1 // Copyright (c) 2013 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef CONTENT_RENDERER_IMAGE_LOADING_HELPER_H_ 6 #define CONTENT_RENDERER_IMAGE_LOADING_HELPER_H_ 7 8 #include <string> 9 #include <vector> 10 11 #include "base/memory/scoped_vector.h" 12 #include "content/public/renderer/render_frame_observer.h" 13 #include "url/gurl.h" 14 15 class SkBitmap; 16 17 namespace content { 18 19 class MultiResolutionImageResourceFetcher; 20 21 // This class deals with image downloading. 22 // One instance of ImageLoadingHelper is owned by RenderFrame. 23 class ImageLoadingHelper : public RenderFrameObserver { 24 public: 25 explicit ImageLoadingHelper(RenderFrame* render_frame); 26 27 private: 28 virtual ~ImageLoadingHelper(); 29 30 // Message handler. 31 void OnDownloadImage(int id, 32 const GURL& image_url, 33 bool is_favicon, 34 uint32_t max_image_size); 35 36 // Requests to download an image. When done, the ImageLoadingHelper 37 // is notified by way of DidDownloadImage. Returns true if the 38 // request was successfully started, false otherwise. id is used to 39 // uniquely identify the request and passed back to the 40 // DidDownloadImage method. If the image is a favicon, cookies will not be 41 // sent nor accepted during download. If the image has multiple frames, all 42 // the frames whose size <= |max_image_size| are returned. If all of the 43 // frames are larger than |max_image_size|, the smallest frame is resized to 44 // |max_image_size| and is the only result. |max_image_size| == 0 is 45 // interpreted as no max image size. 46 bool DownloadImage(int id, 47 const GURL& image_url, 48 bool is_favicon, 49 uint32_t max_image_size); 50 51 // This callback is triggered when DownloadImage completes, either 52 // succesfully or with a failure. See DownloadImage for more 53 // details. 54 void DidDownloadImage( 55 uint32_t max_image_size, 56 MultiResolutionImageResourceFetcher* fetcher, 57 const std::vector<SkBitmap>& images); 58 59 // Decodes a data: URL image or returns an empty image in case of failure. 60 SkBitmap ImageFromDataUrl(const GURL&) const; 61 62 // RenderFrameObserver implementation. 63 virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE; 64 65 typedef ScopedVector<MultiResolutionImageResourceFetcher> 66 ImageResourceFetcherList; 67 68 // ImageResourceFetchers schedule via DownloadImage. 69 ImageResourceFetcherList image_fetchers_; 70 71 DISALLOW_COPY_AND_ASSIGN(ImageLoadingHelper); 72 }; 73 74 } // namespace content 75 76 #endif // CONTENT_RENDERER_IMAGE_LOADING_HELPER_H_ 77 78