[Add] Possibility for custom widgets.

src/toolkit.c

@@ -13,7 +13,8 @@ typedef enum WidgetType_ {
   WIDGET_TEXT,
   WIDGET_IMAGE,
   WIDGET_LIST,
-	WIDGET_RECT
+	WIDGET_RECT,
+	WIDGET_CUST
 } WidgetType;
 
 typedef enum WidgetStatus_ {
@@ -61,6 +62,10 @@ typedef struct Widget_ {
 			glColour* colour; // Background colour.
 			int border;				// Border.
 		} rct;
+		// Widget cust.
+		struct {
+			void(*render) (double bx, double by);
+		} cst;
   } dat;
 } Widget;
 
@@ -234,6 +239,28 @@ void window_addRect(const unsigned int wid, const int x, const int y, const int
 	else wgt->y = (double)y;
 }
 
+void window_addCust(const unsigned int wid, const int x, const int y,
+			const int w, const int h, char* name, void(*render) (double x, double y)) {
+	
+	Window* wdw = window_wget(wid);
+	Widget* wgt = window_newWidget(wdw);
+
+	// Generic.
+	wgt->type 	= WIDGET_CUST;
+	wgt->name 	= strdup(name);
+
+	// Specific.
+	wgt->dat.cst.render = render;
+
+	// Position/size.
+	wgt->w = (double)w;
+	wgt->h = (double)h;
+	if(x < 0) wgt->x = wdw->w - wgt->w + x;
+	else wgt->x = (double) x;
+	if(y < 0) wgt->y = wdw->h - wgt->h + y;
+	else wgt->y = (double) y;
+}
+
 // Return pointer to newly allocated widget.
 static Widget* window_newWidget(Window* w) {
   Widget* wgt = NULL;
@@ -630,6 +657,9 @@ static void window_render(Window* w) {
 			case WIDGET_RECT:
 				toolkit_renderRect(&w->widgets[i], x, y);
 				break;
+			case WIDGET_CUST:
+				(*w->widgets[i].dat.cst.render)(x, y);
+				break;
     }
   }
 	// Focus widget.

src/toolkit.h

@@ -30,6 +30,11 @@ void window_addRect(const unsigned int wid,
 			const int w, const int h, // size.
 			char* name, glColour* colour, int border); // Properties.
 
+void window_addCust(const unsigned int wid,
+			const int x, const int y, // Position.
+			const int w, const int h,	// Size.
+			char* name, void(*render) (double x, double y));
+
 // Popups and alerts.
 void toolkit_alert(const char* fmt, ...);