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pjs/layout/generic/nsBlockReflowState.cpp

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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>
* L. David Baron <dbaron@fas.harvard.edu>
*/
#include "nsBlockReflowContext.h"
#include "nsBlockReflowState.h"
#include "nsBlockFrame.h"
#include "nsLineLayout.h"
#include "nsIPresContext.h"
#include "nsLayoutAtoms.h"
#include "nsIFrame.h"
#ifdef DEBUG
#include "nsBlockDebugFlags.h"
#endif
nsBlockReflowState::nsBlockReflowState(const nsHTMLReflowState& aReflowState,
nsIPresContext* aPresContext,
nsBlockFrame* aFrame,
const nsHTMLReflowMetrics& aMetrics,
PRBool aBlockMarginRoot)
: mBlock(aFrame),
mPresContext(aPresContext),
mReflowState(aReflowState),
mLastFloaterY(0),
mNextRCFrame(nsnull),
mPrevBottomMargin(0),
mLineNumber(0),
mFlags(0)
{
const nsMargin& borderPadding = BorderPadding();
if (aBlockMarginRoot) {
SetFlag(BRS_ISTOPMARGINROOT, PR_TRUE);
SetFlag(BRS_ISBOTTOMMARGINROOT, PR_TRUE);
}
if (0 != aReflowState.mComputedBorderPadding.top) {
SetFlag(BRS_ISTOPMARGINROOT, PR_TRUE);
}
if (0 != aReflowState.mComputedBorderPadding.bottom) {
SetFlag(BRS_ISBOTTOMMARGINROOT, PR_TRUE);
}
if (GetFlag(BRS_ISTOPMARGINROOT)) {
SetFlag(BRS_APPLYTOPMARGIN, PR_TRUE);
}
mSpaceManager = aReflowState.mSpaceManager;
NS_ASSERTION( nsnull != mSpaceManager, "SpaceManager should be set in nsBlockReflowState" );
if( nsnull != mSpaceManager ) {
// Translate into our content area and then save the
// coordinate system origin for later.
mSpaceManager->Translate(borderPadding.left, borderPadding.top);
mSpaceManager->GetTranslation(mSpaceManagerX, mSpaceManagerY);
}
mReflowStatus = NS_FRAME_COMPLETE;
mPresContext = aPresContext;
mBlock->GetNextInFlow((nsIFrame**)&mNextInFlow);
mKidXMost = 0;
// Compute content area width (the content area is inside the border
// and padding)
if (NS_UNCONSTRAINEDSIZE != aReflowState.mComputedWidth) {
mContentArea.width = aReflowState.mComputedWidth;
}
else {
if (NS_UNCONSTRAINEDSIZE == aReflowState.availableWidth) {
mContentArea.width = NS_UNCONSTRAINEDSIZE;
SetFlag(BRS_UNCONSTRAINEDWIDTH, PR_TRUE);
}
else if (NS_UNCONSTRAINEDSIZE != aReflowState.mComputedMaxWidth) {
// Choose a width based on the content (shrink wrap width) up
// to the maximum width
mContentArea.width = aReflowState.mComputedMaxWidth;
SetFlag(BRS_SHRINKWRAPWIDTH, PR_TRUE);
}
else {
nscoord lr = borderPadding.left + borderPadding.right;
mContentArea.width = aReflowState.availableWidth - lr;
}
}
mHaveRightFloaters = PR_FALSE;
// Compute content area height. Unlike the width, if we have a
// specified style height we ignore it since extra content is
// managed by the "overflow" property. When we don't have a
// specified style height then we may end up limiting our height if
// the availableHeight is constrained (this situation occurs when we
// are paginated).
if (NS_UNCONSTRAINEDSIZE != aReflowState.availableHeight) {
// We are in a paginated situation. The bottom edge is just inside
// the bottom border and padding. The content area height doesn't
// include either border or padding edge.
mBottomEdge = aReflowState.availableHeight - borderPadding.bottom;
mContentArea.height = mBottomEdge - borderPadding.top;
}
else {
// When we are not in a paginated situation then we always use
// an constrained height.
SetFlag(BRS_UNCONSTRAINEDHEIGHT, PR_TRUE);
mContentArea.height = mBottomEdge = NS_UNCONSTRAINEDSIZE;
}
mY = borderPadding.top;
mBand.Init(mSpaceManager, mContentArea);
mPrevChild = nsnull;
mCurrentLine = nsnull;
mPrevLine = nsnull;
const nsStyleText* styleText;
mBlock->GetStyleData(eStyleStruct_Text,
(const nsStyleStruct*&) styleText);
switch (styleText->mWhiteSpace) {
case NS_STYLE_WHITESPACE_PRE:
case NS_STYLE_WHITESPACE_NOWRAP:
SetFlag(BRS_NOWRAP, PR_TRUE);
break;
default:
SetFlag(BRS_NOWRAP, PR_FALSE);
break;
}
SetFlag(BRS_COMPUTEMAXELEMENTSIZE, (nsnull != aMetrics.maxElementSize));
#ifdef NOISY_MAX_ELEMENT_SIZE
printf("BRS: setting compute-MES to %d\n", (nsnull != aMetrics.maxElementSize));
#endif
mMaxElementSize.SizeTo(0, 0);
SetFlag(BRS_COMPUTEMAXWIDTH,
(NS_REFLOW_CALC_MAX_WIDTH == (aMetrics.mFlags & NS_REFLOW_CALC_MAX_WIDTH)));
mMaximumWidth = 0;
mMinLineHeight = nsHTMLReflowState::CalcLineHeight(mPresContext,
aReflowState.rendContext,
aReflowState.frame);
}
nsBlockReflowState::~nsBlockReflowState()
{
// Restore the coordinate system
const nsMargin& borderPadding = BorderPadding();
mSpaceManager->Translate(-borderPadding.left, -borderPadding.top);
}
nsLineBox*
nsBlockReflowState::NewLineBox(nsIFrame* aFrame,
PRInt32 aCount,
PRBool aIsBlock)
{
nsCOMPtr<nsIPresShell> shell;
mPresContext->GetShell(getter_AddRefs(shell));
return NS_NewLineBox(shell, aFrame, aCount, aIsBlock);
}
void
nsBlockReflowState::FreeLineBox(nsLineBox* aLine)
{
if (aLine) {
nsCOMPtr<nsIPresShell> presShell;
mPresContext->GetShell(getter_AddRefs(presShell));
aLine->Destroy(presShell);
}
}
// Compute the amount of available space for reflowing a block frame
// at the current Y coordinate. This method assumes that
// GetAvailableSpace has already been called.
void
nsBlockReflowState::ComputeBlockAvailSpace(nsIFrame* aFrame,
nsSplittableType aSplitType,
const nsStyleDisplay* aDisplay,
nsRect& aResult)
{
#ifdef REALLY_NOISY_REFLOW
printf("CBAS frame=%p has floater count %d\n", aFrame, mBand.GetFloaterCount());
mBand.List();
#endif
aResult.y = mY;
aResult.height = GetFlag(BRS_UNCONSTRAINEDHEIGHT)
? NS_UNCONSTRAINEDSIZE
: mBottomEdge - mY;
const nsMargin& borderPadding = BorderPadding();
/* bug 18445: treat elements mapped to display: block such as text controls
* just like normal blocks */
PRBool treatAsNotSplittable=PR_FALSE;
nsCOMPtr<nsIAtom>frameType;
aFrame->GetFrameType(getter_AddRefs(frameType));
if (frameType) {
// text controls are not splittable, so make a special case here
// XXXldb Why not just set the frame state bit?
if (nsLayoutAtoms::textInputFrame == frameType.get())
treatAsNotSplittable = PR_TRUE;
}
if (NS_FRAME_SPLITTABLE_NON_RECTANGULAR == aSplitType || // normal blocks
NS_FRAME_NOT_SPLITTABLE == aSplitType || // things like images mapped to display: block
PR_TRUE == treatAsNotSplittable) // text input controls mapped to display: block (special case)
{
if (mBand.GetFloaterCount()) {
// Use the float-edge property to determine how the child block
// will interact with the floater.
const nsStyleBorder* borderStyle;
aFrame->GetStyleData(eStyleStruct_Border,
(const nsStyleStruct*&) borderStyle);
switch (borderStyle->mFloatEdge) {
default:
case NS_STYLE_FLOAT_EDGE_CONTENT: // content and only content does runaround of floaters
// The child block will flow around the floater. Therefore
// give it all of the available space.
aResult.x = borderPadding.left;
aResult.width = GetFlag(BRS_UNCONSTRAINEDWIDTH)
? NS_UNCONSTRAINEDSIZE
: mContentArea.width;
break;
case NS_STYLE_FLOAT_EDGE_BORDER:
case NS_STYLE_FLOAT_EDGE_PADDING:
{
// The child block's border should be placed adjacent to,
// but not overlap the floater(s).
nsMargin m(0, 0, 0, 0);
const nsStyleMargin* styleMargin;
aFrame->GetStyleData(eStyleStruct_Margin,
(const nsStyleStruct*&) styleMargin);
styleMargin->GetMargin(m); // XXX percentage margins
if (NS_STYLE_FLOAT_EDGE_PADDING == borderStyle->mFloatEdge) {
// Add in border too
nsMargin b;
borderStyle->GetBorder(b);
m += b;
}
// determine left edge
if (mBand.GetLeftFloaterCount()) {
aResult.x = mAvailSpaceRect.x + borderPadding.left - m.left;
}
else {
aResult.x = borderPadding.left;
}
// determine width
if (GetFlag(BRS_UNCONSTRAINEDWIDTH)) {
aResult.width = NS_UNCONSTRAINEDSIZE;
}
else {
if (mBand.GetRightFloaterCount()) {
if (mBand.GetLeftFloaterCount()) {
aResult.width = mAvailSpaceRect.width + m.left + m.right;
}
else {
aResult.width = mAvailSpaceRect.width + m.right;
}
}
else {
aResult.width = mAvailSpaceRect.width + m.left;
}
}
}
break;
case NS_STYLE_FLOAT_EDGE_MARGIN:
{
// The child block's margins should be placed adjacent to,
// but not overlap the floater.
aResult.x = mAvailSpaceRect.x + borderPadding.left;
aResult.width = mAvailSpaceRect.width;
}
break;
}
}
else {
// Since there are no floaters present the float-edge property
// doesn't matter therefore give the block element all of the
// available space since it will flow around the floater itself.
aResult.x = borderPadding.left;
aResult.width = GetFlag(BRS_UNCONSTRAINEDWIDTH)
? NS_UNCONSTRAINEDSIZE
: mContentArea.width;
}
}
else {
// The frame is clueless about the space manager and therefore we
// only give it free space. An example is a table frame - the
// tables do not flow around floaters.
aResult.x = mAvailSpaceRect.x + borderPadding.left;
aResult.width = mAvailSpaceRect.width;
}
#ifdef REALLY_NOISY_REFLOW
printf(" CBAS: result %d %d %d %d\n", aResult.x, aResult.y, aResult.width, aResult.height);
#endif
}
void
nsBlockReflowState::GetAvailableSpace(nscoord aY)
{
#ifdef DEBUG
// Verify that the caller setup the coordinate system properly
nscoord wx, wy;
mSpaceManager->GetTranslation(wx, wy);
NS_ASSERTION((wx == mSpaceManagerX) && (wy == mSpaceManagerY),
"bad coord system");
#endif
mBand.GetAvailableSpace(aY - BorderPadding().top, mAvailSpaceRect);
#ifdef DEBUG
if (nsBlockFrame::gNoisyReflow) {
nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent);
printf("GetAvailableSpace: band=%d,%d,%d,%d count=%d\n",
mAvailSpaceRect.x, mAvailSpaceRect.y,
mAvailSpaceRect.width, mAvailSpaceRect.height,
mBand.GetTrapezoidCount());
}
#endif
}
PRBool
nsBlockReflowState::ClearPastFloaters(PRUint8 aBreakType)
{
nscoord saveY, deltaY;
PRBool applyTopMargin = PR_FALSE;
switch (aBreakType) {
case NS_STYLE_CLEAR_LEFT:
case NS_STYLE_CLEAR_RIGHT:
case NS_STYLE_CLEAR_LEFT_AND_RIGHT:
// Apply the previous margin before clearing
saveY = mY + mPrevBottomMargin;
ClearFloaters(saveY, aBreakType);
#ifdef NOISY_FLOATER_CLEARING
nsFrame::ListTag(stdout, mBlock);
printf(": ClearPastFloaters: mPrevBottomMargin=%d saveY=%d oldY=%d newY=%d deltaY=%d\n",
mPrevBottomMargin, saveY, saveY - mPrevBottomMargin, mY,
mY - saveY);
#endif
// Determine how far we just moved. If we didn't move then there
// was nothing to clear to don't mess with the normal margin
// collapsing behavior. In either case we need to restore the Y
// coordinate to what it was before the clear.
deltaY = mY - saveY;
if (0 != deltaY) {
// Pretend that the distance we just moved is a previous
// blocks bottom margin. Note that GetAvailableSpace has been
// done so that the available space calculations will be done
// after clearing the appropriate floaters.
//
// What we are doing here is applying CSS2 section 9.5.2's
// rules for clearing - "The top margin of the generated box
// is increased enough that the top border edge is below the
// bottom outer edge of the floating boxes..."
//
// What this will do is cause the top-margin of the block
// frame we are about to reflow to be collapsed with that
// distance.
// XXXldb This doesn't handle collapsing with negative margins
// correctly, although it's arguable what "correct" is.
mPrevBottomMargin = deltaY;
mY = saveY;
// Force margin to be applied in this circumstance
applyTopMargin = PR_TRUE;
}
else {
// Put mY back to its original value since no clearing
// happened. That way the previous blocks bottom margin will
// be applied properly.
mY = saveY - mPrevBottomMargin;
}
break;
}
return applyTopMargin;
}
// Recover the collapsed vertical margin values for aLine. Note that
// the values are not collapsed with aState.mPrevBottomMargin, nor are
// they collapsed with each other when the line height is zero.
void
nsBlockReflowState::RecoverVerticalMargins(nsLineBox* aLine,
PRBool aApplyTopMargin,
nscoord* aTopMarginResult,
nscoord* aBottomMarginResult)
{
if (aLine->IsBlock()) {
// Update band data
GetAvailableSpace();
// Setup reflow state to compute the block childs top and bottom
// margins
nsIFrame* frame = aLine->mFirstChild;
nsRect availSpaceRect;
const nsStyleDisplay* display;
frame->GetStyleData(eStyleStruct_Display,
(const nsStyleStruct*&) display);
nsSplittableType splitType = NS_FRAME_NOT_SPLITTABLE;
frame->IsSplittable(splitType);
ComputeBlockAvailSpace(frame, splitType, display, availSpaceRect);
nsSize availSpace(availSpaceRect.width, availSpaceRect.height);
nsHTMLReflowState reflowState(mPresContext, mReflowState,
frame, availSpace);
// Compute collapsed top margin
nscoord topMargin = 0;
if (aApplyTopMargin) {
topMargin =
nsBlockReflowContext::ComputeCollapsedTopMargin(mPresContext,
reflowState);
}
// Compute collapsed bottom margin
nscoord bottomMargin = reflowState.mComputedMargin.bottom;
bottomMargin =
nsBlockReflowContext::MaxMargin(bottomMargin,
aLine->GetCarriedOutBottomMargin());
*aTopMarginResult = topMargin;
*aBottomMarginResult = bottomMargin;
}
else {
// XXX_ib, see bug 44188
*aTopMarginResult = 0;
*aBottomMarginResult = 0;
}
}
void
nsBlockReflowState::RecoverStateFrom(nsLineBox* aLine,
PRBool aApplyTopMargin,
nsRect* aDamageRect)
{
// Make the line being recovered the current line
mCurrentLine = aLine;
// Update aState.mPrevChild as if we had reflowed all of the frames
// in this line.
mPrevChild = aLine->LastChild();
// Recover mKidXMost and mMaxElementSize
nscoord xmost = aLine->mBounds.XMost();
if (xmost > mKidXMost) {
#ifdef DEBUG
if (CRAZY_WIDTH(xmost)) {
nsFrame::ListTag(stdout, mBlock);
printf(": WARNING: xmost:%d\n", xmost);
}
#endif
#ifdef NOISY_KIDXMOST
printf("%p RecoverState block %p aState.mKidXMost=%d\n", this, mBlock, xmost);
#endif
mKidXMost = xmost;
}
if (GetFlag(BRS_COMPUTEMAXELEMENTSIZE)) {
#ifdef NOISY_MAX_ELEMENT_SIZE
printf("nsBlockReflowState::RecoverStateFrom block %p caching max width %d\n", mBlock, aLine->mMaxElementWidth);
#endif
UpdateMaxElementSize(nsSize(aLine->mMaxElementWidth, aLine->mBounds.height));
}
// If computing the maximum width, then update mMaximumWidth
if (GetFlag(BRS_COMPUTEMAXWIDTH)) {
#ifdef NOISY_MAXIMUM_WIDTH
printf("nsBlockReflowState::RecoverStateFrom block %p caching max width %d\n", mBlock, aLine->mMaximumWidth);
#endif
UpdateMaximumWidth(aLine->mMaximumWidth);
}
// The line may have clear before semantics.
if (aLine->IsBlock() && aLine->HasBreak()) {
// Clear past floaters before the block if the clear style is not none
aApplyTopMargin = ClearPastFloaters(aLine->GetBreakType());
#ifdef NOISY_VERTICAL_MARGINS
nsFrame::ListTag(stdout, mBlock);
printf(": RecoverStateFrom: y=%d child ", mY);
nsFrame::ListTag(stdout, aLine->mFirstChild);
printf(" has clear of %d => %s, mPrevBottomMargin=%d\n", aLine->mBreakType,
aApplyTopMargin ? "applyTopMargin" : "nope", mPrevBottomMargin);
#endif
}
// Recover mPrevBottomMargin and calculate the line's new Y
// coordinate (newLineY)
nscoord newLineY = mY;
nsRect lineCombinedArea;
aLine->GetCombinedArea(&lineCombinedArea);
if (aLine->IsBlock()) {
if ((0 == aLine->mBounds.height) && (0 == lineCombinedArea.height)) {
// The line's top and bottom margin values need to be collapsed
// with the mPrevBottomMargin to determine a new
// mPrevBottomMargin value.
nscoord topMargin, bottomMargin;
RecoverVerticalMargins(aLine, aApplyTopMargin,
&topMargin, &bottomMargin);
nscoord m = nsBlockReflowContext::MaxMargin(bottomMargin,
mPrevBottomMargin);
m = nsBlockReflowContext::MaxMargin(m, topMargin);
mPrevBottomMargin = m;
}
else {
// Recover the top and bottom margins for this line
nscoord topMargin, bottomMargin;
RecoverVerticalMargins(aLine, aApplyTopMargin,
&topMargin, &bottomMargin);
// Compute the collapsed top margin value
nscoord collapsedTopMargin =
nsBlockReflowContext::MaxMargin(topMargin, mPrevBottomMargin);
// The lineY is just below the collapsed top margin value. The
// mPrevBottomMargin gets set to the bottom margin value for the
// line.
newLineY += collapsedTopMargin;
mPrevBottomMargin = bottomMargin;
}
}
else if (0 == aLine->GetHeight()) {
// For empty inline lines we leave the previous bottom margin
// alone so that it's collpased with the next line.
}
else {
// For non-empty inline lines the previous margin is applied
// before the line. Therefore apply it now and zero it out.
newLineY += mPrevBottomMargin;
mPrevBottomMargin = 0;
}
// Save away the old combined area for later
nsRect oldCombinedArea = lineCombinedArea;
// Slide the frames in the line by the computed delta. This also
// updates the lines Y coordinate and the combined area's Y
// coordinate.
nscoord finalDeltaY = newLineY - aLine->mBounds.y;
mBlock->SlideLine(*this, aLine, finalDeltaY);
// aLine has been slided, but...
// XXX it is not necessary to worry about the ascent of mBlock here, right?
// Indeed, depending on the status of the first line of mBlock, we can either have:
// case first line of mBlock is dirty : it will be reflowed by mBlock and so
// mBlock->mAscent will be recomputed by the block frame, and we will
// never enter into this RecoverStateFrom(aLine) function.
// case first line of mBlock is clean : it is untouched by the incremental reflow.
// In other words, aLine is never equals to mBlock->mLines in this function.
// so mBlock->mAscent will remain unchanged.
// Place floaters for this line into the space manager
if (aLine->HasFloaters()) {
// Undo border/padding translation since the nsFloaterCache's
// coordinates are relative to the frame not relative to the
// border/padding.
const nsMargin& bp = BorderPadding();
mSpaceManager->Translate(-bp.left, -bp.top);
// Place the floaters into the space-manager again. Also slide
// them, just like the regular frames on the line.
nsRect r;
nsFloaterCache* fc = aLine->GetFirstFloater();
while (fc) {
fc->mRegion.y += finalDeltaY;
fc->mCombinedArea.y += finalDeltaY;
nsIFrame* floater = fc->mPlaceholder->GetOutOfFlowFrame();
floater->GetRect(r);
floater->MoveTo(mPresContext, r.x, r.y + finalDeltaY);
#ifdef DEBUG
if (nsBlockFrame::gNoisyReflow || nsBlockFrame::gNoisySpaceManager) {
nscoord tx, ty;
mSpaceManager->GetTranslation(tx, ty);
nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent);
printf("RecoverState: txy=%d,%d (%d,%d) ",
tx, ty, mSpaceManagerX, mSpaceManagerY);
nsFrame::ListTag(stdout, floater);
printf(" r.y=%d finalDeltaY=%d (sum=%d) region={%d,%d,%d,%d}\n",
r.y, finalDeltaY, r.y + finalDeltaY,
fc->mRegion.x, fc->mRegion.y,
fc->mRegion.width, fc->mRegion.height);
}
#endif
mSpaceManager->AddRectRegion(floater, fc->mRegion);
mLastFloaterY = fc->mRegion.y;
fc = fc->Next();
}
#ifdef DEBUG
if (nsBlockFrame::gNoisyReflow || nsBlockFrame::gNoisySpaceManager) {
mSpaceManager->List(stdout);
}
#endif
// And then put the translation back again
mSpaceManager->Translate(bp.left, bp.top);
}
// Recover mY
mY = aLine->mBounds.YMost();
// Compute the damage area
if (aDamageRect) {
if (0 == finalDeltaY) {
aDamageRect->Empty();
} else {
aLine->GetCombinedArea(&lineCombinedArea);
aDamageRect->UnionRect(oldCombinedArea, lineCombinedArea);
}
}
// XXX Does this do anything? It doesn't seem to work.... (bug 29413)
// It's possible that the line has clear after semantics
if (!aLine->IsBlock() && aLine->HasBreak()) {
PRUint8 breakType = aLine->GetBreakType();
switch (breakType) {
case NS_STYLE_CLEAR_LEFT:
case NS_STYLE_CLEAR_RIGHT:
case NS_STYLE_CLEAR_LEFT_AND_RIGHT:
ClearFloaters(mY, breakType);
break;
}
}
}
PRBool
nsBlockReflowState::IsImpactedByFloater() const
{
#ifdef REALLY_NOISY_REFLOW
printf("nsBlockReflowState::IsImpactedByFloater %p returned %d\n",
this, mBand.GetFloaterCount());
#endif
return mBand.GetFloaterCount();
}
void
nsBlockReflowState::InitFloater(nsLineLayout& aLineLayout,
nsPlaceholderFrame* aPlaceholder)
{
// Set the geometric parent of the floater
nsIFrame* floater = aPlaceholder->GetOutOfFlowFrame();
floater->SetParent(mBlock);
// Then add the floater to the current line and place it when
// appropriate
AddFloater(aLineLayout, aPlaceholder, PR_TRUE);
}
// This is called by the line layout's AddFloater method when a
// place-holder frame is reflowed in a line. If the floater is a
// left-most child (it's x coordinate is at the line's left margin)
// then the floater is place immediately, otherwise the floater
// placement is deferred until the line has been reflowed.
// XXXldb This behavior doesn't quite fit with CSS1 and CSS2 --
// technically we're supposed let the current line flow around the
// float as well unless it won't fit next to what we already have.
// But nobody else implements it that way...
void
nsBlockReflowState::AddFloater(nsLineLayout& aLineLayout,
nsPlaceholderFrame* aPlaceholder,
PRBool aInitialReflow)
{
NS_PRECONDITION(nsnull != mCurrentLine, "null ptr");
// Allocate a nsFloaterCache for the floater
nsFloaterCache* fc = mFloaterCacheFreeList.Alloc();
fc->mPlaceholder = aPlaceholder;
fc->mIsCurrentLineFloater = aLineLayout.CanPlaceFloaterNow();
// Now place the floater immediately if possible. Otherwise stash it
// away in mPendingFloaters and place it later.
if (fc->mIsCurrentLineFloater) {
// Record this floater in the current-line list
mCurrentLineFloaters.Append(fc);
// Because we are in the middle of reflowing a placeholder frame
// within a line (and possibly nested in an inline frame or two
// that's a child of our block) we need to restore the space
// manager's translation to the space that the block resides in
// before placing the floater.
nscoord ox, oy;
mSpaceManager->GetTranslation(ox, oy);
nscoord dx = ox - mSpaceManagerX;
nscoord dy = oy - mSpaceManagerY;
mSpaceManager->Translate(-dx, -dy);
// And then place it
PRBool isLeftFloater;
FlowAndPlaceFloater(fc, &isLeftFloater);
// Pass on updated available space to the current inline reflow engine
GetAvailableSpace();
aLineLayout.UpdateBand(mAvailSpaceRect.x + BorderPadding().left, mY,
GetFlag(BRS_UNCONSTRAINEDWIDTH) ? NS_UNCONSTRAINEDSIZE : mAvailSpaceRect.width,
mAvailSpaceRect.height,
isLeftFloater,
aPlaceholder->GetOutOfFlowFrame());
// Restore coordinate system
mSpaceManager->Translate(dx, dy);
}
else {
// This floater will be placed after the line is done (it is a
// below-current-line floater).
mBelowCurrentLineFloaters.Append(fc);
}
}
void
nsBlockReflowState::UpdateMaxElementSize(const nsSize& aMaxElementSize)
{
#ifdef NOISY_MAX_ELEMENT_SIZE
nsSize oldSize = mMaxElementSize;
#endif
if (aMaxElementSize.width > mMaxElementSize.width) {
mMaxElementSize.width = aMaxElementSize.width;
}
if (aMaxElementSize.height > mMaxElementSize.height) {
mMaxElementSize.height = aMaxElementSize.height;
}
#ifdef NOISY_MAX_ELEMENT_SIZE
if ((mMaxElementSize.width != oldSize.width) ||
(mMaxElementSize.height != oldSize.height)) {
nsFrame::IndentBy(stdout, mBlock->GetDepth());
if (NS_UNCONSTRAINEDSIZE == mReflowState.availableWidth) {
printf("PASS1 ");
}
nsFrame::ListTag(stdout, mBlock);
printf(": old max-element-size=%d,%d new=%d,%d\n",
oldSize.width, oldSize.height,
mMaxElementSize.width, mMaxElementSize.height);
}
#endif
}
void
nsBlockReflowState::UpdateMaximumWidth(nscoord aMaximumWidth)
{
if (aMaximumWidth > mMaximumWidth) {
#ifdef NOISY_MAXIMUM_WIDTH
printf("nsBlockReflowState::UpdateMaximumWidth block %p caching max width %d\n", mBlock, aMaximumWidth);
#endif
mMaximumWidth = aMaximumWidth;
}
}
PRBool
nsBlockReflowState::CanPlaceFloater(const nsRect& aFloaterRect,
PRUint8 aFloats)
{
// If the current Y coordinate is not impacted by any floaters
// then by definition the floater fits.
PRBool result = PR_TRUE;
if (0 != mBand.GetFloaterCount()) {
// XXX We should allow overflow by up to half a pixel here (bug 21193).
if (mAvailSpaceRect.width < aFloaterRect.width) {
// The available width is too narrow (and its been impacted by a
// prior floater)
result = PR_FALSE;
}
else {
// At this point we know that there is enough horizontal space for
// the floater (somewhere). Lets see if there is enough vertical
// space.
if (mAvailSpaceRect.height < aFloaterRect.height) {
// The available height is too short. However, its possible that
// there is enough open space below which is not impacted by a
// floater.
//
// Compute the X coordinate for the floater based on its float
// type, assuming its placed on the current line. This is
// where the floater will be placed horizontally if it can go
// here.
nscoord xa;
if (NS_STYLE_FLOAT_LEFT == aFloats) {
xa = mAvailSpaceRect.x;
}
else {
xa = mAvailSpaceRect.XMost() - aFloaterRect.width;
// In case the floater is too big, don't go past the left edge
if (xa < mAvailSpaceRect.x) {
xa = mAvailSpaceRect.x;
}
}
nscoord xb = xa + aFloaterRect.width;
// Calculate the top and bottom y coordinates, again assuming
// that the floater is placed on the current line.
const nsMargin& borderPadding = BorderPadding();
nscoord ya = mY - borderPadding.top;
if (ya < 0) {
// CSS2 spec, 9.5.1 rule [4]: "A floating box's outer top may not
// be higher than the top of its containing block." (Since the
// containing block is the content edge of the block box, this
// means the margin edge of the floater can't be higher than the
// content edge of the block that contains it.)
ya = 0;
}
nscoord yb = ya + aFloaterRect.height;
nscoord saveY = mY;
for (;;) {
// Get the available space at the new Y coordinate
mY += mAvailSpaceRect.height;
GetAvailableSpace();
if (0 == mBand.GetFloaterCount()) {
// Winner. This band has no floaters on it, therefore
// there can be no overlap.
break;
}
// Check and make sure the floater won't intersect any
// floaters on this band. The floaters starting and ending
// coordinates must be entirely in the available space.
if ((xa < mAvailSpaceRect.x) || (xb > mAvailSpaceRect.XMost())) {
// The floater can't go here.
result = PR_FALSE;
break;
}
// See if there is now enough height for the floater.
if (yb < mY + mAvailSpaceRect.height) {
// Winner. The bottom Y coordinate of the floater is in
// this band.
break;
}
}
// Restore Y coordinate and available space information
// regardless of the outcome.
mY = saveY;
GetAvailableSpace();
}
}
}
return result;
}
void
nsBlockReflowState::FlowAndPlaceFloater(nsFloaterCache* aFloaterCache,
PRBool* aIsLeftFloater)
{
// Save away the Y coordinate before placing the floater. We will
// restore mY at the end after placing the floater. This is
// necessary because any adjustments to mY during the floater
// placement are for the floater only, not for any non-floating
// content.
nscoord saveY = mY;
// Grab the compatibility mode
nsCompatibility mode;
mPresContext->GetCompatibilityMode(&mode);
nsIFrame* floater = aFloaterCache->mPlaceholder->GetOutOfFlowFrame();
// Grab the floater's display information
const nsStyleDisplay* floaterDisplay;
floater->GetStyleData(eStyleStruct_Display,
(const nsStyleStruct*&)floaterDisplay);
// This will hold the floater's geometry when we've found a place
// for it to live.
nsRect region;
// Advance mY to mLastFloaterY (if it's not past it already) to
// enforce 9.5.1 rule [2]; i.e., make sure that a float isn't
// ``above'' another float that preceded it in the flow.
mY = NS_MAX(mLastFloaterY, mY);
// See if the floater should clear any preceeding floaters...
if (NS_STYLE_CLEAR_NONE != floaterDisplay->mBreakType) {
// XXXldb Does this handle vertical margins correctly?
ClearFloaters(mY, floaterDisplay->mBreakType);
}
else {
// Get the band of available space
GetAvailableSpace();
}
// Reflow the floater
mBlock->ReflowFloater(*this, aFloaterCache->mPlaceholder, aFloaterCache->mCombinedArea,
aFloaterCache->mMargins, aFloaterCache->mOffsets);
// Get the floaters bounding box and margin information
floater->GetRect(region);
#ifdef DEBUG
if (nsBlockFrame::gNoisyReflow) {
nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent);
printf("flowed floater: ");
nsFrame::ListTag(stdout, floater);
printf(" (%d,%d,%d,%d)\n",
region.x, region.y, region.width, region.height);
}
#endif
// Adjust the floater size by its margin. That's the area that will
// impact the space manager.
region.width += aFloaterCache->mMargins.left + aFloaterCache->mMargins.right;
region.height += aFloaterCache->mMargins.top + aFloaterCache->mMargins.bottom;
// Find a place to place the floater. The CSS2 spec doesn't want
// floaters overlapping each other or sticking out of the containing
// block if possible (CSS2 spec section 9.5.1, see the rule list).
NS_ASSERTION((NS_STYLE_FLOAT_LEFT == floaterDisplay->mFloats) ||
(NS_STYLE_FLOAT_RIGHT == floaterDisplay->mFloats),
"invalid float type");
// In backwards compatibility mode, we don't bother to see if a
// floated table can ``really'' fit: in old browsers, floating
// tables are horizontally stacked regardless of available space.
// (See bug 43086 about tables vs. non-tables.)
if ((eCompatibility_NavQuirks != mode) ||
(NS_STYLE_DISPLAY_TABLE != floaterDisplay->mDisplay)) {
// Can the floater fit here?
while (! CanPlaceFloater(region, floaterDisplay->mFloats)) {
// Nope. Advance to the next band.
mY += mAvailSpaceRect.height;
GetAvailableSpace();
}
}
// Assign an x and y coordinate to the floater. Note that the x,y
// coordinates are computed <b>relative to the translation in the
// spacemanager</b> which means that the impacted region will be
// <b>inside</b> the border/padding area.
PRBool okToAddRectRegion = PR_TRUE;
PRBool isLeftFloater;
if (NS_STYLE_FLOAT_LEFT == floaterDisplay->mFloats) {
isLeftFloater = PR_TRUE;
region.x = mAvailSpaceRect.x;
}
else {
isLeftFloater = PR_FALSE;
if (NS_UNCONSTRAINEDSIZE != mAvailSpaceRect.XMost())
region.x = mAvailSpaceRect.XMost() - region.width;
else {
okToAddRectRegion = PR_FALSE;
region.x = mAvailSpaceRect.x;
}
}
*aIsLeftFloater = isLeftFloater;
const nsMargin& borderPadding = BorderPadding();
region.y = mY - borderPadding.top;
if (region.y < 0) {
// CSS2 spec, 9.5.1 rule [4]: "A floating box's outer top may not
// be higher than the top of its containing block." (Since the
// containing block is the content edge of the block box, this
// means the margin edge of the floater can't be higher than the
// content edge of the block that contains it.)
region.y = 0;
}
// Place the floater in the space manager
if (okToAddRectRegion) {
#ifdef DEBUG
nsresult rv =
#endif
mSpaceManager->AddRectRegion(floater, region);
NS_ABORT_IF_FALSE(NS_SUCCEEDED(rv), "bad floater placement");
}
// Save away the floaters region in the spacemanager, after making
// it relative to the containing block's frame instead of relative
// to the spacemanager translation (which is inset by the
// border+padding).
aFloaterCache->mRegion.x = region.x + borderPadding.left;
aFloaterCache->mRegion.y = region.y + borderPadding.top;
aFloaterCache->mRegion.width = region.width;
aFloaterCache->mRegion.height = region.height;
#ifdef NOISY_SPACEMANAGER
nscoord tx, ty;
mSpaceManager->GetTranslation(tx, ty);
nsFrame::ListTag(stdout, mBlock);
printf(": PlaceFloater: AddRectRegion: txy=%d,%d (%d,%d) {%d,%d,%d,%d}\n",
tx, ty, mSpaceManagerX, mSpaceManagerY,
aFloaterCache->mRegion.x, aFloaterCache->mRegion.y,
aFloaterCache->mRegion.width, aFloaterCache->mRegion.height);
#endif
// Set the origin of the floater frame, in frame coordinates. These
// coordinates are <b>not</b> relative to the spacemanager
// translation, therefore we have to factor in our border/padding.
nscoord x = borderPadding.left + aFloaterCache->mMargins.left + region.x;
nscoord y = borderPadding.top + aFloaterCache->mMargins.top + region.y;
// If floater is relatively positioned, factor that in as well
// XXXldb Should this be done after handling the combined area
// below?
if (NS_STYLE_POSITION_RELATIVE == floaterDisplay->mPosition) {
x += aFloaterCache->mOffsets.left;
y += aFloaterCache->mOffsets.top;
}
// Position the floater and make sure and views are properly positioned
nsIView* view;
floater->MoveTo(mPresContext, x, y);
floater->GetView(mPresContext, &view);
if (view) {
nsContainerFrame::PositionFrameView(mPresContext, floater, view);
} else {
nsContainerFrame::PositionChildViews(mPresContext, floater);
}
// Update the floater combined area state
nsRect combinedArea = aFloaterCache->mCombinedArea;
combinedArea.x += x;
combinedArea.y += y;
if (!isLeftFloater &&
(GetFlag(BRS_UNCONSTRAINEDWIDTH) || GetFlag(BRS_SHRINKWRAPWIDTH))) {
// When we are placing a right floater in an unconstrained situation or
// when shrink wrapping, we don't apply it to the floater combined area
// immediately. Otherwise we end up with an infinitely wide combined
// area. Instead, we save it away in mRightFloaterCombinedArea so that
// later on when we know the width of a line we can compute a better value.
if (!mHaveRightFloaters) {
mRightFloaterCombinedArea = combinedArea;
mHaveRightFloaters = PR_TRUE;
}
else {
nsBlockFrame::CombineRects(combinedArea, mRightFloaterCombinedArea);
}
}
else {
nsBlockFrame::CombineRects(combinedArea, mFloaterCombinedArea);
}
// Remember the y-coordinate of the floater we've just placed
mLastFloaterY = mY;
// Now restore mY
mY = saveY;
#ifdef DEBUG
if (nsBlockFrame::gNoisyReflow) {
nsRect r;
floater->GetRect(r);
nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent);
printf("placed floater: ");
nsFrame::ListTag(stdout, floater);
printf(" %d,%d,%d,%d\n", r.x, r.y, r.width, r.height);
}
#endif
}
/**
* Place below-current-line floaters.
*/
void
nsBlockReflowState::PlaceBelowCurrentLineFloaters(nsFloaterCacheList& aList)
{
nsFloaterCache* fc = aList.Head();
while (fc) {
if (!fc->mIsCurrentLineFloater) {
#ifdef DEBUG
if (nsBlockFrame::gNoisyReflow) {
nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent);
printf("placing bcl floater: ");
nsFrame::ListTag(stdout, fc->mPlaceholder->GetOutOfFlowFrame());
printf("\n");
}
#endif
// Place the floater
PRBool isLeftFloater;
FlowAndPlaceFloater(fc, &isLeftFloater);
}
fc = fc->Next();
}
}
void
nsBlockReflowState::ClearFloaters(nscoord aY, PRUint8 aBreakType)
{
#ifdef DEBUG
if (nsBlockFrame::gNoisyReflow) {
nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent);
printf("clear floaters: in: mY=%d aY=%d(%d)\n",
mY, aY, aY - BorderPadding().top);
}
#endif
#ifdef NOISY_FLOATER_CLEARING
printf("nsBlockReflowState::ClearFloaters: aY=%d breakType=%d\n",
aY, aBreakType);
mSpaceManager->List(stdout);
#endif
const nsMargin& bp = BorderPadding();
nscoord newY = mBand.ClearFloaters(aY - bp.top, aBreakType);
mY = newY + bp.top;
GetAvailableSpace();
#ifdef DEBUG
if (nsBlockFrame::gNoisyReflow) {
nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent);
printf("clear floaters: out: mY=%d(%d)\n", mY, mY - bp.top);
}
#endif
}
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