Print Preview: Print in the background.

chrome/browser/printing/background_printing_manager.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.
+
+#ifndef CHROME_BROWSER_PRINTING_BACKGROUND_PRINTING_MANAGER_H_
+#define CHROME_BROWSER_PRINTING_BACKGROUND_PRINTING_MANAGER_H_
+#pragma once
+
+#include <set>
+
+#include "base/compiler_specific.h"
+#include "base/memory/ref_counted.h"
+#include "base/threading/non_thread_safe.h"
+#include "content/common/notification_observer.h"
+#include "content/common/notification_registrar.h"
+
+class TabContentsWrapper;
+
+namespace printing {
+
+// Manages hidden tabs that prints documents in the background.
+// The hidden tabs are no longer part of any Browser / TabStripModel.
+// They get deleted when the tab finishes printing.
+class BackgroundPrintingManager
+    : public base::NonThreadSafe,

[sky, 2011/05/06 16:37:55]

Does this class really need to be ref counted? If so, make the destructor
private and add the necessary friend so it can be deleted.

[Lei Zhang, 2011/05/06 18:49:01]

No, it doesn't. Removed.

+      public base::RefCountedThreadSafe<BackgroundPrintingManager>,
+      public NotificationObserver {
+ public:
+  BackgroundPrintingManager();
+  ~BackgroundPrintingManager();
+
+  // Hides a TabContentsWrapper.
+  void HideTabContents(TabContentsWrapper* content);

[sky, 2011/05/06 16:37:55]

Did you consider using OwnTabContents? At a minimum document this takes
ownership of the tab and deletes it when done.

[Lei Zhang, 2011/05/06 18:49:01]

Do you mean renaming this to OwnTabContents? I can't find "OwnTabContents" in
code search.

+
+  // Let others iterate over the list of background printing tabs.
+  std::set<TabContentsWrapper*>::const_iterator begin();
+  std::set<TabContentsWrapper*>::const_iterator end();
+
+  // NotificationObserver overrides:
+  virtual void Observe(NotificationType type,
+                       const NotificationSource& source,
+                       const NotificationDetails& details) OVERRIDE;
+
+ private:
+  // The set of tabs managed by BackgroundPrintingManager.
+  std::set<TabContentsWrapper*> printing_contents_;
+
+  NotificationRegistrar registrar_;
+
+  DISALLOW_COPY_AND_ASSIGN(BackgroundPrintingManager);
+};
+
+}  // namespace printing
+
+#endif  // CHROME_BROWSER_PRINTING_BACKGROUND_PRINTING_MANAGER_H_