gecko/layout/generic/nsHTMLReflowMetrics.h

288 lines
9.3 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.org 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
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* ***** END LICENSE BLOCK ***** */
/* struct containing the output from nsIFrame::Reflow */
#ifndef nsHTMLReflowMetrics_h___
#define nsHTMLReflowMetrics_h___
#include <stdio.h>
#include "nsISupports.h"
#include "nsMargin.h"
#include "nsRect.h"
#include "nsBoundingMetrics.h"
//----------------------------------------------------------------------
// Option flags
#define NS_REFLOW_CALC_BOUNDING_METRICS 0x0001
/**
* When we store overflow areas as an array of scrollable and visual
* overflow, we use these indices.
*
* eOverflowType_LENGTH is needed (for gcc 4.5.*, at least) to ensure
* that 2 is a valid value of nsOverflowType for use in
* NS_FOR_FRAME_OVERFLOW_TYPES.
*/
enum nsOverflowType { eVisualOverflow, eScrollableOverflow,
eOverflowType_LENGTH };
#define NS_FOR_FRAME_OVERFLOW_TYPES(var_) \
for (nsOverflowType var_ = nsOverflowType(0); var_ < 2; \
var_ = nsOverflowType(var_ + 1))
struct nsOverflowAreas {
private:
nsRect mRects[2];
public:
nsRect& Overflow(size_t aIndex) {
NS_ASSERTION(0 <= aIndex && aIndex < 2, "index out of range");
return mRects[aIndex];
}
const nsRect& Overflow(size_t aIndex) const {
NS_ASSERTION(0 <= aIndex && aIndex < 2, "index out of range");
return mRects[aIndex];
}
nsRect& VisualOverflow() { return mRects[eVisualOverflow]; }
const nsRect& VisualOverflow() const { return mRects[eVisualOverflow]; }
nsRect& ScrollableOverflow() { return mRects[eScrollableOverflow]; }
const nsRect& ScrollableOverflow() const { return mRects[eScrollableOverflow]; }
nsOverflowAreas() {
// default-initializes to zero due to nsRect's default constructor
}
nsOverflowAreas(const nsRect& aVisualOverflow,
const nsRect& aScrollableOverflow)
{
mRects[eVisualOverflow] = aVisualOverflow;
mRects[eScrollableOverflow] = aScrollableOverflow;
}
nsOverflowAreas(const nsOverflowAreas& aOther) {
*this = aOther;
}
nsOverflowAreas& operator=(const nsOverflowAreas& aOther) {
mRects[0] = aOther.mRects[0];
mRects[1] = aOther.mRects[1];
return *this;
}
bool operator==(const nsOverflowAreas& aOther) const {
// Scrollable overflow is a point-set rectangle and visual overflow
// is a pixel-set rectangle.
return VisualOverflow().IsEqualInterior(aOther.VisualOverflow()) &&
ScrollableOverflow().IsEqualEdges(aOther.ScrollableOverflow());
}
bool operator!=(const nsOverflowAreas& aOther) const {
return !(*this == aOther);
}
nsOverflowAreas operator+(const nsPoint& aPoint) const {
nsOverflowAreas result(*this);
result += aPoint;
return result;
}
nsOverflowAreas& operator+=(const nsPoint& aPoint) {
mRects[0] += aPoint;
mRects[1] += aPoint;
return *this;
}
void Clear() {
mRects[0].SetRect(0, 0, 0, 0);
mRects[1].SetRect(0, 0, 0, 0);
}
// Mutates |this| by unioning both overflow areas with |aOther|.
void UnionWith(const nsOverflowAreas& aOther);
// Mutates |this| by unioning both overflow areas with |aRect|.
void UnionAllWith(const nsRect& aRect);
// Mutates |this| by setting both overflow areas to |aRect|.
void SetAllTo(const nsRect& aRect);
};
/**
* An nsCollapsingMargin represents a vertical collapsing margin between
* blocks as described in section 8.3.1 of CSS2,
* <URL: http://www.w3.org/TR/REC-CSS2/box.html#collapsing-margins >.
*
* All adjacent vertical margins collapse, and the resulting margin is
* the sum of the largest positive margin included and the smallest (most
* negative) negative margin included.
*/
struct nsCollapsingMargin {
private:
nscoord mMostPos; // the largest positive margin included
nscoord mMostNeg; // the smallest negative margin included
public:
nsCollapsingMargin()
: mMostPos(0),
mMostNeg(0)
{
}
nsCollapsingMargin(const nsCollapsingMargin& aOther)
: mMostPos(aOther.mMostPos),
mMostNeg(aOther.mMostNeg)
{
}
bool operator==(const nsCollapsingMargin& aOther)
{
return mMostPos == aOther.mMostPos &&
mMostNeg == aOther.mMostNeg;
}
bool operator!=(const nsCollapsingMargin& aOther)
{
return !(*this == aOther);
}
nsCollapsingMargin& operator=(const nsCollapsingMargin& aOther)
{
mMostPos = aOther.mMostPos;
mMostNeg = aOther.mMostNeg;
return *this;
}
void Include(nscoord aCoord)
{
if (aCoord > mMostPos)
mMostPos = aCoord;
else if (aCoord < mMostNeg)
mMostNeg = aCoord;
}
void Include(const nsCollapsingMargin& aOther)
{
if (aOther.mMostPos > mMostPos)
mMostPos = aOther.mMostPos;
if (aOther.mMostNeg < mMostNeg)
mMostNeg = aOther.mMostNeg;
}
void Zero()
{
mMostPos = 0;
mMostNeg = 0;
}
bool IsZero() const
{
return (mMostPos == 0) && (mMostNeg == 0);
}
nscoord get() const
{
return mMostPos + mMostNeg;
}
};
/**
* Reflow metrics used to return the frame's desired size and alignment
* information.
*
* @see #Reflow()
*/
struct nsHTMLReflowMetrics {
nscoord width, height; // [OUT] desired width and height (border-box)
nscoord ascent; // [OUT] baseline (from top), or ASK_FOR_BASELINE
PRUint32 mFlags;
enum { ASK_FOR_BASELINE = nscoord_MAX };
// Metrics that _exactly_ enclose the text to allow precise MathML placements.
// If the NS_REFLOW_CALC_BOUNDING_METRICS flag is set, then the caller is
// requesting that you also compute additional details about your inner
// bounding box and italic correction. For example, the bounding box of
// msup is the smallest rectangle that _exactly_ encloses both the text
// of the base and the text of the superscript.
nsBoundingMetrics mBoundingMetrics; // [OUT]
// Carried out bottom margin values. This is the collapsed
// (generational) bottom margin value.
nsCollapsingMargin mCarriedOutBottomMargin;
// For frames that have content that overflow their content area
// (HasOverflowAreas() is true) these rectangles represent the total
// area of the frame including visible overflow, i.e., don't include
// overflowing content that is hidden. The rects are in the local
// coordinate space of the frame, and should be at least as big as the
// desired size. If there is no content that overflows, then the
// overflow area is identical to the desired size and should be {0, 0,
// width, height}.
nsOverflowAreas mOverflowAreas;
nsRect& VisualOverflow()
{ return mOverflowAreas.VisualOverflow(); }
const nsRect& VisualOverflow() const
{ return mOverflowAreas.VisualOverflow(); }
nsRect& ScrollableOverflow()
{ return mOverflowAreas.ScrollableOverflow(); }
const nsRect& ScrollableOverflow() const
{ return mOverflowAreas.ScrollableOverflow(); }
// Set all of mOverflowAreas to (0, 0, width, height).
void SetOverflowAreasToDesiredBounds();
// Union all of mOverflowAreas with (0, 0, width, height).
void UnionOverflowAreasWithDesiredBounds();
// XXXldb Should |aFlags| generally be passed from parent to child?
// Some places do it, and some don't. |aFlags| should perhaps go away
// entirely.
// XXX width/height/ascent are OUT parameters and so they shouldn't
// have to be initialized, but there are some bad frame classes that
// aren't properly setting them when returning from Reflow()...
nsHTMLReflowMetrics(PRUint32 aFlags = 0)
: width(0), height(0), ascent(ASK_FOR_BASELINE), mFlags(aFlags)
{}
};
#endif /* nsHTMLReflowMetrics_h___ */