gecko-dev/layout/generic/nsBlockReflowState.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* state used in reflow of block frames */
#ifndef nsBlockReflowState_h__
#define nsBlockReflowState_h__
#include "nsFloatManager.h"
#include "nsLineBox.h"
#include "nsHTMLReflowState.h"
class nsBlockFrame;
class nsFrameList;
class nsOverflowContinuationTracker;
// block reflow state flags
#define BRS_UNCONSTRAINEDBSIZE 0x00000001
#define BRS_ISBSTARTMARGINROOT 0x00000002 // Is this frame a root for block
#define BRS_ISBENDMARGINROOT 0x00000004 // direction start/end margin collapsing?
#define BRS_APPLYBSTARTMARGIN 0x00000008 // See ShouldApplyTopMargin
#define BRS_ISFIRSTINFLOW 0x00000010
// Set when mLineAdjacentToTop is valid
#define BRS_HAVELINEADJACENTTOTOP 0x00000020
// Set when the block has the equivalent of NS_BLOCK_FLOAT_MGR
#define BRS_FLOAT_MGR 0x00000040
// Set when nsLineLayout::LineIsEmpty was true at the end of reflowing
// the current line
#define BRS_LINE_LAYOUT_EMPTY 0x00000080
#define BRS_ISOVERFLOWCONTAINER 0x00000100
// Our mPushedFloats list is stored on the blocks' proptable
#define BRS_PROPTABLE_FLOATCLIST 0x00000200
// Set when the pref layout.float-fragments-inside-column.enabled is true.
#define BRS_FLOAT_FRAGMENTS_INSIDE_COLUMN_ENABLED 0x00000400
#define BRS_LASTFLAG BRS_FLOAT_FRAGMENTS_INSIDE_COLUMN_ENABLED
class nsBlockReflowState {
public:
nsBlockReflowState(const nsHTMLReflowState& aReflowState,
nsPresContext* aPresContext,
nsBlockFrame* aFrame,
bool aBStartMarginRoot, bool aBEndMarginRoot,
bool aBlockNeedsFloatManager,
nscoord aConsumedBSize = NS_INTRINSICSIZE);
/**
* Get the available reflow space (the area not occupied by floats)
* for the current y coordinate. The available space is relative to
* our coordinate system, which is the content box, with (0, 0) in the
* upper left.
*
* Returns whether there are floats present at the given block-direction
* coordinate and within the inline size of the content rect.
*/
nsFlowAreaRect GetFloatAvailableSpace() const
{ return GetFloatAvailableSpace(mBCoord); }
nsFlowAreaRect GetFloatAvailableSpace(nscoord aBCoord) const
{ return GetFloatAvailableSpaceWithState(aBCoord, nullptr); }
nsFlowAreaRect
GetFloatAvailableSpaceWithState(nscoord aBCoord,
nsFloatManager::SavedState *aState) const;
nsFlowAreaRect
GetFloatAvailableSpaceForBSize(nscoord aBCoord, nscoord aBSize,
nsFloatManager::SavedState *aState) const;
/*
* The following functions all return true if they were able to
* place the float, false if the float did not fit in available
* space.
* aLineLayout is null when we are reflowing pushed floats (because
* they are not associated with a line box).
*/
bool AddFloat(nsLineLayout* aLineLayout,
nsIFrame* aFloat,
nscoord aAvailableISize);
private:
bool CanPlaceFloat(nscoord aFloatISize,
const nsFlowAreaRect& aFloatAvailableSpace);
public:
bool FlowAndPlaceFloat(nsIFrame* aFloat);
private:
void PushFloatPastBreak(nsIFrame* aFloat);
public:
void PlaceBelowCurrentLineFloats(nsFloatCacheFreeList& aFloats,
nsLineBox* aLine);
// Returns the first coordinate >= aBCoord that clears the
// floats indicated by aBreakType and has enough inline size between floats
// (or no floats remaining) to accomodate aReplacedBlock.
nscoord ClearFloats(nscoord aBCoord, uint8_t aBreakType,
nsIFrame *aReplacedBlock = nullptr,
uint32_t aFlags = 0);
// Advances to the next band, i.e., the next horizontal stripe in
// which there is a different set of floats.
// Return false if it did not advance, which only happens for
// constrained heights (and means that we should get pushed to the
// next column/page).
bool AdvanceToNextBand(const mozilla::LogicalRect& aFloatAvailableSpace,
nscoord *aBCoord) const {
mozilla::WritingMode wm = mReflowState.GetWritingMode();
if (aFloatAvailableSpace.BSize(wm) > 0) {
// See if there's room in the next band.
*aBCoord += aFloatAvailableSpace.BSize(wm);
} else {
if (mReflowState.AvailableHeight() != NS_UNCONSTRAINEDSIZE) {
// Stop trying to clear here; we'll just get pushed to the
// next column or page and try again there.
return false;
}
NS_NOTREACHED("avail space rect with zero height!");
*aBCoord += 1;
}
return true;
}
bool ReplacedBlockFitsInAvailSpace(nsIFrame* aReplacedBlock,
const nsFlowAreaRect& aFloatAvailableSpace) const;
bool IsAdjacentWithTop() const {
return mBCoord == mBorderPadding.BStart(mReflowState.GetWritingMode());
}
/**
* Return mBlock's computed physical border+padding with GetSkipSides applied.
*/
const mozilla::LogicalMargin& BorderPadding() const {
return mBorderPadding;
}
/**
* Retrieve the block-direction size "consumed" by any previous-in-flows.
*/
nscoord GetConsumedBSize();
// Reconstruct the previous block-end margin that goes before |aLine|.
void ReconstructMarginBefore(nsLineList::iterator aLine);
// Caller must have called GetAvailableSpace for the correct position
// (which need not be the current mBCoord).
void ComputeReplacedBlockOffsetsForFloats(nsIFrame* aFrame,
const mozilla::LogicalRect& aFloatAvailableSpace,
nscoord& aIStartResult,
nscoord& aIEndResult) const;
// Caller must have called GetAvailableSpace for the current mBCoord
void ComputeBlockAvailSpace(nsIFrame* aFrame,
const nsStyleDisplay* aDisplay,
const nsFlowAreaRect& aFloatAvailableSpace,
bool aBlockAvoidsFloats,
mozilla::LogicalRect& aResult);
protected:
void RecoverFloats(nsLineList::iterator aLine, nscoord aDeltaBCoord);
public:
void RecoverStateFrom(nsLineList::iterator aLine, nscoord aDeltaBCoord);
void AdvanceToNextLine() {
if (GetFlag(BRS_LINE_LAYOUT_EMPTY)) {
SetFlag(BRS_LINE_LAYOUT_EMPTY, false);
} else {
mLineNumber++;
}
}
//----------------------------------------
// This state is the "global" state computed once for the reflow of
// the block.
// The block frame that is using this object
nsBlockFrame* mBlock;
nsPresContext* mPresContext;
const nsHTMLReflowState& mReflowState;
nsFloatManager* mFloatManager;
// The coordinates within the float manager where the block is being
// placed <b>after</b> taking into account the blocks border and
// padding. This, therefore, represents the inner "content area" (in
// spacemanager coordinates) where child frames will be placed,
// including child blocks and floats.
nscoord mFloatManagerI, mFloatManagerB;
// XXX get rid of this
nsReflowStatus mReflowStatus;
// The float manager state as it was before the contents of this
// block. This is needed for positioning bullets, since we only want
// to move the bullet to flow around floats that were before this
// block, not floats inside of it.
nsFloatManager::SavedState mFloatManagerStateBefore;
nscoord mBEndEdge;
// The content area to reflow child frames within. This is within
// this frame's coordinate system and writing mode, which means
// mContentArea.IStart == BorderPadding().IStart and
// mContentArea.BStart == BorderPadding().BStart.
// The block size may be NS_UNCONSTRAINEDSIZE, which indicates that there
// is no page/column boundary below (the common case).
// mContentArea.BEnd() should only be called after checking that
// mContentArea.BSize is not NS_UNCONSTRAINEDSIZE; otherwise
// coordinate overflow may occur.
mozilla::LogicalRect mContentArea;
nscoord ContentIStart() const {
return mContentArea.IStart(mReflowState.GetWritingMode());
}
nscoord ContentISize() const {
return mContentArea.ISize(mReflowState.GetWritingMode());
}
nscoord ContentIEnd() const {
return mContentArea.IEnd(mReflowState.GetWritingMode());
}
nscoord ContentBStart() const {
return mContentArea.BStart(mReflowState.GetWritingMode());
}
nscoord ContentBSize() const {
return mContentArea.BSize(mReflowState.GetWritingMode());
}
nscoord ContentBEnd() const {
return mContentArea.BEnd(mReflowState.GetWritingMode());
}
mozilla::LogicalSize ContentSize(mozilla::WritingMode aWM) const {
mozilla::WritingMode wm = mReflowState.GetWritingMode();
return mContentArea.Size(wm).ConvertTo(aWM, wm);
}
// Physical size. Use only for physical <-> logical coordinate conversion.
nsSize mContainerSize;
const nsSize& ContainerSize() const { return mContainerSize; }
// Continuation out-of-flow float frames that need to move to our
// next in flow are placed here during reflow. It's a pointer to
// a frame list stored in the block's property table.
nsFrameList *mPushedFloats;
// This method makes sure pushed floats are accessible to
// StealFrame. Call it before adding any frames to mPushedFloats.
void SetupPushedFloatList();
/**
* Append aFloatCont and its next-in-flows within the same block to
* mPushedFloats. aFloatCont should not be on any child list when
* making this call. Its next-in-flows will be removed from
* mBlock using StealFrame() before being added to mPushedFloats.
* All appended frames will be marked NS_FRAME_IS_PUSHED_FLOAT.
*/
void AppendPushedFloatChain(nsIFrame* aFloatCont);
// Track child overflow continuations.
nsOverflowContinuationTracker* mOverflowTracker;
//----------------------------------------
// This state is "running" state updated by the reflow of each line
// in the block. This same state is "recovered" when a line is not
// dirty and is passed over during incremental reflow.
// The current line being reflowed
// If it is mBlock->end_lines(), then it is invalid.
nsLineList::iterator mCurrentLine;
// When BRS_HAVELINEADJACENTTOTOP is set, this refers to a line
// which we know is adjacent to the top of the block (in other words,
// all lines before it are empty and do not have clearance. This line is
// always before the current line.
nsLineList::iterator mLineAdjacentToTop;
// The current block-direction coordinate in the block
nscoord mBCoord;
// mBlock's computed physical border+padding with GetSkipSides applied.
mozilla::LogicalMargin mBorderPadding;
// The overflow areas of all floats placed so far
nsOverflowAreas mFloatOverflowAreas;
nsFloatCacheFreeList mFloatCacheFreeList;
// Previous child. This is used when pulling up a frame to update
// the sibling list.
nsIFrame* mPrevChild;
// The previous child frames collapsed bottom margin value.
nsCollapsingMargin mPrevBEndMargin;
// The current next-in-flow for the block. When lines are pulled
// from a next-in-flow, this is used to know which next-in-flow to
// pull from. When a next-in-flow is emptied of lines, we advance
// this to the next next-in-flow.
nsBlockFrame* mNextInFlow;
//----------------------------------------
// Temporary line-reflow state. This state is used during the reflow
// of a given line, but doesn't have meaning before or after.
// The list of floats that are "current-line" floats. These are
// added to the line after the line has been reflowed, to keep the
// list fiddling from being N^2.
nsFloatCacheFreeList mCurrentLineFloats;
// The list of floats which are "below current-line"
// floats. These are reflowed/placed after the line is reflowed
// and placed. Again, this is done to keep the list fiddling from
// being N^2.
nsFloatCacheFreeList mBelowCurrentLineFloats;
nscoord mMinLineHeight;
int32_t mLineNumber;
int16_t mFlags;
uint8_t mFloatBreakType;
// The amount of computed block-direction size "consumed" by previous-in-flows.
nscoord mConsumedBSize;
void SetFlag(uint32_t aFlag, bool aValue)
{
NS_ASSERTION(aFlag<=BRS_LASTFLAG, "bad flag");
if (aValue) { // set flag
mFlags |= aFlag;
}
else { // unset flag
mFlags &= ~aFlag;
}
}
bool GetFlag(uint32_t aFlag) const
{
NS_ASSERTION(aFlag<=BRS_LASTFLAG, "bad flag");
return !!(mFlags & aFlag);
}
};
#endif // nsBlockReflowState_h__