1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/layout/generic/nsSplittableFrame.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,109 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +/*
1.10 + * base class for rendering objects that can be split across lines,
1.11 + * columns, or pages
1.12 + */
1.13 +
1.14 +#ifndef nsSplittableFrame_h___
1.15 +#define nsSplittableFrame_h___
1.16 +
1.17 +#include "mozilla/Attributes.h"
1.18 +#include "nsFrame.h"
1.19 +
1.20 +// Derived class that allows splitting
1.21 +class nsSplittableFrame : public nsFrame
1.22 +{
1.23 +public:
1.24 + NS_DECL_FRAMEARENA_HELPERS
1.25 +
1.26 + virtual void Init(nsIContent* aContent,
1.27 + nsIFrame* aParent,
1.28 + nsIFrame* aPrevInFlow) MOZ_OVERRIDE;
1.29 +
1.30 + virtual nsSplittableType GetSplittableType() const MOZ_OVERRIDE;
1.31 +
1.32 + virtual void DestroyFrom(nsIFrame* aDestructRoot) MOZ_OVERRIDE;
1.33 +
1.34 + /*
1.35 + * Frame continuations can be either fluid or not:
1.36 + * Fluid continuations ("in-flows") are the result of line breaking,
1.37 + * column breaking, or page breaking.
1.38 + * Other (non-fluid) continuations can be the result of BiDi frame splitting.
1.39 + * A "flow" is a chain of fluid continuations.
1.40 + */
1.41 +
1.42 + // Get the previous/next continuation, regardless of its type (fluid or non-fluid).
1.43 + virtual nsIFrame* GetPrevContinuation() const MOZ_OVERRIDE;
1.44 + virtual nsIFrame* GetNextContinuation() const MOZ_OVERRIDE;
1.45 +
1.46 + // Set a previous/next non-fluid continuation.
1.47 + virtual void SetPrevContinuation(nsIFrame*) MOZ_OVERRIDE;
1.48 + virtual void SetNextContinuation(nsIFrame*) MOZ_OVERRIDE;
1.49 +
1.50 + // Get the first/last continuation for this frame.
1.51 + virtual nsIFrame* FirstContinuation() const MOZ_OVERRIDE;
1.52 + virtual nsIFrame* LastContinuation() const MOZ_OVERRIDE;
1.53 +
1.54 +#ifdef DEBUG
1.55 + // Can aFrame2 be reached from aFrame1 by following prev/next continuations?
1.56 + static bool IsInPrevContinuationChain(nsIFrame* aFrame1, nsIFrame* aFrame2);
1.57 + static bool IsInNextContinuationChain(nsIFrame* aFrame1, nsIFrame* aFrame2);
1.58 +#endif
1.59 +
1.60 + // Get the previous/next continuation, only if it is fluid (an "in-flow").
1.61 + nsIFrame* GetPrevInFlow() const;
1.62 + nsIFrame* GetNextInFlow() const;
1.63 +
1.64 + virtual nsIFrame* GetPrevInFlowVirtual() const MOZ_OVERRIDE { return GetPrevInFlow(); }
1.65 + virtual nsIFrame* GetNextInFlowVirtual() const MOZ_OVERRIDE { return GetNextInFlow(); }
1.66 +
1.67 + // Set a previous/next fluid continuation.
1.68 + virtual void SetPrevInFlow(nsIFrame*) MOZ_OVERRIDE;
1.69 + virtual void SetNextInFlow(nsIFrame*) MOZ_OVERRIDE;
1.70 +
1.71 + // Get the first/last frame in the current flow.
1.72 + virtual nsIFrame* FirstInFlow() const MOZ_OVERRIDE;
1.73 + virtual nsIFrame* LastInFlow() const MOZ_OVERRIDE;
1.74 +
1.75 + // Remove the frame from the flow. Connects the frame's prev-in-flow
1.76 + // and its next-in-flow. This should only be called in frame Destroy() methods.
1.77 + static void RemoveFromFlow(nsIFrame* aFrame);
1.78 +
1.79 +protected:
1.80 + nsSplittableFrame(nsStyleContext* aContext) : nsFrame(aContext) {}
1.81 +
1.82 + /**
1.83 + * Determine the height consumed by our previous-in-flows.
1.84 + *
1.85 + * @note (bz) This makes laying out a splittable frame with N in-flows
1.86 + * O(N^2)! So, use this function with caution and minimize the number
1.87 + * of calls to this method.
1.88 + */
1.89 + nscoord GetConsumedHeight() const;
1.90 +
1.91 + /**
1.92 + * Retrieve the effective computed height of this frame, which is the computed
1.93 + * height, minus the height consumed by any previous in-flows.
1.94 + */
1.95 + nscoord GetEffectiveComputedHeight(const nsHTMLReflowState& aReflowState,
1.96 + nscoord aConsumed = NS_INTRINSICSIZE) const;
1.97 +
1.98 + /**
1.99 + * @see nsIFrame::GetLogicalSkipSides()
1.100 + * @see nsIFrame::ApplyLogicalSkipSides()
1.101 + */
1.102 + virtual int GetLogicalSkipSides(const nsHTMLReflowState* aReflowState = nullptr) const MOZ_OVERRIDE;
1.103 +
1.104 +#ifdef DEBUG
1.105 + virtual void DumpBaseRegressionData(nsPresContext* aPresContext, FILE* out, int32_t aIndent) MOZ_OVERRIDE;
1.106 +#endif
1.107 +
1.108 + nsIFrame* mPrevContinuation;
1.109 + nsIFrame* mNextContinuation;
1.110 +};
1.111 +
1.112 +#endif /* nsSplittableFrame_h___ */
