ui/views/accessible_pane_view.h

   1 // Copyright (c) 2011 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 UI_VIEWS_ACCESSIBLE_PANE_VIEW_H_
   6 #define UI_VIEWS_ACCESSIBLE_PANE_VIEW_H_
   7
   8 #include "base/containers/hash_tables.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "base/memory/weak_ptr.h"
  11 #include "ui/base/accelerators/accelerator.h"
  12 #include "ui/views/focus/focus_manager.h"
  13 #include "ui/views/view.h"
  14
  15 namespace views {
  16 class FocusSearch;
  17
  18 // This class provides keyboard access to any view that extends it, typically
  19 // a toolbar.  The user sets focus to a control in this view by pressing
  20 // F6 to traverse all panes, or by pressing a shortcut that jumps directly
  21 // to this pane.
  22 class VIEWS_EXPORT AccessiblePaneView : public View,
  23                                         public FocusChangeListener,
  24                                         public FocusTraversable {
  25  public:
  26   AccessiblePaneView();
  27   virtual ~AccessiblePaneView();
  28
  29   // Set focus to the pane with complete keyboard access.
  30   // Focus will be restored to the last focused view if the user escapes.
  31   // If |initial_focus| is not NULL, that control will get
  32   // the initial focus, if it's enabled and focusable. Returns true if
  33   // the pane was able to receive focus.
  34   virtual bool SetPaneFocus(View* initial_focus);
  35
  36   // Set focus to the pane with complete keyboard access, with the
  37   // focus initially set to the default child. Focus will be restored
  38   // to the last focused view if the user escapes.
  39   // Returns true if the pane was able to receive focus.
  40   virtual bool SetPaneFocusAndFocusDefault();
  41
  42   // Overridden from View:
  43   virtual FocusTraversable* GetPaneFocusTraversable() OVERRIDE;
  44   virtual bool AcceleratorPressed(const ui::Accelerator& accelerator)
  45       OVERRIDE;
  46   virtual void SetVisible(bool flag) OVERRIDE;
  47   virtual void GetAccessibleState(ui::AXViewState* state) OVERRIDE;
  48   virtual void RequestFocus() OVERRIDE;
  49
  50   // Overridden from FocusChangeListener:
  51   virtual void OnWillChangeFocus(View* focused_before,
  52                                  View* focused_now) OVERRIDE;
  53   virtual void OnDidChangeFocus(View* focused_before,
  54                                 View* focused_now) OVERRIDE;
  55
  56   // Overridden from FocusTraversable:
  57   virtual FocusSearch* GetFocusSearch() OVERRIDE;
  58   virtual FocusTraversable* GetFocusTraversableParent() OVERRIDE;
  59   virtual View* GetFocusTraversableParentView() OVERRIDE;
  60
  61   // For testing only.
  62   const ui::Accelerator& home_key() const { return home_key_; }
  63   const ui::Accelerator& end_key() const { return end_key_; }
  64   const ui::Accelerator& escape_key() const { return escape_key_; }
  65   const ui::Accelerator& left_key() const { return left_key_; }
  66   const ui::Accelerator& right_key() const { return right_key_; }
  67
  68  protected:
  69   // A subclass can override this to provide a default focusable child
  70   // other than the first focusable child.
  71   virtual View* GetDefaultFocusableChild();
  72
  73   // Returns the parent of |v|. Subclasses can override this if
  74   // they need custom focus search behavior.
  75   virtual View* GetParentForFocusSearch(View* v);
  76
  77   // Returns true if |v| is contained within the hierarchy rooted at |root|
  78   // for the purpose of focus searching. Subclasses can override this if
  79   // they need custom focus search behavior.
  80   virtual bool ContainsForFocusSearch(View* root, const View* v);
  81
  82   // Remove pane focus.
  83   virtual void RemovePaneFocus();
  84
  85   View* GetFirstFocusableChild();
  86   View* GetLastFocusableChild();
  87
  88   FocusManager* focus_manager() const { return focus_manager_; }
  89
  90   // When finishing navigation by pressing ESC, it is allowed to surrender the
  91   // focus to another window if if |allow| is set and no previous view can be
  92   // found.
  93   void set_allow_deactivate_on_esc(bool allow) {
  94     allow_deactivate_on_esc_ = allow;
  95   }
  96
  97  private:
  98   bool pane_has_focus_;
  99
 100   // If true, the panel should be de-activated upon escape when no active view
 101   // is known where to return to.
 102   bool allow_deactivate_on_esc_;
 103
 104   base::WeakPtrFactory<AccessiblePaneView> method_factory_;
 105
 106   // Save the focus manager rather than calling GetFocusManager(),
 107   // so that we can remove focus listeners in the destructor.
 108   FocusManager* focus_manager_;
 109
 110   // Our custom focus search implementation that traps focus in this
 111   // pane and traverses all views that are focusable for accessibility,
 112   // not just those that are normally focusable.
 113   scoped_ptr<FocusSearch> focus_search_;
 114
 115   // Registered accelerators
 116   ui::Accelerator home_key_;
 117   ui::Accelerator end_key_;
 118   ui::Accelerator escape_key_;
 119   ui::Accelerator left_key_;
 120   ui::Accelerator right_key_;
 121
 122   // View storage id for the last focused view that's not within this pane.
 123   int last_focused_view_storage_id_;
 124
 125   friend class AccessiblePaneViewFocusSearch;
 126
 127   DISALLOW_COPY_AND_ASSIGN(AccessiblePaneView);
 128 };
 129
 130 }  // namespace views
 131
 132 #endif  // UI_VIEWS_ACCESSIBLE_PANE_VIEW_H_