Use CanvasImageSource union type instead of overloading

Source/core/html/canvas/CanvasRenderingContext2D.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008 Dirk Schulze <krit@webkit.org>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  * Copyright (C) 2012, 2013 Intel Corporation. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
  *
@@ skipping 1465 matching lines @@
     FloatSize offset = dstRect->location() - scaledSrcLocation;
 
     srcRect->intersect(imageRect);
 
     // To clip the destination rectangle in the same proportion, transform the clipped src rect
     *dstRect = *srcRect;
     dstRect->scale(scale.width(), scale.height());
     dstRect->move(offset);
 }
 
-void CanvasRenderingContext2D::drawImage(CanvasImageSource* imageSource, float x, float y, ExceptionState& exceptionState)
+static inline CanvasImageSource* toImageSourceInternal(const CanvasImageSourceUnion& value)
 {
-    FloatSize sourceRectSize = imageSource->sourceSize();
-    FloatSize destRectSize = imageSource->defaultDestinationSize();
-    drawImageInternal(imageSource, 0, 0, sourceRectSize.width(), sourceRectSize.height(), x, y, destRectSize.width(), destRectSize.height(), exceptionState);
+    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(CanvasImageSource* imageSource,
+void CanvasRenderingContext2D::drawImage(const CanvasImageSourceUnion& imageSource, float x, float y, ExceptionState& 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(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)
 {
     HTMLVideoElement* video = static_cast<HTMLVideoElement*>(imageSource);
     GraphicsContextStateSaver stateSaver(*c);
     c->clip(dstRect);
     c->translate(dstRect.x(), dstRect.y());
     c->scale(dstRect.width() / srcRect.width(), dstRect.height() / srcRect.height());
     c->translate(-srcRect.x(), -srcRect.y());
@@ skipping 161 matching lines @@
 {
     if (r0 < 0 || r1 < 0) {
         exceptionState.throwDOMException(IndexSizeError, String::format("The %s provided is less than 0.", r0 < 0 ? "r0" : "r1"));
         return nullptr;
     }
 
     RefPtrWillBeRawPtr<CanvasGradient> gradient = CanvasGradient::create(FloatPoint(x0, y0), r0, FloatPoint(x1, y1), r1);
     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);
     if (exceptionState.hadException())
         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.");
         return nullptr;
     case InvalidSourceImageStatus:
         imageForRendering = Image::nullImage();
         break;
     case IncompleteSourceImageStatus:
         return nullptr;
     default:
     case ExternalSourceImageStatus: // should not happen when mode is CopySourceImageIfVolatile
         ASSERT_NOT_REACHED();
         return nullptr;
     }
     ASSERT(imageForRendering);
 
-    bool originClean = !wouldTaintOrigin(imageSource);
+    bool originClean = !wouldTaintOrigin(imageSourceInternal);
 
     return CanvasPattern::create(imageForRendering.release(), repeatMode, originClean);
 }
 
 bool CanvasRenderingContext2D::computeDirtyRect(const FloatRect& localRect, FloatRect* dirtyRect)
 {
     FloatRect clipBounds;
     if (!drawingContext()->getTransformedClipBounds(&clipBounds))
         return false;
     return computeDirtyRect(localRect, clipBounds, dirtyRect);
@@ skipping 720 matching lines @@
 
 unsigned CanvasRenderingContext2D::hitRegionsCount() const
 {
     if (m_hitRegionManager)
         return m_hitRegionManager->getHitRegionsCount();
 
     return 0;
 }
 
 } // namespace blink