chrome/browser/bitmap_fetcher/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_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/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::ImageRequest {
  27  public:
  28   BitmapFetcher(const GURL& url, BitmapFetcherDelegate* delegate);
  29   ~BitmapFetcher() override;
  30
  31   const GURL& url() const { return url_; }
  32   net::URLFetcher* url_fetcher() { return url_fetcher_.get(); }
  33
  34   // Initializes internal fetcher.  After this function returns url_fetcher()
  35   // can be accessed to configure it further (eg. add user data to request).
  36   // All configuration must be done before Start() is called.
  37   // Values for |load_flags| are defined in net/base/load_flags.h.  In general,
  38   // |net::LOAD_NORMAL| is appropriate.  Init may be called more than once in
  39   // some cases.  If so, subsequent starts will be ignored.
  40   void Init(net::URLRequestContextGetter* request_context,
  41             const std::string& referrer,
  42             net::URLRequest::ReferrerPolicy referrer_policy,
  43             int load_flags);
  44
  45   // Start fetching the URL with the fetcher. The delegate is notified
  46   // asynchronously when done.  Start may be called more than once in some
  47   // cases.  If so, subsequent starts will be ignored since the operation is
  48   // already in progress.
  49   void Start();
  50
  51   // Methods inherited from URLFetcherDelegate
  52
  53   // This will be called when the URL has been fetched, successfully or not.
  54   // Use accessor methods on |source| to get the results.
  55   void OnURLFetchComplete(const net::URLFetcher* source) override;
  56
  57   // This will be called when some part of the response is read. |current|
  58   // denotes the number of bytes received up to the call, and |total| is the
  59   // expected total size of the response (or -1 if not determined).
  60   void OnURLFetchDownloadProgress(const net::URLFetcher* source,
  61                                   int64 current,
  62                                   int64 total) override;
  63
  64   // Methods inherited from ImageDecoder::ImageRequest
  65
  66   // Called when image is decoded. |decoder| is used to identify the image in
  67   // case of decoding several images simultaneously.  This will not be called
  68   // on the UI thread.
  69   void OnImageDecoded(const SkBitmap& decoded_image) override;
  70
  71   // Called when decoding image failed.
  72   void OnDecodeImageFailed() override;
  73
  74  private:
  75   // Alerts the delegate that a failure occurred.
  76   void ReportFailure();
  77
  78   scoped_ptr<net::URLFetcher> url_fetcher_;
  79   const GURL url_;
  80   BitmapFetcherDelegate* const delegate_;
  81
  82   DISALLOW_COPY_AND_ASSIGN(BitmapFetcher);
  83 };
  84
  85 }  // namespace chrome
  86
  87 #endif  // CHROME_BROWSER_BITMAP_FETCHER_BITMAP_FETCHER_H_