| // 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_WM_CORE_FOCUS_RULES_H_ |
| #define UI_WM_CORE_FOCUS_RULES_H_ |
| |
| #include "ui/wm/wm_export.h" |
| |
| namespace aura { |
| class Window; |
| } |
| |
| namespace wm { |
| |
| // Implemented by an object that establishes the rules about what can be |
| // focused or activated. |
| class WM_EXPORT FocusRules { |
| public: |
| virtual ~FocusRules() {} |
| |
| // Returns true if |window| is a toplevel window. Whether or not a window |
| // is considered toplevel is determined by a similar set of rules that |
| // govern activation and focus. Not all toplevel windows are activatable, |
| // call CanActivateWindow() to determine if a window can be activated. |
| virtual bool IsToplevelWindow(aura::Window* window) const = 0; |
| // Returns true if |window| can be activated or focused. |
| virtual bool CanActivateWindow(aura::Window* window) const = 0; |
| // For CanFocusWindow(), NULL is supported, because NULL is a valid focusable |
| // window (in the case of clearing focus). |
| virtual bool CanFocusWindow(aura::Window* window) const = 0; |
| |
| // Returns the toplevel window containing |window|. Not all toplevel windows |
| // are activatable, call GetActivatableWindow() instead to return the |
| // activatable window, which might be in a different hierarchy. |
| // Will return NULL if |window| is not contained by a window considered to be |
| // a toplevel window. |
| virtual aura::Window* GetToplevelWindow(aura::Window* window) const = 0; |
| // Returns the activatable or focusable window given an attempt to activate or |
| // focus |window|. Some possible scenarios (not intended to be exhaustive): |
| // - |window| is a child of a non-focusable window and so focus must be set |
| // according to rules defined by the delegate, e.g. to a parent. |
| // - |window| is an activatable window that is the transient parent of a modal |
| // window, so attempts to activate |window| should result in the modal |
| // transient being activated instead. |
| // These methods may return NULL if they are unable to find an activatable |
| // or focusable window given |window|. |
| virtual aura::Window* GetActivatableWindow(aura::Window* window) const = 0; |
| virtual aura::Window* GetFocusableWindow(aura::Window* window) const = 0; |
| |
| // Returns the next window to activate in the event that |ignore| is no longer |
| // activatable. This function is called when something is happening to |
| // |ignore| that means it can no longer have focus or activation, including |
| // but not limited to: |
| // - it or its parent hierarchy is being hidden, or removed from the |
| // RootWindow. |
| // - it is being destroyed. |
| // - it is being explicitly deactivated. |
| // |ignore| cannot be NULL. |
| virtual aura::Window* GetNextActivatableWindow( |
| aura::Window* ignore) const = 0; |
| }; |
| |
| } // namespace wm |
| |
| #endif // UI_WM_CORE_FOCUS_RULES_H_ |