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      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_BITMAP_FETCHER_H_
      6 #define CHROME_BROWSER_BITMAP_FETCHER_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 "net/url_request/url_request.h"
     13 #include "third_party/skia/include/core/SkBitmap.h"
     14 #include "url/gurl.h"
     15 
     16 namespace net {
     17 class URLFetcher;
     18 class URLRequestContextGetter;
     19 }  // namespace net
     20 
     21 namespace chrome {
     22 
     23 // Asynchrounously fetches an image from the given URL and returns the
     24 // decoded Bitmap to the provided BitmapFetcherDelegate.
     25 class BitmapFetcher : public net::URLFetcherDelegate,
     26                       public ImageDecoder::Delegate {
     27  public:
     28   BitmapFetcher(const GURL& url, BitmapFetcherDelegate* delegate);
     29   virtual ~BitmapFetcher();
     30 
     31   const GURL& url() const { return url_; }
     32 
     33   // Start fetching the URL with the fetcher. The delegate is notified
     34   // asynchronously when done.  Start may be called more than once in some
     35   // cases.  If so, subsequent starts will be ignored since the operation is
     36   // already in progress.  Arguments are used to configure the internal fetcher.
     37   // Values for |load_flags| are defined in net/base/load_flags.h.  In general,
     38   // |net::LOAD_NORMAL| is appropriate.
     39   void Start(net::URLRequestContextGetter* request_context,
     40              const std::string& referrer,
     41              net::URLRequest::ReferrerPolicy referrer_policy,
     42              int load_flags);
     43 
     44   // Methods inherited from URLFetcherDelegate
     45 
     46   // This will be called when the URL has been fetched, successfully or not.
     47   // Use accessor methods on |source| to get the results.
     48   virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
     49 
     50   // This will be called when some part of the response is read. |current|
     51   // denotes the number of bytes received up to the call, and |total| is the
     52   // expected total size of the response (or -1 if not determined).
     53   virtual void OnURLFetchDownloadProgress(const net::URLFetcher* source,
     54                                           int64 current,
     55                                           int64 total) OVERRIDE;
     56 
     57   // Methods inherited from ImageDecoder::Delegate
     58 
     59   // Called when image is decoded. |decoder| is used to identify the image in
     60   // case of decoding several images simultaneously.  This will not be called
     61   // on the UI thread.
     62   virtual void OnImageDecoded(const ImageDecoder* decoder,
     63                               const SkBitmap& decoded_image) OVERRIDE;
     64 
     65   // Called when decoding image failed.
     66   virtual void OnDecodeImageFailed(const ImageDecoder* decoder) OVERRIDE;
     67 
     68  private:
     69   // Alerts the delegate that a failure occurred.
     70   void ReportFailure();
     71 
     72   scoped_ptr<net::URLFetcher> url_fetcher_;
     73   scoped_refptr<ImageDecoder> image_decoder_;
     74   const GURL url_;
     75   BitmapFetcherDelegate* const delegate_;
     76 
     77   DISALLOW_COPY_AND_ASSIGN(BitmapFetcher);
     78 };
     79 
     80 }  // namespace chrome
     81 
     82 #endif  // CHROME_BROWSER_BITMAP_FETCHER_BITMAP_FETCHER_H_
     83