# File gtk/sample/gtk-demo/drawingarea.rb, line 173 def draw_brush(widget, x, y) update_rect = Gdk::Rectangle.new(x - 3, y - 3, 6, 6) # Paint to the pixmap, where we store our state @pixmap.draw_rectangle(widget.style.black_gc, true, update_rect.x, update_rect.y, update_rect.width, update_rect.height) # Now invalidate the affected region of the drawing area. widget.window.invalidate(update_rect, false) end