Merge InstantPage into InstantTab.

chrome/browser/ui/search/instant_tab.h

-// Copyright 2012 The Chromium Authors. All rights reserved.
+// Copyright 2013 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_SEARCH_INSTANT_TAB_H_
 #define CHROME_BROWSER_UI_SEARCH_INSTANT_TAB_H_
 
 #include "base/compiler_specific.h"
+#include "base/gtest_prod_util.h"
 #include "base/macros.h"
-#include "chrome/browser/ui/search/instant_page.h"
+#include "chrome/browser/ui/search/search_model_observer.h"
+#include "content/public/browser/web_contents_observer.h"
+#include "ui/base/page_transition_types.h"
 
-// InstantTab represents a committed page (i.e. an actual tab on the tab strip)
-// that supports the Instant API.
-class InstantTab : public InstantPage {
+class GURL;
+
+namespace content {
+class RenderFrameHost;
+class WebContents;
+}
+
+// InstantTab is used to exchange messages with a page that implements the
+// Instant/Embedded Search API (http://dev.chromium.org/embeddedsearch).
+class InstantTab : public content::WebContentsObserver,
+                    public SearchModelObserver {
  public:
-  explicit InstantTab(InstantPage::Delegate* delegate);
+  // InstantTab calls its delegate in response to messages received from the
+  // page. Each method is called with the |contents| corresponding to the page
+  // we are observing.
+  class Delegate {
+   public:
+    // Called upon determination of Instant API support. Either in response to
+    // the page loading or because we received some other message.
+    virtual void InstantSupportDetermined(const content::WebContents* contents,
+                                          bool supports_instant) = 0;
+
+    // Called when the page is about to navigate to |url|.
+    virtual void InstantTabAboutToNavigateMainFrame(
+        const content::WebContents* contents,
+        const GURL& url) = 0;
+
+   protected:
+    virtual ~Delegate();
+  };
+
+  explicit InstantTab(Delegate* delegate);
+
   ~InstantTab() override;
 
-  // Start observing |contents| for messages. Sends a message to determine if
-  // the page supports the Instant API.
-  void Init(content::WebContents* contents);
+  // Sets |web_contents| as the page to communicate with. |web_contents| may be
+  // NULL, which effectively stops all communication.
+  void Init(content::WebContents* web_contents);
+
+  // Returns true if the page is known to support the Instant API. This starts
+  // out false, and is set to true whenever we get any message from the page.
+  // Once true, it never becomes false (the page isn't expected to drop API
+  // support suddenly).
+  bool supports_instant() const;
+
+  // Returns true if the page is the local NTP (i.e. its URL is
+  // chrome::kChromeSearchLocalNTPURL).
+  bool IsLocal() const;
 
  private:
-  // Overridden from InstantPage:
-  bool ShouldProcessAboutToNavigateMainFrame() override;
+  FRIEND_TEST_ALL_PREFIXES(InstantTabTest, IsLocal);
+  FRIEND_TEST_ALL_PREFIXES(InstantTabTest,
+                           DetermineIfPageSupportsInstant_Local);
+  FRIEND_TEST_ALL_PREFIXES(InstantTabTest,
+                           DetermineIfPageSupportsInstant_NonLocal);
+  FRIEND_TEST_ALL_PREFIXES(InstantTabTest,
+                           PageURLDoesntBelongToInstantRenderer);
+  FRIEND_TEST_ALL_PREFIXES(InstantTabTest, PageSupportsInstant);
+
+  // Overridden from content::WebContentsObserver:
+  void DidCommitProvisionalLoadForFrame(
+      content::RenderFrameHost* render_frame_host,
+      const GURL& url,
+      ui::PageTransition transition_type) override;
+
+  // Overridden from SearchModelObserver:
+  void ModelChanged(const SearchModel::State& old_state,
+                    const SearchModel::State& new_state) override;
+
+  // Update the status of Instant support.
+  void InstantSupportDetermined(bool supports_instant);
+
+  void ClearContents();
+
+  Delegate* const delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(InstantTab);
 };
 
 #endif  // CHROME_BROWSER_UI_SEARCH_INSTANT_TAB_H_