KeyboardGrabber: use pointer instead of boolean, add destination win

re #287, #288

Author: bk138

src/gui/keyboardgrab/KeyboardGrabber.h

@@ -10,8 +10,10 @@ class KeyboardGrabber
 
   void grab(wxWindow* window);
   void ungrab();
-  bool isGrabbed() const { return m_grabbed; }
+  bool isGrabbed() const { return m_grab != nullptr; }
+  wxWindow* getDestinationWindow() const { return m_destinationWindow; }
 
 private:
-  bool m_grabbed = false;
+  void* m_grab = nullptr;
+  wxWindow* m_destinationWindow = nullptr;
 };

src/gui/keyboardgrab/KeyboardGrabberGtk.cpp

@@ -20,12 +20,12 @@ void KeyboardGrabber::showPermissionDialog()
 
 void KeyboardGrabber::grab(wxWindow* window)
 {
-  if(m_grabbed)
+  if(m_grab)
     return;
 
   gdk_keyboard_grab(gtk_widget_get_window(window->GetHandle()), True, GDK_CURRENT_TIME);
 
-  m_grabbed = true;
+  m_grab = (void*)0x1; // Grab active
   wxLogDebug("%s", __func__);
 }
 
@@ -34,6 +34,6 @@ void KeyboardGrabber::ungrab()
 {
   gdk_keyboard_ungrab(GDK_CURRENT_TIME);
 
-  m_grabbed = false;
+  m_grab = nullptr;
   wxLogDebug("%s", __func__);
 }

src/gui/keyboardgrab/KeyboardGrabberNull.cpp

@@ -14,11 +14,11 @@ void KeyboardGrabber::showPermissionDialog()
 
 void KeyboardGrabber::grab(wxWindow*)
 {
-  m_grabbed = true;
+  m_grab = (void*)0x1; // Grab active
 }
 
 
 void KeyboardGrabber::ungrab()
 {
-  m_grabbed = false;
+  m_grab = nullptr;
 }