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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef UI_AURA_WINDOW_OBSERVER_H_
#define UI_AURA_WINDOW_OBSERVER_H_
#include "base/macros.h"
#include "base/strings/string16.h"
#include "ui/aura/aura_export.h"
#include "ui/compositor/property_change_reason.h"
namespace gfx {
class Rect;
class Transform;
} // namespace gfx
namespace aura {
class Window;
class AURA_EXPORT WindowObserver {
public:
struct HierarchyChangeParams {
enum HierarchyChangePhase {
HIERARCHY_CHANGING,
HIERARCHY_CHANGED
};
Window* target; // The window that was added or removed.
Window* new_parent;
Window* old_parent;
HierarchyChangePhase phase;
Window* receiver; // The window receiving the notification.
};
WindowObserver();
// Called when a window is added or removed. Notifications are sent to the
// following hierarchies in this order:
// 1. |target|.
// 2. |target|'s child hierarchy.
// 3. |target|'s parent hierarchy in its |old_parent|
// (only for Changing notifications).
// 3. |target|'s parent hierarchy in its |new_parent|.
// (only for Changed notifications).
// This sequence is performed via the Changing and Changed notifications below
// before and after the change is committed.
virtual void OnWindowHierarchyChanging(const HierarchyChangeParams& params) {}
virtual void OnWindowHierarchyChanged(const HierarchyChangeParams& params) {}
// Invoked when |new_window| has been added as a child of this window.
virtual void OnWindowAdded(Window* new_window) {}
// Invoked prior to removing |window| as a child of this window.
virtual void OnWillRemoveWindow(Window* window) {}
// Invoked when this window's parent window changes. |parent| may be NULL.
virtual void OnWindowParentChanged(Window* window, Window* parent) {}
// Invoked when SetProperty(), ClearProperty(), or
// NativeWidgetAura::SetNativeWindowProperty() is called on the window.
// |key| is either a WindowProperty<T>* (SetProperty, ClearProperty)
// or a const char* (SetNativeWindowProperty). Either way, it can simply be
// compared for equality with the property constant. |old| is the old property
// value, which must be cast to the appropriate type before use.
virtual void OnWindowPropertyChanged(Window* window,
const void* key,
intptr_t old) {}
// Invoked when SetVisible() is invoked on a window. |visible| is the
// value supplied to SetVisible(). If |visible| is true, window->IsVisible()
// may still return false. See description in Window::IsVisible() for details.
virtual void OnWindowVisibilityChanging(Window* window, bool visible) {}
// When the visibility of a Window changes OnWindowVisibilityChanged() is
// called for all observers attached to descendants of the Window as well
// as all observers attached to ancestors of the Window. The Window supplied
// to OnWindowVisibilityChanged() is the Window that Show()/Hide() was called
// on.
virtual void OnWindowVisibilityChanged(Window* window, bool visible) {}
// Invoked when the bounds of the |window|'s layer change. |old_bounds| and
// |new_bounds| are in parent coordinates. |reason| indicates whether the
// bounds were set directly or by an animation. This will be called at every
// step of a bounds animation. The client can determine whether the animation
// is ending by calling window->layer()->GetAnimator()->IsAnimatingProperty(
// ui::LayerAnimationElement::BOUNDS).
virtual void OnWindowBoundsChanged(Window* window,
const gfx::Rect& old_bounds,
const gfx::Rect& new_bounds,
ui::PropertyChangeReason reason) {}
// Invoked when the opacity of the |window|'s layer is set (even if it didn't
// change). |reason| indicates whether the opacity was set directly or by an
// animation. This won't necessarily be called at every step of an animation.
// However, it will always be called before the first frame of the animation
// is rendered and when the animation ends. The client can determine whether
// the animation is ending by calling
// window->layer()->GetAnimator()->IsAnimatingProperty(
// ui::LayerAnimationElement::OPACITY).
virtual void OnWindowOpacitySet(Window* window,
ui::PropertyChangeReason reason) {}
// Invoked before Window::SetTransform() sets the transform of a window.
virtual void OnWindowTargetTransformChanging(
Window* window,
const gfx::Transform& new_transform) {}
// Invoked when the transform of |window| is set (even if it didn't change).
// |reason| indicates whether the transform was set directly or by an
// animation. This won't necessarily be called at every step of an animation.
// However, it will always be called before the first frame of the animation
// is rendered and when the animation ends. The client can determine whether
// the animation is ending by calling
// window->layer()->GetAnimator()->IsAnimatingProperty(
// ui::LayerAnimationElement::TRANSFORM).
virtual void OnWindowTransformed(Window* window,
ui::PropertyChangeReason reason) {}
// Invoked when |window|'s position among its siblings in the stacking order
// has changed.
virtual void OnWindowStackingChanged(Window* window) {}
// Invoked when the Window is being destroyed (i.e. from the start of its
// destructor). This is called before the window is removed from its parent.
virtual void OnWindowDestroying(Window* window) {}
// Invoked when the Window has been destroyed (i.e. at the end of
// its destructor). This is called after the window is removed from
// its parent. Window automatically removes its WindowObservers
// before calling this method, so the following code is no op.
//
// void MyWindowObserver::OnWindowDestroyed(aura::Window* window) {
// window->RemoveObserver(this);
// }
virtual void OnWindowDestroyed(Window* window) {}
// Called when a Window has been added to a RootWindow.
virtual void OnWindowAddedToRootWindow(Window* window) {}
// Called when a Window is about to be removed from a root Window.
// |new_root| contains the new root Window if it is being added to one
// atomically.
virtual void OnWindowRemovingFromRootWindow(Window* window,
Window* new_root) {}
// Called when the window title has changed.
virtual void OnWindowTitleChanged(Window* window) {}
// Called when the window's layer is recreated. The new layer may not carry
// animations from the old layer and animation observers attached to the old
// layer won't automatically be attached to the new layer. Clients that need
// to know when window animations end should implement this method and call
// window->layer()->GetAnimator()->
// (is_animating|IsAnimatingProperty|IsAnimatingOnePropertyOf)() from it.
virtual void OnWindowLayerRecreated(Window* window) {}
// Called when the app embedded in |window| disconnects (is no longer
// embedded).
virtual void OnEmbeddedAppDisconnected(Window* window);
protected:
virtual ~WindowObserver();
private:
friend class Window;
// Called when this is added as an observer on |window|.
void OnObservingWindow(Window* window);
// Called when this is removed from the observers on |window|.
void OnUnobservingWindow(Window* window);
// Tracks the number of windows being observed to track down
// http://crbug.com/365364.
int observing_;
DISALLOW_COPY_AND_ASSIGN(WindowObserver);
};
} // namespace aura
#endif // UI_AURA_WINDOW_OBSERVER_H_