ui/wm/core/transient_window_manager.h

   1 // Copyright 2014 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 UI_WM_CORE_TRANSIENT_WINDOW_MANAGER_H_
   6 #define UI_WM_CORE_TRANSIENT_WINDOW_MANAGER_H_
   7
   8 #include <vector>
   9
  10 #include "base/observer_list.h"
  11 #include "ui/aura/window_observer.h"
  12 #include "ui/wm/wm_export.h"
  13
  14 namespace wm {
  15
  16 class TransientWindowObserver;
  17
  18 // TransientWindowManager manages the set of transient children for a window
  19 // along with the transient parent. Transient children get the following
  20 // behavior:
  21 // . The transient parent destroys any transient children when it is
  22 //   destroyed. This means a transient child is destroyed if either its parent
  23 //   or transient parent is destroyed.
  24 // . If a transient child and its transient parent share the same parent, then
  25 //   transient children are always ordered above the transient parent.
  26 // . If a transient parent is hidden, it hides all transient children.
  27 //   For show operation, please refer to |set_parent_controls_visibility(bool)|.
  28 // Transient windows are typically used for popups and menus.
  29 // TODO(sky): when we nuke TransientWindowClient rename this to
  30 // TransientWindowController.
  31 class WM_EXPORT TransientWindowManager : public aura::WindowObserver {
  32  public:
  33   typedef std::vector<aura::Window*> Windows;
  34
  35   ~TransientWindowManager() override;
  36
  37   // Returns the TransientWindowManager for |window|. This never returns NULL.
  38   static TransientWindowManager* Get(aura::Window* window);
  39
  40   // Returns the TransientWindowManager for |window| only if it already exists.
  41   // WARNING: this may return NULL.
  42   static const TransientWindowManager* Get(const aura::Window* window);
  43
  44   void AddObserver(TransientWindowObserver* observer);
  45   void RemoveObserver(TransientWindowObserver* observer);
  46
  47   // Adds or removes a transient child.
  48   void AddTransientChild(aura::Window* child);
  49   void RemoveTransientChild(aura::Window* child);
  50
  51   // Setting true lets the transient parent show this transient
  52   // child when the parent is shown. If this was shown when the
  53   // transient parent is hidden, it remains hidden and gets shown
  54   // when the transient parent is shown. This is false by default.
  55   void set_parent_controls_visibility(bool parent_controls_visibility) {
  56     parent_controls_visibility_ = parent_controls_visibility;
  57   }
  58
  59   const Windows& transient_children() const { return transient_children_; }
  60
  61   aura::Window* transient_parent() { return transient_parent_; }
  62   const aura::Window* transient_parent() const { return transient_parent_; }
  63
  64   // Returns true if in the process of stacking |window_| on top of |target|.
  65   // That is, when the stacking order of a window changes
  66   // (OnWindowStackingChanged()) the transients may get restacked as well. This
  67   // function can be used to detect if TransientWindowManager is in the process
  68   // of stacking a transient as the result of window stacking changing.
  69   bool IsStackingTransient(const aura::Window* target) const;
  70
  71  private:
  72   explicit TransientWindowManager(aura::Window* window);
  73
  74   // Stacks transient descendants of this window that are its siblings just
  75   // above it.
  76   void RestackTransientDescendants();
  77
  78   // Update the window's visibility following the transient parent's
  79   // visibility. See |set_parent_controls_visibility(bool)| for more details.
  80   void UpdateTransientChildVisibility(bool visible);
  81
  82   // WindowObserver:
  83   void OnWindowParentChanged(aura::Window* window,
  84                              aura::Window* parent) override;
  85   void OnWindowVisibilityChanged(aura::Window* window, bool visible) override;
  86   void OnWindowStackingChanged(aura::Window* window) override;
  87   void OnWindowDestroying(aura::Window* window) override;
  88
  89   aura::Window* window_;
  90   aura::Window* transient_parent_;
  91   Windows transient_children_;
  92
  93   // If non-null we're actively restacking transient as the result of a
  94   // transient ancestor changing.
  95   aura::Window* stacking_target_;
  96
  97   bool parent_controls_visibility_;
  98   bool show_on_parent_visible_;
  99   bool ignore_visibility_changed_event_;
 100
 101   base::ObserverList<TransientWindowObserver> observers_;
 102
 103   DISALLOW_COPY_AND_ASSIGN(TransientWindowManager);
 104 };
 105
 106 }  // namespace wm
 107
 108 #endif  // UI_WM_CORE_TRANSIENT_WINDOW_MANAGER_H_