components/app_modal/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_APP_MODAL_DIALOG_QUEUE_H_
   6 #define COMPONENTS_APP_MODAL_APP_MODAL_DIALOG_QUEUE_H_
   7
   8 #include <deque>
   9
  10 #include "base/basictypes.h"
  11
  12 template <typename T> struct DefaultSingletonTraits;
  13
  14 namespace app_modal {
  15
  16 class AppModalDialog;
  17
  18 // Keeps a queue of AppModalDialogs, making sure only one app modal
  19 // dialog is shown at a time.
  20 // This class is a singleton.
  21 class AppModalDialogQueue {
  22  public:
  23   typedef std::deque<AppModalDialog*>::iterator iterator;
  24
  25   // Returns the singleton instance.
  26   static AppModalDialogQueue* GetInstance();
  27
  28   // Adds a modal dialog to the queue. If there are no other dialogs in the
  29   // queue, the dialog will be shown immediately. Once it is shown, the
  30   // most recently active browser window (or whichever is currently active)
  31   // will be app modal, meaning it will be activated if the user tries to
  32   // activate any other browser windows.
  33   // Note: The AppModalDialog |dialog| must be window modal before it
  34   // can be added as app modal.
  35   void AddDialog(AppModalDialog* dialog);
  36
  37   // Removes the current dialog in the queue (the one that is being shown).
  38   // Shows the next dialog in the queue, if any is present. This does not
  39   // ensure that the currently showing dialog is closed, it just makes it no
  40   // longer app modal.
  41   void ShowNextDialog();
  42
  43   // Activates and shows the current dialog, if the user clicks on one of the
  44   // windows disabled by the presence of an app modal dialog. This forces
  45   // the window to be visible on the display even if desktop manager software
  46   // opened the dialog on another virtual desktop. Assumes there is currently a
  47   // dialog being shown. (Call BrowserList::IsShowingAppModalDialog to test
  48   // this condition).
  49   void ActivateModalDialog();
  50
  51   // Returns true if there is currently an active app modal dialog box.
  52   bool HasActiveDialog() const;
  53
  54   AppModalDialog* active_dialog() { return active_dialog_; }
  55
  56   // Iterators to walk the queue. The queue does not include the currently
  57   // active app modal dialog box.
  58   iterator begin() { return app_modal_dialog_queue_.begin(); }
  59   iterator end() { return app_modal_dialog_queue_.end(); }
  60
  61  private:
  62   friend struct DefaultSingletonTraits<AppModalDialogQueue>;
  63
  64   AppModalDialogQueue();
  65   ~AppModalDialogQueue();
  66
  67   // Shows |dialog| and notifies the BrowserList that a modal dialog is showing.
  68   void ShowModalDialog(AppModalDialog* dialog);
  69
  70   // Returns the next dialog to show. This removes entries from
  71   // app_modal_dialog_queue_ until one is valid or the queue is empty. This
  72   // returns NULL if there are no more dialogs, or all the dialogs in the queue
  73   // are not valid.
  74   AppModalDialog* GetNextDialog();
  75
  76   // Contains all app modal dialogs which are waiting to be shown. The currently
  77   // active modal dialog is not included.
  78   std::deque<AppModalDialog*> app_modal_dialog_queue_;
  79
  80   // The currently active app-modal dialog box's delegate. NULL if there is no
  81   // active app-modal dialog box.
  82   AppModalDialog* active_dialog_;
  83
  84   // Stores if |ShowModalDialog()| is currently being called on an app-modal
  85   // dialog.
  86   bool showing_modal_dialog_;
  87
  88   DISALLOW_COPY_AND_ASSIGN(AppModalDialogQueue);
  89 };
  90
  91 }  // namespace app_modal
  92
  93 #endif  // COMPONENTS_APP_MODAL_APP_MODAL_DIALOG_QUEUE_H_