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			122 lines
		
	
	
	
		
			4.6 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			122 lines
		
	
	
	
		
			4.6 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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| /*
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|  * base class for rendering objects that can be split across lines,
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|  * columns, or pages
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|  */
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| 
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| #ifndef nsSplittableFrame_h___
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| #define nsSplittableFrame_h___
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| 
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| #include "mozilla/Attributes.h"
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| #include "nsFrame.h"
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| 
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| // Derived class that allows splitting
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| class nsSplittableFrame : public nsFrame
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| {
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| public:
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|   NS_DECL_ABSTRACT_FRAME(nsSplittableFrame)
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| 
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|   virtual void Init(nsIContent*       aContent,
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|                     nsContainerFrame* aParent,
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|                     nsIFrame*         aPrevInFlow) override;
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| 
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|   virtual nsSplittableType GetSplittableType() const override;
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| 
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|   virtual void DestroyFrom(nsIFrame* aDestructRoot, PostDestroyData& aPostDestroyData) override;
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| 
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|   /*
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|    * Frame continuations can be either fluid or not:
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|    * Fluid continuations ("in-flows") are the result of line breaking,
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|    * column breaking, or page breaking.
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|    * Other (non-fluid) continuations can be the result of BiDi frame splitting.
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|    * A "flow" is a chain of fluid continuations.
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|    */
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| 
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|   // Get the previous/next continuation, regardless of its type (fluid or non-fluid).
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|   virtual nsIFrame* GetPrevContinuation() const override;
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|   virtual nsIFrame* GetNextContinuation() const override;
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| 
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|   // Set a previous/next non-fluid continuation.
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|   virtual void SetPrevContinuation(nsIFrame*) override;
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|   virtual void SetNextContinuation(nsIFrame*) override;
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| 
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|   // Get the first/last continuation for this frame.
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|   virtual nsIFrame* FirstContinuation() const override;
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|   virtual nsIFrame* LastContinuation() const override;
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| 
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| #ifdef DEBUG
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|   // Can aFrame2 be reached from aFrame1 by following prev/next continuations?
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|   static bool IsInPrevContinuationChain(nsIFrame* aFrame1, nsIFrame* aFrame2);
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|   static bool IsInNextContinuationChain(nsIFrame* aFrame1, nsIFrame* aFrame2);
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| #endif
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| 
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|   // Get the previous/next continuation, only if it is fluid (an "in-flow").
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|   nsIFrame* GetPrevInFlow() const;
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|   nsIFrame* GetNextInFlow() const;
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| 
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|   virtual nsIFrame* GetPrevInFlowVirtual() const override { return GetPrevInFlow(); }
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|   virtual nsIFrame* GetNextInFlowVirtual() const override { return GetNextInFlow(); }
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| 
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|   // Set a previous/next fluid continuation.
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|   virtual void SetPrevInFlow(nsIFrame*) override;
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|   virtual void SetNextInFlow(nsIFrame*) override;
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| 
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|   // Get the first/last frame in the current flow.
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|   virtual nsIFrame* FirstInFlow() const override;
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|   virtual nsIFrame* LastInFlow() const override;
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| 
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|   // Remove the frame from the flow. Connects the frame's prev-in-flow
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|   // and its next-in-flow. This should only be called in frame Destroy() methods.
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|   static void RemoveFromFlow(nsIFrame* aFrame);
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| 
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| protected:
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|   nsSplittableFrame(ComputedStyle* aStyle, ClassID aID)
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|     : nsFrame(aStyle, aID)
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|     , mPrevContinuation(nullptr)
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|     , mNextContinuation(nullptr)
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|   {}
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| 
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|   /**
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|    * Return the sum of the block-axis content size of our prev-in-flows.
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|    * @param aWM a writing-mode to determine the block-axis
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|    *
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|    * @note (bz) This makes laying out a splittable frame with N in-flows
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|    *       O(N^2)! So, use this function with caution and minimize the number
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|    *       of calls to this method.
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|    */
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|   nscoord ConsumedBSize(mozilla::WritingMode aWM) const;
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| 
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|   /**
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|    * Retrieve the effective computed block size of this frame, which is the
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|    * computed block size, minus the block size consumed by any previous in-flows.
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|    */
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|   nscoord GetEffectiveComputedBSize(const ReflowInput& aReflowInput,
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|                                     nscoord aConsumed = NS_INTRINSICSIZE) const;
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| 
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|   /**
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|    * @see nsIFrame::GetLogicalSkipSides()
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|    */
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|   virtual LogicalSides GetLogicalSkipSides(const ReflowInput* aReflowInput = nullptr) const override;
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| 
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|   /**
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|    * A faster version of GetLogicalSkipSides() that is intended to be used
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|    * inside Reflow before it's known if |this| frame will be COMPLETE or not.
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|    * It returns a result that assumes this fragment is the last and thus
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|    * should apply the block-end border/padding etc (except for "true" overflow
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|    * containers which always skip block sides).  You're then expected to
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|    * recalculate the block-end side (as needed) when you know |this| frame's
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|    * reflow status is INCOMPLETE.
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|    * This method is intended for frames that breaks in the block axis.
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|    */
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|   LogicalSides PreReflowBlockLevelLogicalSkipSides() const;
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| 
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|   nsIFrame*   mPrevContinuation;
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|   nsIFrame*   mNextContinuation;
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| };
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| 
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| #endif /* nsSplittableFrame_h___ */
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