chrome/browser/chrome_process_singleton.h

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_BROWSER_CHROME_PROCESS_SINGLETON_H_
   6 #define CHROME_BROWSER_CHROME_PROCESS_SINGLETON_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/files/file_path.h"
  10 #include "chrome/browser/process_singleton.h"
  11 #include "chrome/browser/process_singleton_modal_dialog_lock.h"
  12 #include "chrome/browser/process_singleton_startup_lock.h"
  13 #include "ui/gfx/native_widget_types.h"
  14
  15 // Composes a basic ProcessSingleton with ProcessSingletonStartupLock and
  16 // ProcessSingletonModalDialogLock.
  17 //
  18 // Notifications from ProcessSingleton will be discarded if a modal dialog is
  19 // active. Otherwise, until |Unlock()| is called, they will be queued up.
  20 // Once unlocked, notifications will be passed to the client-supplied
  21 // NotificationCallback.
  22 //
  23 // The client must ensure that SetActiveModalDialog is called appropriately when
  24 // dialogs are displayed or dismissed during startup. While a dialog is active:
  25 // 1. Neither this process nor the invoking process will handle the command
  26 //    line.
  27 // 2. The active dialog is brought to the foreground and/or the taskbar icon
  28 //    flashed (using ::SetForegroundWindow on Windows).
  29 class ChromeProcessSingleton {
  30  public:
  31   ChromeProcessSingleton(
  32       const base::FilePath& user_data_dir,
  33       const ProcessSingleton::NotificationCallback& notification_callback);
  34
  35   ChromeProcessSingleton(
  36       const base::FilePath& user_data_dir,
  37       const ProcessSingleton::NotificationCallback& notification_callback,
  38       const ProcessSingletonModalDialogLock::SetForegroundWindowHandler&
  39           set_foreground_window_handler);
  40
  41   ~ChromeProcessSingleton();
  42
  43   // Notify another process, if available. Otherwise sets ourselves as the
  44   // singleton instance. Returns PROCESS_NONE if we became the singleton
  45   // instance. Callers are guaranteed to either have notified an existing
  46   // process or have grabbed the singleton (unless the profile is locked by an
  47   // unreachable process).
  48   ProcessSingleton::NotifyResult NotifyOtherProcessOrCreate();
  49
  50   // Clear any lock state during shutdown.
  51   void Cleanup();
  52
  53   // Receives a handle to the active modal dialog, or NULL if the active dialog
  54   // is dismissed.
  55   void SetActiveModalDialog(gfx::NativeWindow active_dialog);
  56
  57   // Executes previously queued command-line invocations and allows future
  58   // invocations to be executed immediately.
  59   // This only has an effect the first time it is called.
  60   void Unlock();
  61
  62  private:
  63   // We compose these two locks with the client-supplied notification callback.
  64   // First |modal_dialog_lock_| will discard any notifications that arrive while
  65   // a modal dialog is active. Otherwise, it will pass the notification to
  66   // |startup_lock_|, which will queue notifications until |Unlock()| is called.
  67   // Notifications passing through both locks are finally delivered to our
  68   // client.
  69   ProcessSingletonStartupLock startup_lock_;
  70   ProcessSingletonModalDialogLock modal_dialog_lock_;
  71
  72   // The basic ProcessSingleton
  73   ProcessSingleton process_singleton_;
  74
  75   DISALLOW_COPY_AND_ASSIGN(ChromeProcessSingleton);
  76 };
  77
  78 #endif  // CHROME_BROWSER_CHROME_PROCESS_SINGLETON_H_