chrome/browser/thumbnails/thumbnail_service.h

   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 "components/history/core/common/thumbnail_score.h"
   9 #include "components/keyed_service/core/refcounted_keyed_service.h"
  10 #include "ui/gfx/image/image.h"
  11
  12 class GURL;
  13
  14 namespace base {
  15 class RefCountedMemory;
  16 }
  17
  18 namespace thumbnails {
  19
  20 class ThumbnailingAlgorithm;
  21 struct 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.
  26 class ThumbnailService : public RefcountedKeyedService {
  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   ~ThumbnailService() override {}
  62 };
  63
  64 }  // namespace thumbnails
  65
  66 #endif  // CHROME_BROWSER_THUMBNAILS_THUMBNAIL_SERVICE_H_