Bug 413960, part 2 - Stop sending out unnecessary COORD_CONTEXT_CHANGED/TRANSFORM_CHANGED notifications from nsSVGOuterSVGFrame. r=longsonr.

--HG--
extra : rebase_source : fa0e8a232559e19b9a151a34a8f235154327409b

content/svg/content/src/nsSVGSVGElement.cpp

@@ -1107,7 +1107,8 @@ nsSVGSVGElement::InvalidateTransformNotifyFrame()
     nsISVGSVGFrame* svgframe = do_QueryFrame(frame);
     // might fail this check if we've failed conditional processing
     if (svgframe) {
-      svgframe->NotifyViewportChange();
+      svgframe->NotifyViewportOrTransformChanged(
+                  nsISVGChildFrame::TRANSFORM_CHANGED);
     }
   }
 }

layout/svg/base/src/nsISVGSVGFrame.h

@@ -46,7 +46,14 @@ class nsISVGSVGFrame
 public:
   NS_DECL_QUERYFRAME_TARGET(nsISVGSVGFrame)
 
-  virtual void NotifyViewportChange()=0; 
+  /**
+   * Called when non-attribute changes have caused the element's width/height
+   * or its for-children transform to change, and to get the element to notify
+   * its children appropriately. aFlags must be set to
+   * nsISVGChildFrame::COORD_CONTEXT_CHANGED and/or
+   * nsISVGChildFrame::TRANSFORM_CHANGED.
+   */
+  virtual void NotifyViewportOrTransformChanged(PRUint32 aFlags)=0; 
 };
 
 #endif // __NS_ISVGSVGFRAME_H__

layout/svg/base/src/nsSVGInnerSVGFrame.cpp

@@ -236,9 +236,14 @@ nsSVGInnerSVGFrame::GetFrameForPoint(const nsPoint &aPoint)
 // nsISVGSVGFrame methods:
 
 void
-nsSVGInnerSVGFrame::NotifyViewportChange()
+nsSVGInnerSVGFrame::NotifyViewportOrTransformChanged(PRUint32 aFlags)
 {
-  NS_ERROR("Inner SVG frames should not get Viewport changes.");
+  // The dimensions of inner-<svg> frames are purely defined by their "width"
+  // and "height" attributes, and transform changes can only occur as a result
+  // of changes to their "width", "height", "viewBox" or "preserveAspectRatio"
+  // attributes. Changes to all of these attributes are handled in
+  // AttributeChanged(), so we should never be called.
+  NS_ERROR("Not called for nsSVGInnerSVGFrame");
 }
 
 //----------------------------------------------------------------------

layout/svg/base/src/nsSVGInnerSVGFrame.h

@@ -91,7 +91,7 @@ public:
   virtual gfxMatrix GetCanvasTM();
 
   // nsISVGSVGFrame interface:
-  virtual void NotifyViewportChange();
+  virtual void NotifyViewportOrTransformChanged(PRUint32 aFlags);
 
 protected:
 

layout/svg/base/src/nsSVGOuterSVGFrame.cpp

@@ -415,12 +415,18 @@ nsSVGOuterSVGFrame::Reflow(nsPresContext*           aPresContext,
 
   nsSVGSVGElement *svgElem = static_cast<nsSVGSVGElement*>(mContent);
 
-  if (newViewportSize != svgElem->GetViewportSize() ||
-      mFullZoom != PresContext()->GetFullZoom()) {
+  PRUint32 changeBits = 0;
+  if (newViewportSize != svgElem->GetViewportSize()) {
+    changeBits |= COORD_CONTEXT_CHANGED;
     svgElem->SetViewportSize(newViewportSize);
-    mViewportInitialized = true;
+  }
+  if (mFullZoom != PresContext()->GetFullZoom()) {
+    changeBits |= TRANSFORM_CHANGED;
     mFullZoom = PresContext()->GetFullZoom();
-    NotifyViewportChange();
+  }
+  mViewportInitialized = true;
+  if (changeBits) {
+    NotifyViewportOrTransformChanged(changeBits);
   }
 
   NS_FRAME_TRACE(NS_FRAME_TRACE_CALLS,
@@ -705,30 +711,41 @@ nsSVGOuterSVGFrame::GetType() const
 // nsISVGSVGFrame methods:
 
 void
-nsSVGOuterSVGFrame::NotifyViewportChange()
+nsSVGOuterSVGFrame::NotifyViewportOrTransformChanged(PRUint32 aFlags)
 {
-  // no point in doing anything when were not init'ed yet:
+  NS_ABORT_IF_FALSE(aFlags &&
+                    !(aFlags & ~(COORD_CONTEXT_CHANGED | TRANSFORM_CHANGED)),
+                    "Unexpected aFlags value");
+
+  // No point in doing anything when were not init'ed yet:
   if (!mViewportInitialized) {
     return;
   }
 
-  PRUint32 flags = COORD_CONTEXT_CHANGED;
+  nsSVGSVGElement *content = static_cast<nsSVGSVGElement*>(mContent);
 
-  // viewport changes only affect our transform if we have a viewBox attribute
-#if 1
-  {
-#else
-  // XXX this caused reftest failures (bug 413960)
-  if (mContent->HasAttr(kNameSpaceID_None, nsGkAtoms::viewBox)) {
-#endif
-    // make sure canvas transform matrix gets (lazily) recalculated:
-    mCanvasTM = nsnull;
-
-    flags |= TRANSFORM_CHANGED;
+  if (aFlags & COORD_CONTEXT_CHANGED) {
+    if (content->HasViewBox() || content->ShouldSynthesizeViewBox()) {
+      // Percentage lengths on children resolve against the viewBox rect so we
+      // don't need to notify them of the viewport change, but the viewBox
+      // transform will have changed, so we need to notify them of that instead.
+      aFlags = TRANSFORM_CHANGED;
+    }
+    else if (mCanvasTM && mCanvasTM->IsSingular()) {
+      // A width/height of zero will result in us having a singular mCanvasTM
+      // even when we don't have a viewBox. So we also want to recompute our
+      // mCanvasTM for this width/height change even though we don't have a
+      // viewBox.
+      aFlags |= TRANSFORM_CHANGED;
+    }
   }
 
-  // inform children
-  nsSVGUtils::NotifyChildrenOfSVGChange(this, flags);
+  if (aFlags & TRANSFORM_CHANGED) {
+    // Make sure our canvas transform matrix gets (lazily) recalculated:
+    mCanvasTM = nsnull;
+  }
+
+  nsSVGUtils::NotifyChildrenOfSVGChange(this, aFlags);
 }
 
 //----------------------------------------------------------------------

layout/svg/base/src/nsSVGOuterSVGFrame.h

@@ -114,7 +114,7 @@ public:
                                PRInt32         aModType);
 
   // nsISVGSVGFrame interface:
-  virtual void NotifyViewportChange();
+  virtual void NotifyViewportOrTransformChanged(PRUint32 aFlags);
 
   // nsSVGContainerFrame methods:
   virtual gfxMatrix GetCanvasTM();