1 // Copyright (c) 2012 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 CHROME_BROWSER_IMAGE_DECODER_H_ 6 #define CHROME_BROWSER_IMAGE_DECODER_H_ 7 8 #include <string> 9 #include <vector> 10 11 #include "base/compiler_specific.h" 12 #include "base/memory/ref_counted.h" 13 #include "base/threading/sequenced_worker_pool.h" 14 #include "content/public/browser/utility_process_host_client.h" 15 16 class SkBitmap; 17 18 // Decodes an image in a sandboxed process. 19 class ImageDecoder : public content::UtilityProcessHostClient { 20 public: 21 class Delegate { 22 public: 23 // Called when image is decoded. 24 // |decoder| is used to identify the image in case of decoding several 25 // images simultaneously. 26 virtual void OnImageDecoded(const ImageDecoder* decoder, 27 const SkBitmap& decoded_image) = 0; 28 29 // Called when decoding image failed. Delegate can do some cleanup in 30 // this handler. OnDecodeImageFailed(const ImageDecoder * decoder)31 virtual void OnDecodeImageFailed(const ImageDecoder* decoder) {} 32 33 protected: ~Delegate()34 virtual ~Delegate() {} 35 }; 36 37 enum ImageCodec { 38 DEFAULT_CODEC = 0, // Uses WebKit image decoding (via WebImage). 39 ROBUST_JPEG_CODEC, // Restrict decoding to robust jpeg codec. 40 }; 41 42 ImageDecoder(Delegate* delegate, 43 const std::string& image_data, 44 ImageCodec image_codec); 45 46 // Starts asynchronous image decoding. Once finished, the callback will be 47 // posted back to |task_runner|. 48 void Start(scoped_refptr<base::SequencedTaskRunner> task_runner); 49 get_image_data()50 const std::vector<unsigned char>& get_image_data() const { 51 return image_data_; 52 } 53 set_delegate(Delegate * delegate)54 void set_delegate(Delegate* delegate) { delegate_ = delegate; } set_shrink_to_fit(bool shrink_to_fit)55 void set_shrink_to_fit(bool shrink_to_fit) { shrink_to_fit_ = shrink_to_fit; } 56 57 private: 58 // It's a reference counted object, so destructor is private. 59 virtual ~ImageDecoder(); 60 61 // Overidden from UtilityProcessHostClient: 62 virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE; 63 64 // IPC message handlers. 65 void OnDecodeImageSucceeded(const SkBitmap& decoded_image); 66 void OnDecodeImageFailed(); 67 68 // Launches sandboxed process that will decode the image. 69 void DecodeImageInSandbox(const std::vector<unsigned char>& image_data); 70 71 Delegate* delegate_; 72 std::vector<unsigned char> image_data_; 73 const ImageCodec image_codec_; 74 scoped_refptr<base::SequencedTaskRunner> task_runner_; 75 bool shrink_to_fit_; // if needed for IPC msg size limit 76 77 DISALLOW_COPY_AND_ASSIGN(ImageDecoder); 78 }; 79 80 #endif // CHROME_BROWSER_IMAGE_DECODER_H_ 81