Bug 1708443 - Part 3. Move VectorImage::mIsDrawing to SVGDocumentWrapper. r=tnikkel

Moving mIsDrawing to SVGDocumentWrapper allows us to avoid depending on
VectorImage in a future patch, and instead only keep a reference to
SVGDocumentWrapper. This helps avoid a circular dependency.

Differential Revision: https://phabricator.services.mozilla.com/D111903

image/AutoRestoreSVGState.h

@@ -19,9 +19,9 @@ namespace image {
 class MOZ_STACK_CLASS AutoRestoreSVGState final {
  public:
   AutoRestoreSVGState(const SVGDrawingParameters& aParams,
-                      SVGDocumentWrapper* aSVGDocumentWrapper, bool& aIsDrawing,
+                      SVGDocumentWrapper* aSVGDocumentWrapper,
                       bool aContextPaint)
-      : mIsDrawing(aIsDrawing)
+      : mIsDrawing(aSVGDocumentWrapper->mIsDrawing)
         // Apply any 'preserveAspectRatio' override (if specified) to the root
         // element:
         ,
@@ -29,10 +29,10 @@ class MOZ_STACK_CLASS AutoRestoreSVGState final {
         // Set the animation time:
         ,
         mTime(aSVGDocumentWrapper->GetRootSVGElem(), aParams.animationTime) {
-    MOZ_ASSERT(!aIsDrawing);
+    MOZ_ASSERT(!mIsDrawing.SavedValue());
     MOZ_ASSERT(aSVGDocumentWrapper->GetDocument());
 
-    aIsDrawing = true;
+    aSVGDocumentWrapper->mIsDrawing = true;
 
     // Set context paint (if specified) on the document:
     if (aContextPaint) {

image/SVGDocumentWrapper.cpp

@@ -42,7 +42,9 @@ NS_IMPL_ISUPPORTS(SVGDocumentWrapper, nsIStreamListener, nsIRequestObserver,
                   nsIObserver, nsISupportsWeakReference)
 
 SVGDocumentWrapper::SVGDocumentWrapper()
-    : mIgnoreInvalidation(false), mRegisteredForXPCOMShutdown(false) {}
+    : mIgnoreInvalidation(false),
+      mRegisteredForXPCOMShutdown(false),
+      mIsDrawing(false) {}
 
 SVGDocumentWrapper::~SVGDocumentWrapper() {
   DestroyViewer();

image/SVGDocumentWrapper.h

@@ -31,10 +31,11 @@ class SVGDocument;
 }  // namespace dom
 
 namespace image {
+class AutoRestoreSVGState;
 
 class SVGDocumentWrapper final : public nsIStreamListener,
                                  public nsIObserver,
-                                 nsSupportsWeakReference {
+                                 public nsSupportsWeakReference {
  public:
   SVGDocumentWrapper();
 
@@ -101,6 +102,13 @@ class SVGDocumentWrapper final : public nsIStreamListener,
    */
   bool ShouldIgnoreInvalidation() { return mIgnoreInvalidation; }
 
+  /**
+   * Returns a bool indicating whether the document is currently drawing.
+   *
+   * @return true if the document is drawing. Else, false.
+   */
+  bool IsDrawing() const { return mIsDrawing; }
+
   /**
    * Methods to control animation.
    */
@@ -117,6 +125,8 @@ class SVGDocumentWrapper final : public nsIStreamListener,
   void FlushLayout();
 
  private:
+  friend class AutoRestoreSVGState;
+
   ~SVGDocumentWrapper();
 
   nsresult SetupViewer(nsIRequest* aRequest, nsIContentViewer** aViewer,
@@ -130,9 +140,18 @@ class SVGDocumentWrapper final : public nsIStreamListener,
   nsCOMPtr<nsIStreamListener> mListener;
   bool mIgnoreInvalidation;
   bool mRegisteredForXPCOMShutdown;
+  bool mIsDrawing;
 };
 
 }  // namespace image
 }  // namespace mozilla
 
+/**
+ * Casting SVGDocumentWrapper to nsISupports is ambiguous. This method handles
+ * that.
+ */
+inline nsISupports* ToSupports(mozilla::image::SVGDocumentWrapper* p) {
+  return NS_ISUPPORTS_CAST(nsSupportsWeakReference*, p);
+}
+
 #endif  // mozilla_image_SVGDocumentWrapper_h

image/VectorImage.cpp

@@ -309,7 +309,6 @@ VectorImage::VectorImage(nsIURI* aURI /* = nullptr */)
       mIsInitialized(false),
       mDiscardable(false),
       mIsFullyLoaded(false),
-      mIsDrawing(false),
       mHaveAnimations(false),
       mHasPendingInvalidation(false) {}
 
@@ -717,7 +716,7 @@ VectorImage::GetFrameInternal(const IntSize& aSize,
                      std::move(sourceSurface));
   }
 
-  if (mIsDrawing) {
+  if (mSVGDocumentWrapper->IsDrawing()) {
     NS_WARNING("Refusing to make re-entrant call to VectorImage::Draw");
     return MakeTuple(ImgDrawResult::TEMPORARY_ERROR, decodeSize,
                      RefPtr<SourceSurface>());
@@ -736,8 +735,7 @@ VectorImage::GetFrameInternal(const IntSize& aSize,
   bool didCache;  // Was the surface put into the cache?
   bool contextPaint = aSVGContext && aSVGContext->GetContextPaint();
 
-  AutoRestoreSVGState autoRestore(params, mSVGDocumentWrapper, mIsDrawing,
-                                  contextPaint);
+  AutoRestoreSVGState autoRestore(params, mSVGDocumentWrapper, contextPaint);
 
   RefPtr<gfxDrawable> svgDrawable = CreateSVGDrawable(params);
   RefPtr<SourceSurface> surface = CreateSurface(params, svgDrawable, didCache);
@@ -935,13 +933,12 @@ VectorImage::Draw(gfxContext* aContext, const nsIntSize& aSize,
 
   // else, we need to paint the image:
 
-  if (mIsDrawing) {
+  if (mSVGDocumentWrapper->IsDrawing()) {
     NS_WARNING("Refusing to make re-entrant call to VectorImage::Draw");
     return ImgDrawResult::TEMPORARY_ERROR;
   }
 
-  AutoRestoreSVGState autoRestore(params, mSVGDocumentWrapper, mIsDrawing,
-                                  contextPaint);
+  AutoRestoreSVGState autoRestore(params, mSVGDocumentWrapper, contextPaint);
 
   bool didCache;  // Was the surface put into the cache?
   RefPtr<gfxDrawable> svgDrawable = CreateSVGDrawable(params);
@@ -1014,7 +1011,7 @@ Tuple<RefPtr<SourceSurface>, IntSize> VectorImage::LookupCachedSurface(
 already_AddRefed<SourceSurface> VectorImage::CreateSurface(
     const SVGDrawingParameters& aParams, gfxDrawable* aSVGDrawable,
     bool& aWillCache) {
-  MOZ_ASSERT(mIsDrawing);
+  MOZ_ASSERT(mSVGDocumentWrapper->IsDrawing());
 
   mSVGDocumentWrapper->UpdateViewportBounds(aParams.viewportSize);
   mSVGDocumentWrapper->FlushImageTransformInvalidation();

image/VectorImage.h

@@ -150,7 +150,6 @@ class VectorImage final : public ImageResource, public nsIStreamListener {
   bool mDiscardable;             // Are we discardable?
   bool mIsFullyLoaded;           // Has the SVG document finished
                                  // loading?
-  bool mIsDrawing;               // Are we currently drawing?
   bool mHaveAnimations;          // Is our SVG content SMIL-animated?
                                  // (Only set after mIsFullyLoaded.)
   bool mHasPendingInvalidation;  // Invalidate observers next refresh