widget/windows/WinEventObserver.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef widget_windows_WinEventObserver_h
   8 #define widget_windows_WinEventObserver_h
   9
  10 #include <windows.h>
  11
  12 #include "mozilla/Maybe.h"
  13 #include "nsISupportsImpl.h"
  14 #include "nsTHashSet.h"
  15
  16 namespace mozilla {
  17
  18 namespace widget {
  19
  20 class WinEventObserver {
  21   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(WinEventObserver)
  22  public:
  23   virtual void OnWinEventProc(HWND aHwnd, UINT aMsg, WPARAM aWParam,
  24                               LPARAM aLParam) {}
  25   virtual void Destroy();
  26
  27  protected:
  28   virtual ~WinEventObserver();
  29
  30   bool mDestroyed = false;
  31 };
  32
  33 // Uses singleton window to observe events like display status and session
  34 // change.
  35 class WinEventHub final {
  36   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(WinEventHub)
  37
  38  public:
  39   // Returns true if the singleton exists (or was created). Will return
  40   // false if the singleton couldn't be created, in which case a call
  41   // to Get() will return a nullptr. It is safe to call this function
  42   // repeatedly.
  43   static bool Ensure();
  44   static RefPtr<WinEventHub> Get() { return sInstance; }
  45
  46   void AddObserver(WinEventObserver* aObserver);
  47   void RemoveObserver(WinEventObserver* aObserver);
  48
  49   HWND GetWnd() { return mHWnd; }
  50
  51  private:
  52   WinEventHub();
  53   ~WinEventHub();
  54
  55   static LRESULT CALLBACK WinEventProc(HWND aHwnd, UINT aMsg, WPARAM aWParam,
  56                                        LPARAM aLParam);
  57
  58   bool Initialize();
  59   void ProcessWinEventProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam);
  60
  61   HWND mHWnd = nullptr;
  62   nsTHashSet<nsRefPtrHashKey<WinEventObserver>> mObservers;
  63
  64   static StaticRefPtr<WinEventHub> sInstance;
  65 };
  66
  67 class DisplayStatusListener {
  68  public:
  69   virtual void OnDisplayStateChanged(bool aDisplayOn) = 0;
  70 };
  71
  72 // Observe Display on/off event
  73 class DisplayStatusObserver final : public WinEventObserver {
  74  public:
  75   static already_AddRefed<DisplayStatusObserver> Create(
  76       DisplayStatusListener* aListener);
  77
  78  private:
  79   explicit DisplayStatusObserver(DisplayStatusListener* aListener);
  80   virtual ~DisplayStatusObserver();
  81   void OnWinEventProc(HWND aHwnd, UINT aMsg, WPARAM aWParam,
  82                       LPARAM aLParam) override;
  83
  84   DisplayStatusListener* mListener;
  85
  86   HPOWERNOTIFY mDisplayStatusHandle = nullptr;
  87 };
  88
  89 class SessionChangeListener {
  90  public:
  91   virtual void OnSessionChange(WPARAM aStatusCode,
  92                                Maybe<bool> aIsCurrentSession) = 0;
  93 };
  94
  95 // Observe session lock/unlock event
  96 class SessionChangeObserver : public WinEventObserver {
  97  public:
  98   static already_AddRefed<SessionChangeObserver> Create(
  99       SessionChangeListener* aListener);
 100
 101  private:
 102   explicit SessionChangeObserver(SessionChangeListener* aListener);
 103   virtual ~SessionChangeObserver();
 104
 105   void Initialize();
 106   void OnWinEventProc(HWND aHwnd, UINT aMsg, WPARAM aWParam,
 107                       LPARAM aLParam) override;
 108
 109   SessionChangeListener* mListener;
 110 };
 111
 112 }  // namespace widget
 113 }  // namespace mozilla
 114
 115 #endif  // widget_windows_WinEventObserver_h