Use CanvasImageSource union type instead of overloading

Source/core/html/canvas/CanvasRenderingContext2D.cpp

Index: Source/core/html/canvas/CanvasRenderingContext2D.cpp
diff --git a/Source/core/html/canvas/CanvasRenderingContext2D.cpp b/Source/core/html/canvas/CanvasRenderingContext2D.cpp
index fe0cdba7cea9198e06615357f1ed1a0d008bbeba..ff631c0a2ff171559eecd23d4da6441cb2781650 100644
--- a/Source/core/html/canvas/CanvasRenderingContext2D.cpp
+++ b/Source/core/html/canvas/CanvasRenderingContext2D.cpp
@@ -1483,25 +1483,42 @@ static inline void clipRectsToImageRect(const FloatRect& imageRect, FloatRect* s
     dstRect->move(offset);
 }
 
-void CanvasRenderingContext2D::drawImage(CanvasImageSource* imageSource, float x, float y, ExceptionState& exceptionState)
+static inline CanvasImageSource* toImageSourceInternal(const CanvasImageSourceUnion& value)
+{
+    if (value.isHTMLImageElement())
+        return value.getAsHTMLImageElement().get();
+    if (value.isHTMLVideoElement())
+        return value.getAsHTMLVideoElement().get();
+    if (value.isHTMLCanvasElement())
+        return value.getAsHTMLCanvasElement().get();
+    if (value.isImageBitmap())
+        return value.getAsImageBitmap().get();
+    ASSERT_NOT_REACHED();

[Justin Novosad, 2014/11/05 20:40:52]

Just to be sure, this is not reached even if the argument is a bogus object,
right?  Do the bindings take care of throwing an exception in that case?

[Jens Widell, 2014/11/06 11:44:39]

Yes, the generated code for converting a V8 value to the union container type
will throw an exception if the V8 value doesn't match any of the member types.

There are layout tests that call there functions with various invalid arguments
(the ones whose expected output I modified in this CL.)

+    return nullptr;
+}
+
+void CanvasRenderingContext2D::drawImage(const CanvasImageSourceUnion& imageSource, float x, float y, ExceptionState& exceptionState)
 {
-    FloatSize sourceRectSize = imageSource->sourceSize();
-    FloatSize destRectSize = imageSource->defaultDestinationSize();
-    drawImageInternal(imageSource, 0, 0, sourceRectSize.width(), sourceRectSize.height(), x, y, destRectSize.width(), destRectSize.height(), exceptionState);
+    CanvasImageSource* imageSourceInternal = toImageSourceInternal(imageSource);
+    FloatSize sourceRectSize = imageSourceInternal->sourceSize();
+    FloatSize destRectSize = imageSourceInternal->defaultDestinationSize();
+    drawImageInternal(imageSourceInternal, 0, 0, sourceRectSize.width(), sourceRectSize.height(), x, y, destRectSize.width(), destRectSize.height(), exceptionState);
 }
 
-void CanvasRenderingContext2D::drawImage(CanvasImageSource* imageSource,
+void CanvasRenderingContext2D::drawImage(const CanvasImageSourceUnion& imageSource,
     float x, float y, float width, float height, ExceptionState& exceptionState)
 {
-    FloatSize sourceRectSize = imageSource->sourceSize();
-    drawImageInternal(imageSource, 0, 0, sourceRectSize.width(), sourceRectSize.height(), x, y, width, height, exceptionState);
+    CanvasImageSource* imageSourceInternal = toImageSourceInternal(imageSource);
+    FloatSize sourceRectSize = imageSourceInternal->sourceSize();
+    drawImageInternal(imageSourceInternal, 0, 0, sourceRectSize.width(), sourceRectSize.height(), x, y, width, height, exceptionState);
 }
 
-void CanvasRenderingContext2D::drawImage(CanvasImageSource* imageSource,
+void CanvasRenderingContext2D::drawImage(const CanvasImageSourceUnion& imageSource,
     float sx, float sy, float sw, float sh,
     float dx, float dy, float dw, float dh, ExceptionState& exceptionState)
 {
-    drawImageInternal(imageSource, sx, sy, sw, sh, dx, dy, dw, dh, exceptionState);
+    CanvasImageSource* imageSourceInternal = toImageSourceInternal(imageSource);
+    drawImageInternal(imageSourceInternal, sx, sy, sw, sh, dx, dy, dw, dh, exceptionState);
 }
 
 static void drawVideo(GraphicsContext* c, CanvasImageSource* imageSource, FloatRect srcRect, FloatRect dstRect)
@@ -1683,7 +1700,7 @@ PassRefPtrWillBeRawPtr<CanvasGradient> CanvasRenderingContext2D::createRadialGra
     return gradient.release();
 }
 
-PassRefPtrWillBeRawPtr<CanvasPattern> CanvasRenderingContext2D::createPattern(CanvasImageSource* imageSource,
+PassRefPtrWillBeRawPtr<CanvasPattern> CanvasRenderingContext2D::createPattern(const CanvasImageSourceUnion& imageSource,
     const String& repetitionType, ExceptionState& exceptionState)
 {
     Pattern::RepeatMode repeatMode = CanvasPattern::parseRepetitionType(repetitionType, exceptionState);
@@ -1691,13 +1708,14 @@ PassRefPtrWillBeRawPtr<CanvasPattern> CanvasRenderingContext2D::createPattern(Ca
         return nullptr;
 
     SourceImageStatus status;
-    RefPtr<Image> imageForRendering = imageSource->getSourceImageForCanvas(CopySourceImageIfVolatile, &status);
+    CanvasImageSource* imageSourceInternal = toImageSourceInternal(imageSource);
+    RefPtr<Image> imageForRendering = imageSourceInternal->getSourceImageForCanvas(CopySourceImageIfVolatile, &status);
 
     switch (status) {
     case NormalSourceImageStatus:
         break;
     case ZeroSizeCanvasSourceImageStatus:
-        exceptionState.throwDOMException(InvalidStateError, String::format("The canvas %s is 0.", imageSource->sourceSize().width() ? "height" : "width"));
+        exceptionState.throwDOMException(InvalidStateError, String::format("The canvas %s is 0.", imageSourceInternal->sourceSize().width() ? "height" : "width"));
         return nullptr;
     case UndecodableSourceImageStatus:
         exceptionState.throwDOMException(InvalidStateError, "Source image is in the 'broken' state.");
@@ -1714,7 +1732,7 @@ PassRefPtrWillBeRawPtr<CanvasPattern> CanvasRenderingContext2D::createPattern(Ca
     }
     ASSERT(imageForRendering);
 
-    bool originClean = !wouldTaintOrigin(imageSource);
+    bool originClean = !wouldTaintOrigin(imageSourceInternal);
 
     return CanvasPattern::create(imageForRendering.release(), repeatMode, originClean);
 }