fav icon -> favicon. Pass 1.

BUG=76073
TEST=none; no visible change

Review URL: http://codereview.chromium.org/6679047

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@78076 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 191 insertions, 0 deletions

diff --git a/chrome/browser/favicon_helper.h b/chrome/browser/favicon_helper.h
new file mode 100644
index 0000000..38b20b4
--- /dev/null
+++ b/chrome/browser/favicon_helper.h
@@ -0,0 +1,191 @@
+// 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/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() {}
+    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,
+                                  bool know_favicon,
+                                  scoped_refptr<RefCountedMemory> data,
+                                  bool expired,
+                                  GURL icon_url);
+
+  // 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,
+                     bool know_favicon,
+                     scoped_refptr<RefCountedMemory> data,
+                     bool expired,
+                     GURL icon_url);
+
+  // 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__