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_THUMBNAILS_THUMBNAIL_SERVICE_H_
6#define CHROME_BROWSER_THUMBNAILS_THUMBNAIL_SERVICE_H_
7
8#include "chrome/common/thumbnail_score.h"
9#include "components/browser_context_keyed_service/refcounted_browser_context_keyed_service.h"
10#include "ui/gfx/image/image.h"
11
12class GURL;
13
14namespace base {
15class RefCountedMemory;
16}
17
18namespace thumbnails {
19
20class ThumbnailingAlgorithm;
21struct ThumbnailingContext;
22
23// An interface abstracting access to thumbnails. Intended as a temporary
24// bridge facilitating switch from TopSites as the thumbnail source to a more
25// robust way of handling these artefacts.
26class ThumbnailService : public RefcountedBrowserContextKeyedService {
27 public:
28  // Sets the given thumbnail for the given URL. Returns true if the thumbnail
29  // was updated. False means either the URL wasn't known to us, or we felt
30  // that our current thumbnail was superior to the given one.
31  virtual bool SetPageThumbnail(const ThumbnailingContext& context,
32                                const gfx::Image& thumbnail) = 0;
33
34  // Returns the ThumbnailingAlgorithm used for processing thumbnails.
35  // It is always a new instance, the caller owns it. It will encapsulate the
36  // process of creating a thumbnail from tab contents. The lifetime of these
37  // instances is limited to the act of processing a single tab image. They
38  // are permitted to hold the state of such process.
39  virtual ThumbnailingAlgorithm* GetThumbnailingAlgorithm() const = 0;
40
41  // Gets a thumbnail for a given page. Returns true iff we have the thumbnail.
42  // This may be invoked on any thread.
43  // If an exact thumbnail URL match fails, |prefix_match| specifies whether or
44  // not to try harder by matching the query thumbnail URL as URL prefix (as
45  // defined by UrlIsPrefix()).
46  // As this method may be invoked on any thread the ref count needs to be
47  // incremented before this method returns, so this takes a scoped_refptr*.
48  virtual bool GetPageThumbnail(
49      const GURL& url,
50      bool prefix_match,
51      scoped_refptr<base::RefCountedMemory>* bytes) = 0;
52
53  // Add or updates a |url| for which we should force the capture of a thumbnail
54  // next time it's visited.
55  virtual void AddForcedURL(const GURL& url) = 0;
56
57  // Returns true if the page thumbnail should be updated.
58  virtual bool ShouldAcquirePageThumbnail(const GURL& url) = 0;
59
60 protected:
61  virtual ~ThumbnailService() {}
62};
63
64}  // namespace thumbnails
65
66#endif  // CHROME_BROWSER_THUMBNAILS_THUMBNAIL_SERVICE_H_
67