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.
5 #ifndef UI_VIEWS_WIDGET_ROOT_VIEW_H_
6 #define UI_VIEWS_WIDGET_ROOT_VIEW_H_
10 #include "base/memory/ref_counted.h"
11 #include "ui/events/event_processor.h"
12 #include "ui/views/focus/focus_manager.h"
13 #include "ui/views/focus/focus_search.h"
14 #include "ui/views/view.h"
24 // This is a views-internal API and should not be used externally.
25 // Widget exposes this object as a View*.
27 class PreEventDispatchHandler;
29 ////////////////////////////////////////////////////////////////////////////////
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.
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.
46 class VIEWS_EXPORT RootView : public View,
47 public FocusTraversable,
48 public ui::EventProcessor {
50 static const char kViewClassName[];
52 // Creation and lifetime -----------------------------------------------------
53 explicit RootView(Widget* widget);
56 // Tree operations -----------------------------------------------------------
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();
63 // Called when parent of the host changed.
64 void NotifyNativeViewHierarchyChanged();
66 // Focus ---------------------------------------------------------------------
68 // Used to set the FocusTraversable parent after the view has been created
69 // (typically when the hierarchy changes and this RootView is added/removed).
70 virtual void SetFocusTraversableParent(FocusTraversable* focus_traversable);
72 // Used to set the View parent after the view has been created.
73 virtual void SetFocusTraversableParentView(View* view);
75 // System events -------------------------------------------------------------
77 // Public API for broadcasting theme change notifications to this View
81 // Public API for broadcasting locale change notifications to this View
85 // Overridden from FocusTraversable:
86 virtual FocusSearch* GetFocusSearch() OVERRIDE;
87 virtual FocusTraversable* GetFocusTraversableParent() OVERRIDE;
88 virtual View* GetFocusTraversableParentView() OVERRIDE;
90 // Overridden from ui::EventProcessor:
91 virtual ui::EventTarget* GetRootTarget() OVERRIDE;
92 virtual ui::EventDispatchDetails OnEventFromSource(ui::Event* event) OVERRIDE;
94 // Overridden from View:
95 virtual const Widget* GetWidget() const OVERRIDE;
96 virtual Widget* GetWidget() OVERRIDE;
97 virtual bool IsDrawn() const OVERRIDE;
98 virtual void Layout() OVERRIDE;
99 virtual const char* GetClassName() const OVERRIDE;
100 virtual void SchedulePaintInRect(const gfx::Rect& rect) OVERRIDE;
101 virtual bool OnMousePressed(const ui::MouseEvent& event) OVERRIDE;
102 virtual bool OnMouseDragged(const ui::MouseEvent& event) OVERRIDE;
103 virtual void OnMouseReleased(const ui::MouseEvent& event) OVERRIDE;
104 virtual void OnMouseCaptureLost() OVERRIDE;
105 virtual void OnMouseMoved(const ui::MouseEvent& event) OVERRIDE;
106 virtual void OnMouseExited(const ui::MouseEvent& event) OVERRIDE;
107 virtual bool OnMouseWheel(const ui::MouseWheelEvent& event) OVERRIDE;
108 virtual void SetMouseHandler(View* new_mouse_handler) OVERRIDE;
109 virtual void GetAccessibleState(ui::AXViewState* state) OVERRIDE;
110 virtual void UpdateParentLayer() OVERRIDE;
113 // TODO(tdanderson): Remove RootView::DispatchGestureEvent() once
114 // its targeting and dispatch logic has been moved
115 // elsewhere. See crbug.com/348083.
116 virtual void DispatchGestureEvent(ui::GestureEvent* event);
118 // Overridden from View:
119 virtual void ViewHierarchyChanged(
120 const ViewHierarchyChangedDetails& details) OVERRIDE;
121 virtual void VisibilityChanged(View* starting_from, bool is_visible) OVERRIDE;
122 virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
123 virtual gfx::Vector2d CalculateOffsetToAncestorWithLayer(
124 ui::Layer** layer_parent) OVERRIDE;
125 virtual View::DragInfo* GetDragInfo() OVERRIDE;
128 friend class ::views::View;
129 friend class ::views::Widget;
130 friend class ::views::test::WidgetTest;
132 // Input ---------------------------------------------------------------------
134 // Update the cursor given a mouse event. This is called by non mouse_move
135 // event handlers to honor the cursor desired by views located under the
136 // cursor during drag operations. The location of the mouse should be in the
137 // current coordinate system (i.e. any necessary transformation should be
138 // applied to the point prior to calling this).
139 void UpdateCursor(const ui::MouseEvent& event);
141 // Updates the last_mouse_* fields from e. The location of the mouse should be
142 // in the current coordinate system (i.e. any necessary transformation should
143 // be applied to the point prior to calling this).
144 void SetMouseLocationAndFlags(const ui::MouseEvent& event);
146 // |view| is the view receiving |event|. This function sends the event to all
147 // the Views up the hierarchy that has |notify_enter_exit_on_child_| flag
148 // turned on, but does not contain |sibling|.
149 void NotifyEnterExitOfDescendant(const ui::MouseEvent& event,
154 // Overridden from ui::EventDispatcherDelegate:
155 virtual bool CanDispatchToTarget(ui::EventTarget* target) OVERRIDE;
156 virtual ui::EventDispatchDetails PreDispatchEvent(ui::EventTarget* target,
157 ui::Event* event) OVERRIDE;
158 virtual ui::EventDispatchDetails PostDispatchEvent(
159 ui::EventTarget* target, const ui::Event& event) OVERRIDE;
161 //////////////////////////////////////////////////////////////////////////////
162 // Tree operations -----------------------------------------------------------
167 // Input ---------------------------------------------------------------------
169 // The view currently handing down - drag - up
170 View* mouse_pressed_handler_;
172 // The view currently handling enter / exit
173 View* mouse_move_handler_;
175 // The last view to handle a mouse click, so that we can determine if
176 // a double-click lands on the same view as its single-click part.
177 View* last_click_handler_;
179 // true if mouse_pressed_handler_ has been explicitly set
180 bool explicit_mouse_handler_;
182 // Last position/flag of a mouse press/drag. Used if capture stops and we need
183 // to synthesize a release.
184 int last_mouse_event_flags_;
185 int last_mouse_event_x_;
186 int last_mouse_event_y_;
188 // The view currently handling gesture events. When set, this handler receives
189 // all gesture events, except when there is an event handler for the specific
190 // gesture (e.g. scroll).
191 View* gesture_handler_;
193 // The view currently handling scroll gesture events.
194 View* scroll_gesture_handler_;
196 scoped_ptr<internal::PreEventDispatchHandler> pre_dispatch_handler_;
198 // Focus ---------------------------------------------------------------------
200 // The focus search algorithm.
201 FocusSearch focus_search_;
203 // Whether this root view belongs to the current active window.
206 // The parent FocusTraversable, used for focus traversal.
207 FocusTraversable* focus_traversable_parent_;
209 // The View that contains this RootView. This is used when we have RootView
210 // wrapped inside native components, and is used for the focus traversal.
211 View* focus_traversable_parent_view_;
213 View* event_dispatch_target_;
214 View* old_dispatch_target_;
216 // Drag and drop -------------------------------------------------------------
218 // Tracks drag state for a view.
219 View::DragInfo drag_info_;
221 DISALLOW_IMPLICIT_CONSTRUCTORS(RootView);
224 } // namespace internal
227 #endif // UI_VIEWS_WIDGET_ROOT_VIEW_H_