(svn r20121) -Add: OnHover method for windows.

src/depot_gui.cpp

@@ -558,6 +558,7 @@ struct DepotWindow : Window {
 		this->GetWidget<NWidgetCore>(DEPOT_WIDGET_LOCATION)->tool_tip     = STR_DEPOT_TRAIN_LOCATION_TOOLTIP + type;
 		this->GetWidget<NWidgetCore>(DEPOT_WIDGET_VEHICLE_LIST)->tool_tip = STR_DEPOT_VEHICLE_ORDER_LIST_TRAIN_TOOLTIP + type;
 		this->GetWidget<NWidgetCore>(DEPOT_WIDGET_AUTOREPLACE)->tool_tip  = STR_DEPOT_AUTOREPLACE_TRAIN_TOOLTIP + type;
+		this->GetWidget<NWidgetCore>(DEPOT_WIDGET_MATRIX)->tool_tip       = STR_DEPOT_TRAIN_LIST_TOOLTIP + this->type;
 
 		switch (type) {
 			default: NOT_REACHED();
@@ -843,13 +844,9 @@ struct DepotWindow : Window {
 			args[0] = (whole_chain ? num : v->engine_type);
 			args[1] = (uint64)(size_t)details;
 			GuiShowTooltips(whole_chain ? STR_DEPOT_VEHICLE_TOOLTIP_CHAIN : STR_DEPOT_VEHICLE_TOOLTIP, 2, args, TCC_RIGHT_CLICK);
-		} else {
-			/* Show tooltip help */
-			GuiShowTooltips(STR_DEPOT_TRAIN_LIST_TOOLTIP + this->type, TCC_RIGHT_CLICK);
 		}
 	}
 
-
 	virtual void OnPlaceObject(Point pt, TileIndex tile)
 	{
 		const Vehicle *v = CheckMouseOverVehicle();

src/window.cpp

@@ -409,6 +409,12 @@ static void DispatchHoverEvent(Window *w, int x, int y)
 		GuiShowTooltips(wid->tool_tip);
 		return;
 	}
+
+	/* Widget has no index, so the window is not interested in it. */
+	if (wid->index < 0) return;
+
+	Point pt = { x, y };
+	w->OnHover(pt, wid->index);
 }
 
 /**

src/window_gui.h

@@ -657,6 +657,13 @@ public:
 	 */
 	virtual void OnRightClick(Point pt, int widget) {}
 
+	/**
+	 * The mouse is hovering over a widget in the window, perform an action for it, like opening a custom tooltip.
+	 * @param pt     The point where the mouse is hovering.
+	 * @param widget The widget where the mouse is hovering.
+	 */
+	virtual void OnHover(Point pt, int widget) {}
+
 	/**
 	 * An 'object' is being dragged at the provided position, highlight the target if possible.
 	 * @param pt     The point inside the window that the mouse hovers over.