Instant Extended: Fallback to local preview if the remote instant page is not ready on user input.

chrome/browser/instant/instant_controller.h

 // Copyright 2012 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_INSTANT_INSTANT_CONTROLLER_H_
 #define CHROME_BROWSER_INSTANT_INSTANT_CONTROLLER_H_
 
 #include <list>
 #include <map>
 #include <string>
@@ skipping 169 matching lines @@
 
   // Adds a new event to |debug_events_| and also DVLOG's it. Ensures that
   // |debug_events_| doesn't get too large.
   void LogDebugEvent(const std::string& info) const;
 
   // See comments for |debug_events_| below.
   const std::list<std::pair<int64, std::string> >& debug_events() {
     return debug_events_;
   }
 
+  // Variable accessors required by the InstantLoader.
+  bool extended_enabled() const { return extended_enabled_; }
+  bool instant_enabled() const { return instant_enabled_; }
+  chrome::search::Mode search_mode() const { return search_mode_; }
+  OmniboxFocusState omnibox_focus_state() const { return omnibox_focus_state_; }
+  int start_margin() const { return start_margin_; }
+  int end_margin() const { return end_margin_; }

[sreeram, 2013/01/30 19:28:08]

Won't it be simpler to just have the InstantLoader call into the
InstantController (say controller_->RenderViewCreated()) and have the
InstantController perform all the initializations? Especially since some of
these are already APIs that the IC calls on the IL (such as SetMarginSize(),
SetDisplayInstantResults, etc). Then you don't need all these accessors.

[Shishir, 2013/01/31 23:46:47]

Done.

+
  private:
   FRIEND_TEST_ALL_PREFIXES(InstantTest, OmniboxFocusLoadsInstant);
   FRIEND_TEST_ALL_PREFIXES(InstantTest, SetWithTemplateURL);
   FRIEND_TEST_ALL_PREFIXES(InstantTest, NonInstantSearchProvider);
   FRIEND_TEST_ALL_PREFIXES(InstantTest, InstantLoaderRefresh);
   FRIEND_TEST_ALL_PREFIXES(InstantExtendedTest, ExtendedModeIsOn);
   FRIEND_TEST_ALL_PREFIXES(InstantExtendedTest, OmniboxFocusLoadsInstant);
 
   // Helper for OmniboxFocusChanged. Commit or discard the preview.
   void OmniboxLostFocus(gfx::NativeView view_gaining_focus);
 
   // Ensures that |loader_| uses the Instant URL returned by GetInstantURL(),
   // creating a new loader if necessary. In extended mode, will fallback to
   // using the kLocalOmniboxPopupURL as the Instant URL in case GetInstantURL()
   // returns false. Returns true if an Instant URL could be determined.
   bool EnsureLoaderIsCurrent();
 
   // Recreates the |loader_| with the input |instant_url|. The caller should
   // ensure that the |loader_| is not already on the stack since it is deleted
   // in this call.
   void CreateLoader(const std::string& instant_url,
                     const content::WebContents* active_tab);
 
   // Called when the |loader_| might be stale. If it's actually stale, and the
   // omnibox doesn't have focus, and the preview isn't showing, the |loader_| is
   // deleted and recreated. Else the refresh is skipped.
   void OnStaleLoader();
 
+  // If the |loader_| being used is in fallback mode, it will be switched back
+  // to the remote loader if the loader is not showing and the omnibox does not
+  // have focus.
+  void MaybeSwitchToRemoteLoader();
+
   // If the active tab is an Instant search results page, sets |instant_tab_| to
   // point to it. Else, deletes any existing |instant_tab_|.
   void ResetInstantTab();
 
   // Hide the preview. Also sends an onchange event (with blank query) to the
   // preview, telling it to clear out results for any old queries.
   void HideLoader();
 
   // Like HideLoader(), but doesn't call OnStaleLoader(). Use HideLoader()
   // unless you are going to call loader_.reset() yourself subsequently.
@@ skipping 113 matching lines @@
   // MODE_SEARCH_SUGGESTIONS, except in those cases where this is false.
   bool allow_preview_to_show_search_suggestions_;
 
   // List of events and their timestamps, useful in debugging Instant behaviour.
   mutable std::list<std::pair<int64, std::string> > debug_events_;
 
   DISALLOW_COPY_AND_ASSIGN(InstantController);
 };
 
 #endif  // CHROME_BROWSER_INSTANT_INSTANT_CONTROLLER_H_