Add a focus event send to parents of a widget.

This event allows parent containers and windows to react if the mouse is
pressed down inside it's area. This also works if the selected widget
itself is disabled.

src/gui/widgets/event_executor.hpp

@@ -160,7 +160,17 @@ public:
 	/** See mouse_left_button_double_click. */
 	virtual void mouse_right_button_double_click(tevent_handler&) {}
 
-	/***** ***** ***** ***** mouse right button ***** ***** ***** *****/
+	/***** ***** ***** ***** focus ***** ***** ***** *****/
+
+	/**
+	 * The widget recieves a focus event.
+	 *
+	 * Container classes are notified when a child item gets a mouse down
+	 * event. This can be used to capture the keyboard.
+	 */
+	virtual void focus(tevent_handler&) {}
+
+	/***** ***** ***** ***** keyboard ***** ***** ***** *****/
 
 	/**
 	 * A key is pressed.

src/gui/widgets/event_handler.cpp

@@ -154,6 +154,19 @@ void tevent_handler::handle_event(const SDL_Event& event)
 			mouse_y_ = event.button.y;
 			mouse_over = find_widget(tpoint(mouse_x_, mouse_y_), true);
 
+			/**
+			 * @todo these two events aren't documented in the event overview
+			 * at the end of the file.
+			 */
+			if(!mouse_captured_) {
+				twidget* widget =
+						find_widget(tpoint(mouse_x_, mouse_y_), false);
+				if(widget) {
+					focus_parent_container(widget);
+					focus_parent_window(widget);
+				}
+			}
+
 			switch(event.button.button) {
 				case SDL_BUTTON_LEFT :
 					DBG_G_E << "Event: Left button down.\n";
@@ -520,6 +533,38 @@ void tevent_handler::mouse_click(twidget* widget, tmouse_button& button)
 	}
 }
 
+void tevent_handler::focus_parent_container(twidget* widget)
+{
+	assert(widget);
+
+	twidget* parent = widget->parent();
+	while(parent) {
+
+		tcontainer_* container = dynamic_cast<tcontainer_*>(parent);
+		if(container) {
+			if(container != widget->get_window() && container->get_active()) {
+				container->focus(*this);
+			}
+			return;
+		}
+
+		parent = parent->parent();
+	}
+
+}
+
+void tevent_handler::focus_parent_window(twidget* widget)
+{
+	assert(widget);
+
+	twindow* window = widget->get_window();
+	assert(window);
+
+	if(window->get_active()) {
+		window->focus(*this);
+	}
+}
+
 void tevent_handler::set_hover(const bool test_on_widget)
 {
 	// Only one hover event.

src/gui/widgets/event_handler.hpp

@@ -310,6 +310,29 @@ private:
 	 */
 	void mouse_click(twidget* widget, tmouse_button& button);
 
+
+	/**
+	 * Called when a mouse button is pressed.
+	 *
+	 * When a mouse button is pressed it's direct parent container is
+	 * notified. If the parent container is the parent window this function
+	 * doesn't notify the parent. The funcion focus_parent_window will send
+	 * the event.
+	 *
+	 * @param widget              The widget that generated the event.
+	 */
+	 void focus_parent_container(twidget* widget);
+
+	/**
+	 * Called when a mouse button is pressed.
+	 *
+	 * When a mouse button is pressed it's direct parent window is send the
+	 * focus event.
+	 *
+	 * @param widget              The widget that generated the event.
+	 */
+	 void focus_parent_window(twidget* widget);
+
 	/**
 	 * Raises a hover request.
 	 *

src/gui/widgets/scrollbar_container.cpp

@@ -332,6 +332,13 @@ void tscrollbar_container::key_press(tevent_handler& /*event*/,
 		}
 }
 
+void tscrollbar_container::focus(tevent_handler&)
+{
+	twindow* window = get_window();
+	assert(window);
+	window->keyboard_capture(this);
+}
+
 twidget* tscrollbar_container::find_widget(
 		const tpoint& coordinate, const bool must_be_active)
 {
@@ -382,9 +389,6 @@ bool tscrollbar_container::does_block_easy_close() const
 
 void tscrollbar_container::vertical_scrollbar_click(twidget* caller)
 {
-	/** @todo Hack to capture the keyboard focus. */
-	get_window()->keyboard_capture(this);
-
 	const std::map<std::string, tscrollbar_::tscroll>::const_iterator
 		itor = scroll_lookup().find(caller->id());
 
@@ -396,9 +400,6 @@ void tscrollbar_container::vertical_scrollbar_click(twidget* caller)
 
 void tscrollbar_container::horizontal_scrollbar_click(twidget* caller)
 {
-	/** @todo Hack to capture the keyboard focus. */
-	get_window()->keyboard_capture(this);
-
 	const std::map<std::string, tscrollbar_::tscroll>::const_iterator
 		itor = scroll_lookup().find(caller->id());
 

src/gui/widgets/scrollbar_container.hpp

@@ -115,6 +115,9 @@ public:
 	void key_press(tevent_handler& event,
 		bool& handled, SDLKey key, SDLMod modifier, Uint16 unicode);
 
+	/** Inherted from tevent_executor. */
+	void focus(tevent_handler&);
+
 	/** Inherited from tcontainer_. */
 	bool get_active() const { return state_ != DISABLED; }