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_UI_WEBUI_NTP_THUMBNAIL_SOURCE_H_
6#define CHROME_BROWSER_UI_WEBUI_NTP_THUMBNAIL_SOURCE_H_
7
8#include <string>
9
10#include "base/basictypes.h"
11#include "base/memory/ref_counted.h"
12#include "content/public/browser/url_data_source.h"
13
14class Profile;
15
16namespace base {
17class RefCountedMemory;
18}
19
20namespace thumbnails {
21class ThumbnailService;
22}
23
24// ThumbnailSource is the gateway between network-level chrome: requests for
25// thumbnails and the history/top-sites backend that serves these.
26class ThumbnailSource : public content::URLDataSource {
27 public:
28  ThumbnailSource(Profile* profile, bool capture_thumbnails);
29
30  // content::URLDataSource implementation.
31  virtual std::string GetSource() const OVERRIDE;
32  virtual void StartDataRequest(
33      const std::string& path,
34      int render_process_id,
35      int render_frame_id,
36      const content::URLDataSource::GotDataCallback& callback) OVERRIDE;
37  virtual std::string GetMimeType(const std::string& path) const OVERRIDE;
38  virtual base::MessageLoop* MessageLoopForRequestPath(
39      const std::string& path) const OVERRIDE;
40  virtual bool ShouldServiceRequest(
41      const net::URLRequest* request) const OVERRIDE;
42
43 private:
44  virtual ~ThumbnailSource();
45
46  // Raw PNG representation of the thumbnail to show when the thumbnail
47  // database doesn't have a thumbnail for a webpage.
48  scoped_refptr<base::RefCountedMemory> default_thumbnail_;
49
50  // ThumbnailService.
51  scoped_refptr<thumbnails::ThumbnailService> thumbnail_service_;
52
53  // Only used when servicing requests on the UI thread.
54  Profile* const profile_;
55
56  // Indicate that, when a URL for which we don't have a thumbnail is requested
57  // from this source, then Chrome should capture a thumbnail next time it
58  // navigates to this URL. This is useful when the thumbnail URLs are generated
59  // by an external service rather than TopSites, so Chrome can learn about the
60  // URLs for which it should get thumbnails. Sources that capture thumbnails
61  // are also be more lenient when matching thumbnail URLs by checking for
62  // existing thumbnails in the database that contain a URL matching the prefix
63  // of the requested URL.
64  const bool capture_thumbnails_;
65
66  DISALLOW_COPY_AND_ASSIGN(ThumbnailSource);
67};
68
69#endif  // CHROME_BROWSER_UI_WEBUI_NTP_THUMBNAIL_SOURCE_H_
70