our flex items, so that it ends up
|
||
// with the *actual* amount of packing space.
|
||
for (const FlexItem* item = aLine->GetFirstItem(); item;
|
||
item = item->getNext()) {
|
||
mPackingSpaceRemaining -= item->GetOuterMainSize(mAxis);
|
||
mNumAutoMarginsInMainAxis += item->GetNumAutoMarginsInAxis(mAxis);
|
||
}
|
||
|
||
if (mPackingSpaceRemaining <= 0) {
|
||
// No available packing space to use for resolving auto margins.
|
||
mNumAutoMarginsInMainAxis = 0;
|
||
}
|
||
|
||
// If packing space is negative, 'space-between' behaves like 'flex-start',
|
||
// and 'space-around' behaves like 'center'. In those cases, it's simplest to
|
||
// just pretend we have a different 'justify-content' value and share code.
|
||
if (mPackingSpaceRemaining < 0) {
|
||
if (mJustifyContent == NS_STYLE_JUSTIFY_CONTENT_SPACE_BETWEEN) {
|
||
mJustifyContent = NS_STYLE_JUSTIFY_CONTENT_FLEX_START;
|
||
} else if (mJustifyContent == NS_STYLE_JUSTIFY_CONTENT_SPACE_AROUND) {
|
||
mJustifyContent = NS_STYLE_JUSTIFY_CONTENT_CENTER;
|
||
}
|
||
}
|
||
|
||
// If our main axis is (internally) reversed, swap the justify-content
|
||
// "flex-start" and "flex-end" behaviors:
|
||
if (aAxisTracker.AreAxesInternallyReversed()) {
|
||
if (mJustifyContent == NS_STYLE_JUSTIFY_CONTENT_FLEX_START) {
|
||
mJustifyContent = NS_STYLE_JUSTIFY_CONTENT_FLEX_END;
|
||
} else if (mJustifyContent == NS_STYLE_JUSTIFY_CONTENT_FLEX_END) {
|
||
mJustifyContent = NS_STYLE_JUSTIFY_CONTENT_FLEX_START;
|
||
}
|
||
}
|
||
|
||
// Figure out how much space we'll set aside for auto margins or
|
||
// packing spaces, and advance past any leading packing-space.
|
||
if (mNumAutoMarginsInMainAxis == 0 &&
|
||
mPackingSpaceRemaining != 0 &&
|
||
!aLine->IsEmpty()) {
|
||
switch (mJustifyContent) {
|
||
case NS_STYLE_JUSTIFY_CONTENT_FLEX_START:
|
||
// All packing space should go at the end --> nothing to do here.
|
||
break;
|
||
case NS_STYLE_JUSTIFY_CONTENT_FLEX_END:
|
||
// All packing space goes at the beginning
|
||
mPosition += mPackingSpaceRemaining;
|
||
break;
|
||
case NS_STYLE_JUSTIFY_CONTENT_CENTER:
|
||
// Half the packing space goes at the beginning
|
||
mPosition += mPackingSpaceRemaining / 2;
|
||
break;
|
||
case NS_STYLE_JUSTIFY_CONTENT_SPACE_BETWEEN:
|
||
MOZ_ASSERT(mPackingSpaceRemaining >= 0,
|
||
"negative packing space should make us use 'flex-start' "
|
||
"instead of 'space-between'");
|
||
// 1 packing space between each flex item, no packing space at ends.
|
||
mNumPackingSpacesRemaining = aLine->NumItems() - 1;
|
||
break;
|
||
case NS_STYLE_JUSTIFY_CONTENT_SPACE_AROUND:
|
||
MOZ_ASSERT(mPackingSpaceRemaining >= 0,
|
||
"negative packing space should make us use 'center' "
|
||
"instead of 'space-around'");
|
||
// 1 packing space between each flex item, plus half a packing space
|
||
// at beginning & end. So our number of full packing-spaces is equal
|
||
// to the number of flex items.
|
||
mNumPackingSpacesRemaining = aLine->NumItems();
|
||
if (mNumPackingSpacesRemaining > 0) {
|
||
// The edges (start/end) share one full packing space
|
||
nscoord totalEdgePackingSpace =
|
||
mPackingSpaceRemaining / mNumPackingSpacesRemaining;
|
||
|
||
// ...and we'll use half of that right now, at the start
|
||
mPosition += totalEdgePackingSpace / 2;
|
||
// ...but we need to subtract all of it right away, so that we won't
|
||
// hand out any of it to intermediate packing spaces.
|
||
mPackingSpaceRemaining -= totalEdgePackingSpace;
|
||
mNumPackingSpacesRemaining--;
|
||
}
|
||
break;
|
||
default:
|
||
MOZ_CRASH("Unexpected justify-content value");
|
||
}
|
||
}
|
||
|
||
MOZ_ASSERT(mNumPackingSpacesRemaining == 0 ||
|
||
mNumAutoMarginsInMainAxis == 0,
|
||
"extra space should either go to packing space or to "
|
||
"auto margins, but not to both");
|
||
}
|
||
|
||
void
|
||
MainAxisPositionTracker::ResolveAutoMarginsInMainAxis(FlexItem& aItem)
|
||
{
|
||
if (mNumAutoMarginsInMainAxis) {
|
||
const nsStyleSides& styleMargin = aItem.Frame()->StyleMargin()->mMargin;
|
||
for (uint32_t i = 0; i < eNumAxisEdges; i++) {
|
||
mozilla::Side side = kAxisOrientationToSidesMap[mAxis][i];
|
||
if (styleMargin.GetUnit(side) == eStyleUnit_Auto) {
|
||
// NOTE: This integer math will skew the distribution of remainder
|
||
// app-units towards the end, which is fine.
|
||
nscoord curAutoMarginSize =
|
||
mPackingSpaceRemaining / mNumAutoMarginsInMainAxis;
|
||
|
||
MOZ_ASSERT(aItem.GetMarginComponentForSide(side) == 0,
|
||
"Expecting auto margins to have value '0' before we "
|
||
"resolve them");
|
||
aItem.SetMarginComponentForSide(side, curAutoMarginSize);
|
||
|
||
mNumAutoMarginsInMainAxis--;
|
||
mPackingSpaceRemaining -= curAutoMarginSize;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
void
|
||
MainAxisPositionTracker::TraversePackingSpace()
|
||
{
|
||
if (mNumPackingSpacesRemaining) {
|
||
MOZ_ASSERT(mJustifyContent == NS_STYLE_JUSTIFY_CONTENT_SPACE_BETWEEN ||
|
||
mJustifyContent == NS_STYLE_JUSTIFY_CONTENT_SPACE_AROUND,
|
||
"mNumPackingSpacesRemaining only applies for "
|
||
"space-between/space-around");
|
||
|
||
MOZ_ASSERT(mPackingSpaceRemaining >= 0,
|
||
"ran out of packing space earlier than we expected");
|
||
|
||
// NOTE: This integer math will skew the distribution of remainder
|
||
// app-units towards the end, which is fine.
|
||
nscoord curPackingSpace =
|
||
mPackingSpaceRemaining / mNumPackingSpacesRemaining;
|
||
|
||
mPosition += curPackingSpace;
|
||
mNumPackingSpacesRemaining--;
|
||
mPackingSpaceRemaining -= curPackingSpace;
|
||
}
|
||
}
|
||
|
||
CrossAxisPositionTracker::
|
||
CrossAxisPositionTracker(FlexLine* aFirstLine,
|
||
uint8_t aAlignContent,
|
||
nscoord aContentBoxCrossSize,
|
||
bool aIsCrossSizeDefinite,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
: PositionTracker(aAxisTracker.GetCrossAxis()),
|
||
mPackingSpaceRemaining(0),
|
||
mNumPackingSpacesRemaining(0),
|
||
mAlignContent(aAlignContent)
|
||
{
|
||
MOZ_ASSERT(aFirstLine, "null first line pointer");
|
||
|
||
if (aIsCrossSizeDefinite && !aFirstLine->getNext()) {
|
||
// "If the flex container has only a single line (even if it's a
|
||
// multi-line flex container) and has a definite cross size, the cross
|
||
// size of the flex line is the flex container's inner cross size."
|
||
// SOURCE: http://dev.w3.org/csswg/css-flexbox/#algo-line-break
|
||
// NOTE: This means (by definition) that there's no packing space, which
|
||
// means we don't need to be concerned with "align-conent" at all and we
|
||
// can return early. This is handy, because this is the usual case (for
|
||
// single-line flexbox).
|
||
aFirstLine->SetLineCrossSize(aContentBoxCrossSize);
|
||
return;
|
||
}
|
||
|
||
// NOTE: The rest of this function should essentially match
|
||
// MainAxisPositionTracker's constructor, though with FlexLines instead of
|
||
// FlexItems, and with the additional value "stretch" (and of course with
|
||
// cross sizes instead of main sizes.)
|
||
|
||
// Figure out how much packing space we have (container's cross size minus
|
||
// all the lines' cross sizes). Also, share this loop to count how many
|
||
// lines we have. (We need that count in some cases below.)
|
||
mPackingSpaceRemaining = aContentBoxCrossSize;
|
||
uint32_t numLines = 0;
|
||
for (FlexLine* line = aFirstLine; line; line = line->getNext()) {
|
||
mPackingSpaceRemaining -= line->GetLineCrossSize();
|
||
numLines++;
|
||
}
|
||
|
||
// If packing space is negative, 'space-between' and 'stretch' behave like
|
||
// 'flex-start', and 'space-around' behaves like 'center'. In those cases,
|
||
// it's simplest to just pretend we have a different 'align-content' value
|
||
// and share code.
|
||
if (mPackingSpaceRemaining < 0) {
|
||
if (mAlignContent == NS_STYLE_ALIGN_CONTENT_SPACE_BETWEEN ||
|
||
mAlignContent == NS_STYLE_ALIGN_CONTENT_STRETCH) {
|
||
mAlignContent = NS_STYLE_ALIGN_CONTENT_FLEX_START;
|
||
} else if (mAlignContent == NS_STYLE_ALIGN_CONTENT_SPACE_AROUND) {
|
||
mAlignContent = NS_STYLE_ALIGN_CONTENT_CENTER;
|
||
}
|
||
}
|
||
|
||
// If our cross axis is (internally) reversed, swap the align-content
|
||
// "flex-start" and "flex-end" behaviors:
|
||
if (aAxisTracker.AreAxesInternallyReversed()) {
|
||
if (mAlignContent == NS_STYLE_ALIGN_CONTENT_FLEX_START) {
|
||
mAlignContent = NS_STYLE_ALIGN_CONTENT_FLEX_END;
|
||
} else if (mAlignContent == NS_STYLE_ALIGN_CONTENT_FLEX_END) {
|
||
mAlignContent = NS_STYLE_ALIGN_CONTENT_FLEX_START;
|
||
}
|
||
}
|
||
|
||
// Figure out how much space we'll set aside for packing spaces, and advance
|
||
// past any leading packing-space.
|
||
if (mPackingSpaceRemaining != 0) {
|
||
switch (mAlignContent) {
|
||
case NS_STYLE_ALIGN_CONTENT_FLEX_START:
|
||
// All packing space should go at the end --> nothing to do here.
|
||
break;
|
||
case NS_STYLE_ALIGN_CONTENT_FLEX_END:
|
||
// All packing space goes at the beginning
|
||
mPosition += mPackingSpaceRemaining;
|
||
break;
|
||
case NS_STYLE_ALIGN_CONTENT_CENTER:
|
||
// Half the packing space goes at the beginning
|
||
mPosition += mPackingSpaceRemaining / 2;
|
||
break;
|
||
case NS_STYLE_ALIGN_CONTENT_SPACE_BETWEEN:
|
||
MOZ_ASSERT(mPackingSpaceRemaining >= 0,
|
||
"negative packing space should make us use 'flex-start' "
|
||
"instead of 'space-between'");
|
||
// 1 packing space between each flex line, no packing space at ends.
|
||
mNumPackingSpacesRemaining = numLines - 1;
|
||
break;
|
||
case NS_STYLE_ALIGN_CONTENT_SPACE_AROUND: {
|
||
MOZ_ASSERT(mPackingSpaceRemaining >= 0,
|
||
"negative packing space should make us use 'center' "
|
||
"instead of 'space-around'");
|
||
// 1 packing space between each flex line, plus half a packing space
|
||
// at beginning & end. So our number of full packing-spaces is equal
|
||
// to the number of flex lines.
|
||
mNumPackingSpacesRemaining = numLines;
|
||
// The edges (start/end) share one full packing space
|
||
nscoord totalEdgePackingSpace =
|
||
mPackingSpaceRemaining / mNumPackingSpacesRemaining;
|
||
|
||
// ...and we'll use half of that right now, at the start
|
||
mPosition += totalEdgePackingSpace / 2;
|
||
// ...but we need to subtract all of it right away, so that we won't
|
||
// hand out any of it to intermediate packing spaces.
|
||
mPackingSpaceRemaining -= totalEdgePackingSpace;
|
||
mNumPackingSpacesRemaining--;
|
||
break;
|
||
}
|
||
case NS_STYLE_ALIGN_CONTENT_STRETCH: {
|
||
// Split space equally between the lines:
|
||
MOZ_ASSERT(mPackingSpaceRemaining > 0,
|
||
"negative packing space should make us use 'flex-start' "
|
||
"instead of 'stretch' (and we shouldn't bother with this "
|
||
"code if we have 0 packing space)");
|
||
|
||
uint32_t numLinesLeft = numLines;
|
||
for (FlexLine* line = aFirstLine; line; line = line->getNext()) {
|
||
// Our share is the amount of space remaining, divided by the number
|
||
// of lines remainig.
|
||
MOZ_ASSERT(numLinesLeft > 0, "miscalculated num lines");
|
||
nscoord shareOfExtraSpace = mPackingSpaceRemaining / numLinesLeft;
|
||
nscoord newSize = line->GetLineCrossSize() + shareOfExtraSpace;
|
||
line->SetLineCrossSize(newSize);
|
||
|
||
mPackingSpaceRemaining -= shareOfExtraSpace;
|
||
numLinesLeft--;
|
||
}
|
||
MOZ_ASSERT(numLinesLeft == 0, "miscalculated num lines");
|
||
break;
|
||
}
|
||
default:
|
||
MOZ_CRASH("Unexpected align-content value");
|
||
}
|
||
}
|
||
}
|
||
|
||
void
|
||
CrossAxisPositionTracker::TraversePackingSpace()
|
||
{
|
||
if (mNumPackingSpacesRemaining) {
|
||
MOZ_ASSERT(mAlignContent == NS_STYLE_ALIGN_CONTENT_SPACE_BETWEEN ||
|
||
mAlignContent == NS_STYLE_ALIGN_CONTENT_SPACE_AROUND,
|
||
"mNumPackingSpacesRemaining only applies for "
|
||
"space-between/space-around");
|
||
|
||
MOZ_ASSERT(mPackingSpaceRemaining >= 0,
|
||
"ran out of packing space earlier than we expected");
|
||
|
||
// NOTE: This integer math will skew the distribution of remainder
|
||
// app-units towards the end, which is fine.
|
||
nscoord curPackingSpace =
|
||
mPackingSpaceRemaining / mNumPackingSpacesRemaining;
|
||
|
||
mPosition += curPackingSpace;
|
||
mNumPackingSpacesRemaining--;
|
||
mPackingSpaceRemaining -= curPackingSpace;
|
||
}
|
||
}
|
||
|
||
SingleLineCrossAxisPositionTracker::
|
||
SingleLineCrossAxisPositionTracker(const FlexboxAxisTracker& aAxisTracker)
|
||
: PositionTracker(aAxisTracker.GetCrossAxis())
|
||
{
|
||
}
|
||
|
||
void
|
||
FlexLine::ComputeCrossSizeAndBaseline(const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
nscoord crossStartToFurthestBaseline = nscoord_MIN;
|
||
nscoord crossEndToFurthestBaseline = nscoord_MIN;
|
||
nscoord largestOuterCrossSize = 0;
|
||
for (const FlexItem* item = mItems.getFirst(); item; item = item->getNext()) {
|
||
nscoord curOuterCrossSize =
|
||
item->GetOuterCrossSize(aAxisTracker.GetCrossAxis());
|
||
|
||
if (item->GetAlignSelf() == NS_STYLE_ALIGN_ITEMS_BASELINE &&
|
||
item->GetNumAutoMarginsInAxis(aAxisTracker.GetCrossAxis()) == 0) {
|
||
// FIXME: Once we support "writing-mode", we'll have to do baseline
|
||
// alignment in vertical flex containers here (w/ horizontal cross-axes).
|
||
|
||
// Find distance from our item's cross-start and cross-end margin-box
|
||
// edges to its baseline.
|
||
//
|
||
// Here's a diagram of a flex-item that we might be doing this on.
|
||
// "mmm" is the margin-box, "bbb" is the border-box. The bottom of
|
||
// the text "BASE" is the baseline.
|
||
//
|
||
// ---(cross-start)---
|
||
// ___ ___ ___
|
||
// mmmmmmmmmmmm | |margin-start |
|
||
// m m | _|_ ___ |
|
||
// m bbbbbbbb m |curOuterCrossSize | |crossStartToBaseline
|
||
// m b b m | |ascent |
|
||
// m b BASE b m | _|_ _|_
|
||
// m b b m | |
|
||
// m bbbbbbbb m | |crossEndToBaseline
|
||
// m m | |
|
||
// mmmmmmmmmmmm _|_ _|_
|
||
//
|
||
// ---(cross-end)---
|
||
//
|
||
// We already have the curOuterCrossSize, margin-start, and the ascent.
|
||
// * We can get crossStartToBaseline by adding margin-start + ascent.
|
||
// * If we subtract that from the curOuterCrossSize, we get
|
||
// crossEndToBaseline.
|
||
|
||
nscoord crossStartToBaseline =
|
||
item->GetBaselineOffsetFromOuterCrossEdge(aAxisTracker.GetCrossAxis(),
|
||
eAxisEdge_Start);
|
||
nscoord crossEndToBaseline = curOuterCrossSize - crossStartToBaseline;
|
||
|
||
// Now, update our "largest" values for these (across all the flex items
|
||
// in this flex line), so we can use them in computing the line's cross
|
||
// size below:
|
||
crossStartToFurthestBaseline = std::max(crossStartToFurthestBaseline,
|
||
crossStartToBaseline);
|
||
crossEndToFurthestBaseline = std::max(crossEndToFurthestBaseline,
|
||
crossEndToBaseline);
|
||
} else {
|
||
largestOuterCrossSize = std::max(largestOuterCrossSize, curOuterCrossSize);
|
||
}
|
||
}
|
||
|
||
// The line's baseline offset is the distance from the line's edge (start or
|
||
// end, depending on whether we've flipped the axes) to the furthest
|
||
// item-baseline. The item(s) with that baseline will be exactly aligned with
|
||
// the line's edge.
|
||
mBaselineOffset = aAxisTracker.AreAxesInternallyReversed() ?
|
||
crossEndToFurthestBaseline : crossStartToFurthestBaseline;
|
||
|
||
// The line's cross-size is the larger of:
|
||
// (a) [largest cross-start-to-baseline + largest baseline-to-cross-end] of
|
||
// all baseline-aligned items with no cross-axis auto margins...
|
||
// and
|
||
// (b) largest cross-size of all other children.
|
||
mLineCrossSize = std::max(crossStartToFurthestBaseline +
|
||
crossEndToFurthestBaseline,
|
||
largestOuterCrossSize);
|
||
}
|
||
|
||
void
|
||
FlexItem::ResolveStretchedCrossSize(nscoord aLineCrossSize,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
AxisOrientationType crossAxis = aAxisTracker.GetCrossAxis();
|
||
// We stretch IFF we are align-self:stretch, have no auto margins in
|
||
// cross axis, and have cross-axis size property == "auto". If any of those
|
||
// conditions don't hold up, we won't stretch.
|
||
if (mAlignSelf != NS_STYLE_ALIGN_ITEMS_STRETCH ||
|
||
GetNumAutoMarginsInAxis(crossAxis) != 0 ||
|
||
eStyleUnit_Auto != GetSizePropertyForAxis(mFrame, crossAxis).GetUnit()) {
|
||
return;
|
||
}
|
||
|
||
// If we've already been stretched, we can bail out early, too.
|
||
// No need to redo the calculation.
|
||
if (mIsStretched) {
|
||
return;
|
||
}
|
||
|
||
// Reserve space for margins & border & padding, and then use whatever
|
||
// remains as our item's cross-size (clamped to its min/max range).
|
||
nscoord stretchedSize = aLineCrossSize -
|
||
GetMarginBorderPaddingSizeInAxis(crossAxis);
|
||
|
||
stretchedSize = NS_CSS_MINMAX(stretchedSize, mCrossMinSize, mCrossMaxSize);
|
||
|
||
// Update the cross-size & make a note that it's stretched, so we know to
|
||
// override the reflow state's computed cross-size in our final reflow.
|
||
SetCrossSize(stretchedSize);
|
||
mIsStretched = true;
|
||
}
|
||
|
||
void
|
||
SingleLineCrossAxisPositionTracker::
|
||
ResolveAutoMarginsInCrossAxis(const FlexLine& aLine,
|
||
FlexItem& aItem)
|
||
{
|
||
// Subtract the space that our item is already occupying, to see how much
|
||
// space (if any) is available for its auto margins.
|
||
nscoord spaceForAutoMargins = aLine.GetLineCrossSize() -
|
||
aItem.GetOuterCrossSize(mAxis);
|
||
|
||
if (spaceForAutoMargins <= 0) {
|
||
return; // No available space --> nothing to do
|
||
}
|
||
|
||
uint32_t numAutoMargins = aItem.GetNumAutoMarginsInAxis(mAxis);
|
||
if (numAutoMargins == 0) {
|
||
return; // No auto margins --> nothing to do.
|
||
}
|
||
|
||
// OK, we have at least one auto margin and we have some available space.
|
||
// Give each auto margin a share of the space.
|
||
const nsStyleSides& styleMargin = aItem.Frame()->StyleMargin()->mMargin;
|
||
for (uint32_t i = 0; i < eNumAxisEdges; i++) {
|
||
mozilla::Side side = kAxisOrientationToSidesMap[mAxis][i];
|
||
if (styleMargin.GetUnit(side) == eStyleUnit_Auto) {
|
||
MOZ_ASSERT(aItem.GetMarginComponentForSide(side) == 0,
|
||
"Expecting auto margins to have value '0' before we "
|
||
"update them");
|
||
|
||
// NOTE: integer divison is fine here; numAutoMargins is either 1 or 2.
|
||
// If it's 2 & spaceForAutoMargins is odd, 1st margin gets smaller half.
|
||
nscoord curAutoMarginSize = spaceForAutoMargins / numAutoMargins;
|
||
aItem.SetMarginComponentForSide(side, curAutoMarginSize);
|
||
numAutoMargins--;
|
||
spaceForAutoMargins -= curAutoMarginSize;
|
||
}
|
||
}
|
||
}
|
||
|
||
void
|
||
SingleLineCrossAxisPositionTracker::
|
||
EnterAlignPackingSpace(const FlexLine& aLine,
|
||
const FlexItem& aItem,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
// We don't do align-self alignment on items that have auto margins
|
||
// in the cross axis.
|
||
if (aItem.GetNumAutoMarginsInAxis(mAxis)) {
|
||
return;
|
||
}
|
||
|
||
uint8_t alignSelf = aItem.GetAlignSelf();
|
||
// NOTE: 'stretch' behaves like 'flex-start' once we've stretched any
|
||
// auto-sized items (which we've already done).
|
||
if (alignSelf == NS_STYLE_ALIGN_ITEMS_STRETCH) {
|
||
alignSelf = NS_STYLE_ALIGN_ITEMS_FLEX_START;
|
||
}
|
||
|
||
// If our cross axis is (internally) reversed, swap the align-self
|
||
// "flex-start" and "flex-end" behaviors:
|
||
if (aAxisTracker.AreAxesInternallyReversed()) {
|
||
if (alignSelf == NS_STYLE_ALIGN_ITEMS_FLEX_START) {
|
||
alignSelf = NS_STYLE_ALIGN_ITEMS_FLEX_END;
|
||
} else if (alignSelf == NS_STYLE_ALIGN_ITEMS_FLEX_END) {
|
||
alignSelf = NS_STYLE_ALIGN_ITEMS_FLEX_START;
|
||
}
|
||
}
|
||
|
||
switch (alignSelf) {
|
||
case NS_STYLE_ALIGN_ITEMS_FLEX_START:
|
||
// No space to skip over -- we're done.
|
||
break;
|
||
case NS_STYLE_ALIGN_ITEMS_FLEX_END:
|
||
mPosition += aLine.GetLineCrossSize() - aItem.GetOuterCrossSize(mAxis);
|
||
break;
|
||
case NS_STYLE_ALIGN_ITEMS_CENTER:
|
||
// Note: If cross-size is odd, the "after" space will get the extra unit.
|
||
mPosition +=
|
||
(aLine.GetLineCrossSize() - aItem.GetOuterCrossSize(mAxis)) / 2;
|
||
break;
|
||
case NS_STYLE_ALIGN_ITEMS_BASELINE: {
|
||
// Normally, baseline-aligned items are collectively aligned with the
|
||
// line's cross-start edge; however, if our cross axis is (internally)
|
||
// reversed, we instead align them with the cross-end edge.
|
||
nscoord itemBaselineOffset =
|
||
aItem.GetBaselineOffsetFromOuterCrossEdge(mAxis,
|
||
aAxisTracker.AreAxesInternallyReversed() ?
|
||
eAxisEdge_End : eAxisEdge_Start);
|
||
|
||
nscoord lineBaselineOffset = aLine.GetBaselineOffset();
|
||
|
||
NS_ASSERTION(lineBaselineOffset >= itemBaselineOffset,
|
||
"failed at finding largest baseline offset");
|
||
|
||
// How much do we need to adjust our position (from the line edge),
|
||
// to get the item's baseline to hit the line's baseline offset:
|
||
nscoord baselineDiff = lineBaselineOffset - itemBaselineOffset;
|
||
|
||
if (aAxisTracker.AreAxesInternallyReversed()) {
|
||
// Advance to align item w/ line's flex-end edge (as in FLEX_END case):
|
||
mPosition += aLine.GetLineCrossSize() - aItem.GetOuterCrossSize(mAxis);
|
||
// ...and step *back* by the baseline adjustment:
|
||
mPosition -= baselineDiff;
|
||
} else {
|
||
// mPosition is already at line's flex-start edge.
|
||
// From there, we step *forward* by the baseline adjustment:
|
||
mPosition += baselineDiff;
|
||
}
|
||
break;
|
||
}
|
||
default:
|
||
NS_NOTREACHED("Unexpected align-self value");
|
||
break;
|
||
}
|
||
}
|
||
|
||
FlexboxAxisTracker::FlexboxAxisTracker(
|
||
nsFlexContainerFrame* aFlexContainerFrame)
|
||
: mAreAxesInternallyReversed(false)
|
||
{
|
||
const nsStylePosition* pos = aFlexContainerFrame->StylePosition();
|
||
uint32_t flexDirection = pos->mFlexDirection;
|
||
uint32_t cssDirection =
|
||
aFlexContainerFrame->StyleVisibility()->mDirection;
|
||
|
||
MOZ_ASSERT(cssDirection == NS_STYLE_DIRECTION_LTR ||
|
||
cssDirection == NS_STYLE_DIRECTION_RTL,
|
||
"Unexpected computed value for 'direction' property");
|
||
// (Not asserting for flexDirection here; it's checked by the switch below.)
|
||
|
||
// These are defined according to writing-modes' definitions of
|
||
// start/end (for the inline dimension) and before/after (for the block
|
||
// dimension), here:
|
||
// http://www.w3.org/TR/css3-writing-modes/#logical-directions
|
||
// (NOTE: I'm intentionally not calling this "inlineAxis"/"blockAxis", since
|
||
// those terms have explicit definition in the writing-modes spec, which are
|
||
// the opposite of how I'd be using them here.)
|
||
// XXXdholbert Once we support the 'writing-mode' property, use its value
|
||
// here to further customize inlineDimension & blockDimension.
|
||
|
||
// Inline dimension ("start-to-end"):
|
||
AxisOrientationType inlineDimension =
|
||
cssDirection == NS_STYLE_DIRECTION_RTL ? eAxis_RL : eAxis_LR;
|
||
|
||
// Block dimension ("before-to-after"):
|
||
AxisOrientationType blockDimension = eAxis_TB;
|
||
|
||
// Determine main axis:
|
||
switch (flexDirection) {
|
||
case NS_STYLE_FLEX_DIRECTION_ROW:
|
||
mMainAxis = inlineDimension;
|
||
break;
|
||
case NS_STYLE_FLEX_DIRECTION_ROW_REVERSE:
|
||
mMainAxis = GetReverseAxis(inlineDimension);
|
||
break;
|
||
case NS_STYLE_FLEX_DIRECTION_COLUMN:
|
||
mMainAxis = blockDimension;
|
||
break;
|
||
case NS_STYLE_FLEX_DIRECTION_COLUMN_REVERSE:
|
||
mMainAxis = GetReverseAxis(blockDimension);
|
||
break;
|
||
default:
|
||
MOZ_CRASH("Unexpected computed value for 'flex-flow' property");
|
||
}
|
||
|
||
// Determine cross axis:
|
||
// (This is set up so that a bogus |flexDirection| value will
|
||
// give us blockDimension.
|
||
if (flexDirection == NS_STYLE_FLEX_DIRECTION_COLUMN ||
|
||
flexDirection == NS_STYLE_FLEX_DIRECTION_COLUMN_REVERSE) {
|
||
mCrossAxis = inlineDimension;
|
||
} else {
|
||
mCrossAxis = blockDimension;
|
||
}
|
||
|
||
// "flex-wrap: wrap-reverse" reverses our cross axis.
|
||
if (pos->mFlexWrap == NS_STYLE_FLEX_WRAP_WRAP_REVERSE) {
|
||
mCrossAxis = GetReverseAxis(mCrossAxis);
|
||
}
|
||
|
||
// Master switch to enable/disable bug 983427's code for reversing our axes
|
||
// and reversing some logic, to avoid reflowing children in bottom-to-top
|
||
// order. (This switch can be removed eventually, but for now, it allows
|
||
// this special-case code path to be compared against the normal code path.)
|
||
static bool sPreventBottomToTopChildOrdering = true;
|
||
|
||
if (sPreventBottomToTopChildOrdering) {
|
||
// If either axis is bottom-to-top, we flip both axes (and set a flag
|
||
// so that we can flip some logic to make the reversal transparent).
|
||
if (eAxis_BT == mMainAxis || eAxis_BT == mCrossAxis) {
|
||
mMainAxis = GetReverseAxis(mMainAxis);
|
||
mCrossAxis = GetReverseAxis(mCrossAxis);
|
||
mAreAxesInternallyReversed = true;
|
||
}
|
||
}
|
||
|
||
MOZ_ASSERT(IsAxisHorizontal(mMainAxis) != IsAxisHorizontal(mCrossAxis),
|
||
"main & cross axes should be in different dimensions");
|
||
}
|
||
|
||
// Allocates a new FlexLine, adds it to the given LinkedList (at the front or
|
||
// back depending on aShouldInsertAtFront), and returns a pointer to it.
|
||
static FlexLine*
|
||
AddNewFlexLineToList(LinkedList<FlexLine>& aLines,
|
||
bool aShouldInsertAtFront)
|
||
{
|
||
FlexLine* newLine = new FlexLine();
|
||
if (aShouldInsertAtFront) {
|
||
aLines.insertFront(newLine);
|
||
} else {
|
||
aLines.insertBack(newLine);
|
||
}
|
||
return newLine;
|
||
}
|
||
|
||
void
|
||
nsFlexContainerFrame::GenerateFlexLines(
|
||
nsPresContext* aPresContext,
|
||
const nsHTMLReflowState& aReflowState,
|
||
nscoord aContentBoxMainSize,
|
||
nscoord aAvailableHeightForContent,
|
||
const nsTArray<StrutInfo>& aStruts,
|
||
const FlexboxAxisTracker& aAxisTracker,
|
||
LinkedList<FlexLine>& aLines)
|
||
{
|
||
MOZ_ASSERT(aLines.isEmpty(), "Expecting outparam to start out empty");
|
||
|
||
const bool isSingleLine =
|
||
NS_STYLE_FLEX_WRAP_NOWRAP == aReflowState.mStylePosition->mFlexWrap;
|
||
|
||
// If we're transparently reversing axes, then we'll need to link up our
|
||
// FlexItems and FlexLines in the reverse order, so that the rest of flex
|
||
// layout (with flipped axes) will still produce the correct result.
|
||
// Here, we declare a convenience bool that we'll pass when adding a new
|
||
// FlexLine or FlexItem, to make us insert it at the beginning of its list
|
||
// (so the list ends up reversed).
|
||
const bool shouldInsertAtFront = aAxisTracker.AreAxesInternallyReversed();
|
||
|
||
// We have at least one FlexLine. Even an empty flex container has a single
|
||
// (empty) flex line.
|
||
FlexLine* curLine = AddNewFlexLineToList(aLines, shouldInsertAtFront);
|
||
|
||
nscoord wrapThreshold;
|
||
if (isSingleLine) {
|
||
// Not wrapping. Set threshold to sentinel value that tells us not to wrap.
|
||
wrapThreshold = NS_UNCONSTRAINEDSIZE;
|
||
} else {
|
||
// Wrapping! Set wrap threshold to flex container's content-box main-size.
|
||
wrapThreshold = aContentBoxMainSize;
|
||
|
||
// If the flex container doesn't have a definite content-box main-size
|
||
// (e.g. if we're 'height:auto'), make sure we at least wrap when we hit
|
||
// its max main-size.
|
||
if (wrapThreshold == NS_UNCONSTRAINEDSIZE) {
|
||
const nscoord flexContainerMaxMainSize =
|
||
GET_MAIN_COMPONENT(aAxisTracker,
|
||
aReflowState.ComputedMaxWidth(),
|
||
aReflowState.ComputedMaxHeight());
|
||
|
||
wrapThreshold = flexContainerMaxMainSize;
|
||
}
|
||
|
||
// Also: if we're vertical and paginating, we may need to wrap sooner
|
||
// (before we run off the end of the page)
|
||
if (!IsAxisHorizontal(aAxisTracker.GetMainAxis()) &&
|
||
aAvailableHeightForContent != NS_UNCONSTRAINEDSIZE) {
|
||
wrapThreshold = std::min(wrapThreshold, aAvailableHeightForContent);
|
||
}
|
||
}
|
||
|
||
// Tracks the index of the next strut, in aStruts (and when this hits
|
||
// aStruts.Length(), that means there are no more struts):
|
||
uint32_t nextStrutIdx = 0;
|
||
|
||
// Overall index of the current flex item in the flex container. (This gets
|
||
// checked against entries in aStruts.)
|
||
uint32_t itemIdxInContainer = 0;
|
||
|
||
for (nsFrameList::Enumerator e(mFrames); !e.AtEnd(); e.Next()) {
|
||
nsIFrame* childFrame = e.get();
|
||
|
||
// Honor "page-break-before", if we're multi-line and this line isn't empty:
|
||
if (!isSingleLine && !curLine->IsEmpty() &&
|
||
childFrame->StyleDisplay()->mBreakBefore) {
|
||
curLine = AddNewFlexLineToList(aLines, shouldInsertAtFront);
|
||
}
|
||
|
||
nsAutoPtr<FlexItem> item;
|
||
if (nextStrutIdx < aStruts.Length() &&
|
||
aStruts[nextStrutIdx].mItemIdx == itemIdxInContainer) {
|
||
|
||
// Use the simplified "strut" FlexItem constructor:
|
||
item = new FlexItem(childFrame, aStruts[nextStrutIdx].mStrutCrossSize);
|
||
nextStrutIdx++;
|
||
} else {
|
||
item = GenerateFlexItemForChild(aPresContext, childFrame,
|
||
aReflowState, aAxisTracker);
|
||
}
|
||
|
||
nscoord itemInnerHypotheticalMainSize = item->GetMainSize();
|
||
nscoord itemOuterHypotheticalMainSize =
|
||
item->GetOuterMainSize(aAxisTracker.GetMainAxis());
|
||
|
||
// Check if we need to wrap |item| to a new line
|
||
// (i.e. check if its outer hypothetical main size pushes our line over
|
||
// the threshold)
|
||
if (wrapThreshold != NS_UNCONSTRAINEDSIZE &&
|
||
!curLine->IsEmpty() && // No need to wrap at start of a line.
|
||
wrapThreshold < (curLine->GetTotalOuterHypotheticalMainSize() +
|
||
itemOuterHypotheticalMainSize)) {
|
||
curLine = AddNewFlexLineToList(aLines, shouldInsertAtFront);
|
||
}
|
||
|
||
// Add item to current flex line (and update the line's bookkeeping about
|
||
// how large its items collectively are).
|
||
curLine->AddItem(item.forget(), shouldInsertAtFront,
|
||
itemInnerHypotheticalMainSize,
|
||
itemOuterHypotheticalMainSize);
|
||
|
||
// Honor "page-break-after", if we're multi-line and have more children:
|
||
if (!isSingleLine && childFrame->GetNextSibling() &&
|
||
childFrame->StyleDisplay()->mBreakAfter) {
|
||
curLine = AddNewFlexLineToList(aLines, shouldInsertAtFront);
|
||
}
|
||
itemIdxInContainer++;
|
||
}
|
||
}
|
||
|
||
// Retrieves the content-box main-size of our flex container from the
|
||
// reflow state (specifically, the main-size of *this continuation* of the
|
||
// flex container).
|
||
nscoord
|
||
nsFlexContainerFrame::GetMainSizeFromReflowState(
|
||
const nsHTMLReflowState& aReflowState,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
if (IsAxisHorizontal(aAxisTracker.GetMainAxis())) {
|
||
// Horizontal case is easy -- our main size is our computed width
|
||
// (which is already resolved).
|
||
return aReflowState.ComputedISize();
|
||
}
|
||
|
||
return GetEffectiveComputedBSize(aReflowState);
|
||
}
|
||
|
||
// Returns the largest outer hypothetical main-size of any line in |aLines|.
|
||
// (i.e. the hypothetical main-size of the largest line)
|
||
static nscoord
|
||
GetLargestLineMainSize(const FlexLine* aFirstLine)
|
||
{
|
||
nscoord largestLineOuterSize = 0;
|
||
for (const FlexLine* line = aFirstLine; line; line = line->getNext()) {
|
||
largestLineOuterSize = std::max(largestLineOuterSize,
|
||
line->GetTotalOuterHypotheticalMainSize());
|
||
}
|
||
return largestLineOuterSize;
|
||
}
|
||
|
||
// Returns the content-box main-size of our flex container, based on the
|
||
// available height (if appropriate) and the main-sizes of the flex items.
|
||
static nscoord
|
||
ClampFlexContainerMainSize(const nsHTMLReflowState& aReflowState,
|
||
const FlexboxAxisTracker& aAxisTracker,
|
||
nscoord aUnclampedMainSize,
|
||
nscoord aAvailableHeightForContent,
|
||
const FlexLine* aFirstLine,
|
||
nsReflowStatus& aStatus)
|
||
{
|
||
MOZ_ASSERT(aFirstLine, "null first line pointer");
|
||
|
||
if (IsAxisHorizontal(aAxisTracker.GetMainAxis())) {
|
||
// Horizontal case is easy -- our main size should already be resolved
|
||
// before we get a call to Reflow. We don't have to worry about doing
|
||
// page-breaking or shrinkwrapping in the horizontal axis.
|
||
return aUnclampedMainSize;
|
||
}
|
||
|
||
if (aUnclampedMainSize != NS_INTRINSICSIZE) {
|
||
// Vertical case, with fixed height:
|
||
if (aAvailableHeightForContent == NS_UNCONSTRAINEDSIZE ||
|
||
aUnclampedMainSize < aAvailableHeightForContent) {
|
||
// Not in a fragmenting context, OR no need to fragment because we have
|
||
// more available height than we need. Either way, just use our fixed
|
||
// height. (Note that the reflow state has already done the appropriate
|
||
// min/max-height clamping.)
|
||
return aUnclampedMainSize;
|
||
}
|
||
|
||
// Fragmenting *and* our fixed height is too tall for available height:
|
||
// Mark incomplete so we get a next-in-flow, and take up all of the
|
||
// available height (or the amount of height required by our children, if
|
||
// that's larger; but of course not more than our own computed height).
|
||
// XXXdholbert For now, we don't support pushing children to our next
|
||
// continuation or splitting children, so "amount of height required by
|
||
// our children" is just the main-size (height) of our longest flex line.
|
||
NS_FRAME_SET_INCOMPLETE(aStatus);
|
||
nscoord largestLineOuterSize = GetLargestLineMainSize(aFirstLine);
|
||
|
||
if (largestLineOuterSize <= aAvailableHeightForContent) {
|
||
return aAvailableHeightForContent;
|
||
}
|
||
return std::min(aUnclampedMainSize, largestLineOuterSize);
|
||
}
|
||
|
||
// Vertical case, with auto-height:
|
||
// Resolve auto-height to the largest FlexLine-length, clamped to our
|
||
// computed min/max main-size properties (min-height & max-height).
|
||
// XXXdholbert Handle constrained-aAvailableHeightForContent case here.
|
||
nscoord largestLineOuterSize = GetLargestLineMainSize(aFirstLine);
|
||
return NS_CSS_MINMAX(largestLineOuterSize,
|
||
aReflowState.ComputedMinHeight(),
|
||
aReflowState.ComputedMaxHeight());
|
||
}
|
||
|
||
nscoord
|
||
nsFlexContainerFrame::ComputeCrossSize(const nsHTMLReflowState& aReflowState,
|
||
const FlexboxAxisTracker& aAxisTracker,
|
||
nscoord aSumLineCrossSizes,
|
||
nscoord aAvailableHeightForContent,
|
||
bool* aIsDefinite,
|
||
nsReflowStatus& aStatus)
|
||
{
|
||
MOZ_ASSERT(aIsDefinite, "outparam pointer must be non-null");
|
||
|
||
if (IsAxisHorizontal(aAxisTracker.GetCrossAxis())) {
|
||
// Cross axis is horizontal: our cross size is our computed width
|
||
// (which is already resolved).
|
||
*aIsDefinite = true;
|
||
return aReflowState.ComputedISize();
|
||
}
|
||
|
||
nscoord effectiveComputedBSize = GetEffectiveComputedBSize(aReflowState);
|
||
if (effectiveComputedBSize != NS_INTRINSICSIZE) {
|
||
// Cross-axis is vertical, and we have a fixed height:
|
||
*aIsDefinite = true;
|
||
if (aAvailableHeightForContent == NS_UNCONSTRAINEDSIZE ||
|
||
effectiveComputedBSize < aAvailableHeightForContent) {
|
||
// Not in a fragmenting context, OR no need to fragment because we have
|
||
// more available height than we need. Either way, just use our fixed
|
||
// height. (Note that the reflow state has already done the appropriate
|
||
// min/max-height clamping.)
|
||
return effectiveComputedBSize;
|
||
}
|
||
|
||
// Fragmenting *and* our fixed height is too tall for available height:
|
||
// Mark incomplete so we get a next-in-flow, and take up all of the
|
||
// available height (or the amount of height required by our children, if
|
||
// that's larger; but of course not more than our own computed height).
|
||
// XXXdholbert For now, we don't support pushing children to our next
|
||
// continuation or splitting children, so "amount of height required by
|
||
// our children" is just our line-height.
|
||
NS_FRAME_SET_INCOMPLETE(aStatus);
|
||
if (aSumLineCrossSizes <= aAvailableHeightForContent) {
|
||
return aAvailableHeightForContent;
|
||
}
|
||
return std::min(effectiveComputedBSize, aSumLineCrossSizes);
|
||
}
|
||
|
||
// Cross axis is vertical and we have auto-height: shrink-wrap our line(s),
|
||
// subject to our min-size / max-size constraints in that (vertical) axis.
|
||
// XXXdholbert Handle constrained-aAvailableHeightForContent case here.
|
||
*aIsDefinite = false;
|
||
return NS_CSS_MINMAX(aSumLineCrossSizes,
|
||
aReflowState.ComputedMinHeight(),
|
||
aReflowState.ComputedMaxHeight());
|
||
}
|
||
|
||
void
|
||
FlexLine::PositionItemsInMainAxis(uint8_t aJustifyContent,
|
||
nscoord aContentBoxMainSize,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
MainAxisPositionTracker mainAxisPosnTracker(aAxisTracker, this,
|
||
aJustifyContent,
|
||
aContentBoxMainSize);
|
||
for (FlexItem* item = mItems.getFirst(); item; item = item->getNext()) {
|
||
nscoord itemMainBorderBoxSize =
|
||
item->GetMainSize() +
|
||
item->GetBorderPaddingSizeInAxis(mainAxisPosnTracker.GetAxis());
|
||
|
||
// Resolve any main-axis 'auto' margins on aChild to an actual value.
|
||
mainAxisPosnTracker.ResolveAutoMarginsInMainAxis(*item);
|
||
|
||
// Advance our position tracker to child's upper-left content-box corner,
|
||
// and use that as its position in the main axis.
|
||
mainAxisPosnTracker.EnterMargin(item->GetMargin());
|
||
mainAxisPosnTracker.EnterChildFrame(itemMainBorderBoxSize);
|
||
|
||
item->SetMainPosition(mainAxisPosnTracker.GetPosition());
|
||
|
||
mainAxisPosnTracker.ExitChildFrame(itemMainBorderBoxSize);
|
||
mainAxisPosnTracker.ExitMargin(item->GetMargin());
|
||
mainAxisPosnTracker.TraversePackingSpace();
|
||
}
|
||
}
|
||
|
||
// Helper method to take care of children who ASK_FOR_BASELINE, when
|
||
// we need their baseline.
|
||
static void
|
||
ResolveReflowedChildAscent(nsIFrame* aFrame,
|
||
nsHTMLReflowMetrics& aChildDesiredSize)
|
||
{
|
||
WritingMode wm = aChildDesiredSize.GetWritingMode();
|
||
if (aChildDesiredSize.BlockStartAscent() ==
|
||
nsHTMLReflowMetrics::ASK_FOR_BASELINE) {
|
||
// Use GetFirstLineBaseline(), or just GetBaseline() if that fails.
|
||
nscoord ascent;
|
||
if (nsLayoutUtils::GetFirstLineBaseline(wm, aFrame, &ascent)) {
|
||
aChildDesiredSize.SetBlockStartAscent(ascent);
|
||
} else {
|
||
aChildDesiredSize.SetBlockStartAscent(aFrame->GetLogicalBaseline(wm));
|
||
}
|
||
}
|
||
}
|
||
|
||
/**
|
||
* Given the flex container's "logical ascent" (i.e. distance from the
|
||
* flex container's content-box cross-start edge to its baseline), returns
|
||
* its actual physical ascent value (the distance from the *border-box* top
|
||
* edge to its baseline).
|
||
*/
|
||
static nscoord
|
||
ComputePhysicalAscentFromLogicalAscent(nscoord aLogicalAscent,
|
||
nscoord aContentBoxCrossSize,
|
||
const nsHTMLReflowState& aReflowState,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
return aReflowState.ComputedPhysicalBorderPadding().top +
|
||
PhysicalPosFromLogicalPos(aLogicalAscent, aContentBoxCrossSize,
|
||
aAxisTracker.GetCrossAxis());
|
||
}
|
||
|
||
void
|
||
nsFlexContainerFrame::SizeItemInCrossAxis(
|
||
nsPresContext* aPresContext,
|
||
const FlexboxAxisTracker& aAxisTracker,
|
||
nsHTMLReflowState& aChildReflowState,
|
||
FlexItem& aItem)
|
||
{
|
||
// In vertical flexbox (with horizontal cross-axis), we can just trust the
|
||
// reflow state's computed-width as our cross-size. We also don't need to
|
||
// record the baseline because we'll have converted any "align-self:baseline"
|
||
// items to be "align-self:flex-start" in the FlexItem constructor.
|
||
// FIXME: Once we support writing-mode (vertical text), we will be able to
|
||
// have baseline-aligned items in a vertical flexbox, and we'll need to
|
||
// record baseline information here.
|
||
if (IsAxisHorizontal(aAxisTracker.GetCrossAxis())) {
|
||
MOZ_ASSERT(aItem.GetAlignSelf() != NS_STYLE_ALIGN_ITEMS_BASELINE,
|
||
"In vert flex container, we depend on FlexItem constructor to "
|
||
"convert 'align-self: baseline' to 'align-self: flex-start'");
|
||
aItem.SetCrossSize(aChildReflowState.ComputedWidth());
|
||
return;
|
||
}
|
||
|
||
MOZ_ASSERT(!aItem.HadMeasuringReflow(),
|
||
"We shouldn't need more than one measuring reflow");
|
||
|
||
if (aItem.GetAlignSelf() == NS_STYLE_ALIGN_ITEMS_STRETCH) {
|
||
// This item's got "align-self: stretch", so we probably imposed a
|
||
// stretched computed height on it during its previous reflow. We're
|
||
// not imposing that height for *this* measuring reflow, so we need to
|
||
// tell it to treat this reflow as a vertical resize (regardless of
|
||
// whether any of its ancestors are being resized).
|
||
aChildReflowState.mFlags.mVResize = true;
|
||
}
|
||
nsHTMLReflowMetrics childDesiredSize(aChildReflowState);
|
||
nsReflowStatus childReflowStatus;
|
||
const uint32_t flags = NS_FRAME_NO_MOVE_FRAME;
|
||
ReflowChild(aItem.Frame(), aPresContext,
|
||
childDesiredSize, aChildReflowState,
|
||
0, 0, flags, childReflowStatus);
|
||
aItem.SetHadMeasuringReflow();
|
||
|
||
// XXXdholbert Once we do pagination / splitting, we'll need to actually
|
||
// handle incomplete childReflowStatuses. But for now, we give our kids
|
||
// unconstrained available height, which means they should always complete.
|
||
MOZ_ASSERT(NS_FRAME_IS_COMPLETE(childReflowStatus),
|
||
"We gave flex item unconstrained available height, so it "
|
||
"should be complete");
|
||
|
||
// Tell the child we're done with its initial reflow.
|
||
// (Necessary for e.g. GetBaseline() to work below w/out asserting)
|
||
FinishReflowChild(aItem.Frame(), aPresContext,
|
||
childDesiredSize, &aChildReflowState, 0, 0, flags);
|
||
|
||
// Save the sizing info that we learned from this reflow
|
||
// -----------------------------------------------------
|
||
|
||
// Tentatively store the child's desired content-box cross-size.
|
||
// Note that childDesiredSize is the border-box size, so we have to
|
||
// subtract border & padding to get the content-box size.
|
||
// (Note that at this point in the code, we know our cross axis is vertical,
|
||
// so we don't bother with making aAxisTracker pick the cross-axis component
|
||
// for us.)
|
||
nscoord crossAxisBorderPadding = aItem.GetBorderPadding().TopBottom();
|
||
if (childDesiredSize.Height() < crossAxisBorderPadding) {
|
||
// Child's requested size isn't large enough for its border/padding!
|
||
// This is OK for the trivial nsFrame::Reflow() impl, but other frame
|
||
// classes should know better. So, if we get here, the child had better be
|
||
// an instance of nsFrame (i.e. it should return null from GetType()).
|
||
// XXXdholbert Once we've fixed bug 765861, we should upgrade this to an
|
||
// assertion that trivially passes if bug 765861's flag has been flipped.
|
||
NS_WARN_IF_FALSE(!aItem.Frame()->GetType(),
|
||
"Child should at least request space for border/padding");
|
||
aItem.SetCrossSize(0);
|
||
} else {
|
||
// (normal case)
|
||
aItem.SetCrossSize(childDesiredSize.Height() - crossAxisBorderPadding);
|
||
}
|
||
|
||
// If we need to do baseline-alignment, store the child's ascent.
|
||
if (aItem.GetAlignSelf() == NS_STYLE_ALIGN_ITEMS_BASELINE) {
|
||
ResolveReflowedChildAscent(aItem.Frame(), childDesiredSize);
|
||
aItem.SetAscent(childDesiredSize.BlockStartAscent());
|
||
}
|
||
}
|
||
|
||
void
|
||
FlexLine::PositionItemsInCrossAxis(nscoord aLineStartPosition,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
SingleLineCrossAxisPositionTracker lineCrossAxisPosnTracker(aAxisTracker);
|
||
|
||
for (FlexItem* item = mItems.getFirst(); item; item = item->getNext()) {
|
||
// First, stretch the item's cross size (if appropriate), and resolve any
|
||
// auto margins in this axis.
|
||
item->ResolveStretchedCrossSize(mLineCrossSize, aAxisTracker);
|
||
lineCrossAxisPosnTracker.ResolveAutoMarginsInCrossAxis(*this, *item);
|
||
|
||
// Compute the cross-axis position of this item
|
||
nscoord itemCrossBorderBoxSize =
|
||
item->GetCrossSize() +
|
||
item->GetBorderPaddingSizeInAxis(aAxisTracker.GetCrossAxis());
|
||
lineCrossAxisPosnTracker.EnterAlignPackingSpace(*this, *item, aAxisTracker);
|
||
lineCrossAxisPosnTracker.EnterMargin(item->GetMargin());
|
||
lineCrossAxisPosnTracker.EnterChildFrame(itemCrossBorderBoxSize);
|
||
|
||
item->SetCrossPosition(aLineStartPosition +
|
||
lineCrossAxisPosnTracker.GetPosition());
|
||
|
||
// Back out to cross-axis edge of the line.
|
||
lineCrossAxisPosnTracker.ResetPosition();
|
||
}
|
||
}
|
||
|
||
void
|
||
nsFlexContainerFrame::Reflow(nsPresContext* aPresContext,
|
||
nsHTMLReflowMetrics& aDesiredSize,
|
||
const nsHTMLReflowState& aReflowState,
|
||
nsReflowStatus& aStatus)
|
||
{
|
||
DO_GLOBAL_REFLOW_COUNT("nsFlexContainerFrame");
|
||
DISPLAY_REFLOW(aPresContext, this, aReflowState, aDesiredSize, aStatus);
|
||
PR_LOG(GetFlexContainerLog(), PR_LOG_DEBUG,
|
||
("Reflow() for nsFlexContainerFrame %p\n", this));
|
||
|
||
if (IsFrameTreeTooDeep(aReflowState, aDesiredSize, aStatus)) {
|
||
return;
|
||
}
|
||
|
||
// We (and our children) can only depend on our ancestor's height if we have
|
||
// a percent-height, or if we're positioned and we have "top" and "bottom"
|
||
// set and have height:auto. (There are actually other cases, too -- e.g. if
|
||
// our parent is itself a vertical flex container and we're flexible -- but
|
||
// we'll let our ancestors handle those sorts of cases.)
|
||
const nsStylePosition* stylePos = StylePosition();
|
||
if (stylePos->mHeight.HasPercent() ||
|
||
(StyleDisplay()->IsAbsolutelyPositionedStyle() &&
|
||
eStyleUnit_Auto == stylePos->mHeight.GetUnit() &&
|
||
eStyleUnit_Auto != stylePos->mOffset.GetTopUnit() &&
|
||
eStyleUnit_Auto != stylePos->mOffset.GetBottomUnit())) {
|
||
AddStateBits(NS_FRAME_CONTAINS_RELATIVE_HEIGHT);
|
||
}
|
||
|
||
#ifdef DEBUG
|
||
SanityCheckAnonymousFlexItems();
|
||
#endif // DEBUG
|
||
|
||
// If we've never reordered our children, then we can trust that they're
|
||
// already in DOM-order, and we only need to consider their "order" property
|
||
// when checking them for sortedness & sorting them.
|
||
//
|
||
// After we actually sort them, though, we can't trust that they're in DOM
|
||
// order anymore. So, from that point on, our sort & sorted-order-checking
|
||
// operations need to use a fancier LEQ function that also takes DOM order
|
||
// into account, so that we can honor the spec's requirement that frames w/
|
||
// equal "order" values are laid out in DOM order.
|
||
|
||
if (!HasAnyStateBits(NS_STATE_FLEX_CHILDREN_REORDERED)) {
|
||
if (SortChildrenIfNeeded<IsOrderLEQ>()) {
|
||
AddStateBits(NS_STATE_FLEX_CHILDREN_REORDERED);
|
||
}
|
||
} else {
|
||
SortChildrenIfNeeded<IsOrderLEQWithDOMFallback>();
|
||
}
|
||
|
||
const FlexboxAxisTracker axisTracker(this);
|
||
|
||
// If we're being fragmented into a constrained height, subtract off
|
||
// borderpadding-top from it, to get the available height for our
|
||
// content box. (Don't subtract if we're skipping top border/padding,
|
||
// though.)
|
||
nscoord availableHeightForContent = aReflowState.AvailableHeight();
|
||
if (availableHeightForContent != NS_UNCONSTRAINEDSIZE &&
|
||
!GetSkipSides().Top()) {
|
||
availableHeightForContent -= aReflowState.ComputedPhysicalBorderPadding().top;
|
||
// (Don't let that push availableHeightForContent below zero, though):
|
||
availableHeightForContent = std::max(availableHeightForContent, 0);
|
||
}
|
||
|
||
nscoord contentBoxMainSize = GetMainSizeFromReflowState(aReflowState,
|
||
axisTracker);
|
||
|
||
nsAutoTArray<StrutInfo, 1> struts;
|
||
DoFlexLayout(aPresContext, aDesiredSize, aReflowState, aStatus,
|
||
contentBoxMainSize, availableHeightForContent,
|
||
struts, axisTracker);
|
||
|
||
if (!struts.IsEmpty()) {
|
||
// We're restarting flex layout, with new knowledge of collapsed items.
|
||
DoFlexLayout(aPresContext, aDesiredSize, aReflowState, aStatus,
|
||
contentBoxMainSize, availableHeightForContent,
|
||
struts, axisTracker);
|
||
}
|
||
}
|
||
|
||
// RAII class to clean up a list of FlexLines.
|
||
// Specifically, this removes each line from the list, deletes all the
|
||
// FlexItems in its list, and deletes the FlexLine.
|
||
class MOZ_STACK_CLASS AutoFlexLineListClearer
|
||
{
|
||
public:
|
||
explicit AutoFlexLineListClearer(LinkedList<FlexLine>& aLines
|
||
MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
|
||
: mLines(aLines)
|
||
{
|
||
MOZ_GUARD_OBJECT_NOTIFIER_INIT;
|
||
}
|
||
|
||
~AutoFlexLineListClearer()
|
||
{
|
||
while (FlexLine* line = mLines.popFirst()) {
|
||
while (FlexItem* item = line->mItems.popFirst()) {
|
||
delete item;
|
||
}
|
||
delete line;
|
||
}
|
||
}
|
||
|
||
private:
|
||
LinkedList<FlexLine>& mLines;
|
||
MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
|
||
};
|
||
|
||
void
|
||
nsFlexContainerFrame::DoFlexLayout(nsPresContext* aPresContext,
|
||
nsHTMLReflowMetrics& aDesiredSize,
|
||
const nsHTMLReflowState& aReflowState,
|
||
nsReflowStatus& aStatus,
|
||
nscoord aContentBoxMainSize,
|
||
nscoord aAvailableHeightForContent,
|
||
nsTArray<StrutInfo>& aStruts,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
aStatus = NS_FRAME_COMPLETE;
|
||
|
||
LinkedList<FlexLine> lines;
|
||
AutoFlexLineListClearer cleanupLines(lines);
|
||
|
||
GenerateFlexLines(aPresContext, aReflowState,
|
||
aContentBoxMainSize,
|
||
aAvailableHeightForContent,
|
||
aStruts, aAxisTracker, lines);
|
||
|
||
aContentBoxMainSize =
|
||
ClampFlexContainerMainSize(aReflowState, aAxisTracker,
|
||
aContentBoxMainSize, aAvailableHeightForContent,
|
||
lines.getFirst(), aStatus);
|
||
|
||
for (FlexLine* line = lines.getFirst(); line; line = line->getNext()) {
|
||
line->ResolveFlexibleLengths(aContentBoxMainSize);
|
||
}
|
||
|
||
// Cross Size Determination - Flexbox spec section 9.4
|
||
// ===================================================
|
||
// Calculate the hypothetical cross size of each item:
|
||
nscoord sumLineCrossSizes = 0;
|
||
for (FlexLine* line = lines.getFirst(); line; line = line->getNext()) {
|
||
for (FlexItem* item = line->GetFirstItem(); item; item = item->getNext()) {
|
||
// (If the item's already been stretched, or it's a strut, then it
|
||
// already knows its cross size. Don't bother trying to recalculate it.)
|
||
if (!item->IsStretched() && !item->IsStrut()) {
|
||
WritingMode wm = item->Frame()->GetWritingMode();
|
||
LogicalSize availSize = aReflowState.ComputedSize(wm);
|
||
availSize.BSize(wm) = NS_UNCONSTRAINEDSIZE;
|
||
nsHTMLReflowState childReflowState(aPresContext, aReflowState,
|
||
item->Frame(), availSize);
|
||
// Override computed main-size
|
||
if (IsAxisHorizontal(aAxisTracker.GetMainAxis())) {
|
||
childReflowState.SetComputedWidth(item->GetMainSize());
|
||
} else {
|
||
childReflowState.SetComputedHeight(item->GetMainSize());
|
||
}
|
||
|
||
SizeItemInCrossAxis(aPresContext, aAxisTracker,
|
||
childReflowState, *item);
|
||
}
|
||
}
|
||
// Now that we've finished with this line's items, size the line itself:
|
||
line->ComputeCrossSizeAndBaseline(aAxisTracker);
|
||
sumLineCrossSizes += line->GetLineCrossSize();
|
||
}
|
||
|
||
bool isCrossSizeDefinite;
|
||
const nscoord contentBoxCrossSize =
|
||
ComputeCrossSize(aReflowState, aAxisTracker, sumLineCrossSizes,
|
||
aAvailableHeightForContent, &isCrossSizeDefinite, aStatus);
|
||
|
||
// Set up state for cross-axis alignment, at a high level (outside the
|
||
// scope of a particular flex line)
|
||
CrossAxisPositionTracker
|
||
crossAxisPosnTracker(lines.getFirst(),
|
||
aReflowState.mStylePosition->mAlignContent,
|
||
contentBoxCrossSize, isCrossSizeDefinite,
|
||
aAxisTracker);
|
||
|
||
// Now that we know the cross size of each line (including
|
||
// "align-content:stretch" adjustments, from the CrossAxisPositionTracker
|
||
// constructor), we can create struts for any flex items with
|
||
// "visibility: collapse" (and restart flex layout).
|
||
if (aStruts.IsEmpty()) { // (Don't make struts if we already did)
|
||
BuildStrutInfoFromCollapsedItems(lines.getFirst(), aStruts);
|
||
if (!aStruts.IsEmpty()) {
|
||
// Restart flex layout, using our struts.
|
||
return;
|
||
}
|
||
}
|
||
|
||
// If the container should derive its baseline from the first FlexLine,
|
||
// do that here (while crossAxisPosnTracker is conveniently pointing
|
||
// at the cross-start edge of that line, which the line's baseline offset is
|
||
// measured from):
|
||
nscoord flexContainerAscent;
|
||
if (!aAxisTracker.AreAxesInternallyReversed()) {
|
||
nscoord firstLineBaselineOffset = lines.getFirst()->GetBaselineOffset();
|
||
if (firstLineBaselineOffset == nscoord_MIN) {
|
||
// No baseline-aligned items in line. Use sentinel value to prompt us to
|
||
// get baseline from the first FlexItem after we've reflowed it.
|
||
flexContainerAscent = nscoord_MIN;
|
||
} else {
|
||
flexContainerAscent =
|
||
ComputePhysicalAscentFromLogicalAscent(
|
||
crossAxisPosnTracker.GetPosition() + firstLineBaselineOffset,
|
||
contentBoxCrossSize, aReflowState, aAxisTracker);
|
||
}
|
||
}
|
||
|
||
for (FlexLine* line = lines.getFirst(); line; line = line->getNext()) {
|
||
|
||
// Main-Axis Alignment - Flexbox spec section 9.5
|
||
// ==============================================
|
||
line->PositionItemsInMainAxis(aReflowState.mStylePosition->mJustifyContent,
|
||
aContentBoxMainSize,
|
||
aAxisTracker);
|
||
|
||
// Cross-Axis Alignment - Flexbox spec section 9.6
|
||
// ===============================================
|
||
line->PositionItemsInCrossAxis(crossAxisPosnTracker.GetPosition(),
|
||
aAxisTracker);
|
||
crossAxisPosnTracker.TraverseLine(*line);
|
||
crossAxisPosnTracker.TraversePackingSpace();
|
||
}
|
||
|
||
// If the container should derive its baseline from the last FlexLine,
|
||
// do that here (while crossAxisPosnTracker is conveniently pointing
|
||
// at the cross-end edge of that line, which the line's baseline offset is
|
||
// measured from):
|
||
if (aAxisTracker.AreAxesInternallyReversed()) {
|
||
nscoord lastLineBaselineOffset = lines.getLast()->GetBaselineOffset();
|
||
if (lastLineBaselineOffset == nscoord_MIN) {
|
||
// No baseline-aligned items in line. Use sentinel value to prompt us to
|
||
// get baseline from the last FlexItem after we've reflowed it.
|
||
flexContainerAscent = nscoord_MIN;
|
||
} else {
|
||
flexContainerAscent =
|
||
ComputePhysicalAscentFromLogicalAscent(
|
||
crossAxisPosnTracker.GetPosition() - lastLineBaselineOffset,
|
||
contentBoxCrossSize, aReflowState, aAxisTracker);
|
||
}
|
||
}
|
||
|
||
// Before giving each child a final reflow, calculate the origin of the
|
||
// flex container's content box (with respect to its border-box), so that
|
||
// we can compute our flex item's final positions.
|
||
nsMargin containerBorderPadding(aReflowState.ComputedPhysicalBorderPadding());
|
||
containerBorderPadding.ApplySkipSides(GetSkipSides(&aReflowState));
|
||
const nsPoint containerContentBoxOrigin(containerBorderPadding.left,
|
||
containerBorderPadding.top);
|
||
|
||
// FINAL REFLOW: Give each child frame another chance to reflow, now that
|
||
// we know its final size and position.
|
||
for (const FlexLine* line = lines.getFirst(); line; line = line->getNext()) {
|
||
for (const FlexItem* item = line->GetFirstItem(); item;
|
||
item = item->getNext()) {
|
||
nsPoint physicalPosn = aAxisTracker.PhysicalPointFromLogicalPoint(
|
||
item->GetMainPosition(),
|
||
item->GetCrossPosition(),
|
||
aContentBoxMainSize,
|
||
contentBoxCrossSize);
|
||
// Adjust physicalPosn to be relative to the container's border-box
|
||
// (i.e. its frame rect), instead of the container's content-box:
|
||
physicalPosn += containerContentBoxOrigin;
|
||
|
||
WritingMode wm = item->Frame()->GetWritingMode();
|
||
LogicalSize availSize = aReflowState.ComputedSize(wm);
|
||
availSize.BSize(wm) = NS_UNCONSTRAINEDSIZE;
|
||
nsHTMLReflowState childReflowState(aPresContext, aReflowState,
|
||
item->Frame(), availSize);
|
||
|
||
// Keep track of whether we've overriden the child's computed height
|
||
// and/or width, so we can set its resize flags accordingly.
|
||
bool didOverrideComputedWidth = false;
|
||
bool didOverrideComputedHeight = false;
|
||
|
||
// Override computed main-size
|
||
if (IsAxisHorizontal(aAxisTracker.GetMainAxis())) {
|
||
childReflowState.SetComputedWidth(item->GetMainSize());
|
||
didOverrideComputedWidth = true;
|
||
} else {
|
||
childReflowState.SetComputedHeight(item->GetMainSize());
|
||
didOverrideComputedHeight = true;
|
||
}
|
||
|
||
// Override reflow state's computed cross-size, for stretched items.
|
||
if (item->IsStretched()) {
|
||
MOZ_ASSERT(item->GetAlignSelf() == NS_STYLE_ALIGN_ITEMS_STRETCH,
|
||
"stretched item w/o 'align-self: stretch'?");
|
||
if (IsAxisHorizontal(aAxisTracker.GetCrossAxis())) {
|
||
childReflowState.SetComputedWidth(item->GetCrossSize());
|
||
didOverrideComputedWidth = true;
|
||
} else {
|
||
// If this item's height is stretched, it's a relative height.
|
||
item->Frame()->AddStateBits(NS_FRAME_CONTAINS_RELATIVE_HEIGHT);
|
||
childReflowState.SetComputedHeight(item->GetCrossSize());
|
||
didOverrideComputedHeight = true;
|
||
}
|
||
}
|
||
|
||
// XXXdholbert Might need to actually set the correct margins in the
|
||
// reflow state at some point, so that they can be saved on the frame for
|
||
// UsedMarginProperty(). Maybe doesn't matter though...?
|
||
|
||
// If we're overriding the computed width or height, *and* we had an
|
||
// earlier "measuring" reflow, then this upcoming reflow needs to be
|
||
// treated as a resize.
|
||
if (item->HadMeasuringReflow()) {
|
||
if (didOverrideComputedWidth) {
|
||
// (This is somewhat redundant, since the reflow state already
|
||
// sets mHResize whenever our computed width has changed since the
|
||
// previous reflow. Still, it's nice for symmetry, and it may become
|
||
// necessary once we support orthogonal flows.)
|
||
childReflowState.mFlags.mHResize = true;
|
||
}
|
||
if (didOverrideComputedHeight) {
|
||
childReflowState.mFlags.mVResize = true;
|
||
}
|
||
}
|
||
// NOTE: Be very careful about doing anything else with childReflowState
|
||
// after this point, because some of its methods (e.g. SetComputedWidth)
|
||
// internally call InitResizeFlags and stomp on mVResize & mHResize.
|
||
|
||
nsHTMLReflowMetrics childDesiredSize(childReflowState);
|
||
nsReflowStatus childReflowStatus;
|
||
ReflowChild(item->Frame(), aPresContext,
|
||
childDesiredSize, childReflowState,
|
||
physicalPosn.x, physicalPosn.y,
|
||
0, childReflowStatus);
|
||
|
||
// XXXdholbert Once we do pagination / splitting, we'll need to actually
|
||
// handle incomplete childReflowStatuses. But for now, we give our kids
|
||
// unconstrained available height, which means they should always
|
||
// complete.
|
||
MOZ_ASSERT(NS_FRAME_IS_COMPLETE(childReflowStatus),
|
||
"We gave flex item unconstrained available height, so it "
|
||
"should be complete");
|
||
|
||
childReflowState.ApplyRelativePositioning(&physicalPosn);
|
||
|
||
FinishReflowChild(item->Frame(), aPresContext,
|
||
childDesiredSize, &childReflowState,
|
||
physicalPosn.x, physicalPosn.y, 0);
|
||
|
||
// If this is our first child and we haven't established a baseline for
|
||
// the container yet (i.e. if we don't have 'align-self: baseline' on any
|
||
// children), then use this child's baseline as the container's baseline.
|
||
if (item->Frame() == mFrames.FirstChild() &&
|
||
flexContainerAscent == nscoord_MIN) {
|
||
ResolveReflowedChildAscent(item->Frame(), childDesiredSize);
|
||
|
||
// (We use GetNormalPosition() instead of physicalPosn because we don't
|
||
// want relative positioning on the child to affect the baseline that we
|
||
// read from it).
|
||
WritingMode wm = aReflowState.GetWritingMode();
|
||
flexContainerAscent =
|
||
item->Frame()->GetLogicalNormalPosition(wm,
|
||
childDesiredSize.Width()).B(wm) +
|
||
childDesiredSize.BlockStartAscent();
|
||
}
|
||
}
|
||
}
|
||
|
||
nsSize desiredContentBoxSize =
|
||
aAxisTracker.PhysicalSizeFromLogicalSizes(aContentBoxMainSize,
|
||
contentBoxCrossSize);
|
||
|
||
aDesiredSize.Width() = desiredContentBoxSize.width +
|
||
containerBorderPadding.LeftRight();
|
||
// Does *NOT* include bottom border/padding yet (we add that a bit lower down)
|
||
aDesiredSize.Height() = desiredContentBoxSize.height +
|
||
containerBorderPadding.top;
|
||
|
||
if (flexContainerAscent == nscoord_MIN) {
|
||
// Still don't have our baseline set -- this happens if we have no
|
||
// children (or if our children are huge enough that they have nscoord_MIN
|
||
// as their baseline... in which case, we'll use the wrong baseline, but no
|
||
// big deal)
|
||
NS_WARN_IF_FALSE(lines.getFirst()->IsEmpty(),
|
||
"Have flex items but didn't get an ascent - that's odd "
|
||
"(or there are just gigantic sizes involved)");
|
||
// Per spec, just use the bottom of content-box.
|
||
flexContainerAscent = aDesiredSize.Height();
|
||
}
|
||
aDesiredSize.SetBlockStartAscent(flexContainerAscent);
|
||
|
||
// Now: If we're complete, add bottom border/padding to desired height
|
||
// (unless that pushes us over available height, in which case we become
|
||
// incomplete (unless we already weren't asking for any height, in which case
|
||
// we stay complete to avoid looping forever)).
|
||
// NOTE: If we're auto-height, we allow our bottom border/padding to push us
|
||
// over the available height without requesting a continuation, for
|
||
// consistency with the behavior of "display:block" elements.
|
||
if (NS_FRAME_IS_COMPLETE(aStatus)) {
|
||
// NOTE: We can't use containerBorderPadding.bottom for this, because if
|
||
// we're auto-height, ApplySkipSides will have zeroed it (because it
|
||
// assumed we might get a continuation). We have the correct value in
|
||
// aReflowState.ComputedPhyiscalBorderPadding().bottom, though, so we use that.
|
||
nscoord desiredHeightWithBottomBP =
|
||
aDesiredSize.Height() + aReflowState.ComputedPhysicalBorderPadding().bottom;
|
||
|
||
if (aReflowState.AvailableHeight() == NS_UNCONSTRAINEDSIZE ||
|
||
aDesiredSize.Height() == 0 ||
|
||
desiredHeightWithBottomBP <= aReflowState.AvailableHeight() ||
|
||
aReflowState.ComputedHeight() == NS_INTRINSICSIZE) {
|
||
// Update desired height to include bottom border/padding
|
||
aDesiredSize.Height() = desiredHeightWithBottomBP;
|
||
} else {
|
||
// We couldn't fit bottom border/padding, so we'll need a continuation.
|
||
NS_FRAME_SET_INCOMPLETE(aStatus);
|
||
}
|
||
}
|
||
|
||
// Overflow area = union(my overflow area, kids' overflow areas)
|
||
aDesiredSize.SetOverflowAreasToDesiredBounds();
|
||
for (nsFrameList::Enumerator e(mFrames); !e.AtEnd(); e.Next()) {
|
||
ConsiderChildOverflow(aDesiredSize.mOverflowAreas, e.get());
|
||
}
|
||
|
||
FinishReflowWithAbsoluteFrames(aPresContext, aDesiredSize,
|
||
aReflowState, aStatus);
|
||
|
||
NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize)
|
||
}
|
||
|
||
/* virtual */ nscoord
|
||
nsFlexContainerFrame::GetMinISize(nsRenderingContext* aRenderingContext)
|
||
{
|
||
nscoord minWidth = 0;
|
||
DISPLAY_MIN_WIDTH(this, minWidth);
|
||
|
||
FlexboxAxisTracker axisTracker(this);
|
||
|
||
for (nsFrameList::Enumerator e(mFrames); !e.AtEnd(); e.Next()) {
|
||
nscoord childMinWidth =
|
||
nsLayoutUtils::IntrinsicForContainer(aRenderingContext, e.get(),
|
||
nsLayoutUtils::MIN_ISIZE);
|
||
// For a horizontal single-line flex container, the intrinsic min width is
|
||
// the sum of its items' min widths.
|
||
// For a vertical flex container, or for a multi-line horizontal flex
|
||
// container, the intrinsic min width is the max of its items' min widths.
|
||
if (IsAxisHorizontal(axisTracker.GetMainAxis()) &&
|
||
NS_STYLE_FLEX_WRAP_NOWRAP == StylePosition()->mFlexWrap) {
|
||
minWidth += childMinWidth;
|
||
} else {
|
||
minWidth = std::max(minWidth, childMinWidth);
|
||
}
|
||
}
|
||
return minWidth;
|
||
}
|
||
|
||
/* virtual */ nscoord
|
||
nsFlexContainerFrame::GetPrefISize(nsRenderingContext* aRenderingContext)
|
||
{
|
||
nscoord prefWidth = 0;
|
||
DISPLAY_PREF_WIDTH(this, prefWidth);
|
||
|
||
// XXXdholbert Optimization: We could cache our intrinsic widths like
|
||
// nsBlockFrame does (and return it early from this function if it's set).
|
||
// Whenever anything happens that might change it, set it to
|
||
// NS_INTRINSIC_WIDTH_UNKNOWN (like nsBlockFrame::MarkIntrinsicISizesDirty
|
||
// does)
|
||
FlexboxAxisTracker axisTracker(this);
|
||
|
||
for (nsFrameList::Enumerator e(mFrames); !e.AtEnd(); e.Next()) {
|
||
nscoord childPrefWidth =
|
||
nsLayoutUtils::IntrinsicForContainer(aRenderingContext, e.get(),
|
||
nsLayoutUtils::PREF_ISIZE);
|
||
if (IsAxisHorizontal(axisTracker.GetMainAxis())) {
|
||
prefWidth += childPrefWidth;
|
||
} else {
|
||
prefWidth = std::max(prefWidth, childPrefWidth);
|
||
}
|
||
}
|
||
return prefWidth;
|
||
}
|