gecko/layout/svg/base/src/nsSVGClipPathFrame.h

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#ifndef __NS_SVGCLIPPATHFRAME_H__
#define __NS_SVGCLIPPATHFRAME_H__

#include "nsSVGContainerFrame.h"
#include "gfxMatrix.h"

class nsRenderingContext;

typedef nsSVGContainerFrame nsSVGClipPathFrameBase;

class nsSVGClipPathFrame : public nsSVGClipPathFrameBase
{
  friend nsIFrame*
  NS_NewSVGClipPathFrame(nsIPresShell* aPresShell, nsStyleContext* aContext);
protected:
  nsSVGClipPathFrame(nsStyleContext* aContext)
    : nsSVGClipPathFrameBase(aContext)
    , mInUse(false)
  {
    AddStateBits(NS_STATE_SVG_NONDISPLAY_CHILD);
  }

public:
  NS_DECL_FRAMEARENA_HELPERS

  // nsSVGClipPathFrame methods:
  nsresult ClipPaint(nsRenderingContext* aContext,
                     nsIFrame* aParent,
                     const gfxMatrix &aMatrix);

  bool ClipHitTest(nsIFrame* aParent,
                     const gfxMatrix &aMatrix,
                     const nsPoint &aPoint);

  // Check if this clipPath is made up of more than one geometry object.
  // If so, the clipping API in cairo isn't enough and we need to use
  // mask based clipping.
  bool IsTrivial();

  bool IsValid();

  // nsIFrame interface:
  NS_IMETHOD AttributeChanged(PRInt32         aNameSpaceID,
                              nsIAtom*        aAttribute,
                              PRInt32         aModType);

  NS_IMETHOD Init(nsIContent*      aContent,
                  nsIFrame*        aParent,
                  nsIFrame*        aPrevInFlow);

  /**
   * Get the "type" of the frame
   *
   * @see nsGkAtoms::svgClipPathFrame
   */
  virtual nsIAtom* GetType() const;

#ifdef DEBUG
  NS_IMETHOD GetFrameName(nsAString& aResult) const
  {
    return MakeFrameName(NS_LITERAL_STRING("SVGClipPath"), aResult);
  }
#endif

 private:
  // A helper class to allow us to paint clip paths safely. The helper
  // automatically sets and clears the mInUse flag on the clip path frame
  // (to prevent nasty reference loops). It's easy to mess this up
  // and break things, so this helper makes the code far more robust.
  class AutoClipPathReferencer
  {
  public:
    AutoClipPathReferencer(nsSVGClipPathFrame *aFrame)
       : mFrame(aFrame) {
      NS_ASSERTION(!mFrame->mInUse, "reference loop!");
      mFrame->mInUse = true;
    }
    ~AutoClipPathReferencer() {
      mFrame->mInUse = false;
    }
  private:
    nsSVGClipPathFrame *mFrame;
  };

  nsIFrame *mClipParent;
  nsAutoPtr<gfxMatrix> mClipParentMatrix;
  // recursion prevention flag
  bool mInUse;

  // nsSVGContainerFrame methods:
  virtual gfxMatrix GetCanvasTM();
};

#endif