Instant: Use only one hidden WebContents per profile.

chrome/browser/instant/instant_loader.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_LOADER_H_
 #define CHROME_BROWSER_INSTANT_INSTANT_LOADER_H_
 
 #include "base/basictypes.h"
-#include "base/callback.h"
 #include "base/compiler_specific.h"
+#include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/timer.h"
-#include "chrome/browser/ui/tab_contents/core_tab_helper_delegate.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_registrar.h"
-#include "content/public/browser/web_contents_delegate.h"
+#include "chrome/browser/instant/instant_page.h"
+#include "chrome/browser/instant/instant_service_observer.h"
+#include "chrome/browser/instant/instant_web_contents_container.h"
 
-class GURL;
-class Profile;
+class InstantService;
 
 namespace content {
-struct OpenURLParams;
 class WebContents;
 }
 
-// InstantLoader is used to create and maintain a WebContents where we can
-// preload a page into. It is used by InstantOverlay and InstantNTP to
-// preload an Instant page.
-class InstantLoader : public content::NotificationObserver,
-                      public content::WebContentsDelegate,
-                      public CoreTabHelperDelegate {
+// InstantLoader maintains a hidden WebContents into which it loads the default
+// search engine's Instant URL. InstantLoader is owned by InstantService.
+class InstantLoader : public InstantPage::Delegate,
+                      public InstantServiceObserver,
+                      public InstantWebContentsContainer {
  public:
-  // InstantLoader calls these methods on its delegate in response to certain
-  // changes in the underlying contents.
-  class Delegate {
-   public:
-    // Called after someone has swapped in a different WebContents for ours.
-    virtual void OnSwappedContents() = 0;
-
-    // Called when the underlying contents receive focus.
-    virtual void OnFocus() = 0;
-
-    // Called when the mouse pointer is down.
-    virtual void OnMouseDown() = 0;
-
-    // Called when the mouse pointer is released (or a drag event ends).
-    virtual void OnMouseUp() = 0;
-
-    // Called to open a URL using the underlying contents (see
-    // WebContentsDelegate::OpenURLFromTab). The Delegate should return the
-    // WebContents the URL is opened in, or NULL if the URL wasn't opened
-    // immediately.
-    virtual content::WebContents* OpenURLFromTab(
-        content::WebContents* source,
-        const content::OpenURLParams& params) = 0;
-
-   protected:
-    ~Delegate();
-  };
-
-  explicit InstantLoader(Delegate* delegate);
+  explicit InstantLoader(InstantService* service);
   virtual ~InstantLoader();
 
-  // Creates a new WebContents in the context of |profile| that will be used to
-  // load |instant_url|. The page is not actually loaded until Load() is
-  // called. Uses |active_contents|, if non-NULL, to initialize the size of the
-  // new contents. |on_stale_callback| will be called after kStalePageTimeoutMS
-  // has elapsed after Load() being called.
-  void Init(const GURL& instant_url,
-            Profile* profile,
-            const content::WebContents* active_contents,
-            const base::Closure& on_stale_callback);
+  // Returns whether the |contents_| is known to support the Instant API.
+  bool supports_instant() const { return page_.supports_instant(); }
 
-  // Loads |instant_url_| in |contents_|.
-  void Load();
+  // Creates a new |contents_| and loads the Instant URL into it. If |contents_|
+  // is already valid, does nothing.
+  void InitContents();
 
-  // Returns the contents currently held. May be NULL.
-  content::WebContents* contents() const { return contents_.get(); }
-
-  // Replaces the contents held with |contents|. Any existing contents is
-  // deleted. The expiration timer is not restarted.
-  void SetContents(scoped_ptr<content::WebContents> contents);
-
-  // Releases the contents currently held. Must only be called if contents() is
-  // not NULL.
-  scoped_ptr<content::WebContents> ReleaseContents() WARN_UNUSED_RESULT;
+  // Gives up |contents_| to the caller, and creates a new one in its place.
+  scoped_ptr<content::WebContents> ReleaseContents();
 
  private:
-  // Overridden from content::NotificationObserver:
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
+  FRIEND_TEST_ALL_PREFIXES(InstantTest, InstantLoaderRefresh);
 
-  // Overridden from CoreTabHelperDelegate:
-  virtual void SwapTabContents(content::WebContents* old_contents,
-                               content::WebContents* new_contents) OVERRIDE;
+  // Overridden from InstantPage::Delegate:
+  virtual void RenderViewGone(const content::WebContents* contents) OVERRIDE;
+  virtual void InitSearchBox(const content::WebContents* contents) OVERRIDE;
+  virtual void InstantSupportDetermined(
+      const content::WebContents* contents) OVERRIDE;
+  virtual void SetSuggestion(const content::WebContents* contents,
+                             const InstantSuggestion& suggestion) OVERRIDE;
+  virtual void NavigateToURL(const content::WebContents* contents,
+                             const GURL& url,
+                             content::PageTransition transition,
+                             WindowOpenDisposition disposition) OVERRIDE;
+  virtual void ShowOverlay(const content::WebContents* contents,
+                           int height,
+                           bool is_height_in_pixels) OVERRIDE;
+  virtual void StartKeyCapture(const content::WebContents* contents) OVERRIDE;
+  virtual void StopKeyCapture(const content::WebContents* contents) OVERRIDE;
+  virtual void DeleteMostVisitedItem(const content::WebContents* contents,
+                                     const GURL& url) OVERRIDE;
+  virtual void UndoMostVisitedItemDeletion(const content::WebContents* contents,
+                                           const GURL& url) OVERRIDE;
+  virtual void UndoAllMostVisitedItemDeletions(
+        const content::WebContents* contents) OVERRIDE;
 
-  // Overridden from content::WebContentsDelegate:
-  virtual bool ShouldSuppressDialogs() OVERRIDE;
-  virtual bool ShouldFocusPageAfterCrash() OVERRIDE;
-  virtual void LostCapture() OVERRIDE;
-  virtual void WebContentsFocused(content::WebContents* contents) OVERRIDE;
-  virtual bool CanDownload(content::RenderViewHost* render_view_host,
-                           int request_id,
-                           const std::string& request_method) OVERRIDE;
-  virtual void HandleMouseDown() OVERRIDE;
-  virtual void HandleMouseUp() OVERRIDE;
-  virtual void HandlePointerActivate() OVERRIDE;
-  virtual void HandleGestureEnd() OVERRIDE;
-  virtual void DragEnded() OVERRIDE;
-  virtual bool OnGoToEntryOffset(int offset) OVERRIDE;
-  virtual content::WebContents* OpenURLFromTab(
-      content::WebContents* source,
-      const content::OpenURLParams& params) OVERRIDE;
+  // Overridden from InstantServiceObserver:
+  virtual void InstantStatusChanged() OVERRIDE;
+  virtual void ThemeInfoChanged() OVERRIDE;
+  virtual void MostVisitedItemsChanged() OVERRIDE;
+  virtual void InstantSupportDecided() OVERRIDE;
 
-  Delegate* const delegate_;
-  scoped_ptr<content::WebContents> contents_;
+  // Overridden from InstantWebContentsContainer:
+  virtual void CloseContents(content::WebContents* source) OVERRIDE;
+  virtual void TearDownContents() OVERRIDE;
 
-  // The URL we will be loading.
-  GURL instant_url_;
+  void DeleteContents();
+  void ReloadContents();
 
-  // Called when |stale_page_timer_| fires.
-  base::Closure on_stale_callback_;
-
-  // Used to mark when the page is stale.
-  base::Timer stale_page_timer_;
-
-  // Used to get notifications about renderers.
-  content::NotificationRegistrar registrar_;
+  InstantService* const service_;
+  base::OneShotTimer<InstantLoader> stale_page_timer_;
 
   DISALLOW_COPY_AND_ASSIGN(InstantLoader);
 };
 
 #endif  // CHROME_BROWSER_INSTANT_INSTANT_LOADER_H_