Fix bug #24209 and add a global event scope

This adds a global event scope that an sdl_handler can register to in
order to receive all current events, regardless of the current
scope. Care should be taken to not be registerd in a local event
context and the global context at the same time as it will lead to the
event handler potentially being invoked twice.

This also adds the workaround needed for #24209 in the new event
handler in the video class.

src/events.cpp

@@ -141,6 +141,10 @@ void context::set_focus(const sdl_handler* ptr)
 //in that context. The current context is the one on the top of the stack
 std::deque<context> event_contexts;
 
+//add a global context for event handlers. Whichever object has joined this will always
+//receive all events, regardless of the current context.
+context global_context;
+
 std::vector<pump_monitor*> pump_monitors;
 
 } //end anon namespace
@@ -185,7 +189,12 @@ event_context::~event_context()
 
 sdl_handler::~sdl_handler()
 {
-	leave();
+	if (has_joined_)
+		leave();
+
+	if (has_joined_global_)
+		leave_global();
+
 #if !SDL_VERSION_ATLEAST(2, 0, 0)
 	SDL_EnableUNICODE(unicode_);
 #endif
@@ -227,6 +236,38 @@ void sdl_handler::leave()
 	has_joined_ = false;
 }
 
+void sdl_handler::join_global()
+{
+	if(has_joined_global_) {
+		leave_global(); // should not be in multiple event contexts
+	}
+	//join self
+	global_context.add_handler(this);
+	has_joined_global_ = true;
+
+	//instruct members to join
+	sdl_handler_vector members = handler_members();
+	if(!members.empty()) {
+		for(sdl_handler_vector::iterator i = members.begin(); i != members.end(); ++i) {
+			(*i)->join_global();
+		}
+	}
+}
+
+void sdl_handler::leave_global()
+{
+	sdl_handler_vector members = handler_members();
+	if(!members.empty()) {
+		for(sdl_handler_vector::iterator i = members.begin(); i != members.end(); ++i) {
+			(*i)->leave_global();
+		}
+	}
+
+	global_context.remove_handler(this);
+
+	has_joined_global_ = false;
+}
+
 void focus_handler(const sdl_handler* ptr)
 {
 	if(event_contexts.empty() == false) {
@@ -398,22 +439,14 @@ void pump()
 
 					case SDL_WINDOWEVENT_EXPOSED:
 						update_whole_screen();
-						if (display::get_singleton())
-							display::get_singleton()->redraw_everything();
 						break;
 
-					case SDL_WINDOWEVENT_RESIZED: {
+					case SDL_WINDOWEVENT_RESIZED:
 						info.resize_dimensions.first = event.window.data1;
 						info.resize_dimensions.second = event.window.data2;
 						break;
-					case SDL_WINDOWEVENT_MOVED:
-					case SDL_WINDOWEVENT_CLOSE:
-						break;
-					default:
-						if (display::get_singleton())
-							display::get_singleton()->redraw_everything();
-					}
 				}
+
 				break;
 #else
 			case SDL_ACTIVEEVENT: {
@@ -500,6 +533,11 @@ void pump()
 			}
 		}
 
+		const std::vector<sdl_handler*>& event_handlers = global_context.handlers;
+		for(size_t i1 = 0, i2 = event_handlers.size(); i1 != i2 && i1 < event_handlers.size(); ++i1) {
+			event_handlers[i1]->handle_event(event);
+		}
+
 		if(event_contexts.empty() == false) {
 
 			const std::vector<sdl_handler*>& event_handlers = event_contexts.back().handlers;
@@ -510,6 +548,7 @@ void pump()
 				event_handlers[i1]->handle_event(event);
 			}
 		}
+
 	}
 
 	//inform the pump monitors that an events::pump() has occurred

src/events.hpp

@@ -55,6 +55,9 @@ public:
 	virtual void join(); /*joins the current event context*/
 	virtual void leave(); /*leave the event context*/
 
+	virtual void join_global(); /*join the global event context*/
+	virtual void leave_global(); /*leave the global event context*/
+
 protected:
 	sdl_handler(const bool auto_join=true);
 	virtual ~sdl_handler();
@@ -68,6 +71,7 @@ private:
 	int unicode_;
 #endif
 	bool has_joined_;
+	bool has_joined_global_;
 };
 
 void focus_handler(const sdl_handler* ptr);

src/video.cpp

@@ -60,10 +60,7 @@ void resize_monitor::process(events::pump_info &info) {
 		}
 	}
 #else
-	if(info.resize_dimensions.first > 0 &&
-			info.resize_dimensions.second > 0
-			&& display::get_singleton())
-		display::get_singleton()->redraw_everything();
+	UNUSED(info);
 #endif
 }
 
@@ -355,6 +352,41 @@ void update_whole_screen()
 {
 	update_all = true;
 }
+
+
+void CVideo::video_event_handler::handle_event(const SDL_Event &event)
+{
+#if SDL_VERSION_ATLEAST(2, 0, 0)
+	if (event.type == SDL_WINDOWEVENT) {
+		switch (event.window.event) {
+			case SDL_WINDOWEVENT_RESIZED:
+			case SDL_WINDOWEVENT_RESTORED:
+			case SDL_WINDOWEVENT_SHOWN:
+			case SDL_WINDOWEVENT_EXPOSED:
+				if (display::get_singleton())
+					display::get_singleton()->redraw_everything();
+				break;
+#if !SDL_VERSION_ATLEAST(2, 0, 4) && defined(_WIN32)
+			case SDL_WINDOWEVENT_FOCUS_GAINED:
+
+				if(SDL_GetWindowFlags(*window) & SDL_WINDOW_MAXIMIZED) {
+					SDL_RestoreWindow(*window);
+					SDL_MaximizeWindow(*window);
+				}
+				if(SDL_GetWindowFlags(*window) & SDL_WINDOW_FULLSCREEN_DESKTOP) {
+					SDL_RestoreWindow(*window);
+					SDL_SetWindowFullscreen(*window, SDL_WINDOW_FULLSCREEN_DESKTOP);
+				}
+				break;
+#endif
+		}
+	}
+#else
+	UNUSED(event);
+#endif
+}
+
+
 CVideo::CVideo(FAKE_TYPES type) :
 #ifdef SDL_GPU
 	shader_(),
@@ -581,6 +613,7 @@ int CVideo::setMode( int x, int y, int bits_per_pixel, int flags )
 		// Note that x and y in this particular case refer to width and height of the window, not co-ordinates.
 		window = new sdl::twindow("", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, x, y, flags, SDL_RENDERER_SOFTWARE);
 		window->set_minimum_size(preferences::min_allowed_width(), preferences::min_allowed_height());
+		event_handler_.join_global();
 	} else {
 		if(fullScreen) {
 			window->full_screen();

src/video.hpp

@@ -218,6 +218,12 @@ class CVideo : private boost::noncopyable {
 
 private:
 
+	class video_event_handler : public events::sdl_handler {
+	public:
+		virtual void handle_event(const SDL_Event &event);
+		video_event_handler() :	sdl_handler(false) {}
+	};
+
 	void initSDL();
 #ifdef SDL_GPU
 	void update_overlay(SDL_Rect *rect = NULL);
@@ -233,6 +239,8 @@ private:
 	//if there is no display at all, but we 'fake' it for clients
 	bool fake_screen_;
 
+	video_event_handler event_handler_;
+
 	//variables for help strings
 	int help_string_;