Refactor image handling in Sky

sky/engine/core/loader/CanvasImageLoader.cpp

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "sky/engine/config.h"
+#include "sky/engine/core/loader/CanvasImageLoader.h"
+#include "sky/engine/core/painting/CanvasImage.h"
+#include "sky/engine/platform/image-decoders/ImageDecoder.h"
+#include "sky/engine/platform/SharedBuffer.h"
+
+namespace blink {
+
+CanvasImageLoader::CanvasImageLoader(const String& src, PassOwnPtr<ImageLoaderCallback> callback)
+  : callback_(callback) {
+  // TODO(jackson): Figure out how to determine the proper base URL here
+  url_ = KURL(KURL(), src);
+}
+
+CanvasImageLoader::~CanvasImageLoader() {
+}
+
+void CanvasImageLoader::load() {
+  fetcher_ = adoptPtr(new MojoFetcher(this, url_));
+}
+
+void CanvasImageLoader::OnReceivedResponse(mojo::URLResponsePtr response) {
+  if (response->status_code != 200) {
+    callback_->handleEvent(nullptr);
+    return;
+  }
+  buffer_ = SharedBuffer::create();
+  drainer_ =
+      adoptPtr(new mojo::common::DataPipeDrainer(this, response->body.Pass()));
+}
+
+void CanvasImageLoader::OnDataAvailable(const void* data, size_t num_bytes) {
+  buffer_->append(static_cast<const char*>(data), num_bytes);
+}
+
+void CanvasImageLoader::OnDataComplete() {
+  OwnPtr<ImageDecoder> decoder =
+      ImageDecoder::create(*buffer_.get(), ImageSource::AlphaPremultiplied,
+                           ImageSource::GammaAndColorProfileIgnored);
+  decoder->setData(buffer_.get(), true);
+  if (!decoder->failed() && decoder->frameCount() > 0) {
+    RefPtr<CanvasImage> resultImage = CanvasImage::create();
+    resultImage->setBitmap(decoder->frameBufferAtIndex(0)->getSkBitmap());
+    callback_->handleEvent(resultImage.get());
+  } else {
+    callback_->handleEvent(nullptr);
+  }
+}
+
+}  // namespace blink