GUI2: further progress on touch event backend implementation

src/gui/core/event/dispatcher.cpp

@@ -86,6 +86,10 @@ bool dispatcher::has_event(const ui_event event, const event_queue_type event_ty
 					  event,
 					  dispatcher_implementation::has_handler(event_type,
 															   *this))
+		   || find<set_event_touch>(
+					  event,
+					  dispatcher_implementation::has_handler(event_type,
+															   *this))
 		   || find<set_event_notification>(
 					  event,
 					  dispatcher_implementation::has_handler(event_type,
@@ -246,6 +250,43 @@ bool dispatcher::fire(const ui_event event,
 			trigger_keyboard(key, modifier, unicode));
 }
 
+/** Helper struct to wrap the functor call. */
+class trigger_touch
+{
+public:
+	trigger_touch(const point& pos, const point& distance)
+		: pos_(pos)
+		, distance_(distance)
+	{
+	}
+
+	void operator()(signal_touch_function functor,
+					dispatcher& dispatcher,
+					const ui_event event,
+					bool& handled,
+					bool& halt)
+	{
+		functor(dispatcher, event, handled, halt, pos_, distance_);
+	}
+
+private:
+	point pos_;
+	point distance_;
+};
+
+bool dispatcher::fire(const ui_event event,
+					   widget& target,
+					   const point& pos,
+					   const point& distance)
+{
+	assert(find<set_event_touch>(event, event_in_set()));
+	return fire_event<signal_touch_function>(
+			event,
+			dynamic_cast<widget*>(this),
+			&target,
+			trigger_touch(pos, distance));
+}
+
 /** Helper struct to wrap the functor call. */
 class trigger_notification
 {

src/gui/core/event/dispatcher.hpp

@@ -202,6 +202,19 @@ class dispatcher
 			  const SDL_Keymod modifier,
 			  const utf8::string& unicode);
 
+	/**
+	 * Fires an event which takes touch parameters.
+	 *
+	 * @param event                  The event to fire.
+	 * @param target                 The widget that should receive the event.
+	 * @param pos                    The location touched.
+	 * @param distance               The distance moved.
+	 */
+	bool fire(const ui_event event,
+			  widget& target,
+			  const point& pos,
+			  const point& distance);
+
 	/**
 	 * Fires an event which takes notification parameters.
 	 *

src/gui/core/event/dispatcher_private.hpp

@@ -107,6 +107,7 @@ struct dispatcher_implementation
 
 	IMPLEMENT_EVENT_SIGNAL_WRAPPER(mouse)
 	IMPLEMENT_EVENT_SIGNAL_WRAPPER(keyboard)
+	IMPLEMENT_EVENT_SIGNAL_WRAPPER(touch)
 	IMPLEMENT_EVENT_SIGNAL_WRAPPER(notification)
 	IMPLEMENT_EVENT_SIGNAL_WRAPPER(message)
 

src/gui/core/event/handler.cpp

@@ -218,6 +218,14 @@ class sdl_event_handler : public events::sdl_handler
 	 */
 	dispatcher* keyboard_dispatcher();
 
+	/**
+	 * Fires a generic touch event.
+	 *
+	 * @param position               The position touched.
+	 * @param distance               The distance moved.
+	 */
+	void touch_motion(const point& position, const point& distance);
+
 	/**
 	 * Handles a hat motion event.
 	 *
@@ -414,7 +422,7 @@ void sdl_event_handler::handle_event(const SDL_Event& event)
 			break;
 
 		case SDL_FINGERMOTION:
-			// TODO?
+			touch_motion(point(event.tfinger.x, event.tfinger.y), point(event.tfinger.dx, event.tfinger.dy));
 			break;
 
 #if(defined(_X11) && !defined(__APPLE__)) || defined(_WIN32)
@@ -652,6 +660,13 @@ dispatcher* sdl_event_handler::keyboard_dispatcher()
 	return nullptr;
 }
 
+void sdl_event_handler::touch_motion(const point& position, const point& distance)
+{
+	for(auto& dispatcher : boost::adaptors::reverse(dispatchers_)) {
+		dispatcher->fire(SDL_TOUCH_MOTION , dynamic_cast<widget&>(*dispatcher), position, distance);
+	}
+}
+
 void sdl_event_handler::hat_motion(const SDL_Event& event)
 {
 	const hotkey::hotkey_ptr& hk = hotkey::get_hotkey(event);