layout/svg/base/src/nsSVGClipPathFrame.h

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  36
  37 #ifndef __NS_SVGCLIPPATHFRAME_H__
  38 #define __NS_SVGCLIPPATHFRAME_H__
  39
  40 #include "nsSVGContainerFrame.h"
  41
  42 typedef nsSVGContainerFrame nsSVGClipPathFrameBase;
  43
  44 class nsSVGClipPathFrame : public nsSVGClipPathFrameBase
  45 {
  46   friend nsIFrame*
  47   NS_NewSVGClipPathFrame(nsIPresShell* aPresShell, nsIContent* aContent, nsStyleContext* aContext);
  48 protected:
  49   nsSVGClipPathFrame(nsStyleContext* aContext) :
  50     nsSVGClipPathFrameBase(aContext),
  51     mClipParentMatrix(nsnull),
  52     mInUse(PR_FALSE) {}
  53
  54 public:
  55   // nsSVGClipPathFrame methods:
  56   nsresult ClipPaint(nsSVGRenderState* aContext,
  57                      nsIFrame* aParent,
  58                      nsIDOMSVGMatrix *aMatrix);
  59
  60   PRBool ClipHitTest(nsIFrame* aParent,
  61                      nsIDOMSVGMatrix *aMatrix,
  62                      const nsPoint &aPoint);
  63
  64   // Check if this clipPath is made up of more than one geometry object.
  65   // If so, the clipping API in cairo isn't enough and we need to use
  66   // mask based clipping.
  67   PRBool IsTrivial();
  68
  69   /**
  70    * Get the "type" of the frame
  71    *
  72    * @see nsGkAtoms::svgClipPathFrame
  73    */
  74   virtual nsIAtom* GetType() const;
  75
  76 #ifdef DEBUG
  77   NS_IMETHOD GetFrameName(nsAString& aResult) const
  78   {
  79     return MakeFrameName(NS_LITERAL_STRING("SVGClipPath"), aResult);
  80   }
  81 #endif
  82
  83  private:
  84   // A helper class to allow us to paint clip paths safely. The helper
  85   // automatically sets and clears the mInUse flag on the clip path frame
  86   // (to prevent nasty reference loops). It's easy to mess this up
  87   // and break things, so this helper makes the code far more robust.
  88   class AutoClipPathReferencer
  89   {
  90   public:
  91     AutoClipPathReferencer(nsSVGClipPathFrame *aFrame)
  92        : mFrame(aFrame) {
  93       NS_ASSERTION(mFrame->mInUse == PR_FALSE, "reference loop!");
  94       mFrame->mInUse = PR_TRUE;
  95     }
  96     ~AutoClipPathReferencer() {
  97       mFrame->mInUse = PR_FALSE;
  98     }
  99   private:
 100     nsSVGClipPathFrame *mFrame;
 101   };
 102
 103   nsIFrame *mClipParent;
 104   nsCOMPtr<nsIDOMSVGMatrix> mClipParentMatrix;
 105   // recursion prevention flag
 106   PRPackedBool mInUse;
 107
 108   // nsSVGContainerFrame methods:
 109   virtual already_AddRefed<nsIDOMSVGMatrix> GetCanvasTM();
 110 };
 111
 112 #endif