Move favicon from TabContents to TabContentsWrapper.

chrome/browser/favicon_helper.h

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef CHROME_BROWSER_FAVICON_HELPER_H__
-#define CHROME_BROWSER_FAVICON_HELPER_H__
-#pragma once
-
-#include <map>
-
-#include "base/basictypes.h"
-#include "base/callback.h"
-#include "base/memory/ref_counted.h"
-#include "chrome/browser/favicon_service.h"
-#include "chrome/common/ref_counted_util.h"
-#include "content/browser/cancelable_request.h"
-#include "content/browser/tab_contents/tab_contents_observer.h"
-#include "googleurl/src/gurl.h"
-
-class NavigationEntry;
-class Profile;
-class RefCountedMemory;
-class SkBitmap;
-class TabContents;
-
-// FaviconHelper is used to fetch the favicon for TabContents.
-//
-// FetchFavicon requests the favicon from the favicon service which in turn
-// requests the favicon from the history database. At this point
-// we only know the URL of the page, and not necessarily the url of the
-// favicon. To ensure we handle reloading stale favicons as well as
-// reloading a favicon on page reload we always request the favicon from
-// history regardless of whether the NavigationEntry has a favicon.
-//
-// After the navigation two types of events are delivered (which is
-// first depends upon who is faster): notification from the history
-// db on our request for the favicon (OnFaviconDataForInitialURL),
-// or a message from the renderer giving us the URL of the favicon for
-// the page (SetFaviconURL).
-// . If the history db has a valid up to date favicon for the page, we update
-//   the NavigationEntry and use the favicon.
-// . When we receive the favicon url if it matches that of the NavigationEntry
-//   and the NavigationEntry's favicon is set, we do nothing (everything is
-//   ok).
-// . On the other hand if the database does not know the favicon for url, or
-//   the favicon is out date, or the URL from the renderer does not match that
-//   NavigationEntry we proceed to DownloadFaviconOrAskHistory. Before we
-//   invoke DownloadFaviconOrAskHistory we wait until we've received both
-//   the favicon url and the callback from history. We wait to ensure we
-//   truly know both the favicon url and the state of the database.
-//
-// DownloadFaviconOrAskHistory does the following:
-// . If we have a valid favicon, but it is expired we ask the renderer to
-//   download the favicon.
-// . Otherwise we ask the history database to update the mapping from
-//   page url to favicon url and call us back with the favicon. Remember, it is
-//   possible for the db to already have the favicon, just not the mapping
-//   between page to favicon url. The callback for this is OnFaviconData.
-//
-// OnFaviconData either updates the favicon of the NavigationEntry (if the
-// db knew about the favicon), or requests the renderer to download the
-// favicon.
-//
-// When the renderer downloads the favicon SetFaviconImageData is invoked,
-// at which point we update the favicon of the NavigationEntry and notify
-// the database to save the favicon.
-
-class FaviconHelper : public TabContentsObserver {
- public:
-  explicit FaviconHelper(TabContents* tab_contents);
-  virtual ~FaviconHelper();
-
-  // Initiates loading the favicon for the specified url.
-  void FetchFavicon(const GURL& url);
-
-  // Initiates loading an image from given |image_url|. Returns a download id
-  // for caller to track the request. When download completes, |callback| is
-  // called with the three params: the download_id, a boolean flag to indicate
-  // whether the download succeeds and a SkBitmap as the downloaded image.
-  // Note that |image_size| is a hint for images with multiple sizes. The
-  // downloaded image is not resized to the given image_size. If 0 is passed,
-  // the first frame of the image is returned.
-  typedef Callback3<int, bool, const SkBitmap&>::Type ImageDownloadCallback;
-  int DownloadImage(const GURL& image_url, int image_size,
-                    ImageDownloadCallback* callback);
-
-  // Message Handler.  Must be public, because also called from
-  // PrerenderContents.
-  void OnUpdateFaviconURL(int32 page_id, const GURL& icon_url);
-
- private:
-  struct DownloadRequest {
-    DownloadRequest() : callback(NULL) {}
-    DownloadRequest(const GURL& url,
-                    const GURL& image_url,
-                    ImageDownloadCallback* callback)
-        : url(url),
-          image_url(image_url),
-          callback(callback) {}
-
-    GURL url;
-    GURL image_url;
-    ImageDownloadCallback* callback;
-  };
-
-  // TabContentsObserver implementation.
-  virtual bool OnMessageReceived(const IPC::Message& message);
-
-  void OnDidDownloadFavicon(int id,
-                            const GURL& image_url,
-                            bool errored,
-                            const SkBitmap& image);
-
-  // Return the NavigationEntry for the active entry, or NULL if the active
-  // entries URL does not match that of the URL last passed to FetchFavicon.
-  NavigationEntry* GetEntry();
-
-  Profile* profile();
-
-  FaviconService* GetFaviconService();
-
-  // See description above class for details.
-  void OnFaviconDataForInitialURL(FaviconService::Handle handle,
-                                  history::FaviconData favicon);
-
-  // If the favicon has expired, asks the renderer to download the favicon.
-  // Otherwise asks history to update the mapping between page url and icon
-  // url with a callback to OnFaviconData when done.
-  void DownloadFaviconOrAskHistory(NavigationEntry* entry);
-
-  // See description above class for details.
-  void OnFaviconData(FaviconService::Handle handle,
-                     history::FaviconData favicon);
-
-  // Schedules a download for the specified entry. This adds the request to
-  // download_requests_.
-  int ScheduleDownload(const GURL& url, const GURL& image_url, int image_size,
-                       ImageDownloadCallback* callback);
-
-  // Sets the image data for the favicon. This is invoked asynchronously after
-  // we request the TabContents to download the favicon.
-  void SetFavicon(const GURL& url, const GURL& icon_url, const SkBitmap& image);
-
-  // Converts the image data to an SkBitmap and sets it on the NavigationEntry.
-  // If the TabContents has a delegate, it is notified of the new favicon
-  // (INVALIDATE_FAVICON).
-  void UpdateFavicon(NavigationEntry* entry,
-                     scoped_refptr<RefCountedMemory> data);
-  void UpdateFavicon(NavigationEntry* entry, const SkBitmap& image);
-
-  // Scales the image such that either the width and/or height is 16 pixels
-  // wide. Does nothing if the image is empty.
-  SkBitmap ConvertToFaviconSize(const SkBitmap& image);
-
-  // Returns true if the favicon should be saved.
-  bool ShouldSaveFavicon(const GURL& url);
-
-  // Used for history requests.
-  CancelableRequestConsumer cancelable_consumer_;
-
-  // URL of the page we're requesting the favicon for.
-  GURL url_;
-
-  // Whether we got the url for the page back from the renderer.
-  // See "Favicon Details" in tab_contents.cc for more details.
-  bool got_favicon_url_;
-
-  // Whether we got the initial response for the favicon back from the renderer.
-  // See "Favicon Details" in tab_contents.cc for more details.
-  bool got_favicon_from_history_;
-
-  // Whether the favicon is out of date. If true, it means history knows about
-  // the favicon, but we need to download the favicon because the icon has
-  // expired.
-  // See "Favicon Details" in tab_contents.cc for more details.
-  bool favicon_expired_;
-
-  // Requests to the renderer to download favicons.
-  typedef std::map<int, DownloadRequest> DownloadRequests;
-  DownloadRequests download_requests_;
-
-  DISALLOW_COPY_AND_ASSIGN(FaviconHelper);
-};
-
-#endif  // CHROME_BROWSER_FAVICON_HELPER_H__