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lightning-sunbird  0.9+nobinonly
nsPlaceholderFrame.h
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00001 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
00002 /* ***** BEGIN LICENSE BLOCK *****
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00015  * The Original Code is mozilla.org code.
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00017  * The Initial Developer of the Original Code is
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00024  * Alternatively, the contents of this file may be used under the terms of
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00037 #ifndef nsPlaceholderFrame_h___
00038 #define nsPlaceholderFrame_h___
00039 
00040 #include "nsSplittableFrame.h"
00041 #include "nsLayoutAtoms.h"
00042 
00043 nsresult NS_NewPlaceholderFrame(nsIPresShell* aPresShell, nsIFrame**  aInstancePtrResult);
00044 
00049 class nsPlaceholderFrame : public nsSplittableFrame {
00050 public:
00054   friend nsresult NS_NewPlaceholderFrame(nsIPresShell* aPresShell, nsIFrame**  aInstancePtrResult);
00055   nsPlaceholderFrame();
00056   virtual ~nsPlaceholderFrame();
00057 
00058   // Get/Set the associated out of flow frame
00059   nsIFrame*  GetOutOfFlowFrame() const {return mOutOfFlowFrame;}
00060   void       SetOutOfFlowFrame(nsIFrame* aFrame) {mOutOfFlowFrame = aFrame;}
00061 
00062   // nsIHTMLReflow overrides
00063   NS_IMETHOD Reflow(nsPresContext* aPresContext,
00064                     nsHTMLReflowMetrics& aDesiredSize,
00065                     const nsHTMLReflowState& aReflowState,
00066                     nsReflowStatus& aStatus);
00067 
00068   NS_IMETHOD Destroy(nsPresContext* aPresContext);
00069 
00070   // nsIFrame overrides
00071 #ifdef DEBUG
00072   NS_IMETHOD Paint(nsPresContext*      aPresContext,
00073                    nsIRenderingContext& aRenderingContext,
00074                    const nsRect&        aDirtyRect,
00075                    nsFramePaintLayer    aWhichLayer,
00076                    PRUint32             aFlags = 0);
00077   NS_IMETHOD List(nsPresContext* aPresContext, FILE* out, PRInt32 aIndent) const;
00078 #endif
00079 
00085   virtual nsIAtom* GetType() const;
00086 
00087 #ifdef DEBUG
00088   NS_IMETHOD GetFrameName(nsAString& aResult) const;
00089 #endif
00090 
00091   virtual PRBool IsEmpty() { return PR_TRUE; }
00092   virtual PRBool IsSelfEmpty() { return PR_TRUE; }
00093 
00094 #ifdef ACCESSIBILITY
00095   NS_IMETHOD  GetAccessible(nsIAccessible** aAccessible)
00096   {
00097     nsIFrame *realFrame = GetRealFrameForPlaceholder(this);
00098     return realFrame ? realFrame->GetAccessible(aAccessible) :
00099                        nsSplittableFrame::GetAccessible(aAccessible);
00100   }
00101 #endif
00102 
00107   static nsIFrame* GetRealFrameFor(nsIFrame* aFrame) {
00108     NS_PRECONDITION(aFrame, "Must have a frame to work with");
00109     if (aFrame->GetType() == nsLayoutAtoms::placeholderFrame) {
00110       return GetRealFrameForPlaceholder(aFrame);
00111     }
00112     return aFrame;
00113   }
00114 
00118   static nsIFrame* GetRealFrameForPlaceholder(nsIFrame* aFrame) {
00119     NS_PRECONDITION(aFrame->GetType() == nsLayoutAtoms::placeholderFrame,
00120                     "Must have placeholder frame as input");
00121     nsIFrame* outOfFlow =
00122       NS_STATIC_CAST(nsPlaceholderFrame*, aFrame)->GetOutOfFlowFrame();
00123     NS_ASSERTION(outOfFlow, "Null out-of-flow for placeholder?");
00124     return outOfFlow;
00125   }
00126 
00127 protected:
00128   nsIFrame* mOutOfFlowFrame;
00129 };
00130 
00131 #endif /* nsPlaceholderFrame_h___ */