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 namespace base {
  13 template <typename T> struct DefaultSingletonTraits;
  14 }
  15
  16 namespace app_modal {
  17
  18 class AppModalDialog;
  19
  20 // Keeps a queue of AppModalDialogs, making sure only one app modal
  21 // dialog is shown at a time.
  22 // This class is a singleton.
  23 class AppModalDialogQueue {
  24  public:
  25   typedef std::deque<AppModalDialog*>::iterator iterator;
  26
  27   // Returns the singleton instance.
  28   static AppModalDialogQueue* GetInstance();
  29
  30   // Adds a modal dialog to the queue. If there are no other dialogs in the
  31   // queue, the dialog will be shown immediately. Once it is shown, the
  32   // most recently active browser window (or whichever is currently active)
  33   // will be app modal, meaning it will be activated if the user tries to
  34   // activate any other browser windows.
  35   // Note: The AppModalDialog |dialog| must be window modal before it
  36   // can be added as app modal.
  37   void AddDialog(AppModalDialog* dialog);
  38
  39   // Removes the current dialog in the queue (the one that is being shown).
  40   // Shows the next dialog in the queue, if any is present. This does not
  41   // ensure that the currently showing dialog is closed, it just makes it no
  42   // longer app modal.
  43   void ShowNextDialog();
  44
  45   // Activates and shows the current dialog, if the user clicks on one of the
  46   // windows disabled by the presence of an app modal dialog. This forces
  47   // the window to be visible on the display even if desktop manager software
  48   // opened the dialog on another virtual desktop. Assumes there is currently a
  49   // dialog being shown. (Call BrowserList::IsShowingAppModalDialog to test
  50   // this condition).
  51   void ActivateModalDialog();
  52
  53   // Returns true if there is currently an active app modal dialog box.
  54   bool HasActiveDialog() const;
  55
  56   AppModalDialog* active_dialog() { return active_dialog_; }
  57
  58   // Iterators to walk the queue. The queue does not include the currently
  59   // active app modal dialog box.
  60   iterator begin() { return app_modal_dialog_queue_.begin(); }
  61   iterator end() { return app_modal_dialog_queue_.end(); }
  62
  63  private:
  64   friend struct base::DefaultSingletonTraits<AppModalDialogQueue>;
  65
  66   AppModalDialogQueue();
  67   ~AppModalDialogQueue();
  68
  69   // Shows |dialog| and notifies the BrowserList that a modal dialog is showing.
  70   void ShowModalDialog(AppModalDialog* dialog);
  71
  72   // Returns the next dialog to show. This removes entries from
  73   // app_modal_dialog_queue_ until one is valid or the queue is empty. This
  74   // returns NULL if there are no more dialogs, or all the dialogs in the queue
  75   // are not valid.
  76   AppModalDialog* GetNextDialog();
  77
  78   // Contains all app modal dialogs which are waiting to be shown. The currently
  79   // active modal dialog is not included.
  80   std::deque<AppModalDialog*> app_modal_dialog_queue_;
  81
  82   // The currently active app-modal dialog box's delegate. NULL if there is no
  83   // active app-modal dialog box.
  84   AppModalDialog* active_dialog_;
  85
  86   // Stores if |ShowModalDialog()| is currently being called on an app-modal
  87   // dialog.
  88   bool showing_modal_dialog_;
  89
  90   DISALLOW_COPY_AND_ASSIGN(AppModalDialogQueue);
  91 };
  92
  93 }  // namespace app_modal
  94
  95 #endif  // COMPONENTS_APP_MODAL_APP_MODAL_DIALOG_QUEUE_H_