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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
// vim:cindent:ts=2:et:sw=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/. */
/* class that a parent frame uses to reflow a block frame */
#ifndef nsBlockReflowContext_h___
#define nsBlockReflowContext_h___
#include "nsIFrame.h"
#include "nsHTMLReflowMetrics.h"
class nsBlockReflowState;
struct nsHTMLReflowState;
class nsLineBox;
class nsPresContext;
class nsLineLayout;
struct nsBlockHorizontalAlign;
/**
* An encapsulation of the state and algorithm for reflowing block frames.
*/
class nsBlockReflowContext {
public:
nsBlockReflowContext(nsPresContext* aPresContext,
const nsHTMLReflowState& aParentRS);
~nsBlockReflowContext() { }
void ReflowBlock(const mozilla::LogicalRect& aSpace,
bool aApplyBStartMargin,
nsCollapsingMargin& aPrevMargin,
nscoord aClearance,
bool aIsAdjacentWithBStart,
nsLineBox* aLine,
nsHTMLReflowState& aReflowState,
nsReflowStatus& aReflowStatus,
nsBlockReflowState& aState);
bool PlaceBlock(const nsHTMLReflowState& aReflowState,
bool aForceFit,
nsLineBox* aLine,
nsCollapsingMargin& aBEndMarginResult /* out */,
nsOverflowAreas& aOverflowAreas,
nsReflowStatus aReflowStatus);
nsCollapsingMargin& GetCarriedOutBEndMargin() {
return mMetrics.mCarriedOutBEndMargin;
}
const nsHTMLReflowMetrics& GetMetrics() const {
return mMetrics;
}
/**
* Computes the collapsed block-start margin (in the context's parent's
* writing mode) for a block whose reflow state is in aRS.
* The computed margin is added into aMargin, whose writing mode is the
* parent's mode as found in mMetrics.GetWritingMode(); note this may not be
* the block's own writing mode as found in aRS.
* If aClearanceFrame is null then this is the first optimistic pass which
* shall assume that no frames have clearance, and we clear the HasClearance
* on all frames encountered.
* If non-null, this is the second pass and the caller has decided
* aClearanceFrame needs clearance (and we will therefore stop collapsing
* there); also, this function is responsible for marking it with
* SetHasClearance.
* If in the optimistic pass any frame is encountered that might possibly
* need clearance (i.e., if we really needed the optimism assumption) then
* we set aMayNeedRetry to true.
* We return true if we changed the clearance state of any line and marked it
* dirty.
*/
bool ComputeCollapsedBStartMargin(const nsHTMLReflowState& aRS,
nsCollapsingMargin* aMargin,
nsIFrame* aClearanceFrame,
bool* aMayNeedRetry,
bool* aIsEmpty = nullptr);
protected:
nsPresContext* mPresContext;
const nsHTMLReflowState& mOuterReflowState;
nsIFrame* mFrame;
mozilla::LogicalRect mSpace;
nscoord mICoord, mBCoord, mContainerWidth;
mozilla::WritingMode mWritingMode;
nsHTMLReflowMetrics mMetrics;
nsCollapsingMargin mBStartMargin;
};
#endif /* nsBlockReflowContext_h___ */
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