Tao3D: on_click with draw_selection

color "red"
rectangle -200, 0, 200, 100

rectangle_hue -> 0

active_widget
    color_hsv 20 * rectangle_hue, 1, 1
    rectangle 200, 0, 200, 100
    on_click
        rectangle_hue := rectangle_hue + 20
        refresh 0

draw_selection X, Y, W, H ->
    locally
        color "black", 0.3
        circle X + W/2, Y, 20
        circle X - W/2, Y, 20
        text_box X, Y, W/2, H/2,
            align_center
            vertical_align_center
            text "Hue=" & rectangle_hue