ui/views/widget/root_view.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 UI_VIEWS_WIDGET_ROOT_VIEW_H_
   6 #define UI_VIEWS_WIDGET_ROOT_VIEW_H_
   7
   8 #include <string>
   9
  10 #include "base/memory/ref_counted.h"
  11 #include "ui/events/event_dispatcher.h"
  12 #include "ui/views/focus/focus_manager.h"
  13 #include "ui/views/focus/focus_search.h"
  14 #include "ui/views/view.h"
  15
  16 namespace views {
  17
  18 namespace test {
  19 class RootViewTestHelper;
  20 class WidgetTest;
  21 }
  22
  23 class Widget;
  24
  25 // This is a views-internal API and should not be used externally.
  26 // Widget exposes this object as a View*.
  27 namespace internal {
  28
  29 ////////////////////////////////////////////////////////////////////////////////
  30 // RootView class
  31 //
  32 //  The RootView is the root of a View hierarchy. A RootView is attached to a
  33 //  Widget. The Widget is responsible for receiving events from the host
  34 //  environment, converting them to views-compatible events and then forwarding
  35 //  them to the RootView for propagation into the View hierarchy.
  36 //
  37 //  A RootView can have only one child, called its "Contents View" which is
  38 //  sized to fill the bounds of the RootView (and hence the client area of the
  39 //  Widget). Call SetContentsView() after the associated Widget has been
  40 //  initialized to attach the contents view to the RootView.
  41 //  TODO(beng): Enforce no other callers to AddChildView/tree functions by
  42 //              overriding those methods as private here.
  43 //  TODO(beng): Clean up API further, make Widget a friend.
  44 //  TODO(sky): We don't really want to export this class.
  45 //
  46 class VIEWS_EXPORT RootView : public View,
  47                               public FocusTraversable,
  48                               public ui::EventDispatcherDelegate {
  49  public:
  50   static const char kViewClassName[];
  51
  52   // Creation and lifetime -----------------------------------------------------
  53   explicit RootView(Widget* widget);
  54   virtual ~RootView();
  55
  56   // Tree operations -----------------------------------------------------------
  57
  58   // Sets the "contents view" of the RootView. This is the single child view
  59   // that is responsible for laying out the contents of the widget.
  60   void SetContentsView(View* contents_view);
  61   View* GetContentsView();
  62
  63   // Called when parent of the host changed.
  64   void NotifyNativeViewHierarchyChanged();
  65
  66   // Input ---------------------------------------------------------------------
  67
  68   // Process a key event. Send the event to the focused view and up the focus
  69   // path, and finally to the default keyboard handler, until someone consumes
  70   // it. Returns whether anyone consumed the event.
  71   void DispatchKeyEvent(ui::KeyEvent* event);
  72   void DispatchScrollEvent(ui::ScrollEvent* event);
  73   void DispatchTouchEvent(ui::TouchEvent* event);
  74   virtual void DispatchGestureEvent(ui::GestureEvent* event);
  75
  76   // Focus ---------------------------------------------------------------------
  77
  78   // Used to set the FocusTraversable parent after the view has been created
  79   // (typically when the hierarchy changes and this RootView is added/removed).
  80   virtual void SetFocusTraversableParent(FocusTraversable* focus_traversable);
  81
  82   // Used to set the View parent after the view has been created.
  83   virtual void SetFocusTraversableParentView(View* view);
  84
  85   // System events -------------------------------------------------------------
  86
  87   // Public API for broadcasting theme change notifications to this View
  88   // hierarchy.
  89   void ThemeChanged();
  90
  91   // Public API for broadcasting locale change notifications to this View
  92   // hierarchy.
  93   void LocaleChanged();
  94
  95   // Overridden from FocusTraversable:
  96   virtual FocusSearch* GetFocusSearch() OVERRIDE;
  97   virtual FocusTraversable* GetFocusTraversableParent() OVERRIDE;
  98   virtual View* GetFocusTraversableParentView() OVERRIDE;
  99
 100   // Overridden from View:
 101   virtual const Widget* GetWidget() const OVERRIDE;
 102   virtual Widget* GetWidget() OVERRIDE;
 103   virtual bool IsDrawn() const OVERRIDE;
 104   virtual void Layout() OVERRIDE;
 105   virtual const char* GetClassName() const OVERRIDE;
 106   virtual void SchedulePaintInRect(const gfx::Rect& rect) OVERRIDE;
 107   virtual bool OnMousePressed(const ui::MouseEvent& event) OVERRIDE;
 108   virtual bool OnMouseDragged(const ui::MouseEvent& event) OVERRIDE;
 109   virtual void OnMouseReleased(const ui::MouseEvent& event) OVERRIDE;
 110   virtual void OnMouseCaptureLost() OVERRIDE;
 111   virtual void OnMouseMoved(const ui::MouseEvent& event) OVERRIDE;
 112   virtual void OnMouseExited(const ui::MouseEvent& event) OVERRIDE;
 113   virtual bool OnMouseWheel(const ui::MouseWheelEvent& event) OVERRIDE;
 114   virtual void SetMouseHandler(View* new_mouse_handler) OVERRIDE;
 115   virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE;
 116   virtual void UpdateParentLayer() OVERRIDE;
 117
 118  protected:
 119   // Overridden from View:
 120   virtual void ViewHierarchyChanged(
 121       const ViewHierarchyChangedDetails& details) OVERRIDE;
 122   virtual void VisibilityChanged(View* starting_from, bool is_visible) OVERRIDE;
 123   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
 124   virtual gfx::Vector2d CalculateOffsetToAncestorWithLayer(
 125       ui::Layer** layer_parent) OVERRIDE;
 126   virtual View::DragInfo* GetDragInfo() OVERRIDE;
 127
 128  private:
 129   friend class ::views::View;
 130   friend class ::views::Widget;
 131   friend class ::views::test::RootViewTestHelper;
 132   friend class ::views::test::WidgetTest;
 133
 134   // Input ---------------------------------------------------------------------
 135
 136   // Update the cursor given a mouse event. This is called by non mouse_move
 137   // event handlers to honor the cursor desired by views located under the
 138   // cursor during drag operations. The location of the mouse should be in the
 139   // current coordinate system (i.e. any necessary transformation should be
 140   // applied to the point prior to calling this).
 141   void UpdateCursor(const ui::MouseEvent& event);
 142
 143   // Updates the last_mouse_* fields from e. The location of the mouse should be
 144   // in the current coordinate system (i.e. any necessary transformation should
 145   // be applied to the point prior to calling this).
 146   void SetMouseLocationAndFlags(const ui::MouseEvent& event);
 147
 148   void DispatchEventToTarget(View* target, ui::Event* event);
 149
 150   // |view| is the view receiving |event|. This function sends the event to all
 151   // the Views up the hierarchy that has |notify_enter_exit_on_child_| flag
 152   // turned on, but does not contain |sibling|.
 153   void NotifyEnterExitOfDescendant(const ui::MouseEvent& event,
 154                                    ui::EventType type,
 155                                    View* view,
 156                                    View* sibling);
 157
 158   // Dispatches the KeyEvent to |view| and ancestors until the event is
 159   // handled.
 160   void DispatchKeyEventStartAt(View* view, ui::KeyEvent* event);
 161
 162   // Overridden from ui::EventDispatcherDelegate:
 163   virtual bool CanDispatchToTarget(ui::EventTarget* target) OVERRIDE;
 164
 165   //////////////////////////////////////////////////////////////////////////////
 166
 167   // Tree operations -----------------------------------------------------------
 168
 169   // The host Widget
 170   Widget* widget_;
 171
 172   // Input ---------------------------------------------------------------------
 173
 174   // The view currently handing down - drag - up
 175   View* mouse_pressed_handler_;
 176
 177   // The view currently handling enter / exit
 178   View* mouse_move_handler_;
 179
 180   // The last view to handle a mouse click, so that we can determine if
 181   // a double-click lands on the same view as its single-click part.
 182   View* last_click_handler_;
 183
 184   // true if mouse_pressed_handler_ has been explicitly set
 185   bool explicit_mouse_handler_;
 186
 187   // Last position/flag of a mouse press/drag. Used if capture stops and we need
 188   // to synthesize a release.
 189   int last_mouse_event_flags_;
 190   int last_mouse_event_x_;
 191   int last_mouse_event_y_;
 192
 193   // The view currently handling touch events.
 194   View* touch_pressed_handler_;
 195
 196   // The view currently handling gesture events. When set, this handler receives
 197   // all gesture events, except when there is an event handler for the specific
 198   // gesture (e.g. scroll).
 199   View* gesture_handler_;
 200
 201   // The view currently handling scroll gesture events.
 202   View* scroll_gesture_handler_;
 203
 204   // Focus ---------------------------------------------------------------------
 205
 206   // The focus search algorithm.
 207   FocusSearch focus_search_;
 208
 209   // Whether this root view belongs to the current active window.
 210   // bool activated_;
 211
 212   // The parent FocusTraversable, used for focus traversal.
 213   FocusTraversable* focus_traversable_parent_;
 214
 215   // The View that contains this RootView. This is used when we have RootView
 216   // wrapped inside native components, and is used for the focus traversal.
 217   View* focus_traversable_parent_view_;
 218
 219   View* event_dispatch_target_;
 220
 221   // Drag and drop -------------------------------------------------------------
 222
 223   // Tracks drag state for a view.
 224   View::DragInfo drag_info_;
 225
 226   DISALLOW_IMPLICIT_CONSTRUCTORS(RootView);
 227 };
 228
 229 }  // namespace internal
 230 }  // namespace views
 231
 232 #endif  // UI_VIEWS_WIDGET_ROOT_VIEW_H_