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

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#ifndef __NS_SVGCLIPPATHFRAME_H__
#define __NS_SVGCLIPPATHFRAME_H__

#include "nsSVGContainerFrame.h"

typedef nsSVGContainerFrame nsSVGClipPathFrameBase;

class nsSVGClipPathFrame : public nsSVGClipPathFrameBase
{
  friend nsIFrame*
  NS_NewSVGClipPathFrame(nsIPresShell* aPresShell, nsIContent* aContent, nsStyleContext* aContext);

  nsSVGClipPathFrame(nsStyleContext* aContext) :
    nsSVGClipPathFrameBase(aContext),
    mClipParentMatrix(nsnull),
    mInUse(PR_FALSE) {}

 public:
  // nsSVGClipPathFrame methods:
  nsresult ClipPaint(nsSVGRenderState* aContext,
                     nsISVGChildFrame* aParent,
                     nsIDOMSVGMatrix *aMatrix);

  PRBool ClipHitTest(nsISVGChildFrame* aParent,
                     nsIDOMSVGMatrix *aMatrix,
                     float aX, float aY);

  // 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.
  PRBool IsTrivial();

  /**
   * 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 == PR_FALSE, "reference loop!");
      mFrame->mInUse = PR_TRUE;
    }
    ~AutoClipPathReferencer() {
      mFrame->mInUse = PR_FALSE;
    }
  private:
    nsSVGClipPathFrame *mFrame;
  };

  nsISVGChildFrame *mClipParent;
  nsCOMPtr<nsIDOMSVGMatrix> mClipParentMatrix;

  // nsSVGContainerFrame methods:
  virtual already_AddRefed<nsIDOMSVGMatrix> GetCanvasTM();

  // recursion prevention flag
  PRPackedBool mInUse;
};

nsIContent *
NS_GetSVGClipPathElement(nsIURI *aURI, nsIContent *aContent);

#endif