layout/svg/base/src/nsSVGClipPathFrame.cpp

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  15  * The Original Code is the Mozilla SVG project.
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  17  * The Initial Developer of the Original Code is IBM Corporation.
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  36
  37 #include "nsIDOMDocument.h"
  38 #include "nsIDocument.h"
  39 #include "nsIDOMSVGClipPathElement.h"
  40 #include "nsSVGClipPathFrame.h"
  41 #include "nsGkAtoms.h"
  42 #include "nsSVGUtils.h"
  43 #include "nsSVGClipPathElement.h"
  44 #include "gfxContext.h"
  45 #include "nsIDOMSVGRect.h"
  46
  47 //----------------------------------------------------------------------
  48 // Implementation
  49
  50 nsIFrame*
  51 NS_NewSVGClipPathFrame(nsIPresShell* aPresShell, nsIContent* aContent, nsStyleContext* aContext)
  52 {
  53   nsCOMPtr<nsIDOMSVGClipPathElement> clipPath = do_QueryInterface(aContent);
  54   if (!clipPath) {
  55     NS_ERROR("Can't create frame! Content is not an SVG clipPath!");
  56     return nsnull;
  57   }
  58
  59   return new (aPresShell) nsSVGClipPathFrame(aContext);
  60 }
  61
  62 nsresult
  63 nsSVGClipPathFrame::ClipPaint(nsSVGRenderState* aContext,
  64                               nsIFrame* aParent,
  65                               nsIDOMSVGMatrix *aMatrix)
  66 {
  67   // If the flag is set when we get here, it means this clipPath frame
  68   // has already been used painting the current clip, and the document
  69   // has a clip reference loop.
  70   if (mInUse) {
  71     NS_WARNING("Clip loop detected!");
  72     return NS_OK;
  73   }
  74   AutoClipPathReferencer clipRef(this);
  75
  76   mClipParent = aParent,
  77   mClipParentMatrix = aMatrix;
  78
  79   PRBool isTrivial = IsTrivial();
  80
  81   nsAutoSVGRenderMode mode(aContext,
  82                            isTrivial ? nsSVGRenderState::CLIP
  83                                      : nsSVGRenderState::CLIP_MASK);
  84
  85   for (nsIFrame* kid = mFrames.FirstChild(); kid;
  86        kid = kid->GetNextSibling()) {
  87     nsISVGChildFrame* SVGFrame = nsnull;
  88     CallQueryInterface(kid, &SVGFrame);
  89     if (SVGFrame) {
  90       // The CTM of each frame referencing us can be different.
  91       SVGFrame->NotifySVGChanged(nsISVGChildFrame::SUPPRESS_INVALIDATION |
  92                                  nsISVGChildFrame::TRANSFORM_CHANGED);
  93       SVGFrame->PaintSVG(aContext, nsnull);
  94     }
  95   }
  96
  97   if (isTrivial) {
  98     aContext->GetGfxContext()->Clip();
  99     aContext->GetGfxContext()->NewPath();
 100   }
 101
 102   return NS_OK;
 103 }
 104
 105 PRBool
 106 nsSVGClipPathFrame::ClipHitTest(nsIFrame* aParent,
 107                                 nsIDOMSVGMatrix *aMatrix,
 108                                 const nsPoint &aPoint)
 109 {
 110   // If the flag is set when we get here, it means this clipPath frame
 111   // has already been used in hit testing against the current clip,
 112   // and the document has a clip reference loop.
 113   if (mInUse) {
 114     NS_WARNING("Clip loop detected!");
 115     return PR_FALSE;
 116   }
 117   AutoClipPathReferencer clipRef(this);
 118
 119   mClipParent = aParent,
 120   mClipParentMatrix = aMatrix;
 121
 122   for (nsIFrame* kid = mFrames.FirstChild(); kid;
 123        kid = kid->GetNextSibling()) {
 124     nsISVGChildFrame* SVGFrame = nsnull;
 125     CallQueryInterface(kid, &SVGFrame);
 126     if (SVGFrame) {
 127       // Notify the child frame that we may be working with a
 128       // different transform, so it can update its covered region
 129       // (used to shortcut hit testing).
 130       SVGFrame->NotifySVGChanged(nsISVGChildFrame::TRANSFORM_CHANGED);
 131
 132       if (SVGFrame->GetFrameForPoint(aPoint))
 133         return PR_TRUE;
 134     }
 135   }
 136   return PR_FALSE;
 137 }
 138
 139 PRBool
 140 nsSVGClipPathFrame::IsTrivial()
 141 {
 142   PRBool foundChild = PR_FALSE;
 143
 144   for (nsIFrame* kid = mFrames.FirstChild(); kid;
 145        kid = kid->GetNextSibling()) {
 146     nsISVGChildFrame *svgChild = nsnull;
 147     CallQueryInterface(kid, &svgChild);
 148
 149     if (svgChild) {
 150       // We consider a non-trivial clipPath to be one containing
 151       // either more than one svg child and/or a svg container
 152       if (foundChild || svgChild->IsDisplayContainer())
 153         return PR_FALSE;
 154       foundChild = PR_TRUE;
 155     }
 156   }
 157   return PR_TRUE;
 158 }
 159
 160 nsIAtom *
 161 nsSVGClipPathFrame::GetType() const
 162 {
 163   return nsGkAtoms::svgClipPathFrame;
 164 }
 165
 166 already_AddRefed<nsIDOMSVGMatrix>
 167 nsSVGClipPathFrame::GetCanvasTM()
 168 {
 169   NS_ASSERTION(mClipParentMatrix, "null parent matrix");
 170
 171   nsSVGClipPathElement *clipPath = static_cast<nsSVGClipPathElement*>
 172                                               (mContent);
 173
 174   nsCOMPtr<nsIDOMSVGMatrix> localTM = clipPath->GetLocalTransformMatrix();
 175
 176   nsCOMPtr<nsIDOMSVGMatrix> canvasTM;
 177
 178   if (localTM)
 179     mClipParentMatrix->Multiply(localTM, getter_AddRefs(canvasTM));
 180   else
 181     canvasTM = mClipParentMatrix;
 182
 183   return nsSVGUtils::AdjustMatrixForUnits(canvasTM,
 184                                           &clipPath->mEnumAttributes[nsSVGClipPathElement::CLIPPATHUNITS],
 185                                           mClipParent);
 186 }