pjs/layout/generic/nsBlockFrame.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 1.0 (the "NPL"); you may not use this file except in
* compliance with the NPL. You may obtain a copy of the NPL at
* http://www.mozilla.org/NPL/
*
* Software distributed under the NPL is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
* for the specific language governing rights and limitations under the
* NPL.
*
* The Initial Developer of this code under the NPL is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All Rights
* Reserved.
*/
#ifndef nsBlockFrame_h___
#define nsBlockFrame_h___
#include "nsHTMLContainerFrame.h"
#include "nsIFloaterContainer.h"
#include "nsIHTMLFrameType.h"
#include "nsIRunaround.h"
#include "nsVoidArray.h"
struct BlockBandData;
struct nsMargin;
struct nsStyleFont;
/**
* Block frames have some state which needs to be made
* available to child frames for proper reflow. This structure
* describes that state.
*/
struct nsBlockReflowState {
// True if this is the first line of text in a block container
PRPackedBool firstLine;
// True if leading whitespace is allowed to show
PRPackedBool allowLeadingWhitespace;
// This is set when some child frame needs a break after it's placed
PRPackedBool breakAfterChild;
// This is set when a child needs a break before it's placed. Note
// that this value is set by a child AFTER we have called it's
// ResizeReflow method.
PRPackedBool breakBeforeChild;
// This is set when the first child should be treated specially
// because it's an inside list item bullet.
// XXX this can go away once we have a way for the bullet's style
// molecule to *not* be the same as it's parent's
PRPackedBool firstChildIsInsideBullet;
// For pre-formatted text, this is our current column
PRIntn column;
// The next list ordinal value
PRInt32 nextListOrdinal;
//----------------------------------------------------------------------
// State from here on down is not to be used by block child frames!
// Space manager to use
nsISpaceManager* spaceManager;
// Block's style data
nsStyleFont* font;
nsStyleMolecule* mol;
// Block's available size (computed from the block's parent)
nsSize availSize;
// Current band of available space. Used for doing runaround
BlockBandData* currentBand;
// Pointer to a max-element-size (nsnull if none required)
nsSize* maxElementSize;
// The maximum x-most of our lines and block-level elements. This is used to
// compute our desired size, and includes our left border/padding. For block-
// level elements this also includes the block's right margin.
nscoord kidXMost;
// Current reflow position
nscoord y;
// Current line state
nscoord x; // inline elements only. not include border/padding
PRBool isInline; // whether the current is inline or block
nsVoidArray lineLengths; // line length temporary storage
PRIntn currentLineNumber; // index into mLines
nsIFrame* lineStart; // frame starting the line
PRInt32 lineLength; // length of line
nscoord* ascents; // ascent information for each child
nscoord maxAscent; // max ascent for this line
nscoord maxDescent; // max descent for this line
nscoord lineWidth; // current width of line
#if 0
nscoord maxPosTopMargin; // maximum positive top margin
nscoord maxNegTopMargin; // maximum negative top margin
#else
nscoord topMargin; // current top margin
#endif
nscoord maxPosBottomMargin; // maximum positive bottom margin
nscoord maxNegBottomMargin; // maximum negative bottom margin
nsSize lineMaxElementSize; // max element size for current line
PRBool lastContentIsComplete; // reflow status of last child on line
nsVoidArray floaterToDo; // list of floaters to place below current line
PRInt32 maxAscents; // size of ascent buffer
nscoord ascentBuf[20];
PRPackedBool needRelativePos; // some kid in line needs relative pos
// Previous line state that we carry forward to the next line
nsIFrame* prevLineLastFrame;
nscoord prevLineHeight; // height of the previous line
nscoord prevMaxPosBottomMargin; // maximum posative bottom margin
nscoord prevMaxNegBottomMargin; // maximum negative bottom margin
PRBool prevLineLastContentIsComplete;
// Sanitized version of mol->borderPadding; if this block frame is a
// pseudo-frame then the margin will be zero'd.
nsMargin borderPadding;
PRPackedBool justifying; // we are justifying
// Status from last PlaceAndReflowChild
nsIFrame::ReflowStatus reflowStatus;
// Flags for whether the max size is unconstrained
PRBool unconstrainedWidth;
PRBool unconstrainedHeight;
nsBlockReflowState();
~nsBlockReflowState();
void Init(const nsSize& aMaxSize, nsSize* aMaxElementSize,
nsStyleFont* aFont, nsStyleMolecule* aMol, nsISpaceManager* aSpaceManager);
void AddAscent(nscoord aAscent);
void AdvanceToNextLine(nsIFrame* aPrevLineLastFrame, nscoord aPrevLineHeight);
#ifdef NS_DEBUG
void DumpLine();
void DumpList();
#endif
};
//----------------------------------------------------------------------
/**
* <h2>Block Reflow</h2>
*
* The block frame reflow machinery performs "2D" layout. Inline
* elements are flowed into logical lines (left to right or right to
* left) and the lines are stacked vertically. Block elements are
* flowed onto their own line after flushing out any preceeding line.<p>
*
* After a line is ready to be flushed out, vertical alignment is
* performed. Vertical alignment may require the line to consume more
* vertical space than is available thus causing the entire line to
* be pushed. <p>
*
* After vertical alignment is done, horizontal alignment (including
* justification) is performed. Finally, relative positioning is done
* on any elements that require it. <p>
*
* During reflow, the block frame will make available to child frames
* it's reflow state using the presentation shell's cached data
* mechanism. <p>
*
* <h2>Reflowing Mapped Content</h2>
* <h2>Pullup</h2>
* <h2>Reflowing Unmapped Content</h2>
* <h2>Content Insertion Handling</h2>
* <h2>Content Deletion Handling</h2>
* <h2>Style Change Handling</h2>
*
* <h3>Assertions</h3>
* <b>mLastContentIsComplete</b> always reflects the state of the last
* child frame on our chlid list.
*/
class nsBlockFrame : public nsHTMLContainerFrame, public nsIHTMLFrameType,
public nsIRunaround, public nsIFloaterContainer
{
public:
/**
* Create a new block frame that maps the given piece of content.
*/
static nsresult NewFrame(nsIFrame** aInstancePtrResult,
nsIContent* aContent,
PRInt32 aIndexInParent,
nsIFrame* aParent);
NS_IMETHOD QueryInterface(const nsIID& aIID, void** aInstancePtr);
virtual ReflowStatus ResizeReflow(nsIPresContext* aPresContext,
nsISpaceManager* aSpaceManager,
const nsSize& aMaxSize,
nsRect& aDesiredRect,
nsSize* aMaxElementSize);
virtual ReflowStatus IncrementalReflow(nsIPresContext* aPresContext,
nsISpaceManager* aSpaceManager,
const nsSize& aMaxSize,
nsRect& aDesiredRect,
nsReflowCommand& aReflowCommand);
virtual void ContentAppended(nsIPresShell* aShell,
nsIPresContext* aPresContext,
nsIContent* aContainer);
virtual nsIFrame* CreateContinuingFrame(nsIPresContext* aPresContext,
nsIFrame* aParent);
virtual PRBool AddFloater(nsIPresContext* aCX,
nsIFrame* aFloater,
PlaceholderFrame* aPlaceholder);
virtual void PlaceFloater(nsIPresContext* aCX,
nsIFrame* aFloater,
PlaceholderFrame* aPlaceholder);
virtual void ListTag(FILE* out = stdout) const;
virtual nsHTMLFrameType GetFrameType() const;
protected:
nsBlockFrame(nsIContent* aContent,
PRInt32 aIndexInParent,
nsIFrame* aParent);
virtual ~nsBlockFrame();
virtual PRIntn GetSkipSides() const;
PRBool MoreToReflow(nsIPresContext* aCX);
nscoord GetTopMarginFor(nsIPresContext* aCX,
nsBlockReflowState& aState,
nsStyleMolecule* aKidMol,
PRBool aIsInline);
PRBool AdvanceToNextLine(nsIPresContext* aPresContext,
nsBlockReflowState& aState);
void AddInlineChildToLine(nsIPresContext* aCX,
nsBlockReflowState& aState,
nsIFrame* aKidFrame,
nsReflowMetrics& aKidSize,
nsSize* aKidMaxElementSize,
nsStyleMolecule* aKidMol);
void AddBlockChild(nsIPresContext* aCX,
nsBlockReflowState& aState,
nsIFrame* aKidFrame,
nsRect& aKidRect,
nsSize* aKidMaxElementSize,
nsStyleMolecule* aKidMol);
void GetAvailSize(nsSize& aResult,
nsBlockReflowState& aState,
nsStyleMolecule* aKidMol,
PRBool aIsInline);
PRIntn PlaceAndReflowChild(nsIPresContext* aCX,
nsBlockReflowState& aState,
nsIFrame* kidFrame,
nsStyleMolecule* aKidMol);
void PushKids(nsBlockReflowState& aState);
void SetupState(nsIPresContext* aCX, nsBlockReflowState& aState,
const nsSize& aMaxSize, nsSize* aMaxElementSize,
nsISpaceManager* aSpaceManager);
ReflowStatus DoResizeReflow(nsIPresContext* aPresContext,
nsBlockReflowState& aState,
nsRect& aDesiredRect);
PRBool ReflowMappedChildren(nsIPresContext* aPresContext,
nsBlockReflowState& aState);
PRBool PullUpChildren(nsIPresContext* aCX,
nsBlockReflowState& aState);
ReflowStatus ReflowAppendedChildren(nsIPresContext* aPresContext,
nsBlockReflowState& aState);
void JustifyLines(nsIPresContext* aPresContext, nsBlockReflowState& aState);
PRBool IsLeftMostChild(nsIFrame* aFrame);
void GetAvailableSpaceBand(nsBlockReflowState& aState, nscoord aY);
void PlaceBelowCurrentLineFloaters(nsIPresContext* aCX,
nsBlockReflowState& aState,
nscoord aY);
void ClearFloaters(nsBlockReflowState& aState, PRUint32 aClear);
#ifdef NS_DEBUG
void DumpFlow() const;
#endif
/**
* Array of lines lengths. For each logical line of children, this array
* contains a count of the number of children on the line.
*/
PRInt32* mLines;
PRInt32 mNumLines;
nsBlockReflowState* mCurrentState;
};
#endif /* nsBlockFrame_h___ */