Implement "Copy image" for canvas (blink side).

Source/core/editing/Editor.cpp

Index: Source/core/editing/Editor.cpp
diff --git a/Source/core/editing/Editor.cpp b/Source/core/editing/Editor.cpp
index 46c228337d3a554e165cde4a54143eaba723b84d..2f1f978fc83c26205711186bd0344dc82c7e029a 100644
--- a/Source/core/editing/Editor.cpp
+++ b/Source/core/editing/Editor.cpp
@@ -69,6 +69,7 @@
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Settings.h"
 #include "core/frame/UseCounter.h"
+#include "core/html/HTMLCanvasElement.h"
 #include "core/html/HTMLImageElement.h"
 #include "core/html/HTMLInputElement.h"
 #include "core/html/HTMLTextAreaElement.h"
@@ -426,14 +427,22 @@ static void writeImageNodeToPasteboard(Pasteboard* pasteboard, Node* node, const
     ASSERT(pasteboard);
     ASSERT(node);
 
-    if (!(node->renderer() && node->renderer()->isImage()))
+    RenderObject* renderer = node->renderer();

[yosin_UTC9, 2014/06/20 04:24:10]

It seems it is better to call
|node->document().updateLayoutIgnorePendingStylesheets()| to make sure |node| to
have |RenderObject|.

[zino, 2014/06/20 07:07:09]

Done.

+    if (!renderer)
         return;
 
-    RenderImage* renderer = toRenderImage(node->renderer());
-    ImageResource* cachedImage = renderer->cachedImage();
-    if (!cachedImage || cachedImage->errorOccurred())
+    Image* image = 0;

[yosin_UTC9, 2014/06/20 04:24:10]

nit: How about having helper function to return |Image| from |node|?

Image* image = imageFromNode(node);
if (!image)
   return;

static Image* imageFromNode(const Node* node) 
{
    node->document().updateLayoutIgnorePendingStylesheets();
    RenderObject* renderer = node->renderer();
    if (!renderer || !renderer->isImage())
        return nullptr;
    if (RenderImage* renderImage = toRenderImage(renderer)) {
        ImageResource* cachedImage = renderImage->cachedImage();
        if (!cachedImage || cachedImage->errorOccurred())
            return nullptr;
         return cachedImage->imageForRenderer(renderImage);
     }
     if (renderer->isCanvas())
         return toHTMLCanvasElement(node)->copiedImage();
     return nullptr;
}

[zino, 2014/06/20 07:07:08]

Done.

+    if (renderer->isImage()) {
+        RenderImage* renderImage = toRenderImage(renderer);
+        ImageResource* cachedImage = renderImage->cachedImage();
+        if (!cachedImage || cachedImage->errorOccurred())
+            return;
+        image = cachedImage->imageForRenderer(renderImage);
+    } else if (renderer->isCanvas()) {
+        image = toHTMLCanvasElement(node)->copiedImage();
+    } else {
         return;
-    Image* image = cachedImage->imageForRenderer(renderer);
+    }
     ASSERT(image);
 
     // FIXME: This should probably be reconciled with HitTestResult::absoluteImageURL.
@@ -444,6 +453,8 @@ static void writeImageNodeToPasteboard(Pasteboard* pasteboard, Node* node, const
         urlString = toElement(node)->getAttribute(XLinkNames::hrefAttr);
     else if (isHTMLEmbedElement(*node) || isHTMLObjectElement(*node))
         urlString = toElement(node)->imageSourceURL();
+    else if (isHTMLCanvasElement(*node))
+        urlString = AtomicString("data:,[canvas]");

[yosin_UTC9, 2014/06/20 04:24:10]

Just curiosity, what "data:,[canvas]" is? Where do we expand them real URL?

[zino, 2014/06/20 07:07:09]

I thought that the URL is not needed in the case of canvas because it is always
large dataURL.
Many native app uses binary image data usually but some JS app or service seems
to use dataURL instead of binary data.
So, I updated related codes.

     KURL url = urlString.isEmpty() ? KURL() : node->document().completeURL(stripLeadingAndTrailingHTMLSpaces(urlString));
 
     pasteboard->writeImage(image, url, title);