Instant: Use only one hidden WebContents per profile.

chrome/browser/ui/browser_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_UI_BROWSER_INSTANT_CONTROLLER_H_
 #define CHROME_BROWSER_UI_BROWSER_INSTANT_CONTROLLER_H_
 
 #include "base/basictypes.h"
-#include "base/compiler_specific.h"
-#include "base/prefs/public/pref_change_registrar.h"
-#include "chrome/browser/instant/instant_controller.h"
+#include "base/memory/scoped_ptr.h"
 #include "chrome/browser/instant/instant_unload_handler.h"
-#include "chrome/browser/ui/search/search_model_observer.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_registrar.h"
+#include "content/public/common/page_transition_types.h"
 #include "ui/base/window_open_disposition.h"
 
 class Browser;
+class GURL;
+class InstantController;
 struct InstantSuggestion;
-class PrefRegistrySyncable;
-class PrefService;
-class Profile;
-class ThemeService;
 
 namespace content {
 class WebContents;
 }
 
 namespace gfx {
 class Rect;
 }
 
 namespace chrome {
 
-class BrowserInstantController : public content::NotificationObserver,
-                                 public search::SearchModelObserver {
+// BrowserInstantController is a bridge between Browser and InstantController.
+// It is owned by Browser, and in turn, owns InstantController.
+class BrowserInstantController {
  public:
   explicit BrowserInstantController(Browser* browser);
   virtual ~BrowserInstantController();
 
-  // Returns true if Instant is enabled in a visible, preview-showing mode.
-  static bool IsInstantEnabled(Profile* profile);
+  InstantController* instant() const { return instant_.get(); }
 
-  // Registers Instant related preferences.
-  static void RegisterUserPrefs(PrefService* prefs,
-                                PrefRegistrySyncable* registry);
+  // --------------------------------------------------------------------------
+  // Methods invoked by |browser_|
 
-  // If |url| is the new tab page URL, set |target_contents| to the preloaded
+  // If |url| is the new tab page URL, sets |target_contents| to the preloaded
   // NTP contents from InstantController. If |source_contents| is not NULL, we
   // replace it with the new |target_contents| in the tabstrip and delete
   // |source_contents|. Otherwise, the caller owns |target_contents| and is
   // responsible for inserting it into the tabstrip.
   //
   // Returns true if and only if we update |target_contents|.
-  bool MaybeSwapInInstantNTPContents(
-      const GURL& url,
-      content::WebContents* source_contents,
-      content::WebContents** target_contents);
+  bool MaybeSwapInInstantNTPContents(const GURL& url,
+                                     content::WebContents* source_contents,
+                                     content::WebContents** target_contents);
 
-  // Commits the current Instant, returning true on success. This is intended
-  // for use from OpenCurrentURL.
+  // Commits the current Instant overlay, returning true on success. This is
+  // intended to be invoked by |browser_| from OpenCurrentURL.
   bool OpenInstant(WindowOpenDisposition disposition);
 
-  // Returns the Profile associated with the Browser that owns this object.
-  Profile* profile() const;
+  // --------------------------------------------------------------------------
+  // Methods invoked by |instant_|
 
-  // Returns the InstantController or NULL if there is no InstantController for
-  // this BrowserInstantController.
-  InstantController* instant() { return &instant_; }
+  // Commits the |overlay| by merging it into the active tab or a new tab.
+  void CommitInstant(scoped_ptr<content::WebContents> overlay,
+                     content::PageTransition transition,
+                     bool in_new_tab);
 
-  // Invoked by |instant_| to commit the |preview| by merging it into the active
-  // tab or adding it as a new tab.
-  void CommitInstant(scoped_ptr<content::WebContents> preview, bool in_new_tab);
-
-  // Invoked by |instant_| to autocomplete the |suggestion| into the omnibox.
+  // Autocompletes the |suggestion| into the omnibox.
   void SetInstantSuggestion(const InstantSuggestion& suggestion);
 
-  // Invoked by |instant_| to commit the omnibox's suggested text.
-  // Call-through to OmniboxEditModel::CommitSuggestedText.
+  // Commits the omnibox's suggested text (gray text).
   void CommitSuggestedText(bool skip_inline_autocomplete);
 
-  // Invoked by |instant_| to get the bounds that the preview is placed at,
-  // in screen coordinates.
-  gfx::Rect GetInstantBounds();
+  // Returns the bounds that the overlay is placed at, in screen coordinates.
+  gfx::Rect GetInstantBounds() const;
 
-  // Invoked by |instant_| to notify that the preview gained focus, usually due
-  // to the user clicking on it.
-  void InstantPreviewFocused();
+  // Notifies |browser_| that the overlay gained focus, usually due to the user
+  // clicking on it.
+  void InstantOverlayFocused();
 
-  // Invoked by |instant_| to give the omnibox focus invisibly.
+  // Focuses the omnibox invisibly.
   void FocusOmniboxInvisibly();
 
-  // Invoked by |instant_| to get the currently active tab, over which the
-  // preview would be shown.
+  // Returns the currently active tab, over which the overlay would be shown.
   content::WebContents* GetActiveWebContents() const;
 
-  // Invoked by |browser_| when the active tab changes.
-  void ActiveTabChanged();
-
-  // Invoked by |browser_| when the active tab is about to be deactivated.
-  void TabDeactivated(content::WebContents* contents);
-
-  // Invoked by |instant_| or |browser_| to update theme information for NTP.
-  // Set |parse_theme_info| to true to force re-parsing of theme information.
-  void UpdateThemeInfo(bool parse_theme_info);
-
-  // Invoked by the InstantController when it wants to open a URL.
+  // Requests |browser_| to perform a browser-initiated navigation.
   void OpenURL(const GURL& url,
                content::PageTransition transition,
                WindowOpenDisposition disposition);
 
-  // Sets the stored omnibox bounds.
-  void SetOmniboxBounds(const gfx::Rect& bounds);
-
  private:
-  // Sets the value of |instant_| based on value from profile. Invoked
-  // on pref change.
-  void ResetInstant();
-
-  // Overridden from search::SearchModelObserver:
-  virtual void ModeChanged(const search::Mode& old_mode,
-                           const search::Mode& new_mode) OVERRIDE;
-
-  // content::NotificationObserver implementation.
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
-
-  // Helper for handling theme change.
-  void OnThemeChanged(ThemeService* theme_service);
-
   // Replaces the contents at tab |index| with |new_contents| and deletes the
   // existing contents.
   void ReplaceWebContentsAt(int index,
                             scoped_ptr<content::WebContents> new_contents);
 
   Browser* const browser_;
-
-  InstantController instant_;
+  scoped_ptr<InstantController> instant_;
   InstantUnloadHandler instant_unload_handler_;
 
-  // Theme-related data for NTP preview to adopt themes.
-  bool initialized_theme_info_;  // True if theme_info_ has been initialized.
-  ThemeBackgroundInfo theme_info_;
-
-  PrefChangeRegistrar profile_pref_registrar_;
-
-  content::NotificationRegistrar registrar_;
-
   DISALLOW_COPY_AND_ASSIGN(BrowserInstantController);
 };
 
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_UI_BROWSER_INSTANT_CONTROLLER_H_