pjs/layout/generic/nsLineLayout.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* The contents of this file are subject to the Netscape 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/NPL/
*
* 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 Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
* Steve Clark <buster@netscape.com>
* Robert O'Callahan <roc+moz@cs.cmu.edu>
* 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.
*/
#ifndef nsLineLayout_h___
#define nsLineLayout_h___
#include "nsFrame.h"
#include "nsVoidArray.h"
#include "nsLineBox.h"
class nsISpaceManager;
class nsBlockReflowState;
class nsPlaceholderFrame;
struct nsStyleText;
#define NS_LINELAYOUT_NUM_FRAMES 5
#define NS_LINELAYOUT_NUM_SPANS 5
class nsLineLayout {
public:
nsLineLayout(nsIPresContext* aPresContext,
nsISpaceManager* aSpaceManager,
const nsHTMLReflowState* aOuterReflowState,
PRBool aComputeMaxElementSize);
nsLineLayout(nsIPresContext* aPresContext);
~nsLineLayout();
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 aImpactedByFloaters,
PRBool aIsTopOfPage);
void EndLineReflow();
void UpdateBand(nscoord aX, nscoord aY, nscoord aWidth, nscoord aHeight,
PRBool aPlacedLeftFloater,
nsIFrame* aFloaterFrame);
nsresult BeginSpan(nsIFrame* aFrame,
const nsHTMLReflowState* aSpanReflowState,
nscoord aLeftEdge,
nscoord aRightEdge);
void EndSpan(nsIFrame* aFrame, nsSize& aSizeResult,
nsSize* aMaxElementSize);
PRBool InStrictMode();
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,
nsIFrame** aNextRCFrame,
nsReflowStatus& aReflowStatus,
nsHTMLReflowMetrics* aMetrics,
PRBool& aPushedFrame);
nscoord GetCarriedOutBottomMargin() const {
return mCarriedOutBottomMargin;
}
nsresult AddBulletFrame(nsIFrame* aFrame,
const nsHTMLReflowMetrics& aMetrics);
void RemoveBulletFrame(nsIFrame* aFrame) {
PushFrame(aFrame);
}
void VerticalAlignFrames(nsLineBox* aLineBox,
nsSize& aMaxElementSizeResult,
nscoord& aLineBoxAscent);
PRBool TrimTrailingWhiteSpace();
PRBool HorizontalAlignFrames(nsRect& aLineBounds,
PRBool aAllowJustify,
PRBool aShrinkWrapWidth);
void RelativePositionFrames(nsRect& aCombinedArea);
//----------------------------------------
// Supporting methods and data for flags
protected:
#define LL_ENDSINWHITESPACE 0x00000001
#define LL_UNDERSTANDSNWHITESPACE 0x00000002
#define LL_TEXTSTARTSWITHNBSP 0x00000004
#define LL_FIRSTLETTERSTYLEOK 0x00000008
#define LL_ISTOPOFPAGE 0x00000010
#define LL_UPDATEDBAND 0x00000020
#define LL_IMPACTEDBYFLOATERS 0x00000040
#define LL_LASTFLOATERWASLETTERFRAME 0x00000080
#define LL_CANPLACEFLOATER 0x00000100
#define LL_KNOWSTRICTMODE 0x00000200
#define LL_INSTRICTMODE 0x00000400
#define LL_LINEENDSINBR 0x00000800
#define LL_LASTFLAG LL_LINEENDSINBR
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 SetTextStartsWithNBSP(PRBool aYes) {
SetFlag(LL_TEXTSTARTSWITHNBSP, aYes);
}
void RecordWordFrame(nsIFrame* aWordFrame) {
mWordFrames.AppendElement(aWordFrame);
}
PRBool InWord() const {
return 0 != mWordFrames.Count();
}
void ForgetWordFrame(nsIFrame* aFrame);
void ForgetWordFrames() {
mWordFrames.Clear();
}
nsIFrame* FindNextText(nsIPresContext* aPresContext, nsIFrame* aFrame);
PRBool CanPlaceFloaterNow() const;
PRBool LineIsEmpty() const;
PRBool LineIsBreakable() const;
PRBool GetLineEndsInBR() const
{
return GetFlag(LL_LINEENDSINBR);
}
void SetLineEndsInBR(PRBool aOn)
{
SetFlag(LL_LINEENDSINBR, aOn);
}
//----------------------------------------
// Inform the line-layout about the presence of a floating frame
// XXX get rid of this: use get-frame-type?
void InitFloater(nsPlaceholderFrame* aFrame);
void AddFloater(nsPlaceholderFrame* aFrame);
//----------------------------------------
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(nsIPresContext *aPresContext,
nsIFrame *aFrame);
//----------------------------------------
nsIPresContext* mPresContext;
protected:
// This state is constant for a given block frame doing line layout
nsISpaceManager* mSpaceManager;
const nsStyleText* mStyleText;
const nsHTMLReflowState* mBlockReflowState;
nsBlockReflowState* mBlockRS;/* XXX hack! */
nscoord mMinLineHeight;
PRPackedBool mComputeMaxElementSize;
PRUint8 mTextAlign;
// 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;
PRUint8 mPlacedFloaters;
PRInt32 mTotalPlacedFrames;
nsVoidArray mWordFrames;
nscoord mTopEdge;
nscoord mBottomEdge;
nscoord mMaxTopBoxHeight;
nscoord mMaxBottomBoxHeight;
nscoord mCarriedOutBottomMargin;
// 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;
nsSize mMaxElementSize;
nsRect mCombinedArea;
// From reflow-state
nsMargin mMargin;
nsMargin mBorderPadding;
nsMargin mOffsets;
// Other state we use
PRUint8 mVerticalAlign;
// state for text justification
PRInt32 mJustificationNumSpaces;
PRInt32 mJustificationNumLetters;
// 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_LASTFLAG PFD_ISBULLET
PRPackedBool mFlags;
void SetFlag(PRUint32 aFlag, PRBool aValue)
{
NS_ASSERTION(aFlag<=PFD_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<=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 mFrameDataBuf[NS_LINELAYOUT_NUM_FRAMES];
PerFrameData* mFrameFreeList;
PRInt32 mInitialFramesFreed;
#if defined(AIX) || defined(XP_OS2_VACPP)
public:
#endif
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 mContainsFloater;
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;
}
};
#if defined(AIX) || defined(XP_OS2_VACPP)
protected:
#endif
PerSpanData mSpanDataBuf[NS_LINELAYOUT_NUM_SPANS];
PerSpanData* mSpanFreeList;
PRInt32 mInitialSpansFreed;
PerSpanData* mRootSpan;
PerSpanData* mCurrentSpan;
PRInt32 mSpanDepth;
#ifdef DEBUG
PRInt32 mSpansAllocated, mSpansFreed;
PRInt32 mFramesAllocated, mFramesFreed;
#endif
nsresult NewPerFrameData(PerFrameData** aResult);
nsresult NewPerSpanData(PerSpanData** aResult);
void FreeSpan(PerSpanData* psd);
PRBool InBlockContext() const {
return mSpanDepth == 0;
}
void PushFrame(nsIFrame* aFrame);
void ApplyLeftMargin(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;
};
nscoord ApplyFrameJustification(PerSpanData* aPSD, FrameJustificationState* aState);
#ifdef DEBUG
void DumpPerSpanData(PerSpanData* psd, PRInt32 aIndent);
#endif
};
#endif /* nsLineLayout_h___ */