ash/wm/base_layout_manager.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 ASH_WM_BASE_LAYOUT_MANAGER_H_
   6 #define ASH_WM_BASE_LAYOUT_MANAGER_H_
   7
   8 #include <set>
   9
  10 #include "ash/ash_export.h"
  11 #include "ash/shell_observer.h"
  12 #include "base/basictypes.h"
  13 #include "base/compiler_specific.h"
  14 #include "ui/aura/client/activation_change_observer.h"
  15 #include "ui/aura/layout_manager.h"
  16 #include "ui/aura/window_observer.h"
  17 #include "ui/base/events/event_handler.h"
  18 #include "ui/base/ui_base_types.h"
  19
  20 namespace aura {
  21 class RootWindow;
  22 class Window;
  23 }
  24
  25 namespace ash {
  26 namespace internal {
  27
  28 // BaseLayoutManager is the simplest possible implementation for a window
  29 // layout manager. It listens for changes to kShowStateKey and resizes the
  30 // window appropriately.  Subclasses should be sure to invoke the base class
  31 // for adding and removing windows, otherwise show state will not be tracked
  32 // properly.
  33 class ASH_EXPORT BaseLayoutManager
  34     : public aura::LayoutManager,
  35       public ash::ShellObserver,
  36       public aura::WindowObserver,
  37       public aura::client::ActivationChangeObserver {
  38  public:
  39   typedef std::set<aura::Window*> WindowSet;
  40
  41   explicit BaseLayoutManager(aura::RootWindow* root_window);
  42   virtual ~BaseLayoutManager();
  43
  44   const WindowSet& windows() const { return windows_; }
  45
  46   // Given a |window| and tentative |restore_bounds|, returns new bounds that
  47   // ensure that at least a few pixels of the screen background are visible
  48   // outside the edges of the window.
  49   static gfx::Rect BoundsWithScreenEdgeVisible(aura::Window* window,
  50                                                const gfx::Rect& restore_bounds);
  51
  52   // LayoutManager overrides:
  53   virtual void OnWindowResized() OVERRIDE;
  54   virtual void OnWindowAddedToLayout(aura::Window* child) OVERRIDE;
  55   virtual void OnWillRemoveWindowFromLayout(aura::Window* child) OVERRIDE;
  56   virtual void OnWindowRemovedFromLayout(aura::Window* child) OVERRIDE;
  57   virtual void OnChildWindowVisibilityChanged(aura::Window* child,
  58                                               bool visible) OVERRIDE;
  59   virtual void SetChildBounds(aura::Window* child,
  60                               const gfx::Rect& requested_bounds) OVERRIDE;
  61
  62   // ash::ShellObserver overrides:
  63   virtual void OnDisplayWorkAreaInsetsChanged() OVERRIDE;
  64
  65   // WindowObserver overrides:
  66   virtual void OnWindowPropertyChanged(aura::Window* window,
  67                                        const void* key,
  68                                        intptr_t old) OVERRIDE;
  69   virtual void OnWindowDestroying(aura::Window* window) OVERRIDE;
  70   virtual void OnWindowBoundsChanged(aura::Window* window,
  71                                      const gfx::Rect& old_bounds,
  72                                      const gfx::Rect& new_bounds) OVERRIDE;
  73
  74   // aura::client::ActivationChangeObserver overrides:
  75   virtual void OnWindowActivated(aura::Window* gained_active,
  76                                  aura::Window* lost_active) OVERRIDE;
  77
  78  protected:
  79   enum AdjustWindowReason {
  80     ADJUST_WINDOW_DISPLAY_SIZE_CHANGED,
  81     ADJUST_WINDOW_WORK_AREA_INSETS_CHANGED,
  82   };
  83
  84   // Invoked from OnWindowPropertyChanged() if |kShowStateKey| changes.
  85   virtual void ShowStateChanged(aura::Window* window,
  86                                 ui::WindowShowState last_show_state);
  87
  88   // Adjusts the window's bounds when the display area changes for given
  89   // window. This happens when the display size, work area insets or
  90   // the display on which the window exists has changed.
  91   // If this is called for a display size change (i.e. |reason|
  92   // is ADJUST_WINDOW_DISPLAY_SIZE_CHANGED), the non-maximized/non-fullscreen
  93   // windows are readjusted to make sure the window is completely within the
  94   // display region. Otherwise, it makes sure at least some parts of the window
  95   // is on display.
  96   virtual void AdjustAllWindowsBoundsForWorkAreaChange(
  97       AdjustWindowReason reason);
  98
  99   // Adjusts the sizes of the specific window in respond to a screen change or
 100   // display-area size change.
 101   virtual void AdjustWindowBoundsForWorkAreaChange(aura::Window* window,
 102                                                    AdjustWindowReason reason);
 103
 104   aura::RootWindow* root_window() { return root_window_; }
 105
 106  private:
 107   // Update window bounds based on a change in show state.
 108   void UpdateBoundsFromShowState(aura::Window* window);
 109
 110   // Set of windows we're listening to.
 111   WindowSet windows_;
 112
 113   aura::RootWindow* root_window_;
 114
 115   DISALLOW_COPY_AND_ASSIGN(BaseLayoutManager);
 116 };
 117
 118 }  // namespace internal
 119 }  // namespace ash
 120
 121 #endif  // ASH_WM_BASE_LAYOUT_MANAGER_H_