1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/layout/generic/nsBlockReflowContext.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,91 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +// vim:cindent:ts=2:et:sw=2:
1.6 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +/* class that a parent frame uses to reflow a block frame */
1.11 +
1.12 +#ifndef nsBlockReflowContext_h___
1.13 +#define nsBlockReflowContext_h___
1.14 +
1.15 +#include "nsIFrame.h"
1.16 +#include "nsHTMLReflowMetrics.h"
1.17 +
1.18 +class nsBlockReflowState;
1.19 +struct nsHTMLReflowState;
1.20 +class nsLineBox;
1.21 +class nsPresContext;
1.22 +class nsLineLayout;
1.23 +struct nsBlockHorizontalAlign;
1.24 +
1.25 +/**
1.26 + * An encapsulation of the state and algorithm for reflowing block frames.
1.27 + */
1.28 +class nsBlockReflowContext {
1.29 +public:
1.30 + nsBlockReflowContext(nsPresContext* aPresContext,
1.31 + const nsHTMLReflowState& aParentRS);
1.32 + ~nsBlockReflowContext() { }
1.33 +
1.34 + nsresult ReflowBlock(const nsRect& aSpace,
1.35 + bool aApplyTopMargin,
1.36 + nsCollapsingMargin& aPrevMargin,
1.37 + nscoord aClearance,
1.38 + bool aIsAdjacentWithTop,
1.39 + nsLineBox* aLine,
1.40 + nsHTMLReflowState& aReflowState,
1.41 + nsReflowStatus& aReflowStatus,
1.42 + nsBlockReflowState& aState);
1.43 +
1.44 + bool PlaceBlock(const nsHTMLReflowState& aReflowState,
1.45 + bool aForceFit,
1.46 + nsLineBox* aLine,
1.47 + nsCollapsingMargin& aBottomMarginResult /* out */,
1.48 + nsOverflowAreas& aOverflowAreas,
1.49 + nsReflowStatus aReflowStatus,
1.50 + nscoord aContainerWidth);
1.51 +
1.52 + nsCollapsingMargin& GetCarriedOutBottomMargin() {
1.53 + return mMetrics.mCarriedOutBottomMargin;
1.54 + }
1.55 +
1.56 + nscoord GetTopMargin() const {
1.57 + return mTopMargin.get();
1.58 + }
1.59 +
1.60 + const nsHTMLReflowMetrics& GetMetrics() const {
1.61 + return mMetrics;
1.62 + }
1.63 +
1.64 + /**
1.65 + * Computes the collapsed top margin for a block whose reflow state is in aRS.
1.66 + * The computed margin is added into aMargin.
1.67 + * If aClearanceFrame is null then this is the first optimistic pass which shall assume
1.68 + * that no frames have clearance, and we clear the HasClearance on all frames encountered.
1.69 + * If non-null, this is the second pass and
1.70 + * the caller has decided aClearanceFrame needs clearance (and we will
1.71 + * therefore stop collapsing there); also, this function is responsible for marking
1.72 + * it with SetHasClearance.
1.73 + * If in the optimistic pass any frame is encountered that might possibly need
1.74 + * clearance (i.e., if we really needed the optimism assumption) then we set aMayNeedRetry
1.75 + * to true.
1.76 + * We return true if we changed the clearance state of any line and marked it dirty.
1.77 + */
1.78 + static bool ComputeCollapsedTopMargin(const nsHTMLReflowState& aRS,
1.79 + nsCollapsingMargin* aMargin, nsIFrame* aClearanceFrame,
1.80 + bool* aMayNeedRetry, bool* aIsEmpty = nullptr);
1.81 +
1.82 +protected:
1.83 + nsPresContext* mPresContext;
1.84 + const nsHTMLReflowState& mOuterReflowState;
1.85 +
1.86 + nsIFrame* mFrame;
1.87 + nsRect mSpace;
1.88 +
1.89 + nscoord mX, mY;
1.90 + nsHTMLReflowMetrics mMetrics;
1.91 + nsCollapsingMargin mTopMargin;
1.92 +};
1.93 +
1.94 +#endif /* nsBlockReflowContext_h___ */
