forked from mirrors/gecko-dev
		
	 b798773da4
			
		
	
	
		b798773da4
		
	
	
	
	
		
			
			* Rename `mBreakType` to `mFloatClearType` in nsLineBox and nsReflowStatus and the methods around it. * Rename `mBreakType` to `mClear` in nsStyleDisplay. * Many other method parameters or local variables rename such as from `aBreakType` to `aClearType`. Differential Revision: https://phabricator.services.mozilla.com/D158276
		
			
				
	
	
		
			438 lines
		
	
	
	
		
			17 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			438 lines
		
	
	
	
		
			17 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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| /* vim: set ts=8 sts=2 et sw=2 tw=80: */
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| /* This Source Code Form is subject to the terms of the Mozilla Public
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|  * License, v. 2.0. If a copy of the MPL was not distributed with this
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|  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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| 
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| /* class that a parent frame uses to reflow a block frame */
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| 
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| #include "nsBlockReflowContext.h"
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| #include "BlockReflowState.h"
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| #include "nsFloatManager.h"
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| #include "nsColumnSetFrame.h"
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| #include "nsContainerFrame.h"
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| #include "nsBlockFrame.h"
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| #include "nsLineBox.h"
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| #include "nsLayoutUtils.h"
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| 
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| using namespace mozilla;
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| 
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| #ifdef DEBUG
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| #  include "nsBlockDebugFlags.h"  // For NOISY_BLOCK_DIR_MARGINS
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| #endif
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| 
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| nsBlockReflowContext::nsBlockReflowContext(nsPresContext* aPresContext,
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|                                            const ReflowInput& aParentRI)
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|     : mPresContext(aPresContext),
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|       mOuterReflowInput(aParentRI),
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|       mFrame(nullptr),
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|       mSpace(aParentRI.GetWritingMode()),
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|       mICoord(0),
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|       mBCoord(0),
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|       mMetrics(aParentRI) {}
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| 
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| static nsIFrame* DescendIntoBlockLevelFrame(nsIFrame* aFrame) {
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|   LayoutFrameType type = aFrame->Type();
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|   if (type == LayoutFrameType::ColumnSet) {
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|     static_cast<nsColumnSetFrame*>(aFrame)->DrainOverflowColumns();
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|     nsIFrame* child = aFrame->PrincipalChildList().FirstChild();
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|     if (child) {
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|       return DescendIntoBlockLevelFrame(child);
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|     }
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|   }
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|   return aFrame;
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| }
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| 
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| bool nsBlockReflowContext::ComputeCollapsedBStartMargin(
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|     const ReflowInput& aRI, nsCollapsingMargin* aMargin,
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|     nsIFrame* aClearanceFrame, bool* aMayNeedRetry, bool* aBlockIsEmpty) {
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|   WritingMode wm = aRI.GetWritingMode();
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|   WritingMode parentWM = mMetrics.GetWritingMode();
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| 
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|   // Include block-start element of frame's margin
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|   aMargin->Include(aRI.ComputedLogicalMargin(parentWM).BStart(parentWM));
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| 
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|   // The inclusion of the block-end margin when empty is done by the caller
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|   // since it doesn't need to be done by the top-level (non-recursive)
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|   // caller.
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| 
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| #ifdef NOISY_BLOCK_DIR_MARGINS
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|   aRI.mFrame->ListTag(stdout);
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|   printf(": %d => %d\n", aRI.ComputedLogicalMargin(wm).BStart(wm),
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|          aMargin->get());
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| #endif
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| 
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|   bool dirtiedLine = false;
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|   bool setBlockIsEmpty = false;
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| 
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|   // Calculate the frame's generational block-start-margin from its child
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|   // blocks. Note that if the frame has a non-zero block-start-border or
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|   // block-start-padding then this step is skipped because it will be a margin
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|   // root.  It is also skipped if the frame is a margin root for other
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|   // reasons.
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|   nsIFrame* frame = DescendIntoBlockLevelFrame(aRI.mFrame);
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|   nsPresContext* prescontext = frame->PresContext();
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|   nsBlockFrame* block = nullptr;
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|   if (0 == aRI.ComputedLogicalBorderPadding(wm).BStart(wm)) {
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|     block = do_QueryFrame(frame);
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|     if (block) {
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|       bool bStartMarginRoot, unused;
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|       block->IsMarginRoot(&bStartMarginRoot, &unused);
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|       if (bStartMarginRoot) {
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|         block = nullptr;
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|       }
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|     }
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|   }
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| 
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|   // iterate not just through the lines of 'block' but also its
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|   // overflow lines and the normal and overflow lines of its next in
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|   // flows. Note that this will traverse some frames more than once:
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|   // for example, if A contains B and A->nextinflow contains
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|   // B->nextinflow, we'll traverse B->nextinflow twice. But this is
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|   // OK because our traversal is idempotent.
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|   for (; block; block = static_cast<nsBlockFrame*>(block->GetNextInFlow())) {
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|     for (int overflowLines = 0; overflowLines <= 1; ++overflowLines) {
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|       nsBlockFrame::LineIterator line;
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|       nsBlockFrame::LineIterator line_end;
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|       bool anyLines = true;
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|       if (overflowLines) {
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|         nsBlockFrame::FrameLines* frames = block->GetOverflowLines();
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|         nsLineList* lines = frames ? &frames->mLines : nullptr;
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|         if (!lines) {
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|           anyLines = false;
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|         } else {
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|           line = lines->begin();
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|           line_end = lines->end();
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|         }
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|       } else {
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|         line = block->LinesBegin();
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|         line_end = block->LinesEnd();
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|       }
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|       for (; anyLines && line != line_end; ++line) {
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|         if (!aClearanceFrame && line->HasClearance()) {
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|           // If we don't have a clearance frame, then we're computing
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|           // the collapsed margin in the first pass, assuming that all
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|           // lines have no clearance. So clear their clearance flags.
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|           line->ClearHasClearance();
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|           line->MarkDirty();
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|           dirtiedLine = true;
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|         }
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| 
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|         bool isEmpty;
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|         if (line->IsInline()) {
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|           isEmpty = line->IsEmpty();
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|         } else {
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|           nsIFrame* kid = line->mFirstChild;
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|           if (kid == aClearanceFrame) {
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|             line->SetHasClearance();
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|             line->MarkDirty();
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|             dirtiedLine = true;
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|             if (!setBlockIsEmpty && aBlockIsEmpty) {
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|               setBlockIsEmpty = true;
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|               *aBlockIsEmpty = false;
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|             }
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|             goto done;
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|           }
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|           // Here is where we recur. Now that we have determined that a
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|           // generational collapse is required we need to compute the
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|           // child blocks margin and so in so that we can look into
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|           // it. For its margins to be computed we need to have a reflow
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|           // input for it.
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| 
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|           // We may have to construct an extra reflow input here if
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|           // we drilled down through a block wrapper. At the moment
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|           // we can only drill down one level so we only have to support
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|           // one extra reflow input.
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|           const ReflowInput* outerReflowInput = &aRI;
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|           if (frame != aRI.mFrame) {
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|             NS_ASSERTION(frame->GetParent() == aRI.mFrame,
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|                          "Can only drill through one level of block wrapper");
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|             LogicalSize availSpace = aRI.ComputedSize(frame->GetWritingMode());
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|             outerReflowInput =
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|                 new ReflowInput(prescontext, aRI, frame, availSpace);
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|           }
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|           {
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|             LogicalSize availSpace =
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|                 outerReflowInput->ComputedSize(kid->GetWritingMode());
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|             ReflowInput innerReflowInput(prescontext, *outerReflowInput, kid,
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|                                          availSpace);
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|             // Record that we're being optimistic by assuming the kid
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|             // has no clearance
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|             if (kid->StyleDisplay()->mClear != StyleClear::None ||
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|                 !nsBlockFrame::BlockCanIntersectFloats(kid)) {
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|               *aMayNeedRetry = true;
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|             }
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|             if (ComputeCollapsedBStartMargin(innerReflowInput, aMargin,
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|                                              aClearanceFrame, aMayNeedRetry,
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|                                              &isEmpty)) {
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|               line->MarkDirty();
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|               dirtiedLine = true;
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|             }
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|             if (isEmpty) {
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|               LogicalMargin innerMargin =
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|                   innerReflowInput.ComputedLogicalMargin(parentWM);
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|               aMargin->Include(innerMargin.BEnd(parentWM));
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|             }
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|           }
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|           if (outerReflowInput != &aRI) {
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|             delete const_cast<ReflowInput*>(outerReflowInput);
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|           }
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|         }
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|         if (!isEmpty) {
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|           if (!setBlockIsEmpty && aBlockIsEmpty) {
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|             setBlockIsEmpty = true;
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|             *aBlockIsEmpty = false;
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|           }
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|           goto done;
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|         }
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|       }
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|       if (!setBlockIsEmpty && aBlockIsEmpty) {
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|         // The first time we reach here is when this is the first block
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|         // and we have processed all its normal lines.
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|         setBlockIsEmpty = true;
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|         // All lines are empty, or we wouldn't be here!
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|         *aBlockIsEmpty = aRI.mFrame->IsSelfEmpty();
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|       }
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|     }
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|   }
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| done:
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| 
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|   if (!setBlockIsEmpty && aBlockIsEmpty) {
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|     *aBlockIsEmpty = aRI.mFrame->IsEmpty();
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|   }
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| 
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| #ifdef NOISY_BLOCK_DIR_MARGINS
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|   aRI.mFrame->ListTag(stdout);
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|   printf(": => %d\n", aMargin->get());
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| #endif
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| 
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|   return dirtiedLine;
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| }
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| 
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| void nsBlockReflowContext::ReflowBlock(const LogicalRect& aSpace,
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|                                        bool aApplyBStartMargin,
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|                                        nsCollapsingMargin& aPrevMargin,
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|                                        nscoord aClearance, nsLineBox* aLine,
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|                                        ReflowInput& aFrameRI,
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|                                        nsReflowStatus& aFrameReflowStatus,
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|                                        BlockReflowState& aState) {
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|   mFrame = aFrameRI.mFrame;
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|   mWritingMode = aState.mReflowInput.GetWritingMode();
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|   mContainerSize = aState.ContainerSize();
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|   mSpace = aSpace;
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| 
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|   if (!aState.IsAdjacentWithBStart()) {
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|     aFrameRI.mFlags.mIsTopOfPage = false;  // make sure this is cleared
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|   }
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| 
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|   if (aApplyBStartMargin) {
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|     mBStartMargin = aPrevMargin;
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| 
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| #ifdef NOISY_BLOCK_DIR_MARGINS
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|     mOuterReflowInput.mFrame->ListTag(stdout);
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|     printf(": reflowing ");
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|     mFrame->ListTag(stdout);
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|     printf(" margin => %d, clearance => %d\n", mBStartMargin.get(), aClearance);
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| #endif
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| 
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|     // Adjust the available size if it's constrained so that the
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|     // child frame doesn't think it can reflow into its margin area.
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|     if (mWritingMode.IsOrthogonalTo(mFrame->GetWritingMode())) {
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|       if (NS_UNCONSTRAINEDSIZE != aFrameRI.AvailableISize()) {
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|         aFrameRI.SetAvailableISize(std::max(
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|             0, aFrameRI.AvailableISize() - mBStartMargin.get() - aClearance));
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|       }
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|     } else {
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|       if (NS_UNCONSTRAINEDSIZE != aFrameRI.AvailableBSize()) {
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|         aFrameRI.SetAvailableBSize(std::max(
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|             0, aFrameRI.AvailableBSize() - mBStartMargin.get() - aClearance));
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|       }
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|     }
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|   } else {
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|     // nsBlockFrame::ReflowBlock might call us multiple times with
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|     // *different* values of aApplyBStartMargin.
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|     mBStartMargin.Zero();
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|   }
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| 
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|   nscoord tI = 0, tB = 0;
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|   // The values of x and y do not matter for floats, so don't bother
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|   // calculating them. Floats are guaranteed to have their own float
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|   // manager, so tI and tB don't matter.  mICoord and mBCoord don't
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|   // matter becacuse they are only used in PlaceBlock, which is not used
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|   // for floats.
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|   if (aLine) {
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|     // Compute inline/block coordinate where reflow will begin. Use the
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|     // rules from 10.3.3 to determine what to apply. At this point in the
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|     // reflow auto inline-start/end margins will have a zero value.
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|     LogicalMargin usedMargin = aFrameRI.ComputedLogicalMargin(mWritingMode);
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|     mICoord = mSpace.IStart(mWritingMode) + usedMargin.IStart(mWritingMode);
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|     mBCoord = mSpace.BStart(mWritingMode) + mBStartMargin.get() + aClearance;
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| 
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|     LogicalRect space(
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|         mWritingMode, mICoord, mBCoord,
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|         mSpace.ISize(mWritingMode) - usedMargin.IStartEnd(mWritingMode),
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|         mSpace.BSize(mWritingMode) - usedMargin.BStartEnd(mWritingMode));
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|     tI = space.LineLeft(mWritingMode, mContainerSize);
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|     tB = mBCoord;
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| 
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|     if (!mFrame->HasAnyStateBits(NS_BLOCK_FLOAT_MGR)) {
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|       aFrameRI.mBlockDelta =
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|           mOuterReflowInput.mBlockDelta + mBCoord - aLine->BStart();
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|     }
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|   }
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| 
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| #ifdef DEBUG
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|   mMetrics.ISize(mWritingMode) = nscoord(0xdeadbeef);
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|   mMetrics.BSize(mWritingMode) = nscoord(0xdeadbeef);
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| #endif
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| 
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|   mOuterReflowInput.mFloatManager->Translate(tI, tB);
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|   mFrame->Reflow(mPresContext, mMetrics, aFrameRI, aFrameReflowStatus);
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|   mOuterReflowInput.mFloatManager->Translate(-tI, -tB);
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| 
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| #ifdef DEBUG
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|   if (!aFrameReflowStatus.IsInlineBreakBefore()) {
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|     if ((ABSURD_SIZE(mMetrics.ISize(mWritingMode)) ||
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|          ABSURD_SIZE(mMetrics.BSize(mWritingMode))) &&
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|         !mFrame->GetParent()->IsAbsurdSizeAssertSuppressed()) {
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|       printf("nsBlockReflowContext: ");
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|       mFrame->ListTag(stdout);
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|       printf(" metrics=%d,%d!\n", mMetrics.ISize(mWritingMode),
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|              mMetrics.BSize(mWritingMode));
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|     }
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|     if ((mMetrics.ISize(mWritingMode) == nscoord(0xdeadbeef)) ||
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|         (mMetrics.BSize(mWritingMode) == nscoord(0xdeadbeef))) {
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|       printf("nsBlockReflowContext: ");
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|       mFrame->ListTag(stdout);
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|       printf(" didn't set i/b %d,%d!\n", mMetrics.ISize(mWritingMode),
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|              mMetrics.BSize(mWritingMode));
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|     }
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|   }
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| #endif
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| 
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|   if (!mFrame->HasOverflowAreas()) {
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|     mMetrics.SetOverflowAreasToDesiredBounds();
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|   }
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| 
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|   if (!aFrameReflowStatus.IsInlineBreakBefore() &&
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|       !aFrameRI.WillReflowAgainForClearance() &&
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|       aFrameReflowStatus.IsFullyComplete()) {
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|     // If mFrame is fully-complete and has a next-in-flow, we need to delete
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|     // them now. Do not do this when a break-before is signaled or when a
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|     // clearance frame is discovered in mFrame's subtree because mFrame is going
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|     // to get reflowed again (whether the frame is (in)complete is undefined in
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|     // that case anyway).
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|     if (nsIFrame* kidNextInFlow = mFrame->GetNextInFlow()) {
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|       // Remove all of the childs next-in-flows. Make sure that we ask
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|       // the right parent to do the removal (it's possible that the
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|       // parent is not this because we are executing pullup code).
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|       // Floats will eventually be removed via nsBlockFrame::RemoveFloat
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|       // which detaches the placeholder from the float.
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|       nsOverflowContinuationTracker::AutoFinish fini(aState.mOverflowTracker,
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|                                                      mFrame);
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|       kidNextInFlow->GetParent()->DeleteNextInFlowChild(kidNextInFlow, true);
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|     }
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|   }
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| }
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| 
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| /**
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|  * Attempt to place the block frame within the available space.  If
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|  * it fits, apply inline-dir ("horizontal") positioning (CSS 10.3.3),
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|  * collapse margins (CSS2 8.3.1). Also apply relative positioning.
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|  */
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| bool nsBlockReflowContext::PlaceBlock(const ReflowInput& aReflowInput,
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|                                       bool aForceFit, nsLineBox* aLine,
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|                                       nsCollapsingMargin& aBEndMarginResult,
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|                                       OverflowAreas& aOverflowAreas,
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|                                       const nsReflowStatus& aReflowStatus) {
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|   // Compute collapsed block-end margin value.
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|   WritingMode parentWM = mMetrics.GetWritingMode();
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| 
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|   // Don't apply the block-end margin if the block has a *later* sibling across
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|   // column-span split.
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|   if (aReflowStatus.IsComplete() && !mFrame->HasColumnSpanSiblings()) {
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|     aBEndMarginResult = mMetrics.mCarriedOutBEndMargin;
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|     aBEndMarginResult.Include(
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|         aReflowInput.ComputedLogicalMargin(parentWM).BEnd(parentWM));
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|   } else {
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|     // The used block-end-margin is set to zero before a break.
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|     aBEndMarginResult.Zero();
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|   }
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| 
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|   nscoord backupContainingBlockAdvance = 0;
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| 
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|   // Check whether the block's block-end margin collapses with its block-start
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|   // margin. See CSS 2.1 section 8.3.1; those rules seem to match
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|   // nsBlockFrame::IsEmpty(). Any such block must have zero block-size so
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|   // check that first. Note that a block can have clearance and still
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|   // have adjoining block-start/end margins, because the clearance goes
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|   // above the block-start margin.
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|   // Mark the frame as non-dirty; it has been reflowed (or we wouldn't
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|   // be here), and we don't want to assert in CachedIsEmpty()
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|   mFrame->RemoveStateBits(NS_FRAME_IS_DIRTY);
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|   bool empty = 0 == mMetrics.BSize(parentWM) && aLine->CachedIsEmpty();
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|   if (empty) {
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|     // Collapse the block-end margin with the block-start margin that was
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|     // already applied.
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|     aBEndMarginResult.Include(mBStartMargin);
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| 
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| #ifdef NOISY_BLOCK_DIR_MARGINS
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|     printf("  ");
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|     mOuterReflowInput.mFrame->ListTag(stdout);
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|     printf(": ");
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|     mFrame->ListTag(stdout);
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|     printf(
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|         " -- collapsing block start & end margin together; BStart=%d "
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|         "spaceBStart=%d\n",
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|         mBCoord, mSpace.BStart(mWritingMode));
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| #endif
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|     // Section 8.3.1 of CSS 2.1 says that blocks with adjoining
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|     // "top/bottom" (i.e. block-start/end) margins whose top margin collapses
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|     // with their parent's top margin should have their top border-edge at the
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|     // top border-edge of their parent. We actually don't have to do
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|     // anything special to make this happen. In that situation,
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|     // nsBlockFrame::ShouldApplyBStartMargin will have returned false,
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|     // and mBStartMargin and aClearance will have been zero in
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|     // ReflowBlock.
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| 
 | |
|     // If we did apply our block-start margin, but now we're collapsing it
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|     // into the block-end margin, we need to back up the containing
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|     // block's bCoord-advance by our block-start margin so that it doesn't get
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|     // counted twice. Note that here we're allowing the line's bounds
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|     // to become different from the block's position; we do this
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|     // because the containing block will place the next line at the
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|     // line's BEnd, and it must place the next line at a different
 | |
|     // point from where this empty block will be.
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|     backupContainingBlockAdvance = mBStartMargin.get();
 | |
|   }
 | |
| 
 | |
|   // See if the frame fit. If it's the first frame or empty then it
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|   // always fits. If the block-size is unconstrained then it always fits,
 | |
|   // even if there's some sort of integer overflow that makes bCoord +
 | |
|   // mMetrics.BSize() appear to go beyond the available block size.
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|   if (!empty && !aForceFit &&
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|       mSpace.BSize(mWritingMode) != NS_UNCONSTRAINEDSIZE) {
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|     nscoord bEnd =
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|         mBCoord - backupContainingBlockAdvance + mMetrics.BSize(mWritingMode);
 | |
|     if (bEnd > mSpace.BEnd(mWritingMode)) {
 | |
|       // didn't fit, we must acquit.
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|       mFrame->DidReflow(mPresContext, &aReflowInput);
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|       return false;
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|     }
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|   }
 | |
| 
 | |
|   aLine->SetBounds(mWritingMode, mICoord,
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|                    mBCoord - backupContainingBlockAdvance,
 | |
|                    mMetrics.ISize(mWritingMode), mMetrics.BSize(mWritingMode),
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|                    mContainerSize);
 | |
| 
 | |
|   // Now place the frame and complete the reflow process
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|   nsContainerFrame::FinishReflowChild(
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|       mFrame, mPresContext, mMetrics, &aReflowInput, mWritingMode,
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|       LogicalPoint(mWritingMode, mICoord, mBCoord), mContainerSize,
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|       nsIFrame::ReflowChildFlags::ApplyRelativePositioning);
 | |
| 
 | |
|   aOverflowAreas = mMetrics.mOverflowAreas + mFrame->GetPosition();
 | |
| 
 | |
|   return true;
 | |
| }
 |