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/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,
+      public NotificationObserver {
+ public:
+  BackgroundPrintingManager();
+  virtual ~BackgroundPrintingManager();
+
+  // Takes ownership of |content| and deletes it when |content| finishes
+  // printing. This removes the TabContentsWrapper from its TabStrip and
+  // hides it from the user.
+  void OwnTabContents(TabContentsWrapper* content);
+
+  // 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_