chrome/browser/bitmap_fetcher.h

   1 // Copyright 2014 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_BITMAP_FETCHER_H_
   6 #define CHROME_BROWSER_BITMAP_FETCHER_H_
   7
   8 #include "base/memory/scoped_ptr.h"
   9 #include "chrome/browser/bitmap_fetcher_delegate.h"
  10 #include "chrome/browser/image_decoder.h"
  11 #include "net/url_request/url_fetcher_delegate.h"
  12 #include "third_party/skia/include/core/SkBitmap.h"
  13 #include "url/gurl.h"
  14
  15 namespace net {
  16 class URLFetcher;
  17 class URLRequestContextGetter;
  18 }  // namespace net
  19
  20 namespace chrome {
  21
  22 // Asynchrounously fetches an image from the given URL and returns the
  23 // decoded Bitmap to the provided BitmapFetcherDelegate.
  24 class BitmapFetcher : public net::URLFetcherDelegate,
  25                       public ImageDecoder::Delegate {
  26  public:
  27   BitmapFetcher(const GURL& url, BitmapFetcherDelegate* delegate);
  28   virtual ~BitmapFetcher();
  29
  30   const GURL& url() const { return url_; }
  31
  32   // Start fetching the URL with the fetcher. The delegate is notified
  33   // asynchronously when done.  Start may be called more than once in some
  34   // cases.  If so, subsequent starts will be ignored since the operation is
  35   // already in progress.
  36   void Start(net::URLRequestContextGetter* request_context);
  37
  38   // Methods inherited from URLFetcherDelegate
  39
  40   // This will be called when the URL has been fetched, successfully or not.
  41   // Use accessor methods on |source| to get the results.
  42   virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
  43
  44   // This will be called when some part of the response is read. |current|
  45   // denotes the number of bytes received up to the call, and |total| is the
  46   // expected total size of the response (or -1 if not determined).
  47   virtual void OnURLFetchDownloadProgress(const net::URLFetcher* source,
  48                                           int64 current,
  49                                           int64 total) OVERRIDE;
  50
  51   // Methods inherited from ImageDecoder::Delegate
  52
  53   // Called when image is decoded. |decoder| is used to identify the image in
  54   // case of decoding several images simultaneously.  This will not be called
  55   // on the UI thread.
  56   virtual void OnImageDecoded(const ImageDecoder* decoder,
  57                               const SkBitmap& decoded_image) OVERRIDE;
  58
  59   // Called when decoding image failed.
  60   virtual void OnDecodeImageFailed(const ImageDecoder* decoder) OVERRIDE;
  61
  62  private:
  63   // Alerts the delegate that a failure occurred.
  64   void ReportFailure();
  65
  66   scoped_ptr<net::URLFetcher> url_fetcher_;
  67   scoped_refptr<ImageDecoder> image_decoder_;
  68   const GURL url_;
  69   BitmapFetcherDelegate* const delegate_;
  70
  71   DISALLOW_COPY_AND_ASSIGN(BitmapFetcher);
  72 };
  73
  74 }  // namespace chrome
  75
  76 #endif  // CHROME_BROWSER_BITMAP_FETCHER_H_