Implement print preview tab controller.

chrome/browser/printing/print_preview_tab_controller.h

+// Copyright (c) 2010 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_PRINTING_PRINT_PREVIEW_TAB_CONTROLLER_H_
+#define CHROME_BROWSER_PRINTING_PRINT_PREVIEW_TAB_CONTROLLER_H_
+#pragma once
+
+#include <map>
+
+#include "base/ref_counted.h"
+#include "chrome/common/notification_observer.h"
+#include "chrome/common/notification_registrar.h"
+
+class Browser;
+class TabContents;
+
+namespace printing {
+
+// For print preview, a print preview (PP) tab should be linked with the

[James Hawkins, 2010/11/16 02:15:42]

s/should be/is/

[kmadhusu, 2010/11/16 18:16:09]

Done.

+// 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 should be focused/activated. There may be more than one PP tab
+// open. There is 1:1 relationship between PP tabs and initiating tabs. This

[James Hawkins, 2010/11/16 02:15:42]

s/is 1:1/is a 1:1/

[kmadhusu, 2010/11/16 18:16:09]

Done.

+// class manages PP tabs and initiator tabs.
+class PrintPreviewTabController
+  : public base::RefCounted<PrintPreviewTabController>,
+    public NotificationObserver {
+ public:
+  static PrintPreviewTabController* GetInstance();
+
+  PrintPreviewTabController();
+
+  virtual ~PrintPreviewTabController();
+
+  // Get/Create the print preview tab for initiator_tab.
+  // |browser_window_id| is used to identify |initiator_tab| browser window.

[James Hawkins, 2010/11/16 02:15:42]

"|browser_window_id| is the browser window containing |initiator_tab|."

[kmadhusu, 2010/11/16 18:16:09]

Done.

+  TabContents* GetOrCreatePreviewTab(
+      TabContents* initiator_tab, int browser_window_id);
+
+  // Notification observer implementation.
+  virtual void Observe(NotificationType type,
+                       const NotificationSource& source,
+                       const NotificationDetails& details);
+
+ private:
+  friend class base::RefCounted<PrintPreviewTabController>;
+
+  // Returns true if |tab| is a print preview tab.
+  bool IsPreviewTab(TabContents* tab);

[James Hawkins, 2010/11/16 02:15:42]

IsPrintPreviewTab

[kmadhusu, 2010/11/16 18:16:09]

Done.

+
+  // Return the initiator tab for |preview_tab| or return NULL.

[James Hawkins, 2010/11/16 02:15:42]

Returns

[kmadhusu, 2010/11/16 18:16:09]

Done.

+  TabContents* GetInitiatorTab(TabContents* preview_tab);
+
+  // Return preview tab for |current_tab| or return NULL.

[James Hawkins, 2010/11/16 02:15:42]

Returns

[kmadhusu, 2010/11/16 18:16:09]

Done.

+  // If |current_tab| is preview tab return |current_tab|.

[James Hawkins, 2010/11/16 02:15:42]

returns

[kmadhusu, 2010/11/16 18:16:09]

Done.

+  TabContents* GetPreviewTab(TabContents* current_tab);

[James Hawkins, 2010/11/16 02:15:42]

s/current/initiator/

[Lei Zhang, 2010/11/16 02:24:23]

The tab being passed in is arbitrary. It is not always an initiator tab.

[James Hawkins, 2010/11/16 02:27:15]

Then "current" is also wrong and should be changed.

[James Hawkins, 2010/11/16 02:27:15]

Taking Lei's comment into account, I believe this should be changed to:

TabContents* GetPrintPreviewForTab(TabContents* tab);

[kmadhusu, 2010/11/16 18:16:09]

Done.

+
+  // Create a new print preview tab.

[James Hawkins, 2010/11/16 02:15:42]

Creates

[kmadhusu, 2010/11/16 18:16:09]

Done.

+  TabContents* CreatePrintPreviewTab(
+      TabContents* initiator_tab, int browser_window_id);
+
+  // Add/Remove observers for notifications from |tab|.

[James Hawkins, 2010/11/16 02:15:42]

Adds/Removes

[kmadhusu, 2010/11/16 18:16:09]

Done.

+  void AddObservers(TabContents* tab);
+  void RemoveObservers(TabContents* tab);
+
+  // 1:1 relationship between initiator tab and print preview tab.
+  // Key: Preview tab.
+  // Value: Initiator tab.
+  typedef std::map<TabContents*, TabContents*> PrintPreviewTabMap;
+  PrintPreviewTabMap preview_tab_map_;
+
+  // A registrar for listening for TAB_CONTENTS_DESTROYED notification.
+  NotificationRegistrar registrar_;
+
+  // Are we waiting for a new preview tab with NavigationType::NEW_PAGE? If so,

[James Hawkins, 2010/11/16 02:15:42]

It's best not to describe a member variable w/ a question. This is typically
done as:

// True if the controller is waiting for a new preview tab via
NavigationType::NEW_PAGE

Another note here: don't use "we" in comments, describe what "we" is actually
referring to.

[kmadhusu, 2010/11/16 18:16:09]

Done.

+  // do nothing in observer.
+  bool waiting_for_new_preview_page_;
+
+  DISALLOW_COPY_AND_ASSIGN(PrintPreviewTabController);
+};
+
+}  // namespace printing

[James Hawkins, 2010/11/16 02:15:42]

Blank line after this.

[kmadhusu, 2010/11/16 18:16:09]

Done.

+#endif  // CHROME_BROWSER_PRINTING_PRINT_PREVIEW_TAB_CONTROLLER_H_