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/root_window_observer.h"
  17 #include "ui/aura/window_observer.h"
  18 #include "ui/base/events/event_handler.h"
  19 #include "ui/base/ui_base_types.h"
  20
  21 namespace aura {
  22 class RootWindow;
  23 class Window;
  24 }
  25
  26 namespace ash {
  27 namespace internal {
  28
  29 // BaseLayoutManager is the simplest possible implementation for a window
  30 // layout manager. It listens for changes to kShowStateKey and resizes the
  31 // window appropriately.  Subclasses should be sure to invoke the base class
  32 // for adding and removing windows, otherwise show state will not be tracked
  33 // properly.
  34 class ASH_EXPORT BaseLayoutManager
  35     : public aura::LayoutManager,
  36       public aura::RootWindowObserver,
  37       public ash::ShellObserver,
  38       public aura::WindowObserver,
  39       public aura::client::ActivationChangeObserver {
  40  public:
  41   typedef std::set<aura::Window*> WindowSet;
  42
  43   explicit BaseLayoutManager(aura::RootWindow* root_window);
  44   virtual ~BaseLayoutManager();
  45
  46   const WindowSet& windows() const { return windows_; }
  47
  48   // Given a |window| and tentative |restore_bounds|, returns new bounds that
  49   // ensure that at least a few pixels of the screen background are visible
  50   // outside the edges of the window.
  51   static gfx::Rect BoundsWithScreenEdgeVisible(aura::Window* window,
  52                                                const gfx::Rect& restore_bounds);
  53
  54   // LayoutManager overrides:
  55   virtual void OnWindowResized() OVERRIDE;
  56   virtual void OnWindowAddedToLayout(aura::Window* child) OVERRIDE;
  57   virtual void OnWillRemoveWindowFromLayout(aura::Window* child) OVERRIDE;
  58   virtual void OnWindowRemovedFromLayout(aura::Window* child) OVERRIDE;
  59   virtual void OnChildWindowVisibilityChanged(aura::Window* child,
  60                                               bool visible) OVERRIDE;
  61   virtual void SetChildBounds(aura::Window* child,
  62                               const gfx::Rect& requested_bounds) OVERRIDE;
  63
  64   // RootWindowObserver overrides:
  65   virtual void OnRootWindowResized(const aura::RootWindow* root,
  66                                    const gfx::Size& old_size) OVERRIDE;
  67
  68   // ash::ShellObserver overrides:
  69   virtual void OnDisplayWorkAreaInsetsChanged() OVERRIDE;
  70
  71   // WindowObserver overrides:
  72   virtual void OnWindowPropertyChanged(aura::Window* window,
  73                                        const void* key,
  74                                        intptr_t old) OVERRIDE;
  75   virtual void OnWindowDestroying(aura::Window* window) OVERRIDE;
  76
  77   // aura::client::ActivationChangeObserver overrides:
  78   virtual void OnWindowActivated(aura::Window* gained_active,
  79                                  aura::Window* lost_active) OVERRIDE;
  80
  81  protected:
  82   // Invoked from OnWindowPropertyChanged() if |kShowStateKey| changes.
  83   virtual void ShowStateChanged(aura::Window* window,
  84                                 ui::WindowShowState last_show_state);
  85
  86  private:
  87   // Update window bounds based on a change in show state.
  88   void UpdateBoundsFromShowState(aura::Window* window);
  89
  90   // Adjusts the window sizes when the screen changes its size or its
  91   // work area insets.
  92   void AdjustWindowSizesForScreenChange();
  93
  94   // Set of windows we're listening to.
  95   WindowSet windows_;
  96
  97   aura::RootWindow* root_window_;
  98
  99   DISALLOW_COPY_AND_ASSIGN(BaseLayoutManager);
 100 };
 101
 102 }  // namespace internal
 103 }  // namespace ash
 104
 105 #endif  // ASH_WM_BASE_LAYOUT_MANAGER_H_