components/app_modal_dialogs/app_modal_dialog_queue.h

   1 // Copyright (c) 2012 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 COMPONENTS_APP_MODAL_DIALOGS_APP_MODAL_DIALOG_QUEUE_H_
   6 #define COMPONENTS_APP_MODAL_DIALOGS_APP_MODAL_DIALOG_QUEUE_H_
   7
   8 #include <deque>
   9
  10 #include "base/basictypes.h"
  11
  12 class AppModalDialog;
  13
  14 template <typename T> struct DefaultSingletonTraits;
  15
  16 // Keeps a queue of AppModalDialogs, making sure only one app modal
  17 // dialog is shown at a time.
  18 // This class is a singleton.
  19 class AppModalDialogQueue {
  20  public:
  21   typedef std::deque<AppModalDialog*>::iterator iterator;
  22
  23   // Returns the singleton instance.
  24   static AppModalDialogQueue* GetInstance();
  25
  26   // Adds a modal dialog to the queue. If there are no other dialogs in the
  27   // queue, the dialog will be shown immediately. Once it is shown, the
  28   // most recently active browser window (or whichever is currently active)
  29   // will be app modal, meaning it will be activated if the user tries to
  30   // activate any other browser windows.
  31   // Note: The AppModalDialog |dialog| must be window modal before it
  32   // can be added as app modal.
  33   void AddDialog(AppModalDialog* dialog);
  34
  35   // Removes the current dialog in the queue (the one that is being shown).
  36   // Shows the next dialog in the queue, if any is present. This does not
  37   // ensure that the currently showing dialog is closed, it just makes it no
  38   // longer app modal.
  39   void ShowNextDialog();
  40
  41   // Activates and shows the current dialog, if the user clicks on one of the
  42   // windows disabled by the presence of an app modal dialog. This forces
  43   // the window to be visible on the display even if desktop manager software
  44   // opened the dialog on another virtual desktop. Assumes there is currently a
  45   // dialog being shown. (Call BrowserList::IsShowingAppModalDialog to test
  46   // this condition).
  47   void ActivateModalDialog();
  48
  49   // Returns true if there is currently an active app modal dialog box.
  50   bool HasActiveDialog() const;
  51
  52   AppModalDialog* active_dialog() { return active_dialog_; }
  53
  54   // Iterators to walk the queue. The queue does not include the currently
  55   // active app modal dialog box.
  56   iterator begin() { return app_modal_dialog_queue_.begin(); }
  57   iterator end() { return app_modal_dialog_queue_.end(); }
  58
  59  private:
  60   friend struct DefaultSingletonTraits<AppModalDialogQueue>;
  61
  62   AppModalDialogQueue();
  63   ~AppModalDialogQueue();
  64
  65   // Shows |dialog| and notifies the BrowserList that a modal dialog is showing.
  66   void ShowModalDialog(AppModalDialog* dialog);
  67
  68   // Returns the next dialog to show. This removes entries from
  69   // app_modal_dialog_queue_ until one is valid or the queue is empty. This
  70   // returns NULL if there are no more dialogs, or all the dialogs in the queue
  71   // are not valid.
  72   AppModalDialog* GetNextDialog();
  73
  74   // Contains all app modal dialogs which are waiting to be shown. The currently
  75   // active modal dialog is not included.
  76   std::deque<AppModalDialog*> app_modal_dialog_queue_;
  77
  78   // The currently active app-modal dialog box's delegate. NULL if there is no
  79   // active app-modal dialog box.
  80   AppModalDialog* active_dialog_;
  81
  82   // Stores if |ShowModalDialog()| is currently being called on an app-modal
  83   // dialog.
  84   bool showing_modal_dialog_;
  85
  86   DISALLOW_COPY_AND_ASSIGN(AppModalDialogQueue);
  87 };
  88
  89 #endif  // COMPONENTS_APP_MODAL_DIALOGS_APP_MODAL_DIALOG_QUEUE_H_