gecko/layout/generic/nsHTMLReflowState.cpp
2007-10-01 22:57:45 -07:00

2281 lines
89 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Communicator client code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/* struct containing the input to nsIFrame::Reflow */
#include "nsCOMPtr.h"
#include "nsStyleConsts.h"
#include "nsCSSAnonBoxes.h"
#include "nsFrame.h"
#include "nsIContent.h"
#include "nsGkAtoms.h"
#include "nsPresContext.h"
#include "nsIPresShell.h"
#include "nsIDeviceContext.h"
#include "nsIRenderingContext.h"
#include "nsIFontMetrics.h"
#include "nsBlockFrame.h"
#include "nsLineBox.h"
#include "nsImageFrame.h"
#include "nsTableFrame.h"
#include "nsTableCellFrame.h"
#include "nsIServiceManager.h"
#include "nsIPercentHeightObserver.h"
#include "nsContentUtils.h"
#include "nsLayoutUtils.h"
#ifdef IBMBIDI
#include "nsBidiUtils.h"
#endif
#ifdef NS_DEBUG
#undef NOISY_VERTICAL_ALIGN
#else
#undef NOISY_VERTICAL_ALIGN
#endif
// Prefs-driven control for |text-decoration: blink|
static PRPackedBool sPrefIsLoaded = PR_FALSE;
static PRPackedBool sBlinkIsAllowed = PR_TRUE;
enum eNormalLineHeightControl {
eUninitialized = -1,
eNoExternalLeading = 0, // does not include external leading
eIncludeExternalLeading, // use whatever value font vendor provides
eCompensateLeading // compensate leading if leading provided by font vendor is not enough
};
#ifdef FONT_LEADING_APIS_V2
static eNormalLineHeightControl sNormalLineHeightControl = eUninitialized;
#endif
// Initialize a <b>root</b> reflow state with a rendering context to
// use for measuring things.
nsHTMLReflowState::nsHTMLReflowState(nsPresContext* aPresContext,
nsIFrame* aFrame,
nsIRenderingContext* aRenderingContext,
const nsSize& aAvailableSpace)
: nsCSSOffsetState(aFrame, aRenderingContext)
, mReflowDepth(0)
, mBlockDelta(0)
{
NS_PRECONDITION(aPresContext, "no pres context");
NS_PRECONDITION(aRenderingContext, "no rendering context");
NS_PRECONDITION(aFrame, "no frame");
parentReflowState = nsnull;
availableWidth = aAvailableSpace.width;
availableHeight = aAvailableSpace.height;
mSpaceManager = nsnull;
mLineLayout = nsnull;
mFlags.mSpecialHeightReflow = PR_FALSE;
mFlags.mIsTopOfPage = PR_FALSE;
mFlags.mTableIsSplittable = PR_FALSE;
mFlags.mNextInFlowUntouched = PR_FALSE;
mFlags.mAssumingHScrollbar = mFlags.mAssumingVScrollbar = PR_FALSE;
mFlags.mHasClearance = PR_FALSE;
mDiscoveredClearance = nsnull;
mPercentHeightObserver = nsnull;
mPercentHeightReflowInitiator = nsnull;
Init(aPresContext);
#ifdef IBMBIDI
mRightEdge = NS_UNCONSTRAINEDSIZE;
#endif
}
static PRBool CheckNextInFlowParenthood(nsIFrame* aFrame, nsIFrame* aParent)
{
nsIFrame* frameNext = aFrame->GetNextInFlow();
nsIFrame* parentNext = aParent->GetNextInFlow();
return frameNext && parentNext && frameNext->GetParent() == parentNext;
}
// Initialize a reflow state for a child frames reflow. Some state
// is copied from the parent reflow state; the remaining state is
// computed.
nsHTMLReflowState::nsHTMLReflowState(nsPresContext* aPresContext,
const nsHTMLReflowState& aParentReflowState,
nsIFrame* aFrame,
const nsSize& aAvailableSpace,
nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight,
PRBool aInit)
: nsCSSOffsetState(aFrame, aParentReflowState.rendContext)
, mReflowDepth(aParentReflowState.mReflowDepth + 1)
, mFlags(aParentReflowState.mFlags)
, mBlockDelta(0)
{
NS_PRECONDITION(aPresContext, "no pres context");
NS_PRECONDITION(aFrame, "no frame");
NS_PRECONDITION((aContainingBlockWidth == -1) ==
(aContainingBlockHeight == -1),
"cb width and height should only be non-default together");
NS_PRECONDITION(aInit == PR_TRUE || aInit == PR_FALSE,
"aInit out of range for PRBool");
NS_PRECONDITION(!mFlags.mSpecialHeightReflow ||
!NS_SUBTREE_DIRTY(aFrame),
"frame should be clean when getting special height reflow");
parentReflowState = &aParentReflowState;
// If the parent is dirty, then the child is as well.
// XXX Are the other cases where the parent reflows a child a second
// time, as a resize?
if (!mFlags.mSpecialHeightReflow)
frame->AddStateBits(parentReflowState->frame->GetStateBits() &
NS_FRAME_IS_DIRTY);
availableWidth = aAvailableSpace.width;
availableHeight = aAvailableSpace.height;
mSpaceManager = aParentReflowState.mSpaceManager;
if (frame->IsFrameOfType(nsIFrame::eLineParticipant))
mLineLayout = aParentReflowState.mLineLayout;
else
mLineLayout = nsnull;
mFlags.mIsTopOfPage = aParentReflowState.mFlags.mIsTopOfPage;
mFlags.mNextInFlowUntouched = aParentReflowState.mFlags.mNextInFlowUntouched &&
CheckNextInFlowParenthood(aFrame, aParentReflowState.frame);
mFlags.mAssumingHScrollbar = mFlags.mAssumingVScrollbar = PR_FALSE;
mFlags.mHasClearance = PR_FALSE;
mDiscoveredClearance = nsnull;
mPercentHeightObserver = (aParentReflowState.mPercentHeightObserver &&
aParentReflowState.mPercentHeightObserver->NeedsToObserve(*this))
? aParentReflowState.mPercentHeightObserver : nsnull;
mPercentHeightReflowInitiator = aParentReflowState.mPercentHeightReflowInitiator;
if (aInit) {
Init(aPresContext, aContainingBlockWidth, aContainingBlockHeight);
}
#ifdef IBMBIDI
mRightEdge = aParentReflowState.mRightEdge;
#endif // IBMBIDI
}
inline void
nsCSSOffsetState::ComputeWidthDependentValue(nscoord aContainingBlockWidth,
const nsStyleCoord& aCoord,
nscoord& aResult)
{
aResult = nsLayoutUtils::ComputeWidthDependentValue(rendContext, frame,
aContainingBlockWidth,
aCoord);
}
inline nscoord
nsCSSOffsetState::ComputeWidthValue(nscoord aContainingBlockWidth,
nscoord aContentEdgeToBoxSizing,
nscoord aBoxSizingToMarginEdge,
const nsStyleCoord& aCoord)
{
return nsLayoutUtils::ComputeWidthValue(rendContext, frame,
aContainingBlockWidth,
aContentEdgeToBoxSizing,
aBoxSizingToMarginEdge,
aCoord);
}
nscoord
nsCSSOffsetState::ComputeWidthValue(nscoord aContainingBlockWidth,
PRUint8 aBoxSizing,
const nsStyleCoord& aCoord)
{
nscoord inside = 0, outside = mComputedBorderPadding.LeftRight() +
mComputedMargin.LeftRight();
switch (aBoxSizing) {
case NS_STYLE_BOX_SIZING_BORDER:
inside = mComputedBorderPadding.LeftRight();
break;
case NS_STYLE_BOX_SIZING_PADDING:
inside = mComputedPadding.LeftRight();
break;
}
outside -= inside;
return ComputeWidthValue(aContainingBlockWidth, inside,
outside, aCoord);
}
inline void
nsCSSOffsetState::ComputeHeightDependentValue(nscoord aContainingBlockHeight,
const nsStyleCoord& aCoord,
nscoord& aResult)
{
aResult = nsLayoutUtils::ComputeHeightDependentValue(rendContext, frame,
aContainingBlockHeight,
aCoord);
}
void
nsHTMLReflowState::SetComputedWidth(nscoord aComputedWidth)
{
NS_ASSERTION(frame, "Must have a frame!");
// It'd be nice to assert that |frame| is not in reflow, but this fails for
// two reasons:
//
// 1) Viewport frames reset the computed width on a copy of their reflow
// state when reflowing fixed-pos kids. In that case we actually don't
// want to mess with the resize flags, because comparing the frame's rect
// to the munged computed width is pointless.
// 2) nsFrame::BoxReflow creates a reflow state for its parent. This reflow
// state is not used to reflow the parent, but just as a parent for the
// frame's own reflow state. So given a nsBoxFrame inside some non-XUL
// (like a text control, for example), we'll end up creating a reflow
// state for the parent while the parent is reflowing.
NS_PRECONDITION(aComputedWidth >= 0, "Invalid computed width");
if (mComputedWidth != aComputedWidth) {
mComputedWidth = aComputedWidth;
if (frame->GetType() != nsGkAtoms::viewportFrame) { // Or check GetParent()?
InitResizeFlags(frame->PresContext());
}
}
}
void
nsHTMLReflowState::SetComputedHeight(nscoord aComputedHeight)
{
NS_ASSERTION(frame, "Must have a frame!");
// It'd be nice to assert that |frame| is not in reflow, but this fails for
// two reasons:
//
// 1) Viewport frames reset the computed height on a copy of their reflow
// state when reflowing fixed-pos kids. In that case we actually don't
// want to mess with the resize flags, because comparing the frame's rect
// to the munged computed width is pointless.
// 2) nsFrame::BoxReflow creates a reflow state for its parent. This reflow
// state is not used to reflow the parent, but just as a parent for the
// frame's own reflow state. So given a nsBoxFrame inside some non-XUL
// (like a text control, for example), we'll end up creating a reflow
// state for the parent while the parent is reflowing.
NS_PRECONDITION(aComputedHeight >= 0, "Invalid computed height");
if (mComputedHeight != aComputedHeight) {
mComputedHeight = aComputedHeight;
if (frame->GetType() != nsGkAtoms::viewportFrame) { // Or check GetParent()?
InitResizeFlags(frame->PresContext());
}
}
}
void
nsHTMLReflowState::Init(nsPresContext* aPresContext,
nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight,
const nsMargin* aBorder,
const nsMargin* aPadding)
{
NS_ASSERTION(availableWidth != NS_UNCONSTRAINEDSIZE,
"shouldn't use unconstrained widths anymore");
mStylePosition = frame->GetStylePosition();
mStyleDisplay = frame->GetStyleDisplay();
mStyleVisibility = frame->GetStyleVisibility();
mStyleBorder = frame->GetStyleBorder();
mStyleMargin = frame->GetStyleMargin();
mStylePadding = frame->GetStylePadding();
mStyleText = frame->GetStyleText();
InitFrameType();
InitCBReflowState();
InitConstraints(aPresContext, aContainingBlockWidth, aContainingBlockHeight, aBorder, aPadding);
InitResizeFlags(aPresContext);
NS_ASSERTION((mFrameType == NS_CSS_FRAME_TYPE_INLINE &&
!frame->IsFrameOfType(nsIFrame::eReplaced)) ||
frame->GetType() == nsGkAtoms::textFrame ||
mComputedWidth != NS_UNCONSTRAINEDSIZE,
"shouldn't use unconstrained widths anymore");
}
void nsHTMLReflowState::InitCBReflowState()
{
if (!parentReflowState) {
mCBReflowState = nsnull;
return;
}
if (parentReflowState->frame->IsContainingBlock() ||
// Absolutely positioned frames should always be kids of the frames that
// determine their containing block
(NS_FRAME_GET_TYPE(mFrameType) == NS_CSS_FRAME_TYPE_ABSOLUTE)) {
// a block inside a table cell needs to use the table cell
if (parentReflowState->parentReflowState &&
IS_TABLE_CELL(parentReflowState->parentReflowState->frame->GetType())) {
mCBReflowState = parentReflowState->parentReflowState;
} else {
mCBReflowState = parentReflowState;
}
return;
}
mCBReflowState = parentReflowState->mCBReflowState;
}
/* Check whether CalcQuirkContainingBlockHeight would stop on the
* given reflow state, using its block as a height. (essentially
* returns false for any case in which CalcQuirkContainingBlockHeight
* has a "continue" in its main loop.)
*
* XXX Maybe refactor CalcQuirkContainingBlockHeight so it uses
* this function as well
*/
static PRBool
IsQuirkContainingBlockHeight(const nsHTMLReflowState* rs)
{
nsIAtom* frameType = rs->frame->GetType();
if (nsGkAtoms::blockFrame == frameType ||
nsGkAtoms::areaFrame == frameType ||
nsGkAtoms::scrollFrame == frameType) {
if (nsGkAtoms::areaFrame == frameType) {
// Skip over scrolled-content area frames
if (rs->frame->GetStyleContext()->GetPseudoType() ==
nsCSSAnonBoxes::scrolledContent) {
return PR_FALSE;
}
}
// Note: This next condition could change due to a style change,
// but that would cause a style reflow anyway, which means we're ok.
if (NS_AUTOHEIGHT == rs->ComputedHeight()) {
if (!rs->frame->GetStyleDisplay()->IsAbsolutelyPositioned()) {
return PR_FALSE;
}
}
}
return PR_TRUE;
}
void
nsHTMLReflowState::InitResizeFlags(nsPresContext* aPresContext)
{
mFlags.mHResize = !(frame->GetStateBits() & NS_FRAME_IS_DIRTY) &&
frame->GetSize().width !=
mComputedWidth + mComputedBorderPadding.LeftRight();
// XXX Should we really need to null check mCBReflowState? (We do for
// at least nsBoxFrame).
if (IS_TABLE_CELL(frame->GetType()) &&
(mFlags.mSpecialHeightReflow ||
(frame->GetFirstInFlow()->GetStateBits() &
NS_TABLE_CELL_HAD_SPECIAL_REFLOW)) &&
(frame->GetStateBits() & NS_FRAME_CONTAINS_RELATIVE_HEIGHT)) {
// Need to set the bit on the cell so that
// mCBReflowState->mFlags.mVResize is set correctly below when
// reflowing descendant.
mFlags.mVResize = PR_TRUE;
} else if (mCBReflowState && !frame->IsContainingBlock()) {
// XXX Is this problematic for relatively positioned inlines acting
// as containing block for absolutely positioned elements?
mFlags.mVResize = mCBReflowState->mFlags.mVResize;
} else if (mComputedHeight == NS_AUTOHEIGHT) {
if (eCompatibility_NavQuirks == aPresContext->CompatibilityMode() &&
mCBReflowState) {
mFlags.mVResize = mCBReflowState->mFlags.mVResize;
} else {
mFlags.mVResize = mFlags.mHResize || NS_SUBTREE_DIRTY(frame);
}
} else {
// not 'auto' height
mFlags.mVResize = frame->GetSize().height !=
mComputedHeight + mComputedBorderPadding.TopBottom();
}
const PRBool dependsOnCBHeight =
mStylePosition->mHeight.GetUnit() == eStyleUnit_Percent ||
mStylePosition->mMinHeight.GetUnit() == eStyleUnit_Percent ||
mStylePosition->mMaxHeight.GetUnit() == eStyleUnit_Percent ||
mStylePosition->mOffset.GetTopUnit() == eStyleUnit_Percent ||
mStylePosition->mOffset.GetBottomUnit() == eStyleUnit_Percent ||
frame->IsBoxFrame();
// If we're the child of a table cell that performs special height
// reflows and we could be the child that requires them, always set
// the vertical resize in case this is the first pass before the
// special height reflow.
if (!mFlags.mVResize && mCBReflowState &&
IS_TABLE_CELL(mCBReflowState->frame->GetType()) &&
dependsOnCBHeight)
mFlags.mVResize = PR_TRUE;
// Set NS_FRAME_CONTAINS_RELATIVE_HEIGHT if it's needed.
// It would be nice to check that |mComputedHeight != NS_AUTOHEIGHT|
// &&ed with the percentage height check. However, this doesn't get
// along with table special height reflows, since a special height
// reflow (a quirk that makes such percentage heights work on children
// of table cells) can cause not just a single percentage height to
// become fixed, but an entire descendant chain of percentage heights
// to become fixed.
if (dependsOnCBHeight && mCBReflowState) {
const nsHTMLReflowState *rs = this;
PRBool hitCBReflowState = PR_FALSE;
do {
rs = rs->parentReflowState;
if (!rs) {
break;
}
if (rs->frame->GetStateBits() & NS_FRAME_CONTAINS_RELATIVE_HEIGHT)
break; // no need to go further
rs->frame->AddStateBits(NS_FRAME_CONTAINS_RELATIVE_HEIGHT);
// Keep track of whether we've hit the containing block, because
// we need to go at least that far.
if (rs == mCBReflowState) {
hitCBReflowState = PR_TRUE;
}
} while (!hitCBReflowState ||
(eCompatibility_NavQuirks == aPresContext->CompatibilityMode() &&
!IsQuirkContainingBlockHeight(rs)));
// Note: We actually don't need to set the
// NS_FRAME_CONTAINS_RELATIVE_HEIGHT bit for the cases
// where we hit the early break statements in
// CalcQuirkContainingBlockHeight. But it doesn't hurt
// us to set the bit in these cases.
}
if (frame->GetStateBits() & NS_FRAME_IS_DIRTY) {
// If we're reflowing everything, then we'll find out if we need
// to re-set this.
frame->RemoveStateBits(NS_FRAME_CONTAINS_RELATIVE_HEIGHT);
}
}
/* static */
nscoord
nsHTMLReflowState::GetContainingBlockContentWidth(const nsHTMLReflowState* aReflowState)
{
const nsHTMLReflowState* rs = aReflowState->mCBReflowState;
if (!rs)
return 0;
return rs->mComputedWidth;
}
/* static */
nsIFrame*
nsHTMLReflowState::GetContainingBlockFor(const nsIFrame* aFrame)
{
NS_PRECONDITION(aFrame, "Must have frame to work with");
nsIFrame* container = aFrame->GetParent();
if (aFrame->GetStyleDisplay()->IsAbsolutelyPositioned()) {
// Absolutely positioned frames are just kids of their containing
// blocks (which may happen to be inlines).
return container;
}
while (container && !container->IsContainingBlock()) {
container = container->GetParent();
}
return container;
}
void
nsHTMLReflowState::InitFrameType()
{
const nsStyleDisplay *disp = mStyleDisplay;
nsCSSFrameType frameType;
// Section 9.7 of the CSS2 spec indicates that absolute position
// takes precedence over float which takes precedence over display.
// Make sure the frame was actually moved out of the flow, and don't
// just assume what the style says
// XXXldb nsRuleNode::ComputeDisplayData should take care of this, right?
if (frame->GetStateBits() & NS_FRAME_OUT_OF_FLOW) {
if (disp->IsAbsolutelyPositioned()) {
frameType = NS_CSS_FRAME_TYPE_ABSOLUTE;
//XXXfr hack for making frames behave properly when in overflow container lists
// see bug 154892; need to revisit later
if (frame->GetPrevInFlow())
frameType = NS_CSS_FRAME_TYPE_BLOCK;
}
else if (NS_STYLE_FLOAT_NONE != disp->mFloats) {
frameType = NS_CSS_FRAME_TYPE_FLOATING;
} else {
NS_ASSERTION(disp->mDisplay == NS_STYLE_DISPLAY_POPUP,
"unknown out of flow frame type");
frameType = NS_CSS_FRAME_TYPE_UNKNOWN;
}
}
else {
switch (disp->mDisplay) {
case NS_STYLE_DISPLAY_BLOCK:
case NS_STYLE_DISPLAY_LIST_ITEM:
case NS_STYLE_DISPLAY_TABLE:
case NS_STYLE_DISPLAY_TABLE_CAPTION:
frameType = NS_CSS_FRAME_TYPE_BLOCK;
break;
case NS_STYLE_DISPLAY_INLINE:
case NS_STYLE_DISPLAY_INLINE_BLOCK:
case NS_STYLE_DISPLAY_MARKER:
case NS_STYLE_DISPLAY_INLINE_TABLE:
case NS_STYLE_DISPLAY_INLINE_BOX:
case NS_STYLE_DISPLAY_INLINE_GRID:
case NS_STYLE_DISPLAY_INLINE_STACK:
frameType = NS_CSS_FRAME_TYPE_INLINE;
break;
case NS_STYLE_DISPLAY_RUN_IN:
case NS_STYLE_DISPLAY_COMPACT:
// XXX need to look ahead at the frame's sibling
frameType = NS_CSS_FRAME_TYPE_BLOCK;
break;
case NS_STYLE_DISPLAY_TABLE_CELL:
case NS_STYLE_DISPLAY_TABLE_ROW_GROUP:
case NS_STYLE_DISPLAY_TABLE_COLUMN:
case NS_STYLE_DISPLAY_TABLE_COLUMN_GROUP:
case NS_STYLE_DISPLAY_TABLE_HEADER_GROUP:
case NS_STYLE_DISPLAY_TABLE_FOOTER_GROUP:
case NS_STYLE_DISPLAY_TABLE_ROW:
frameType = NS_CSS_FRAME_TYPE_INTERNAL_TABLE;
break;
case NS_STYLE_DISPLAY_NONE:
default:
frameType = NS_CSS_FRAME_TYPE_UNKNOWN;
break;
}
}
// See if the frame is replaced
if (frame->IsFrameOfType(nsIFrame::eReplacedContainsBlock)) {
frameType = NS_FRAME_REPLACED_CONTAINS_BLOCK(frameType);
} else if (frame->IsFrameOfType(nsIFrame::eReplaced)) {
frameType = NS_FRAME_REPLACED(frameType);
}
mFrameType = frameType;
}
void
nsHTMLReflowState::ComputeRelativeOffsets(const nsHTMLReflowState* cbrs,
nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight)
{
nsStyleCoord coord;
// Compute the 'left' and 'right' values. 'Left' moves the boxes to the right,
// and 'right' moves the boxes to the left. The computed values are always:
// left=-right
PRBool leftIsAuto = eStyleUnit_Auto == mStylePosition->mOffset.GetLeftUnit();
PRBool rightIsAuto = eStyleUnit_Auto == mStylePosition->mOffset.GetRightUnit();
// Check for percentage based values and an unconstrained containing
// block width. Treat them like 'auto'
if (NS_UNCONSTRAINEDSIZE == aContainingBlockWidth) {
if (eStyleUnit_Percent == mStylePosition->mOffset.GetLeftUnit()) {
leftIsAuto = PR_TRUE;
}
if (eStyleUnit_Percent == mStylePosition->mOffset.GetRightUnit()) {
rightIsAuto = PR_TRUE;
}
}
// If neither 'left' not 'right' are auto, then we're over-constrained and
// we ignore one of them
if (!leftIsAuto && !rightIsAuto) {
if (mCBReflowState &&
NS_STYLE_DIRECTION_RTL == mCBReflowState->mStyleVisibility->mDirection) {
leftIsAuto = PR_TRUE;
} else {
rightIsAuto = PR_TRUE;
}
}
if (leftIsAuto) {
if (rightIsAuto) {
// If both are 'auto' (their initial values), the computed values are 0
mComputedOffsets.left = mComputedOffsets.right = 0;
} else {
// 'Right' isn't 'auto' so compute its value
ComputeWidthDependentValue(aContainingBlockWidth,
mStylePosition->mOffset.GetRight(coord),
mComputedOffsets.right);
// Computed value for 'left' is minus the value of 'right'
mComputedOffsets.left = -mComputedOffsets.right;
}
} else {
NS_ASSERTION(rightIsAuto, "unexpected specified constraint");
// 'Left' isn't 'auto' so compute its value
ComputeWidthDependentValue(aContainingBlockWidth,
mStylePosition->mOffset.GetLeft(coord),
mComputedOffsets.left);
// Computed value for 'right' is minus the value of 'left'
mComputedOffsets.right = -mComputedOffsets.left;
}
// Compute the 'top' and 'bottom' values. The 'top' and 'bottom' properties
// move relatively positioned elements up and down. They also must be each
// other's negative
PRBool topIsAuto = eStyleUnit_Auto == mStylePosition->mOffset.GetTopUnit();
PRBool bottomIsAuto = eStyleUnit_Auto == mStylePosition->mOffset.GetBottomUnit();
// Check for percentage based values and a containing block height that
// depends on the content height. Treat them like 'auto'
if (NS_AUTOHEIGHT == aContainingBlockHeight) {
if (eStyleUnit_Percent == mStylePosition->mOffset.GetTopUnit()) {
topIsAuto = PR_TRUE;
}
if (eStyleUnit_Percent == mStylePosition->mOffset.GetBottomUnit()) {
bottomIsAuto = PR_TRUE;
}
}
// If neither is 'auto', 'bottom' is ignored
if (!topIsAuto && !bottomIsAuto) {
bottomIsAuto = PR_TRUE;
}
if (topIsAuto) {
if (bottomIsAuto) {
// If both are 'auto' (their initial values), the computed values are 0
mComputedOffsets.top = mComputedOffsets.bottom = 0;
} else {
// 'Bottom' isn't 'auto' so compute its value
ComputeHeightDependentValue(aContainingBlockHeight,
mStylePosition->mOffset.GetBottom(coord),
mComputedOffsets.bottom);
// Computed value for 'top' is minus the value of 'bottom'
mComputedOffsets.top = -mComputedOffsets.bottom;
}
} else {
NS_ASSERTION(bottomIsAuto, "unexpected specified constraint");
// 'Top' isn't 'auto' so compute its value
ComputeHeightDependentValue(aContainingBlockHeight,
mStylePosition->mOffset.GetTop(coord),
mComputedOffsets.top);
// Computed value for 'bottom' is minus the value of 'top'
mComputedOffsets.bottom = -mComputedOffsets.top;
}
}
nsIFrame*
nsHTMLReflowState::GetNearestContainingBlock(nsIFrame* aFrame, nscoord& aCBLeftEdge,
nscoord& aCBWidth)
{
for (aFrame = aFrame->GetParent(); aFrame && !aFrame->IsContainingBlock();
aFrame = aFrame->GetParent())
/* do nothing */;
NS_ASSERTION(aFrame, "Must find containing block somewhere");
NS_ASSERTION(aFrame != frame, "How did that happen?");
/* Now aFrame is the containing block we want */
/* Check whether the containing block is currently being reflown.
If so, use the info from the reflow state. */
const nsHTMLReflowState* state;
if (aFrame->GetStateBits() & NS_FRAME_IN_REFLOW) {
for (state = parentReflowState; state && state->frame != aFrame;
state = state->parentReflowState) {
/* do nothing */
}
} else {
state = nsnull;
}
if (state) {
aCBLeftEdge = state->mComputedBorderPadding.left;
aCBWidth = state->mComputedWidth;
} else {
/* Didn't find a reflow state for aFrame. Just compute the information we
want, on the assumption that aFrame already knows its size. This really
ought to be true by now. */
NS_ASSERTION(!(aFrame->GetStateBits() & NS_FRAME_IN_REFLOW),
"aFrame shouldn't be in reflow; we'll lie if it is");
nsMargin borderPadding = aFrame->GetUsedBorderAndPadding();
aCBLeftEdge = borderPadding.left;
aCBWidth = aFrame->GetSize().width - borderPadding.LeftRight();
}
return aFrame;
}
// When determining the hypothetical box that would have been if the element
// had been in the flow we may not be able to exactly determine both the left
// and right edges. For example, if the element is a non-replaced inline-level
// element we would have to reflow it in order to determine it desired width.
// In that case depending on the progression direction either the left or
// right edge would be marked as not being exact
struct nsHypotheticalBox {
nscoord mLeft, mRight;
nscoord mTop;
PRPackedBool mLeftIsExact, mRightIsExact;
nsHypotheticalBox() {
mLeftIsExact = mRightIsExact = PR_FALSE;
}
};
static PRBool
GetIntrinsicSizeFor(nsIFrame* aFrame, nsSize& aIntrinsicSize)
{
// See if it is an image frame
PRBool result = PR_FALSE;
// Currently the only type of replaced frame that we can get the intrinsic
// size for is an image frame
// XXX We should add back the GetReflowMetrics() function and one of the
// things should be the intrinsic size...
if (aFrame->GetType() == nsGkAtoms::imageFrame) {
nsImageFrame* imageFrame = (nsImageFrame*)aFrame;
imageFrame->GetIntrinsicImageSize(aIntrinsicSize);
result = (aIntrinsicSize != nsSize(0, 0));
}
return result;
}
/**
* aInsideBoxSizing returns the part of the horizontal padding, border,
* and margin that goes inside the edge given by -moz-box-sizing;
* aOutsideBoxSizing returns the rest.
*/
void
nsHTMLReflowState::CalculateHorizBorderPaddingMargin(
nscoord aContainingBlockWidth,
nscoord* aInsideBoxSizing,
nscoord* aOutsideBoxSizing)
{
const nsMargin& border = mStyleBorder->GetBorder();
nsMargin padding, margin;
// See if the style system can provide us the padding directly
if (!mStylePadding->GetPadding(padding)) {
nsStyleCoord left, right;
// We have to compute the left and right values
ComputeWidthDependentValue(aContainingBlockWidth,
mStylePadding->mPadding.GetLeft(left),
padding.left);
ComputeWidthDependentValue(aContainingBlockWidth,
mStylePadding->mPadding.GetRight(right),
padding.right);
}
// See if the style system can provide us the margin directly
if (!mStyleMargin->GetMargin(margin)) {
nsStyleCoord left, right;
// We have to compute the left and right values
if (eStyleUnit_Auto == mStyleMargin->mMargin.GetLeftUnit()) {
// XXX FIXME (or does CalculateBlockSideMargins do this?)
margin.left = 0; // just ignore
} else {
ComputeWidthDependentValue(aContainingBlockWidth,
mStyleMargin->mMargin.GetLeft(left),
margin.left);
}
if (eStyleUnit_Auto == mStyleMargin->mMargin.GetRightUnit()) {
// XXX FIXME (or does CalculateBlockSideMargins do this?)
margin.right = 0; // just ignore
} else {
ComputeWidthDependentValue(aContainingBlockWidth,
mStyleMargin->mMargin.GetRight(right),
margin.right);
}
}
nscoord outside =
padding.LeftRight() + border.LeftRight() + margin.LeftRight();
nscoord inside = 0;
switch (mStylePosition->mBoxSizing) {
case NS_STYLE_BOX_SIZING_BORDER:
inside += border.LeftRight();
// fall through
case NS_STYLE_BOX_SIZING_PADDING:
inside += padding.LeftRight();
}
outside -= inside;
*aInsideBoxSizing = inside;
*aOutsideBoxSizing = outside;
return;
}
/**
* Returns PR_TRUE iff a pre-order traversal of the normal child
* frames rooted at aFrame finds no non-empty frame before aDescendant.
*/
static PRBool AreAllEarlierInFlowFramesEmpty(nsIFrame* aFrame,
nsIFrame* aDescendant, PRBool* aFound) {
if (aFrame == aDescendant) {
*aFound = PR_TRUE;
return PR_TRUE;
}
if (!aFrame->IsSelfEmpty()) {
*aFound = PR_FALSE;
return PR_FALSE;
}
for (nsIFrame* f = aFrame->GetFirstChild(nsnull); f; f = f->GetNextSibling()) {
PRBool allEmpty = AreAllEarlierInFlowFramesEmpty(f, aDescendant, aFound);
if (*aFound || !allEmpty) {
return allEmpty;
}
}
*aFound = PR_FALSE;
return PR_TRUE;
}
// Calculate the hypothetical box that the element would have if it were in
// the flow. The values returned are relative to the padding edge of the
// absolute containing block
void
nsHTMLReflowState::CalculateHypotheticalBox(nsPresContext* aPresContext,
nsIFrame* aPlaceholderFrame,
nsIFrame* aContainingBlock,
nscoord aBlockLeftContentEdge,
nscoord aBlockContentWidth,
const nsHTMLReflowState* cbrs,
nsHypotheticalBox& aHypotheticalBox)
{
NS_ASSERTION(mStyleDisplay->mOriginalDisplay != NS_STYLE_DISPLAY_NONE,
"mOriginalDisplay has not been properly initialized");
// If it's a replaced element and it has a 'auto' value for 'width', see if we
// can get the intrinsic size. This will allow us to exactly determine both the
// left and right edges
PRBool isAutoWidth = mStylePosition->mWidth.GetUnit() == eStyleUnit_Auto;
nsSize intrinsicSize;
PRBool knowIntrinsicSize = PR_FALSE;
if (NS_FRAME_IS_REPLACED(mFrameType) && isAutoWidth) {
// See if we can get the intrinsic size of the element
knowIntrinsicSize = GetIntrinsicSizeFor(frame, intrinsicSize);
}
// See if we can calculate what the box width would have been if the
// element had been in the flow
nscoord boxWidth;
PRBool knowBoxWidth = PR_FALSE;
if ((NS_STYLE_DISPLAY_INLINE == mStyleDisplay->mOriginalDisplay) &&
!NS_FRAME_IS_REPLACED(mFrameType)) {
// For non-replaced inline-level elements the 'width' property doesn't apply,
// so we don't know what the width would have been without reflowing it
} else {
// It's either a replaced inline-level element or a block-level element
// Determine the total amount of horizontal border/padding/margin that
// the element would have had if it had been in the flow. Note that we
// ignore any 'auto' and 'inherit' values
nscoord insideBoxSizing, outsideBoxSizing;
CalculateHorizBorderPaddingMargin(aBlockContentWidth,
&insideBoxSizing, &outsideBoxSizing);
if (NS_FRAME_IS_REPLACED(mFrameType) && isAutoWidth) {
// It's a replaced element with an 'auto' width so the box width is
// its intrinsic size plus any border/padding/margin
if (knowIntrinsicSize) {
boxWidth = intrinsicSize.width + outsideBoxSizing + insideBoxSizing;
knowBoxWidth = PR_TRUE;
}
} else if (isAutoWidth) {
// The box width is the containing block width
boxWidth = aBlockContentWidth;
knowBoxWidth = PR_TRUE;
} else {
// We need to compute it. It's important we do this, because if it's
// percentage based this computed value may be different from the comnputed
// value calculated using the absolute containing block width
boxWidth = ComputeWidthValue(aBlockContentWidth,
insideBoxSizing, outsideBoxSizing,
mStylePosition->mWidth) +
insideBoxSizing + outsideBoxSizing;
knowBoxWidth = PR_TRUE;
}
}
// Get the 'direction' of the block
const nsStyleVisibility* blockVis = aContainingBlock->GetStyleVisibility();
// Get the placeholder x-offset and y-offset in the coordinate
// space of the block frame that contains it
// XXXbz the placeholder is not fully reflown yet if our containing block is
// relatively positioned...
nsPoint placeholderOffset = aPlaceholderFrame->GetOffsetTo(aContainingBlock);
// First, determine the hypothetical box's mTop
nsBlockFrame* blockFrame;
if (NS_SUCCEEDED(aContainingBlock->QueryInterface(kBlockFrameCID,
reinterpret_cast<void**>(&blockFrame)))) {
// We need the immediate child of the block frame, and that may not be
// the placeholder frame
nsIFrame *blockChild =
nsLayoutUtils::FindChildContainingDescendant(blockFrame, aPlaceholderFrame);
nsBlockFrame::line_iterator lineBox = blockFrame->FindLineFor(blockChild);
// How we determine the hypothetical box depends on whether the element
// would have been inline-level or block-level
if (NS_STYLE_DISPLAY_INLINE == mStyleDisplay->mOriginalDisplay) {
// Use the top of the inline box which the placeholder lives in as the
// hypothetical box's top.
aHypotheticalBox.mTop = lineBox->mBounds.y;
} else {
// The element would have been block-level which means it would be below
// the line containing the placeholder frame, unless all the frames
// before it are empty. In that case, it would have been just before
// this line.
// XXXbz the line box is not fully reflown yet if our containing block is
// relatively positioned...
if (lineBox != blockFrame->end_lines()) {
nsIFrame * firstFrame = lineBox->mFirstChild;
PRBool found = PR_FALSE;
PRBool allEmpty = PR_TRUE;
while (firstFrame) { // See bug 223064
allEmpty = AreAllEarlierInFlowFramesEmpty(firstFrame,
aPlaceholderFrame, &found);
if (found || !allEmpty)
break;
firstFrame = firstFrame->GetNextSibling();
}
NS_ASSERTION(firstFrame, "Couldn't find placeholder!");
if (allEmpty) {
// The top of the hypothetical box is the top of the line containing
// the placeholder, since there is nothing in the line before our
// placeholder except empty frames.
aHypotheticalBox.mTop = lineBox->mBounds.y;
} else {
// The top of the hypothetical box is just below the line containing
// the placeholder.
aHypotheticalBox.mTop = lineBox->mBounds.YMost();
}
} else {
// Just use the placeholder's y-offset
aHypotheticalBox.mTop = placeholderOffset.y;
}
}
} else {
// The containing block is not a block, so it's probably something
// like a XUL box, etc.
// Just use the placeholder's y-offset
aHypotheticalBox.mTop = placeholderOffset.y;
}
// Second, determine the hypothetical box's mLeft & mRight
// To determine the left and right offsets we need to look at the block's 'direction'
if (NS_STYLE_DIRECTION_LTR == blockVis->mDirection) {
// How we determine the hypothetical box depends on whether the element
// would have been inline-level or block-level
if (NS_STYLE_DISPLAY_INLINE == mStyleDisplay->mOriginalDisplay) {
// The placeholder represents the left edge of the hypothetical box
aHypotheticalBox.mLeft = placeholderOffset.x;
} else {
aHypotheticalBox.mLeft = aBlockLeftContentEdge;
}
aHypotheticalBox.mLeftIsExact = PR_TRUE;
if (knowBoxWidth) {
aHypotheticalBox.mRight = aHypotheticalBox.mLeft + boxWidth;
aHypotheticalBox.mRightIsExact = PR_TRUE;
} else {
// We can't compute the right edge because we don't know the desired
// width. So instead use the right content edge of the block parent,
// but remember it's not exact
aHypotheticalBox.mRight = aBlockLeftContentEdge + aBlockContentWidth;
aHypotheticalBox.mRightIsExact = PR_FALSE;
}
} else {
// The placeholder represents the right edge of the hypothetical box
if (NS_STYLE_DISPLAY_INLINE == mStyleDisplay->mOriginalDisplay) {
aHypotheticalBox.mRight = placeholderOffset.x;
} else {
aHypotheticalBox.mRight = aBlockLeftContentEdge + aBlockContentWidth;
}
aHypotheticalBox.mRightIsExact = PR_TRUE;
if (knowBoxWidth) {
aHypotheticalBox.mLeft = aHypotheticalBox.mRight - boxWidth;
aHypotheticalBox.mLeftIsExact = PR_TRUE;
} else {
// We can't compute the left edge because we don't know the desired
// width. So instead use the left content edge of the block parent,
// but remember it's not exact
aHypotheticalBox.mLeft = aBlockLeftContentEdge;
aHypotheticalBox.mLeftIsExact = PR_FALSE;
}
}
// The current coordinate space is that of the nearest block to the placeholder.
// Convert to the coordinate space of the absolute containing block
// One weird thing here is that for fixed-positioned elements we want to do
// the conversion incorrectly; specifically we want to ignore any scrolling
// that may have happened;
nsPoint cbOffset;
if (mStyleDisplay->mPosition == NS_STYLE_POSITION_FIXED) {
// In this case, cbrs->frame will always be an ancestor of
// aContainingBlock, so can just walk our way up the frame tree.
// Make sure to not add positions of frames whose parent is a
// scrollFrame, since we're doing fixed positioning, which assumes
// everything is scrolled to (0,0).
cbOffset.MoveTo(0, 0);
do {
NS_ASSERTION(aContainingBlock,
"Should hit cbrs->frame before we run off the frame tree!");
cbOffset += aContainingBlock->GetPositionIgnoringScrolling();
aContainingBlock = aContainingBlock->GetParent();
} while (aContainingBlock != cbrs->frame);
} else {
cbOffset = aContainingBlock->GetOffsetTo(cbrs->frame);
}
aHypotheticalBox.mLeft += cbOffset.x;
aHypotheticalBox.mTop += cbOffset.y;
aHypotheticalBox.mRight += cbOffset.x;
// The specified offsets are relative to the absolute containing block's
// padding edge and our current values are relative to the border edge, so
// translate.
nsMargin border = cbrs->mComputedBorderPadding - cbrs->mComputedPadding;
aHypotheticalBox.mLeft -= border.left;
aHypotheticalBox.mRight -= border.right;
aHypotheticalBox.mTop -= border.top;
}
void
nsHTMLReflowState::InitAbsoluteConstraints(nsPresContext* aPresContext,
const nsHTMLReflowState* cbrs,
nscoord containingBlockWidth,
nscoord containingBlockHeight)
{
NS_PRECONDITION(containingBlockHeight != NS_AUTOHEIGHT,
"containing block height must be constrained");
// Get the placeholder frame
nsIFrame* placeholderFrame;
aPresContext->PresShell()->GetPlaceholderFrameFor(frame, &placeholderFrame);
NS_ASSERTION(nsnull != placeholderFrame, "no placeholder frame");
// Find the nearest containing block frame to the placeholder frame,
// and return its left edge and width.
nscoord cbLeftEdge, cbWidth;
nsIFrame* cbFrame = GetNearestContainingBlock(placeholderFrame, cbLeftEdge,
cbWidth);
// If both 'left' and 'right' are 'auto' or both 'top' and 'bottom' are
// 'auto', then compute the hypothetical box of where the element would
// have been if it had been in the flow
nsHypotheticalBox hypotheticalBox;
if (((eStyleUnit_Auto == mStylePosition->mOffset.GetLeftUnit()) &&
(eStyleUnit_Auto == mStylePosition->mOffset.GetRightUnit())) ||
((eStyleUnit_Auto == mStylePosition->mOffset.GetTopUnit()) &&
(eStyleUnit_Auto == mStylePosition->mOffset.GetBottomUnit()))) {
CalculateHypotheticalBox(aPresContext, placeholderFrame, cbFrame,
cbLeftEdge, cbWidth, cbrs, hypotheticalBox);
}
// Initialize the 'left' and 'right' computed offsets
// XXX Handle new 'static-position' value...
PRBool leftIsAuto = PR_FALSE, rightIsAuto = PR_FALSE;
nsStyleCoord coord;
if (eStyleUnit_Auto == mStylePosition->mOffset.GetLeftUnit()) {
mComputedOffsets.left = 0;
leftIsAuto = PR_TRUE;
} else {
ComputeWidthDependentValue(containingBlockWidth,
mStylePosition->mOffset.GetLeft(coord),
mComputedOffsets.left);
}
if (eStyleUnit_Auto == mStylePosition->mOffset.GetRightUnit()) {
mComputedOffsets.right = 0;
rightIsAuto = PR_TRUE;
} else {
ComputeWidthDependentValue(containingBlockWidth,
mStylePosition->mOffset.GetRight(coord),
mComputedOffsets.right);
}
PRUint8 direction = cbrs ? cbrs->mStyleVisibility->mDirection : NS_STYLE_DIRECTION_LTR;
// Use the horizontal component of the hypothetical box in the cases
// where it's needed.
if (leftIsAuto && rightIsAuto) {
// Use the 'direction' to dictate whether 'left' or 'right' is
// treated like 'static-position'
if (NS_STYLE_DIRECTION_LTR == direction) {
if (hypotheticalBox.mLeftIsExact) {
mComputedOffsets.left = hypotheticalBox.mLeft;
leftIsAuto = PR_FALSE;
} else {
// Well, we don't know 'left' so we have to use 'right' and
// then solve for 'left'
mComputedOffsets.right = hypotheticalBox.mRight;
rightIsAuto = PR_FALSE;
}
} else {
if (hypotheticalBox.mRightIsExact) {
mComputedOffsets.right = containingBlockWidth - hypotheticalBox.mRight;
rightIsAuto = PR_FALSE;
} else {
// Well, we don't know 'right' so we have to use 'left' and
// then solve for 'right'
mComputedOffsets.left = hypotheticalBox.mLeft;
leftIsAuto = PR_FALSE;
}
}
}
// Initialize the 'top' and 'bottom' computed offsets
PRBool topIsAuto = PR_FALSE, bottomIsAuto = PR_FALSE;
if (eStyleUnit_Auto == mStylePosition->mOffset.GetTopUnit()) {
mComputedOffsets.top = 0;
topIsAuto = PR_TRUE;
} else {
nsStyleCoord c;
ComputeHeightDependentValue(containingBlockHeight,
mStylePosition->mOffset.GetTop(c),
mComputedOffsets.top);
}
if (eStyleUnit_Auto == mStylePosition->mOffset.GetBottomUnit()) {
mComputedOffsets.bottom = 0;
bottomIsAuto = PR_TRUE;
} else {
nsStyleCoord c;
ComputeHeightDependentValue(containingBlockHeight,
mStylePosition->mOffset.GetBottom(c),
mComputedOffsets.bottom);
}
if (topIsAuto && bottomIsAuto) {
// Treat 'top' like 'static-position'
mComputedOffsets.top = hypotheticalBox.mTop;
topIsAuto = PR_FALSE;
}
PRBool widthIsAuto = eStyleUnit_Auto == mStylePosition->mWidth.GetUnit();
PRBool heightIsAuto = eStyleUnit_Auto == mStylePosition->mHeight.GetUnit();
PRBool shrinkWrap = leftIsAuto || rightIsAuto;
nsSize size =
frame->ComputeSize(rendContext,
nsSize(containingBlockWidth,
containingBlockHeight),
containingBlockWidth, // XXX or availableWidth?
nsSize(mComputedMargin.LeftRight() +
mComputedOffsets.LeftRight(),
mComputedMargin.TopBottom() +
mComputedOffsets.TopBottom()),
nsSize(mComputedBorderPadding.LeftRight() -
mComputedPadding.LeftRight(),
mComputedBorderPadding.TopBottom() -
mComputedPadding.TopBottom()),
nsSize(mComputedPadding.LeftRight(),
mComputedPadding.TopBottom()),
shrinkWrap);
mComputedWidth = size.width;
mComputedHeight = size.height;
// XXX Now that we have ComputeSize, can we condense many of the
// branches off of widthIsAuto?
if (leftIsAuto) {
// We know 'right' is not 'auto' anymore thanks to the hypothetical
// box code above.
// Solve for 'left'.
if (widthIsAuto) {
// XXXldb This, and the corresponding code in
// nsAbsoluteContainingBlock.cpp, could probably go away now that
// we always compute widths.
mComputedOffsets.left = NS_AUTOOFFSET;
} else {
mComputedOffsets.left = containingBlockWidth - mComputedMargin.left -
mComputedBorderPadding.left - mComputedWidth - mComputedBorderPadding.right -
mComputedMargin.right - mComputedOffsets.right;
}
} else if (rightIsAuto) {
// We know 'left' is not 'auto' anymore thanks to the hypothetical
// box code above.
// Solve for 'right'.
if (widthIsAuto) {
// XXXldb This, and the corresponding code in
// nsAbsoluteContainingBlock.cpp, could probably go away now that
// we always compute widths.
mComputedOffsets.right = NS_AUTOOFFSET;
} else {
mComputedOffsets.right = containingBlockWidth - mComputedOffsets.left -
mComputedMargin.left - mComputedBorderPadding.left - mComputedWidth -
mComputedBorderPadding.right - mComputedMargin.right;
}
} else {
// Neither 'left' nor 'right' is 'auto'. However, the width might
// still not fill all the available space (even though we didn't
// shrink-wrap) in case:
// * width was specified
// * we're dealing with a replaced element
// * width was constrained by min-width or max-width.
nscoord availMarginSpace = containingBlockWidth -
mComputedOffsets.LeftRight() -
mComputedMargin.LeftRight() -
mComputedBorderPadding.LeftRight() -
mComputedWidth;
PRBool marginLeftIsAuto =
eStyleUnit_Auto == mStyleMargin->mMargin.GetLeftUnit();
PRBool marginRightIsAuto =
eStyleUnit_Auto == mStyleMargin->mMargin.GetRightUnit();
if (availMarginSpace < 0 ||
(!marginLeftIsAuto && !marginRightIsAuto)) {
// We're over-constrained so use 'direction' to dictate which
// value to ignore. (And note that the spec says to ignore 'left'
// or 'right' rather than 'margin-left' or 'margin-right'.)
if (NS_STYLE_DIRECTION_LTR == direction) {
// Ignore the specified value for 'right'.
mComputedOffsets.right += availMarginSpace;
} else {
// Ignore the specified value for 'left'.
mComputedOffsets.left += availMarginSpace;
}
} else if (marginLeftIsAuto) {
if (marginRightIsAuto) {
// Both 'margin-left' and 'margin-right' are 'auto', so they get
// equal values
mComputedMargin.left = availMarginSpace / 2;
mComputedMargin.right = availMarginSpace - mComputedMargin.left;
} else {
// Just 'margin-left' is 'auto'
mComputedMargin.left = availMarginSpace - mComputedMargin.right;
}
} else {
// Just 'margin-right' is 'auto'
mComputedMargin.right = availMarginSpace - mComputedMargin.left;
}
}
if (topIsAuto) {
// solve for 'top'
if (heightIsAuto) {
mComputedOffsets.top = NS_AUTOOFFSET;
} else {
mComputedOffsets.top = containingBlockHeight - mComputedMargin.top -
mComputedBorderPadding.top - mComputedHeight - mComputedBorderPadding.bottom -
mComputedMargin.bottom - mComputedOffsets.bottom;
}
} else if (bottomIsAuto) {
// solve for 'bottom'
if (heightIsAuto) {
mComputedOffsets.bottom = NS_AUTOOFFSET;
} else {
mComputedOffsets.bottom = containingBlockHeight - mComputedOffsets.top -
mComputedMargin.top - mComputedBorderPadding.top - mComputedHeight -
mComputedBorderPadding.bottom - mComputedMargin.bottom;
}
} else {
// Neither 'top' nor 'bottom' is 'auto'.
nscoord autoHeight = containingBlockHeight -
mComputedOffsets.TopBottom() -
mComputedMargin.TopBottom() -
mComputedBorderPadding.TopBottom();
if (autoHeight < 0) {
autoHeight = 0;
}
if (mComputedHeight == NS_UNCONSTRAINEDSIZE) {
// For non-replaced elements with 'height' auto, the 'height'
// fills the remaining space.
mComputedHeight = autoHeight;
// XXX Do these need box-sizing adjustments?
if (mComputedHeight > mComputedMaxHeight)
mComputedHeight = mComputedMaxHeight;
if (mComputedHeight < mComputedMinHeight)
mComputedHeight = mComputedMinHeight;
}
// The height might still not fill all the available space in case:
// * height was specified
// * we're dealing with a replaced element
// * height was constrained by min-height or max-height.
nscoord availMarginSpace = autoHeight - mComputedHeight;
PRBool marginTopIsAuto =
eStyleUnit_Auto == mStyleMargin->mMargin.GetTopUnit();
PRBool marginBottomIsAuto =
eStyleUnit_Auto == mStyleMargin->mMargin.GetBottomUnit();
if (availMarginSpace < 0 || (!marginTopIsAuto && !marginBottomIsAuto)) {
// We're over-constrained so ignore the specified value for
// 'bottom'. (And note that the spec says to ignore 'bottom'
// rather than 'margin-bottom'.)
mComputedOffsets.bottom += availMarginSpace;
} else if (marginTopIsAuto) {
if (marginBottomIsAuto) {
// Both 'margin-top' and 'margin-bottom' are 'auto', so they get
// equal values
mComputedMargin.top = availMarginSpace / 2;
mComputedMargin.bottom = availMarginSpace - mComputedMargin.top;
} else {
// Just 'margin-top' is 'auto'
mComputedMargin.top = availMarginSpace - mComputedMargin.bottom;
}
} else {
// Just 'margin-bottom' is 'auto'
mComputedMargin.bottom = availMarginSpace - mComputedMargin.top;
}
}
}
nscoord
GetVerticalMarginBorderPadding(const nsHTMLReflowState* aReflowState)
{
nscoord result = 0;
if (!aReflowState) return result;
// zero auto margins
nsMargin margin = aReflowState->mComputedMargin;
if (NS_AUTOMARGIN == margin.top)
margin.top = 0;
if (NS_AUTOMARGIN == margin.bottom)
margin.bottom = 0;
result += margin.top + margin.bottom;
result += aReflowState->mComputedBorderPadding.top +
aReflowState->mComputedBorderPadding.bottom;
return result;
}
/* Get the height based on the viewport of the containing block specified
* in aReflowState when the containing block has mComputedHeight == NS_AUTOHEIGHT
* This will walk up the chain of containing blocks looking for a computed height
* until it finds the canvas frame, or it encounters a frame that is not a block,
* area, or scroll frame. This handles compatibility with IE (see bug 85016 and bug 219693)
*
* When we encounter scrolledContent area frames, we skip over them, since they are guaranteed to not be useful for computing the containing block.
*
* See also IsQuirkContainingBlockHeight.
*/
static nscoord
CalcQuirkContainingBlockHeight(const nsHTMLReflowState* aCBReflowState)
{
nsHTMLReflowState* firstAncestorRS = nsnull; // a candidate for html frame
nsHTMLReflowState* secondAncestorRS = nsnull; // a candidate for body frame
// initialize the default to NS_AUTOHEIGHT as this is the containings block
// computed height when this function is called. It is possible that we
// don't alter this height especially if we are restricted to one level
nscoord result = NS_AUTOHEIGHT;
const nsHTMLReflowState* rs = aCBReflowState;
for (; rs; rs = (nsHTMLReflowState *)(rs->parentReflowState)) {
nsIAtom* frameType = rs->frame->GetType();
// if the ancestor is auto height then skip it and continue up if it
// is the first block/area frame and possibly the body/html
if (nsGkAtoms::blockFrame == frameType ||
nsGkAtoms::areaFrame == frameType ||
nsGkAtoms::scrollFrame == frameType) {
if (nsGkAtoms::areaFrame == frameType) {
// Skip over scrolled-content area frames
if (rs->frame->GetStyleContext()->GetPseudoType() ==
nsCSSAnonBoxes::scrolledContent) {
continue;
}
}
secondAncestorRS = firstAncestorRS;
firstAncestorRS = (nsHTMLReflowState*)rs;
// If the current frame we're looking at is positioned, we don't want to
// go any further (see bug 221784). The behavior we want here is: 1) If
// not auto-height, use this as the percentage base. 2) If auto-height,
// keep looking, unless the frame is positioned.
if (NS_AUTOHEIGHT == rs->ComputedHeight()) {
if (rs->frame->GetStyleDisplay()->IsAbsolutelyPositioned()) {
break;
} else {
continue;
}
}
}
else if (nsGkAtoms::canvasFrame == frameType) {
// Use scroll frames' computed height if we have one, this will
// allow us to get viewport height for native scrollbars.
nsHTMLReflowState* scrollState = (nsHTMLReflowState *)rs->parentReflowState;
if (nsGkAtoms::scrollFrame == scrollState->frame->GetType()) {
rs = scrollState;
}
}
else if (nsGkAtoms::pageContentFrame == frameType) {
nsIFrame* prevInFlow = rs->frame->GetPrevInFlow();
// only use the page content frame for a height basis if it is the first in flow
if (prevInFlow)
break;
}
else {
break;
}
// if the ancestor is the page content frame then the percent base is
// the avail height, otherwise it is the computed height
result = (nsGkAtoms::pageContentFrame == frameType)
? rs->availableHeight : rs->ComputedHeight();
// if unconstrained - don't sutract borders - would result in huge height
if (NS_AUTOHEIGHT == result) return result;
// if we got to the canvas or page content frame, then subtract out
// margin/border/padding for the BODY and HTML elements
if ((nsGkAtoms::canvasFrame == frameType) ||
(nsGkAtoms::pageContentFrame == frameType)) {
result -= GetVerticalMarginBorderPadding(firstAncestorRS);
result -= GetVerticalMarginBorderPadding(secondAncestorRS);
#ifdef DEBUG
// make sure the first ancestor is the HTML and the second is the BODY
if (firstAncestorRS) {
nsIContent* frameContent = firstAncestorRS->frame->GetContent();
if (frameContent) {
nsIAtom *contentTag = frameContent->Tag();
NS_ASSERTION(contentTag == nsGkAtoms::html, "First ancestor is not HTML");
}
}
if (secondAncestorRS) {
nsIContent* frameContent = secondAncestorRS->frame->GetContent();
if (frameContent) {
nsIAtom *contentTag = frameContent->Tag();
NS_ASSERTION(contentTag == nsGkAtoms::body, "Second ancestor is not BODY");
}
}
#endif
}
// if we got to the html frame, then subtract out
// margin/border/padding for the BODY element
else if (nsGkAtoms::areaFrame == frameType) {
// make sure it is the body
if (nsGkAtoms::canvasFrame == rs->parentReflowState->frame->GetType()) {
result -= GetVerticalMarginBorderPadding(secondAncestorRS);
}
}
break;
}
// Make sure not to return a negative height here!
return PR_MAX(result, 0);
}
// Called by InitConstraints() to compute the containing block rectangle for
// the element. Handles the special logic for absolutely positioned elements
void
nsHTMLReflowState::ComputeContainingBlockRectangle(nsPresContext* aPresContext,
const nsHTMLReflowState* aContainingBlockRS,
nscoord& aContainingBlockWidth,
nscoord& aContainingBlockHeight)
{
// Unless the element is absolutely positioned, the containing block is
// formed by the content edge of the nearest block-level ancestor
aContainingBlockWidth = aContainingBlockRS->mComputedWidth;
aContainingBlockHeight = aContainingBlockRS->mComputedHeight;
if (NS_FRAME_GET_TYPE(mFrameType) == NS_CSS_FRAME_TYPE_ABSOLUTE) {
// See if the ancestor is block-level or inline-level
if (NS_FRAME_GET_TYPE(aContainingBlockRS->mFrameType) == NS_CSS_FRAME_TYPE_INLINE) {
// Base our size on the actual size of the frame. In cases when this is
// completely bogus (eg initial reflow), this code shouldn't even be
// called, since the code in nsPositionedInlineFrame::Reflow will pass in
// the containing block dimensions to our constructor.
// XXXbz we should be taking the in-flows into account too, but
// that's very hard.
nsMargin computedBorder = aContainingBlockRS->mComputedBorderPadding -
aContainingBlockRS->mComputedPadding;
aContainingBlockWidth = aContainingBlockRS->frame->GetRect().width -
computedBorder.LeftRight();;
NS_ASSERTION(aContainingBlockWidth >= 0,
"Negative containing block width!");
aContainingBlockHeight = aContainingBlockRS->frame->GetRect().height -
computedBorder.TopBottom();
NS_ASSERTION(aContainingBlockHeight >= 0,
"Negative containing block height!");
} else {
// If the ancestor is block-level, the containing block is formed by the
// padding edge of the ancestor
aContainingBlockWidth += aContainingBlockRS->mComputedPadding.LeftRight();
// If the containing block is the initial containing block and it has a
// height that depends on its content, then use the viewport height instead.
// This gives us a reasonable value against which to compute percentage
// based heights and to do bottom relative positioning
if ((NS_AUTOHEIGHT == aContainingBlockHeight) &&
nsLayoutUtils::IsInitialContainingBlock(aContainingBlockRS->frame)) {
// Use the viewport height as the containing block height
const nsHTMLReflowState* rs = aContainingBlockRS->parentReflowState;
while (rs) {
aContainingBlockHeight = rs->mComputedHeight;
rs = rs->parentReflowState;
}
} else {
aContainingBlockHeight +=
aContainingBlockRS->mComputedPadding.TopBottom();
}
}
} else {
// an element in quirks mode gets a containing block based on looking for a
// parent with a non-auto height if the element has a percent height
if (NS_AUTOHEIGHT == aContainingBlockHeight) {
if (eCompatibility_NavQuirks == aPresContext->CompatibilityMode() &&
mStylePosition->mHeight.GetUnit() == eStyleUnit_Percent) {
aContainingBlockHeight = CalcQuirkContainingBlockHeight(aContainingBlockRS);
}
}
}
}
// Prefs callback to pick up changes
PR_STATIC_CALLBACK(int)
PrefsChanged(const char *aPrefName, void *instance)
{
sBlinkIsAllowed =
nsContentUtils::GetBoolPref("browser.blink_allowed", sBlinkIsAllowed);
return 0; /* PREF_OK */
}
// Check to see if |text-decoration: blink| is allowed. The first time
// called, register the callback and then force-load the pref. After that,
// just use the cached value.
static PRBool BlinkIsAllowed(void)
{
if (!sPrefIsLoaded) {
// Set up a listener and check the initial value
nsContentUtils::RegisterPrefCallback("browser.blink_allowed", PrefsChanged,
nsnull);
PrefsChanged(nsnull, nsnull);
sPrefIsLoaded = PR_TRUE;
}
return sBlinkIsAllowed;
}
#ifdef FONT_LEADING_APIS_V2
static eNormalLineHeightControl GetNormalLineHeightCalcControl(void)
{
if (sNormalLineHeightControl == eUninitialized) {
// browser.display.normal_lineheight_calc_control is not user
// changeable, so no need to register callback for it.
sNormalLineHeightControl =
static_cast<eNormalLineHeightControl>
(nsContentUtils::GetIntPref("browser.display.normal_lineheight_calc_control", eNoExternalLeading));
}
return sNormalLineHeightControl;
}
#endif
// XXX refactor this code to have methods for each set of properties
// we are computing: width,height,line-height; margin; offsets
void
nsHTMLReflowState::InitConstraints(nsPresContext* aPresContext,
nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight,
const nsMargin* aBorder,
const nsMargin* aPadding)
{
// If this is the root frame, then set the computed width and
// height equal to the available space
if (nsnull == parentReflowState) {
// XXXldb This doesn't mean what it used to!
InitOffsets(aContainingBlockWidth, aBorder, aPadding);
// Override mComputedMargin since reflow roots start from the
// frame's boundary, which is inside the margin.
mComputedMargin.SizeTo(0, 0, 0, 0);
mComputedOffsets.SizeTo(0, 0, 0, 0);
mComputedWidth = availableWidth - mComputedBorderPadding.LeftRight();
if (mComputedWidth < 0)
mComputedWidth = 0;
if (availableHeight != NS_UNCONSTRAINEDSIZE) {
mComputedHeight = availableHeight - mComputedBorderPadding.TopBottom();
if (mComputedHeight < 0)
mComputedHeight = 0;
} else {
mComputedHeight = NS_UNCONSTRAINEDSIZE;
}
mComputedMinWidth = mComputedMinHeight = 0;
mComputedMaxWidth = mComputedMaxHeight = NS_UNCONSTRAINEDSIZE;
} else {
// Get the containing block reflow state
const nsHTMLReflowState* cbrs = mCBReflowState;
NS_ASSERTION(nsnull != cbrs, "no containing block");
// If we weren't given a containing block width and height, then
// compute one
if (aContainingBlockWidth == -1) {
ComputeContainingBlockRectangle(aPresContext, cbrs, aContainingBlockWidth,
aContainingBlockHeight);
}
#if 0
nsFrame::ListTag(stdout, frame); printf(": cb=");
nsFrame::ListTag(stdout, cbrs->frame); printf(" size=%d,%d\n", aContainingBlockWidth, aContainingBlockHeight);
#endif
// See if the containing block height is based on the size of its
// content
nsIAtom* fType;
if (NS_AUTOHEIGHT == aContainingBlockHeight) {
// See if the containing block is (1) a scrolled frame, i.e. its
// parent is a scroll frame. The presence of the intervening
// frame (that the scroll frame scrolls) needs to be hidden from
// the containingBlockHeight calcuation, or (2) a cell frame which needs
// to use the mComputedHeight of the cell instead of what the cell block passed in.
if (cbrs->parentReflowState) {
nsIFrame* f = cbrs->parentReflowState->frame;
fType = f->GetType();
if (nsGkAtoms::scrollFrame == fType) {
// Use the scroll frame's computed height instead
aContainingBlockHeight = cbrs->parentReflowState->mComputedHeight;
}
else {
fType = cbrs->frame->GetType();
if (IS_TABLE_CELL(fType)) {
// use the cell's computed height
aContainingBlockHeight = cbrs->mComputedHeight;
}
}
}
}
InitOffsets(aContainingBlockWidth, aBorder, aPadding);
nsStyleUnit heightUnit = mStylePosition->mHeight.GetUnit();
// Check for a percentage based height and a containing block height
// that depends on the content height
// XXX twiddling heightUnit doesn't help anymore
if (eStyleUnit_Percent == heightUnit) {
if (NS_AUTOHEIGHT == aContainingBlockHeight) {
// this if clause enables %-height on replaced inline frames,
// such as images. See bug 54119. The else clause "heightUnit = eStyleUnit_Auto;"
// used to be called exclusively.
if (NS_FRAME_REPLACED(NS_CSS_FRAME_TYPE_INLINE) == mFrameType ||
NS_FRAME_REPLACED_CONTAINS_BLOCK(
NS_CSS_FRAME_TYPE_INLINE) == mFrameType) {
// Get the containing block reflow state
NS_ASSERTION(nsnull != cbrs, "no containing block");
// in quirks mode, get the cb height using the special quirk method
if (eCompatibility_NavQuirks == aPresContext->CompatibilityMode()) {
if (!IS_TABLE_CELL(fType)) {
aContainingBlockHeight = CalcQuirkContainingBlockHeight(cbrs);
if (aContainingBlockHeight == NS_AUTOHEIGHT) {
heightUnit = eStyleUnit_Auto;
}
}
else {
heightUnit = eStyleUnit_Auto;
}
}
// in standard mode, use the cb height. if it's "auto", as will be the case
// by default in BODY, use auto height as per CSS2 spec.
else
{
if (NS_AUTOHEIGHT != cbrs->mComputedHeight)
aContainingBlockHeight = cbrs->mComputedHeight;
else
heightUnit = eStyleUnit_Auto;
}
}
else {
// default to interpreting the height like 'auto'
heightUnit = eStyleUnit_Auto;
}
}
}
// Compute our offsets if the element is relatively positioned. We need
// the correct containing block width and height here, which is why we need
// to do it after all the quirks-n-such above.
if (NS_STYLE_POSITION_RELATIVE == mStyleDisplay->mPosition) {
ComputeRelativeOffsets(cbrs, aContainingBlockWidth, aContainingBlockHeight);
} else {
// Initialize offsets to 0
mComputedOffsets.SizeTo(0, 0, 0, 0);
}
// Calculate the computed values for min and max properties. Note that
// this MUST come after we've computed our border and padding.
ComputeMinMaxValues(aContainingBlockWidth, aContainingBlockHeight, cbrs);
// Calculate the computed width and height. This varies by frame type
if (NS_CSS_FRAME_TYPE_INTERNAL_TABLE == mFrameType) {
// Internal table elements. The rules vary depending on the type.
// Calculate the computed width
PRBool rowOrRowGroup = PR_FALSE;
nsStyleUnit widthUnit = mStylePosition->mWidth.GetUnit();
if ((NS_STYLE_DISPLAY_TABLE_ROW == mStyleDisplay->mDisplay) ||
(NS_STYLE_DISPLAY_TABLE_ROW_GROUP == mStyleDisplay->mDisplay)) {
// 'width' property doesn't apply to table rows and row groups
widthUnit = eStyleUnit_Auto;
rowOrRowGroup = PR_TRUE;
}
if (eStyleUnit_Auto == widthUnit) {
mComputedWidth = availableWidth;
if ((mComputedWidth != NS_UNCONSTRAINEDSIZE) && !rowOrRowGroup){
// Internal table elements don't have margins. Only tables and
// cells have border and padding
mComputedWidth -= mComputedBorderPadding.left +
mComputedBorderPadding.right;
}
} else {
NS_ASSERTION(widthUnit == mStylePosition->mWidth.GetUnit(),
"unexpected width unit change");
mComputedWidth = ComputeWidthValue(aContainingBlockWidth,
mStylePosition->mBoxSizing,
mStylePosition->mWidth);
}
// Calculate the computed height
if ((NS_STYLE_DISPLAY_TABLE_COLUMN == mStyleDisplay->mDisplay) ||
(NS_STYLE_DISPLAY_TABLE_COLUMN_GROUP == mStyleDisplay->mDisplay)) {
// 'height' property doesn't apply to table columns and column groups
heightUnit = eStyleUnit_Auto;
}
if (eStyleUnit_Auto == heightUnit) {
mComputedHeight = NS_AUTOHEIGHT;
} else {
NS_ASSERTION(heightUnit == mStylePosition->mHeight.GetUnit(),
"unexpected height unit change");
ComputeHeightDependentValue(aContainingBlockHeight,
mStylePosition->mHeight,
mComputedHeight);
}
// Doesn't apply to table elements
mComputedMinWidth = mComputedMinHeight = 0;
mComputedMaxWidth = mComputedMaxHeight = NS_UNCONSTRAINEDSIZE;
} else if (NS_FRAME_GET_TYPE(mFrameType) == NS_CSS_FRAME_TYPE_ABSOLUTE) {
// XXX not sure if this belongs here or somewhere else - cwk
InitAbsoluteConstraints(aPresContext, cbrs, aContainingBlockWidth,
aContainingBlockHeight);
} else {
PRBool isBlock =
NS_CSS_FRAME_TYPE_BLOCK == NS_FRAME_GET_TYPE(mFrameType);
nsSize size =
frame->ComputeSize(rendContext,
nsSize(aContainingBlockWidth,
aContainingBlockHeight),
availableWidth,
nsSize(mComputedMargin.LeftRight(),
mComputedMargin.TopBottom()),
nsSize(mComputedBorderPadding.LeftRight() -
mComputedPadding.LeftRight(),
mComputedBorderPadding.TopBottom() -
mComputedPadding.TopBottom()),
nsSize(mComputedPadding.LeftRight(),
mComputedPadding.TopBottom()),
!isBlock);
mComputedWidth = size.width;
mComputedHeight = size.height;
if (isBlock)
CalculateBlockSideMargins(availableWidth, mComputedWidth);
}
}
// Check for blinking text and permission to display it
mFlags.mBlinks = (parentReflowState && parentReflowState->mFlags.mBlinks);
if (!mFlags.mBlinks && BlinkIsAllowed()) {
const nsStyleTextReset* st = frame->GetStyleTextReset();
mFlags.mBlinks =
((st->mTextDecoration & NS_STYLE_TEXT_DECORATION_BLINK) != 0);
}
}
void
nsCSSOffsetState::InitOffsets(nscoord aContainingBlockWidth,
const nsMargin *aBorder,
const nsMargin *aPadding)
{
// Compute margins from the specified margin style information. These
// become the default computed values, and may be adjusted below
// XXX fix to provide 0,0 for the top&bottom margins for
// inline-non-replaced elements
ComputeMargin(aContainingBlockWidth);
const nsStyleDisplay *disp = frame->GetStyleDisplay();
PRBool isThemed = frame->IsThemed(disp);
nsPresContext *presContext = frame->PresContext();
if (isThemed &&
presContext->GetTheme()->GetWidgetPadding(presContext->DeviceContext(),
frame, disp->mAppearance,
&mComputedPadding)) {
mComputedPadding.top = presContext->DevPixelsToAppUnits(mComputedPadding.top);
mComputedPadding.right = presContext->DevPixelsToAppUnits(mComputedPadding.right);
mComputedPadding.bottom = presContext->DevPixelsToAppUnits(mComputedPadding.bottom);
mComputedPadding.left = presContext->DevPixelsToAppUnits(mComputedPadding.left);
}
else if (aPadding) { // padding is an input arg
mComputedPadding.top = aPadding->top;
mComputedPadding.right = aPadding->right;
mComputedPadding.bottom = aPadding->bottom;
mComputedPadding.left = aPadding->left;
}
else {
ComputePadding(aContainingBlockWidth);
}
if (isThemed) {
presContext->GetTheme()->GetWidgetBorder(presContext->DeviceContext(),
frame, disp->mAppearance,
&mComputedBorderPadding);
mComputedBorderPadding.top =
presContext->DevPixelsToAppUnits(mComputedBorderPadding.top);
mComputedBorderPadding.right =
presContext->DevPixelsToAppUnits(mComputedBorderPadding.right);
mComputedBorderPadding.bottom =
presContext->DevPixelsToAppUnits(mComputedBorderPadding.bottom);
mComputedBorderPadding.left =
presContext->DevPixelsToAppUnits(mComputedBorderPadding.left);
}
else if (aBorder) { // border is an input arg
mComputedBorderPadding = *aBorder;
}
else {
mComputedBorderPadding = frame->GetStyleBorder()->GetBorder();
}
mComputedBorderPadding += mComputedPadding;
if (frame->GetType() == nsGkAtoms::tableFrame) {
nsTableFrame *tableFrame = static_cast<nsTableFrame*>(frame);
if (tableFrame->IsBorderCollapse()) {
// border-collapsed tables don't use any of their padding, and
// only part of their border. We need to do this here before we
// try to do anything like handling 'auto' widths,
// '-moz-box-sizing', or 'auto' margins.
mComputedPadding.SizeTo(0,0,0,0);
mComputedBorderPadding = tableFrame->GetIncludedOuterBCBorder();
}
}
}
// This code enforces section 10.3.3 of the CSS2 spec for this formula:
//
// 'margin-left' + 'border-left-width' + 'padding-left' + 'width' +
// 'padding-right' + 'border-right-width' + 'margin-right'
// = width of containing block
//
// Note: the width unit is not auto when this is called
void
nsHTMLReflowState::CalculateBlockSideMargins(nscoord aAvailWidth,
nscoord aComputedWidth)
{
NS_ASSERTION(NS_UNCONSTRAINEDSIZE != aComputedWidth &&
NS_UNCONSTRAINEDSIZE != aAvailWidth,
"this shouldn't happen anymore");
nscoord sum = mComputedMargin.left + mComputedBorderPadding.left +
aComputedWidth + mComputedBorderPadding.right + mComputedMargin.right;
if (sum == aAvailWidth)
// The sum is already correct
return;
// Determine the left and right margin values. The width value
// remains constant while we do this.
// Calculate how much space is available for margins
nscoord availMarginSpace = aAvailWidth - sum;
// If the available margin space is negative, then don't follow the
// usual overconstraint rules.
if (availMarginSpace < 0) {
if (mCBReflowState &&
mCBReflowState->mStyleVisibility->mDirection == NS_STYLE_DIRECTION_RTL) {
mComputedMargin.left += availMarginSpace;
} else {
mComputedMargin.right += availMarginSpace;
}
return;
}
// The css2 spec clearly defines how block elements should behave
// in section 10.3.3.
PRBool isAutoLeftMargin =
eStyleUnit_Auto == mStyleMargin->mMargin.GetLeftUnit();
PRBool isAutoRightMargin =
eStyleUnit_Auto == mStyleMargin->mMargin.GetRightUnit();
if (!isAutoLeftMargin && !isAutoRightMargin) {
// Neither margin is 'auto' so we're over constrained. Use the
// 'direction' property of the parent to tell which margin to
// ignore
// First check if there is an HTML alignment that we should honor
const nsHTMLReflowState* prs = parentReflowState;
if (frame->GetType() == nsGkAtoms::tableFrame) {
NS_ASSERTION(prs->frame->GetType() == nsGkAtoms::tableOuterFrame,
"table not inside outer table");
// Center the table within the outer table based on the alignment
// of the outer table's parent.
prs = prs->parentReflowState;
}
if (prs &&
(prs->mStyleText->mTextAlign == NS_STYLE_TEXT_ALIGN_MOZ_LEFT ||
prs->mStyleText->mTextAlign == NS_STYLE_TEXT_ALIGN_MOZ_CENTER ||
prs->mStyleText->mTextAlign == NS_STYLE_TEXT_ALIGN_MOZ_RIGHT)) {
isAutoLeftMargin =
prs->mStyleText->mTextAlign != NS_STYLE_TEXT_ALIGN_MOZ_LEFT;
isAutoRightMargin =
prs->mStyleText->mTextAlign != NS_STYLE_TEXT_ALIGN_MOZ_RIGHT;
}
// Otherwise apply the CSS rules, and ignore one margin by forcing
// it to 'auto', depending on 'direction'.
else if (mCBReflowState &&
NS_STYLE_DIRECTION_RTL == mCBReflowState->mStyleVisibility->mDirection) {
isAutoLeftMargin = PR_TRUE;
}
else {
isAutoRightMargin = PR_TRUE;
}
}
// Logic which is common to blocks and tables
if (isAutoLeftMargin) {
if (isAutoRightMargin) {
// Both margins are 'auto' so their computed values are equal
mComputedMargin.left = availMarginSpace / 2;
mComputedMargin.right = availMarginSpace - mComputedMargin.left;
} else {
mComputedMargin.left += availMarginSpace;
}
} else if (isAutoRightMargin) {
mComputedMargin.right += availMarginSpace;
}
}
#define NORMAL_LINE_HEIGHT_FACTOR 1.2f // in term of emHeight
// For "normal" we use the font's normal line height (em height + leading).
// If both internal leading and external leading specified by font itself
// are zeros, we should compensate this by creating extra (external) leading
// in eCompensateLeading mode. This is necessary because without this
// compensation, normal line height might looks too tight.
// For risk management, we use preference to control the behavior, and
// eNoExternalLeading is the old behavior.
static nscoord
GetNormalLineHeight(nsIFontMetrics* aFontMetrics)
{
NS_PRECONDITION(nsnull != aFontMetrics, "no font metrics");
nscoord normalLineHeight;
#ifdef FONT_LEADING_APIS_V2
nscoord externalLeading, internalLeading, emHeight;
aFontMetrics->GetExternalLeading(externalLeading);
aFontMetrics->GetInternalLeading(internalLeading);
aFontMetrics->GetEmHeight(emHeight);
switch (GetNormalLineHeightCalcControl()) {
case eIncludeExternalLeading:
normalLineHeight = emHeight+ internalLeading + externalLeading;
break;
case eCompensateLeading:
if (!internalLeading && !externalLeading)
normalLineHeight = NSToCoordRound(emHeight * NORMAL_LINE_HEIGHT_FACTOR);
else
normalLineHeight = emHeight+ internalLeading + externalLeading;
break;
default:
//case eNoExternalLeading:
normalLineHeight = emHeight + internalLeading;
}
#else
aFontMetrics->GetNormalLineHeight(normalLineHeight);
#endif // FONT_LEADING_APIS_V2
return normalLineHeight;
}
// Need only one of aRenderingContext and aDeviceContext
static nscoord
ComputeLineHeight(nsIRenderingContext* aRenderingContext,
nsStyleContext* aStyleContext)
{
nscoord lineHeight;
const nsStyleCoord& lhCoord = aStyleContext->GetStyleText()->mLineHeight;
if (!nsLayoutUtils::GetAbsoluteCoord(lhCoord, aRenderingContext,
aStyleContext, lineHeight)) {
const nsStyleFont* font = aStyleContext->GetStyleFont();
if (lhCoord.GetUnit() == eStyleUnit_Factor) {
// For factor units the computed value of the line-height property
// is found by multiplying the factor by the font's computed size
// (adjusted for min-size prefs and text zoom).
float factor = lhCoord.GetFactorValue();
lineHeight = NSToCoordRound(factor * font->mFont.size);
} else {
NS_ASSERTION(eStyleUnit_Normal == lhCoord.GetUnit(), "bad unit");
nsCOMPtr<nsIFontMetrics> fm;
nsLayoutUtils::GetFontMetricsForStyleContext(aStyleContext,
getter_AddRefs(fm));
lineHeight = GetNormalLineHeight(fm);
}
}
return lineHeight;
}
nscoord
nsHTMLReflowState::CalcLineHeight(nsIRenderingContext* aRenderingContext,
nsStyleContext* aStyleContext)
{
NS_PRECONDITION(aRenderingContext, "Must have a rendering context");
NS_PRECONDITION(aStyleContext, "Must have a style context");
nscoord lineHeight = ComputeLineHeight(aRenderingContext, aStyleContext);
NS_ASSERTION(lineHeight >= 0, "ComputeLineHeight screwed up");
return lineHeight;
}
/* static */
void
nsCSSOffsetState::DestroyMarginFunc(void* aFrame,
nsIAtom* aPropertyName,
void* aPropertyValue,
void* aDtorData)
{
delete static_cast<nsMargin*>(aPropertyValue);
}
void
nsCSSOffsetState::ComputeMargin(nscoord aContainingBlockWidth)
{
// If style style can provide us the margin directly, then use it.
const nsStyleMargin *styleMargin = frame->GetStyleMargin();
if (!styleMargin->GetMargin(mComputedMargin)) {
// We have to compute the value
if (NS_UNCONSTRAINEDSIZE == aContainingBlockWidth) {
mComputedMargin.left = 0;
mComputedMargin.right = 0;
if (eStyleUnit_Coord == styleMargin->mMargin.GetLeftUnit()) {
nsStyleCoord left;
styleMargin->mMargin.GetLeft(left),
mComputedMargin.left = left.GetCoordValue();
}
if (eStyleUnit_Coord == styleMargin->mMargin.GetRightUnit()) {
nsStyleCoord right;
styleMargin->mMargin.GetRight(right),
mComputedMargin.right = right.GetCoordValue();
}
} else {
nsStyleCoord left, right;
ComputeWidthDependentValue(aContainingBlockWidth,
styleMargin->mMargin.GetLeft(left),
mComputedMargin.left);
ComputeWidthDependentValue(aContainingBlockWidth,
styleMargin->mMargin.GetRight(right),
mComputedMargin.right);
}
nsStyleCoord top, bottom;
// According to the CSS2 spec, margin percentages are
// calculated with respect to the *width* of the containing
// block, even for margin-top and margin-bottom.
// XXX This isn't true for page boxes, if we implement them.
ComputeWidthDependentValue(aContainingBlockWidth,
styleMargin->mMargin.GetTop(top),
mComputedMargin.top);
ComputeWidthDependentValue(aContainingBlockWidth,
styleMargin->mMargin.GetBottom(bottom),
mComputedMargin.bottom);
// XXX We need to include 'auto' horizontal margins in this too!
frame->SetProperty(nsGkAtoms::usedMarginProperty,
new nsMargin(mComputedMargin),
DestroyMarginFunc);
}
}
void
nsCSSOffsetState::ComputePadding(nscoord aContainingBlockWidth)
{
// If style can provide us the padding directly, then use it.
const nsStylePadding *stylePadding = frame->GetStylePadding();
if (!stylePadding->GetPadding(mComputedPadding)) {
// We have to compute the value
nsStyleCoord left, right, top, bottom;
ComputeWidthDependentValue(aContainingBlockWidth,
stylePadding->mPadding.GetLeft(left),
mComputedPadding.left);
ComputeWidthDependentValue(aContainingBlockWidth,
stylePadding->mPadding.GetRight(right),
mComputedPadding.right);
// According to the CSS2 spec, percentages are calculated with respect to
// containing block width for padding-top and padding-bottom
ComputeWidthDependentValue(aContainingBlockWidth,
stylePadding->mPadding.GetTop(top),
mComputedPadding.top);
ComputeWidthDependentValue(aContainingBlockWidth,
stylePadding->mPadding.GetBottom(bottom),
mComputedPadding.bottom);
frame->SetProperty(nsGkAtoms::usedPaddingProperty,
new nsMargin(mComputedPadding),
DestroyMarginFunc);
}
// a table row/col group, row/col doesn't have padding
// XXXldb Neither do border-collapse tables.
nsIAtom* frameType = frame->GetType();
if (nsGkAtoms::tableRowGroupFrame == frameType ||
nsGkAtoms::tableColGroupFrame == frameType ||
nsGkAtoms::tableRowFrame == frameType ||
nsGkAtoms::tableColFrame == frameType) {
mComputedPadding.top = 0;
mComputedPadding.right = 0;
mComputedPadding.bottom = 0;
mComputedPadding.left = 0;
}
}
void
nsHTMLReflowState::ApplyMinMaxConstraints(nscoord* aFrameWidth,
nscoord* aFrameHeight) const
{
if (aFrameWidth) {
if (NS_UNCONSTRAINEDSIZE != mComputedMaxWidth) {
*aFrameWidth = PR_MIN(*aFrameWidth, mComputedMaxWidth);
}
*aFrameWidth = PR_MAX(*aFrameWidth, mComputedMinWidth);
}
if (aFrameHeight) {
if (NS_UNCONSTRAINEDSIZE != mComputedMaxHeight) {
*aFrameHeight = PR_MIN(*aFrameHeight, mComputedMaxHeight);
}
*aFrameHeight = PR_MAX(*aFrameHeight, mComputedMinHeight);
}
}
void
nsHTMLReflowState::ComputeMinMaxValues(nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight,
const nsHTMLReflowState* aContainingBlockRS)
{
mComputedMinWidth = ComputeWidthValue(aContainingBlockWidth,
mStylePosition->mBoxSizing,
mStylePosition->mMinWidth);
if (eStyleUnit_None == mStylePosition->mMaxWidth.GetUnit()) {
// Specified value of 'none'
mComputedMaxWidth = NS_UNCONSTRAINEDSIZE; // no limit
} else {
mComputedMaxWidth = ComputeWidthValue(aContainingBlockWidth,
mStylePosition->mBoxSizing,
mStylePosition->mMaxWidth);
}
// If the computed value of 'min-width' is greater than the value of
// 'max-width', 'max-width' is set to the value of 'min-width'
if (mComputedMinWidth > mComputedMaxWidth) {
mComputedMaxWidth = mComputedMinWidth;
}
// Check for percentage based values and a containing block height that
// depends on the content height. Treat them like 'auto'
if ((NS_AUTOHEIGHT == aContainingBlockHeight) &&
(eStyleUnit_Percent == mStylePosition->mMinHeight.GetUnit())) {
mComputedMinHeight = 0;
} else {
ComputeHeightDependentValue(aContainingBlockHeight,
mStylePosition->mMinHeight, mComputedMinHeight);
}
nsStyleUnit maxHeightUnit = mStylePosition->mMaxHeight.GetUnit();
if (eStyleUnit_None == maxHeightUnit) {
// Specified value of 'none'
mComputedMaxHeight = NS_UNCONSTRAINEDSIZE; // no limit
} else {
// Check for percentage based values and a containing block height that
// depends on the content height. Treat them like 'auto'
if ((NS_AUTOHEIGHT == aContainingBlockHeight) &&
(eStyleUnit_Percent == maxHeightUnit)) {
mComputedMaxHeight = NS_UNCONSTRAINEDSIZE;
} else {
ComputeHeightDependentValue(aContainingBlockHeight,
mStylePosition->mMaxHeight, mComputedMaxHeight);
}
}
// If the computed value of 'min-height' is greater than the value of
// 'max-height', 'max-height' is set to the value of 'min-height'
if (mComputedMinHeight > mComputedMaxHeight) {
mComputedMaxHeight = mComputedMinHeight;
}
}
void
nsHTMLReflowState::SetTruncated(const nsHTMLReflowMetrics& aMetrics,
nsReflowStatus* aStatus) const
{
if (availableHeight != NS_UNCONSTRAINEDSIZE &&
availableHeight < aMetrics.height &&
!mFlags.mIsTopOfPage) {
*aStatus |= NS_FRAME_TRUNCATED;
} else {
*aStatus &= ~NS_FRAME_TRUNCATED;
}
}