Bug 314627 - implement SVGTSpanElement.getExtentOfChar.

Patch by longsonr@gmail.com, r=tor, sr=jst.

content/svg/content/src/nsSVGPathElement.cpp

@@ -382,12 +382,10 @@ nsSVGPathElement::GetPathFlatten()
   nsIFrame* frame = presShell->GetPrimaryFrameFor(this);
 
   if (!frame) {
-    NS_ERROR("no frame");
     return nsnull;
   }
   
   nsISVGPathFlatten* flattener;
   CallQueryInterface(frame, &flattener);
-  NS_ASSERTION(flattener, "wrong frame type");
   return flattener;
 }

content/svg/content/src/nsSVGTSpanElement.cpp

@@ -44,6 +44,9 @@
 #include "nsSVGLengthList.h"
 #include "nsISVGSVGElement.h"
 #include "nsSVGCoordCtxProvider.h"
+#include "nsISVGTextContentMetrics.h"
+#include "nsIFrame.h"
+#include "nsIDocument.h"
 
 typedef nsSVGGraphicElement nsSVGTSpanElementBase;
 
@@ -80,6 +83,8 @@ public:
 
 protected:
 
+  already_AddRefed<nsISVGTextContentMetrics> GetTextContentMetrics();
+
   // nsIDOMSVGTextPositioning properties:
   nsCOMPtr<nsIDOMSVGAnimatedLengthList> mX;
   nsCOMPtr<nsIDOMSVGAnimatedLengthList> mY;
@@ -297,8 +302,12 @@ NS_IMETHODIMP nsSVGTSpanElement::GetEndPositionOfChar(PRUint32 charnum, nsIDOMSV
 /* nsIDOMSVGRect getExtentOfChar (in unsigned long charnum); */
 NS_IMETHODIMP nsSVGTSpanElement::GetExtentOfChar(PRUint32 charnum, nsIDOMSVGRect **_retval)
 {
-  NS_NOTYETIMPLEMENTED("nsSVGTSpanElement::GetExtentOfChar");
-  return NS_ERROR_NOT_IMPLEMENTED;
+  *_retval = nsnull;
+  nsCOMPtr<nsISVGTextContentMetrics> metrics = GetTextContentMetrics();
+
+  if (!metrics) return NS_ERROR_FAILURE;
+
+  return metrics->GetExtentOfChar(charnum, _retval);
 }
 
 /* float getRotationOfChar (in unsigned long charnum); */
@@ -401,3 +410,32 @@ void nsSVGTSpanElement::ParentChainChanged()
   // recurse into child content:
   nsSVGTSpanElementBase::ParentChainChanged();
 }  
+
+//----------------------------------------------------------------------
+// implementation helpers:
+
+already_AddRefed<nsISVGTextContentMetrics>
+nsSVGTSpanElement::GetTextContentMetrics()
+{
+  nsIDocument* doc = GetCurrentDoc();
+  if (!doc) {
+    NS_ERROR("no document");
+    return nsnull;
+  }
+  
+  nsIPresShell* presShell = doc->GetShellAt(0);
+  if (!presShell) {
+    NS_ERROR("no presshell");
+    return nsnull;
+  }
+
+  nsIFrame* frame = presShell->GetPrimaryFrameFor(this);
+
+  if (!frame) {
+    return nsnull;
+  }
+  
+  nsISVGTextContentMetrics* metrics;
+  CallQueryInterface(frame, &metrics);
+  return metrics;
+}

content/svg/content/src/nsSVGTextElement.cpp

@@ -430,12 +430,10 @@ nsSVGTextElement::GetTextContentMetrics()
   nsIFrame* frame = presShell->GetPrimaryFrameFor(this);
 
   if (!frame) {
-    NS_ERROR("no frame");
     return nsnull;
   }
   
   nsISVGTextContentMetrics* metrics;
   CallQueryInterface(frame, &metrics);
-  NS_ASSERTION(metrics, "wrong frame type");
   return metrics;
 }

layout/svg/base/src/nsSVGTSpanFrame.cpp

@@ -38,6 +38,7 @@
 
 #include "nsSVGTSpanFrame.h"
 #include "nsSVGUtils.h"
+#include "nsDOMError.h"
 
 //----------------------------------------------------------------------
 // Implementation
@@ -168,6 +169,7 @@ NS_INTERFACE_MAP_BEGIN(nsSVGTSpanFrame)
   NS_INTERFACE_MAP_ENTRY(nsISVGChildFrame)
   NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
   NS_INTERFACE_MAP_ENTRY(nsISVGValueObserver)
+  NS_INTERFACE_MAP_ENTRY(nsISVGTextContentMetrics)
 NS_INTERFACE_MAP_END_INHERITING(nsSVGTSpanFrameBase)
 
 
@@ -296,6 +298,17 @@ nsSVGTSpanFrame::DidModifySVGObservable (nsISVGValue* observable,
 }
 
 
+//----------------------------------------------------------------------
+// nsISVGTextContentMetrics
+NS_IMETHODIMP
+nsSVGTSpanFrame::GetExtentOfChar(PRUint32 charnum, nsIDOMSVGRect **_retval)
+{
+  nsISVGGlyphFragmentNode* node = GetFirstGlyphFragmentChildNode();
+  if (!node) return NS_ERROR_DOM_INDEX_SIZE_ERR;
+  return nsSVGUtils::GetExtentOfChar(node, charnum, _retval);
+}
+
+
 //----------------------------------------------------------------------
 // nsISVGChildFrame methods
 

layout/svg/base/src/nsSVGTSpanFrame.h

@@ -59,6 +59,7 @@
 #include "nsISVGGlyphFragmentNode.h"
 #include "nsIDOMSVGRect.h"
 #include "nsISVGOuterSVGFrame.h"
+#include "nsISVGTextContentMetrics.h"
 #include "nsSVGRect.h"
 #include "nsSVGMatrix.h"
 #include "nsINameSpaceManager.h"
@@ -73,6 +74,7 @@ class nsSVGTSpanFrame : public nsSVGTSpanFrameBase,
                         public nsISVGChildFrame,
                         public nsISVGContainerFrame,
                         public nsISVGValueObserver,
+                        public nsISVGTextContentMetrics,
                         public nsSupportsWeakReference
 {
   friend nsIFrame*
@@ -127,6 +129,9 @@ public:
   NS_IMETHOD DidModifySVGObservable (nsISVGValue* observable,
                                      nsISVGValue::modificationType aModType);
 
+  // nsISVGTextContentMetrics
+  NS_IMETHOD GetExtentOfChar(PRUint32 charnum, nsIDOMSVGRect **_retval);
+
   // nsISupportsWeakReference
   // implementation inherited from nsSupportsWeakReference
   

layout/svg/base/src/nsSVGTextFrame.cpp

@@ -68,6 +68,7 @@
 #include "nsSVGUtils.h"
 #include "nsSVGFilterFrame.h"
 #include "nsSVGUtils.h"
+#include "nsDOMError.h"
 
 typedef nsContainerFrame nsSVGTextFrameBase;
 
@@ -191,7 +192,6 @@ protected:
   already_AddRefed<nsIDOMSVGAnimatedTransformList> GetTransform();
   nsISVGGlyphFragmentNode *GetFirstGlyphFragmentChildNode();
   nsISVGGlyphFragmentNode *GetNextGlyphFragmentChildNode(nsISVGGlyphFragmentNode*node);
-  nsISVGGlyphFragmentLeaf *GetGlyphFragmentAtCharNum(PRUint32 charnum);
 
   enum UpdateState{
     unsuspended,
@@ -533,29 +533,11 @@ nsSVGTextFrame::DidModifySVGObservable (nsISVGValue* observable,
 NS_IMETHODIMP
 nsSVGTextFrame::GetExtentOfChar(PRUint32 charnum, nsIDOMSVGRect **_retval)
 {
-  *_retval = nsnull;
-  
   EnsureFragmentTreeUpToDate();
 
-  nsISVGGlyphFragmentLeaf *fragment = GetGlyphFragmentAtCharNum(charnum);
-  if (!fragment) return NS_ERROR_FAILURE; // xxx return some index-out-of-range error
-  
-  // query the renderer metrics for the bounds of the character
-  nsCOMPtr<nsISVGRendererGlyphMetrics> metrics;
-  fragment->GetGlyphMetrics(getter_AddRefs(metrics));
-  if (!metrics) return NS_ERROR_FAILURE;
-  nsresult rv = metrics->GetExtentOfChar(charnum-fragment->GetCharNumberOffset(),
-                                         _retval);
-  if (NS_FAILED(rv)) return NS_ERROR_FAILURE;
-
-  // offset the bounds by the position of the fragment:
-  float x,y;
-  (*_retval)->GetX(&x);
-  (*_retval)->GetY(&y);
-  (*_retval)->SetX(x+fragment->GetGlyphPositionX());
-  (*_retval)->SetY(y+fragment->GetGlyphPositionY());
-
-  return NS_OK;
+  nsISVGGlyphFragmentNode* node = GetFirstGlyphFragmentChildNode();
+  if (!node) return NS_ERROR_DOM_INDEX_SIZE_ERR;
+  return nsSVGUtils::GetExtentOfChar(node, charnum, _retval);
 }
 
 
@@ -1316,24 +1298,3 @@ nsSVGTextFrame::GetNextGlyphFragmentChildNode(nsISVGGlyphFragmentNode*node)
   return retval;
 }
 
-nsISVGGlyphFragmentLeaf *
-nsSVGTextFrame::GetGlyphFragmentAtCharNum(PRUint32 charnum)
-{
-  nsISVGGlyphFragmentLeaf *fragment = nsnull;
-  {
-    nsISVGGlyphFragmentNode* node = GetFirstGlyphFragmentChildNode();
-    if (!node) return nsnull; 
-    fragment = node->GetFirstGlyphFragment();
-  }
-  
-  while(fragment) {
-    PRUint32 count = fragment->GetNumberOfChars();
-    if (count>charnum)
-      return fragment;
-    charnum-=count;
-    fragment = fragment->GetNextGlyphFragment();
-  }
-
-  // not found
-  return nsnull;
-}

layout/svg/base/src/nsSVGUtils.cpp

@@ -49,6 +49,8 @@
 #include "nsIPresShell.h"
 #include "nsSVGUtils.h"
 #include "nsISVGGeometrySource.h"
+#include "nsISVGGlyphFragmentLeaf.h"
+#include "nsISVGRendererGlyphMetrics.h"
 #include "nsNetUtil.h"
 #include "nsIDOMSVGRect.h"
 #include "nsFrameList.h"
@@ -61,6 +63,7 @@
 #include "nsISVGChildFrame.h"
 #include "nsIDOMSVGPoint.h"
 #include "nsSVGPoint.h"
+#include "nsDOMError.h"
 
 #if defined(MOZ_SVG_RENDERER_GDIPLUS)
 #include <windows.h>
@@ -253,6 +256,34 @@ nsSVGUtils::GetBBox(nsFrameList *aFrames, nsIDOMSVGRect **_retval)
   return NS_ERROR_FAILURE;
 }
 
+nsresult
+nsSVGUtils::GetExtentOfChar(nsISVGGlyphFragmentNode* node,
+                            PRUint32 charnum,
+                            nsIDOMSVGRect **_retval)
+{
+  *_retval = nsnull;
+
+  nsISVGGlyphFragmentLeaf *fragment = GetGlyphFragmentAtCharNum(node, charnum);
+  if (!fragment) return NS_ERROR_DOM_INDEX_SIZE_ERR;
+
+  // query the renderer metrics for the bounds of the character
+  nsCOMPtr<nsISVGRendererGlyphMetrics> metrics;
+  fragment->GetGlyphMetrics(getter_AddRefs(metrics));
+  if (!metrics) return NS_ERROR_DOM_INDEX_SIZE_ERR;
+  nsresult rv = metrics->GetExtentOfChar(charnum-fragment->GetCharNumberOffset(),
+                                         _retval);
+  if (NS_FAILED(rv)) return NS_ERROR_DOM_INDEX_SIZE_ERR;
+
+  // offset the bounds by the position of the fragment:
+  float x,y;
+  (*_retval)->GetX(&x);
+  (*_retval)->GetY(&y);
+  (*_retval)->SetX(x+fragment->GetGlyphPositionX());
+  (*_retval)->SetY(y+fragment->GetGlyphPositionY());
+
+  return NS_OK;
+}
+
 void
 nsSVGUtils::FindFilterInvalidation(nsIFrame *aFrame,
                                    nsISVGRendererRegion **aRegion)
@@ -361,3 +392,21 @@ nsSVGUtils::TransformPoint(nsIDOMSVGMatrix *matrix,
   xfpoint->GetX(x);
   xfpoint->GetY(y);
 }
+
+nsISVGGlyphFragmentLeaf *
+nsSVGUtils::GetGlyphFragmentAtCharNum(nsISVGGlyphFragmentNode* node,
+                                      PRUint32 charnum)
+{
+  nsISVGGlyphFragmentLeaf *fragment = node->GetFirstGlyphFragment();
+  
+  while(fragment) {
+    PRUint32 count = fragment->GetNumberOfChars();
+    if (count>charnum)
+      return fragment;
+    charnum-=count;
+    fragment = fragment->GetNextGlyphFragment();
+  }
+
+  // not found
+  return nsnull;
+}

layout/svg/base/src/nsSVGUtils.h

@@ -48,6 +48,8 @@ class nsFrameList;
 class nsIFrame;
 struct nsStyleSVGPaint;
 class nsISVGRendererRegion;
+class nsISVGGlyphFragmentLeaf;
+class nsISVGGlyphFragmentNode;
 class nsIDOMSVGLength;
 class nsIDOMSVGMatrix;
 class nsIURI;
@@ -86,6 +88,13 @@ public:
    */
   static nsresult GetBBox(nsFrameList *aFrames, nsIDOMSVGRect **_retval);
 
+  /*
+   * Determines the bounds of a character
+   */
+  static nsresult GetExtentOfChar(nsISVGGlyphFragmentNode* node,
+                                  PRUint32 charnum,
+                                  nsIDOMSVGRect **_retval);
+
   /*
    * Figures out the worst case invalidation area for a frame, taking
    * into account filters.  Null return if no filter in the hierarcy.
@@ -118,6 +127,14 @@ public:
   static void
   TransformPoint(nsIDOMSVGMatrix *matrix,
                  float *x, float *y);
+
+private:
+  /*
+   * Returns the glyph fragment containing a particular character
+   */
+  static nsISVGGlyphFragmentLeaf *
+  GetGlyphFragmentAtCharNum(nsISVGGlyphFragmentNode* node,
+                            PRUint32 charnum);
 };
 
 #endif