Print Preview: Handle a crashed initiator tab by showing a message in PP.

chrome/browser/printing/print_preview_tab_controller.h

 // 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.
 
 // For print preview, a print preview (PP) tab is linked with the initiator tab
 // that initiated the printing operation. If the tab initiates a second
 // printing operation while the first print preview tab is still open, that PP
 // tab is focused/activated. There may be more than one PP tab open. There is a
 // 1:1 relationship between PP tabs and initiating tabs. This class manages PP
 // tabs and initiator tabs.
 #ifndef CHROME_BROWSER_PRINTING_PRINT_PREVIEW_TAB_CONTROLLER_H_
 
 #define CHROME_BROWSER_PRINTING_PRINT_PREVIEW_TAB_CONTROLLER_H_
 #pragma once
 
 #include <map>
 
 #include "base/memory/ref_counted.h"
 #include "chrome/browser/sessions/session_id.h"
 #include "content/common/notification_observer.h"
 #include "content/common/notification_registrar.h"
 
 class Browser;
+class RenderProcessHost;
 class TabContents;
 
+namespace content {
+struct LoadCommittedDetails;
+}
+
 namespace printing {
 
 class PrintPreviewTabController
     : public base::RefCounted<PrintPreviewTabController>,
       public NotificationObserver {
  public:
   PrintPreviewTabController();
 
   virtual ~PrintPreviewTabController();
 
   static PrintPreviewTabController* GetInstance();
 
   // Initiate print preview for |initiator_tab|.
   // Call this instead of GetOrCreatePreviewTab().
   static void PrintPreview(TabContents* initiator_tab);
 
   // Get/Create the print preview tab for |initiator_tab|.
   // Exposed for unit tests.
   TabContents* GetOrCreatePreviewTab(TabContents* initiator_tab);
 
   // Returns preview tab for |tab|.
   // Returns |tab| if |tab| is a preview tab.
   // Returns NULL if no preview tab exists for |tab|.
   TabContents* GetPrintPreviewForTab(TabContents* tab) const;
 
   // Returns initiator tab for |preview_tab|.
   // Returns NULL if no initiator tab exists for |preview_tab|.
   TabContents* GetInitiatorTab(TabContents* preview_tab);
 
-  // Notification observer implementation.
+  // NotificationObserver implementation.
   virtual void Observe(int type,
                        const NotificationSource& source,
                        const NotificationDetails& details);
 
   // Returns true if |tab| is a print preview tab.
   static bool IsPrintPreviewTab(TabContents* tab);
 
   // Erase the initiator tab info associated with |preview_tab|.
   void EraseInitiatorTabInfo(TabContents* preview_tab);
 
  private:
   friend class base::RefCounted<PrintPreviewTabController>;
 
+  // Handler for the RENDERER_PROCESS_CLOSED notification. This is observed when
+  // the initiator renderer crashed.
+  void OnRendererProcessClosed(RenderProcessHost* rph);
+
+  // Handler for the TAB_CONTENTS_DESTROYED notification. This is observed when
+  // either tab is closed.
+  void OnTabContentsDestroyed(TabContents* tab);
+
+  // Handler for the NAV_ENTRY_COMMITTED notification. This is observed when the
+  // renderer is navigated to a different page.
+  void OnNavEntryCommitted(TabContents* tab,
+                           content::LoadCommittedDetails* details);
+
   // 1:1 relationship between initiator tab and print preview tab.
   // Key: Preview tab.
   // Value: Initiator tab.
   typedef std::map<TabContents*, TabContents*> PrintPreviewTabMap;
 
   // Creates a new print preview tab.
   TabContents* CreatePrintPreviewTab(TabContents* initiator_tab);
 
   // Adds/Removes observers for notifications from |tab|.
   void AddObservers(TabContents* tab);
   void RemoveObservers(TabContents* tab);
 
+  // Mapping between print preview tab and the corresponding initiator tab.
   PrintPreviewTabMap preview_tab_map_;
 
   // A registrar for listening notifications.
   NotificationRegistrar registrar_;
 
   // True if the controller is waiting for a new preview tab via
   // NavigationType::NEW_PAGE.
   bool waiting_for_new_preview_page_;
 
   DISALLOW_COPY_AND_ASSIGN(PrintPreviewTabController);
 };
 
 }  // namespace printing
 
 #endif  // CHROME_BROWSER_PRINTING_PRINT_PREVIEW_TAB_CONTROLLER_H_