gecko-dev/layout/generic/nsLineLayout.h

544 строки
16 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim:cindent:ts=2:et:sw=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):
* Steve Clark <buster@netscape.com>
*
* 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 *****
* This Original Code has been modified by IBM Corporation. Modifications made by IBM
* described herein are Copyright (c) International Business Machines Corporation, 2000.
* Modifications to Mozilla code or documentation identified per MPL Section 3.3
*
* Date Modified by Description of modification
* 04/20/2000 IBM Corp. OS/2 VisualAge build.
*/
/* state and methods used while laying out a single line of a block frame */
#ifndef nsLineLayout_h___
#define nsLineLayout_h___
#include "nsFrame.h"
#include "nsDeque.h"
#include "nsLineBox.h"
#include "nsBlockReflowState.h"
#include "plarena.h"
class nsSpaceManager;
class nsPlaceholderFrame;
struct nsStyleText;
class nsLineLayout {
public:
nsLineLayout(nsPresContext* aPresContext,
nsSpaceManager* aSpaceManager,
const nsHTMLReflowState* aOuterReflowState,
PRBool aComputeMaxElementWidth);
~nsLineLayout();
class ArenaDeque : public nsDeque
{
public:
ArenaDeque() : nsDeque(nsnull) {}
void *operator new(size_t, PLArenaPool &pool);
void operator delete(void *) {} // Dont do anything. Its Arena memory
};
void Init(nsBlockReflowState* aState, nscoord aMinLineHeight,
PRInt32 aLineNumber) {
mBlockRS = aState;
mMinLineHeight = aMinLineHeight;
mLineNumber = aLineNumber;
}
PRInt32 GetColumn() {
return mColumn;
}
void SetColumn(PRInt32 aNewColumn) {
mColumn = aNewColumn;
}
PRInt32 GetLineNumber() const {
return mLineNumber;
}
void BeginLineReflow(nscoord aX, nscoord aY,
nscoord aWidth, nscoord aHeight,
PRBool aImpactedByFloats,
PRBool aIsTopOfPage);
void EndLineReflow();
void UpdateBand(nscoord aX, nscoord aY, nscoord aWidth, nscoord aHeight,
PRBool aPlacedLeftFloat,
nsIFrame* aFloatFrame);
nsresult BeginSpan(nsIFrame* aFrame,
const nsHTMLReflowState* aSpanReflowState,
nscoord aLeftEdge,
nscoord aRightEdge);
void EndSpan(nsIFrame* aFrame, nsSize& aSizeResult,
nscoord* aMaxElementWidth);
PRInt32 GetCurrentSpanCount() const;
void SplitLineTo(PRInt32 aNewCount);
PRBool IsZeroHeight();
// Reflows the frame and returns the reflow status. aPushedFrame is PR_TRUE
// if the frame is pushed to the next line because it doesn't fit
nsresult ReflowFrame(nsIFrame* aFrame,
nsReflowStatus& aReflowStatus,
nsHTMLReflowMetrics* aMetrics,
PRBool& aPushedFrame);
nsresult AddBulletFrame(nsIFrame* aFrame,
const nsHTMLReflowMetrics& aMetrics);
void RemoveBulletFrame(nsIFrame* aFrame) {
PushFrame(aFrame);
}
void VerticalAlignLine(nsLineBox* aLineBox,
nscoord* aMaxElementWidthResult);
PRBool TrimTrailingWhiteSpace();
PRBool HorizontalAlignFrames(nsRect& aLineBounds,
PRBool aAllowJustify,
PRBool aShrinkWrapWidth);
/**
* Handle all the relative positioning in the line, compute the
* combined area (== overflow area) for the line, and handle view
* sizing/positioning and the setting of NS_FRAME_OUTSIDE_CHILDREN.
*/
void RelativePositionFrames(nsRect& aCombinedArea);
//----------------------------------------
// Supporting methods and data for flags
protected:
#define LL_ENDSINWHITESPACE 0x00000001
#define LL_UNDERSTANDSNWHITESPACE 0x00000002
#define LL_FIRSTLETTERSTYLEOK 0x00000008
#define LL_ISTOPOFPAGE 0x00000010
#define LL_UPDATEDBAND 0x00000020
#define LL_IMPACTEDBYFLOATS 0x00000040
#define LL_LASTFLOATWASLETTERFRAME 0x00000080
#define LL_CANPLACEFLOAT 0x00000100
#define LL_LINEENDSINBR 0x00000200
// The "soft-break" flag differs from the "hard-break" flag of <br>. The
// "soft-break" means that a whitespace has been trimmed at the end of the line,
// and therefore its width has not been accounted for (this width can actually be
// large, e.g., if a large word-spacing is set). LL should not be misled into
// placing something where the whitespace was trimmed. See bug 329987.
#define LL_LINEENDSINSOFTBR 0x00000400
#define LL_LASTFLAG LL_LINEENDSINSOFTBR
PRUint16 mFlags;
void SetFlag(PRUint32 aFlag, PRBool aValue)
{
NS_ASSERTION(aFlag<=LL_LASTFLAG, "bad flag");
NS_ASSERTION(aValue==PR_FALSE || aValue==PR_TRUE, "bad value");
if (aValue) { // set flag
mFlags |= aFlag;
}
else { // unset flag
mFlags &= ~aFlag;
}
}
PRBool GetFlag(PRUint32 aFlag) const
{
NS_ASSERTION(aFlag<=LL_LASTFLAG, "bad flag");
PRBool result = (mFlags & aFlag);
if (result) return PR_TRUE;
return PR_FALSE;
}
public:
// Support methods for white-space compression and word-wrapping
// during line reflow
void SetEndsInWhiteSpace(PRBool aState) {
SetFlag(LL_ENDSINWHITESPACE, aState);
}
PRBool GetEndsInWhiteSpace() const {
return GetFlag(LL_ENDSINWHITESPACE);
}
void SetUnderstandsWhiteSpace(PRBool aSetting) {
SetFlag(LL_UNDERSTANDSNWHITESPACE, aSetting);
}
void SetTextJustificationWeights(PRInt32 aNumSpaces, PRInt32 aNumLetters) {
mTextJustificationNumSpaces = aNumSpaces;
mTextJustificationNumLetters = aNumLetters;
}
void RecordWordFrame(nsIFrame* aWordFrame) {
if(mWordFrames || AllocateDeque())
mWordFrames->Push(aWordFrame);
}
PRBool InWord() const {
return mWordFrames && 0 != mWordFrames->GetSize();
}
void ForgetWordFrame(nsIFrame* aFrame);
void ForgetWordFrames() {
if(mWordFrames) {
mWordFrames->Empty();
}
}
nsIFrame* FindNextText(nsPresContext* aPresContext, nsIFrame* aFrame);
PRBool CanPlaceFloatNow() const;
PRBool LineIsBreakable() const;
PRBool GetLineEndsInBR() const
{
return GetFlag(LL_LINEENDSINBR);
}
void SetLineEndsInBR(PRBool aOn)
{
SetFlag(LL_LINEENDSINBR, aOn);
}
PRBool GetLineEndsInSoftBR() const
{
return GetFlag(LL_LINEENDSINSOFTBR);
}
void SetLineEndsInSoftBR(PRBool aOn)
{
SetFlag(LL_LINEENDSINSOFTBR, aOn);
}
PRBool InStrictMode() const
{
return mCompatMode != eCompatibility_NavQuirks;
}
nsCompatibility GetCompatMode() const
{
return mCompatMode;
}
//----------------------------------------
// Inform the line-layout about the presence of a floating frame
// XXX get rid of this: use get-frame-type?
PRBool InitFloat(nsPlaceholderFrame* aFrame, nsReflowStatus& aReflowStatus) {
return mBlockRS->InitFloat(*this, aFrame, aReflowStatus);
}
PRBool AddFloat(nsPlaceholderFrame* aFrame, nsReflowStatus& aReflowStatus) {
return mBlockRS->AddFloat(*this, aFrame, PR_FALSE, aReflowStatus);
}
//----------------------------------------
PRBool GetFirstLetterStyleOK() const {
return GetFlag(LL_FIRSTLETTERSTYLEOK);
}
void SetFirstLetterStyleOK(PRBool aSetting) {
SetFlag(LL_FIRSTLETTERSTYLEOK, aSetting);
}
void SetFirstLetterFrame(nsIFrame* aFrame) {
mFirstLetterFrame = aFrame;
}
//----------------------------------------
static PRBool TreatFrameAsBlock(nsIFrame* aFrame);
static PRBool IsPercentageUnitSides(const nsStyleSides* aSides);
static PRBool IsPercentageAwareReplacedElement(nsPresContext *aPresContext,
nsIFrame *aFrame);
//----------------------------------------
nsPresContext* mPresContext;
protected:
// This state is constant for a given block frame doing line layout
nsSpaceManager* mSpaceManager;
const nsStyleText* mStyleText; // for the block
const nsHTMLReflowState* mBlockReflowState;
// XXX remove this when landing bug 154892 (splitting absolute positioned frames)
friend class nsInlineFrame;
nsBlockReflowState* mBlockRS;/* XXX hack! */
nsCompatibility mCompatMode;
nscoord mMinLineHeight;
PRPackedBool mComputeMaxElementWidth;
PRUint8 mTextAlign;
PRUint8 mPlacedFloats;
// The amount of text indent that we applied to this line, needed for
// max-element-size calculation.
nscoord mTextIndent;
// This state varies during the reflow of a line but is line
// "global" state not span "local" state.
nsIFrame* mFirstLetterFrame;
PRInt32 mLineNumber;
PRInt32 mColumn;
PRInt32 mTextJustificationNumSpaces;
PRInt32 mTextJustificationNumLetters;
nsLineBox* mLineBox;
PRInt32 mTotalPlacedFrames;
ArenaDeque *mWordFrames;
PRBool AllocateDeque();
nscoord mTopEdge;
nscoord mMaxTopBoxHeight;
nscoord mMaxBottomBoxHeight;
// Final computed line-height value after VerticalAlignFrames for
// the block has been called.
nscoord mFinalLineHeight;
// Per-frame data recorded by the line-layout reflow logic. This
// state is the state needed to post-process the line after reflow
// has completed (vertical alignment, horizontal alignment,
// justification and relative positioning).
struct PerSpanData;
struct PerFrameData;
friend struct PerSpanData;
friend struct PerFrameData;
struct PerFrameData {
// link to next/prev frame in same span
PerFrameData* mNext;
PerFrameData* mPrev;
// pointer to child span data if this is an inline container frame
PerSpanData* mSpan;
// The frame and its type
nsIFrame* mFrame;
nsCSSFrameType mFrameType;
// From metrics
nscoord mAscent, mDescent;
nsRect mBounds;
nscoord mMaxElementWidth;
nsRect mCombinedArea;
// From reflow-state
nsMargin mMargin;
nsMargin mBorderPadding;
nsMargin mOffsets;
// state for text justification
PRInt32 mJustificationNumSpaces;
PRInt32 mJustificationNumLetters;
// Other state we use
PRUint8 mVerticalAlign;
// PerFrameData flags
#define PFD_RELATIVEPOS 0x00000001
#define PFD_ISTEXTFRAME 0x00000002
#define PFD_ISNONEMPTYTEXTFRAME 0x00000004
#define PFD_ISNONWHITESPACETEXTFRAME 0x00000008
#define PFD_ISLETTERFRAME 0x00000010
#define PFD_ISSTICKY 0x00000020
#define PFD_ISBULLET 0x00000040
#define PFD_SKIPWHENTRIMMINGWHITESPACE 0x00000080
#define PFD_LASTFLAG PFD_SKIPWHENTRIMMINGWHITESPACE
PRUint8 mFlags;
void SetFlag(PRUint32 aFlag, PRBool aValue)
{
NS_ASSERTION(aFlag<=PFD_LASTFLAG, "bad flag");
NS_ASSERTION(aFlag<=PR_UINT8_MAX, "bad flag");
NS_ASSERTION(aValue==PR_FALSE || aValue==PR_TRUE, "bad value");
if (aValue) { // set flag
mFlags |= aFlag;
}
else { // unset flag
mFlags &= ~aFlag;
}
}
PRBool GetFlag(PRUint32 aFlag) const
{
NS_ASSERTION(aFlag<=PFD_LASTFLAG, "bad flag");
PRBool result = (mFlags & aFlag);
if (result) return PR_TRUE;
return PR_FALSE;
}
PerFrameData* Last() {
PerFrameData* pfd = this;
while (pfd->mNext) {
pfd = pfd->mNext;
}
return pfd;
}
};
PerFrameData* mFrameFreeList;
struct PerSpanData {
union {
PerSpanData* mParent;
PerSpanData* mNextFreeSpan;
};
PerFrameData* mFrame;
PerFrameData* mFirstFrame;
PerFrameData* mLastFrame;
const nsHTMLReflowState* mReflowState;
PRPackedBool mNoWrap;
PRUint8 mDirection;
PRPackedBool mChangedFrameDirection;
PRPackedBool mZeroEffectiveSpanBox;
PRPackedBool mContainsFloat;
nscoord mLeftEdge;
nscoord mX;
nscoord mRightEdge;
nscoord mTopLeading, mBottomLeading;
nscoord mLogicalHeight;
nscoord mMinY, mMaxY;
void AppendFrame(PerFrameData* pfd) {
if (nsnull == mLastFrame) {
mFirstFrame = pfd;
}
else {
mLastFrame->mNext = pfd;
pfd->mPrev = mLastFrame;
}
mLastFrame = pfd;
}
};
PerSpanData* mSpanFreeList;
PerSpanData* mRootSpan;
PerSpanData* mCurrentSpan;
PRInt32 mSpanDepth;
#ifdef DEBUG
PRInt32 mSpansAllocated, mSpansFreed;
PRInt32 mFramesAllocated, mFramesFreed;
#endif
PLArenaPool mArena; // Per span and per frame data
nsresult NewPerFrameData(PerFrameData** aResult);
nsresult NewPerSpanData(PerSpanData** aResult);
void FreeSpan(PerSpanData* psd);
PRBool InBlockContext() const {
return mSpanDepth == 0;
}
void PushFrame(nsIFrame* aFrame);
void ApplyStartMargin(PerFrameData* pfd,
nsHTMLReflowState& aReflowState);
PRBool CanPlaceFrame(PerFrameData* pfd,
const nsHTMLReflowState& aReflowState,
PRBool aNotSafeToBreak,
nsHTMLReflowMetrics& aMetrics,
nsReflowStatus& aStatus);
void PlaceFrame(PerFrameData* pfd,
nsHTMLReflowMetrics& aMetrics);
void UpdateFrames();
void VerticalAlignFrames(PerSpanData* psd);
void PlaceTopBottomFrames(PerSpanData* psd,
nscoord aDistanceFromTop,
nscoord aLineHeight);
void RelativePositionFrames(PerSpanData* psd, nsRect& aCombinedArea);
PRBool TrimTrailingWhiteSpaceIn(PerSpanData* psd, nscoord* aDeltaWidth);
void ComputeJustificationWeights(PerSpanData* psd, PRInt32* numSpaces, PRInt32* numLetters);
struct FrameJustificationState {
PRInt32 mTotalNumSpaces;
PRInt32 mTotalNumLetters;
nscoord mTotalWidthForSpaces;
nscoord mTotalWidthForLetters;
PRInt32 mNumSpacesProcessed;
PRInt32 mNumLettersProcessed;
nscoord mWidthForSpacesProcessed;
nscoord mWidthForLettersProcessed;
};
// Apply justification. The return value is the amount by which the width of
// the span corresponding to aPSD got increased due to justification.
nscoord ApplyFrameJustification(PerSpanData* aPSD,
FrameJustificationState* aState);
#ifdef DEBUG
void DumpPerSpanData(PerSpanData* psd, PRInt32 aIndent);
#endif
};
#endif /* nsLineLayout_h___ */