Demo: widgets

from vpython import *
#----------------------------------------------------------------- Oggetti 3D
box_object      = box     (visible=True)
cone_object     = cone    (visible=False, radius=0.5)
pyramid_object  = pyramid (visible=False)
cylinder_object = cylinder(visible=False, radius=0.5)
#----------------------------------------------------------------- Proprietà degli oggetti
scene.width  = 500
scene.height = 500
running      = True
col          = color.cyan

current_object       = box_object
current_object.color = col
#----------------------------------------------------------------- Binding
def bind_run(evt):
    global running
    running = not running
    
    if(running): evt.text = "Pause"
    else:        evt.text = "Run"
 
def bind_color_1(evt):
    global col
    if(col == color.cyan):                     # cyan -->  red
        current_object.color = col = color.red
        evt.text = "<b>Cyan</b>"
        evt.color = color.cyan
        evt.background = color.red
        r1.checked = False
        r2.checked = True
    else:                                      # red --> cyan
        current_object.color = col = color.cyan
        evt.text = "<b>Red</b>"
        evt.color = color.red
        evt.background = color.cyan
        r1.checked = True
        r2.checked = False
         
def bind_color_2(evt):
    global col
    if(col == color.cyan):                     # cyan --> red
        current_object.color = col = color.red
        cbutton.text = "<b>Cyan</b>"
        cbutton.color = color.cyan
        cbutton.background = color.red
    else:                                      # red --> cyan
        current_object.color = col = color.cyan
        cbutton.text = "<b>Red</b>"
        cbutton.color = color.red
        cbutton.background = color.cyan
 
def bind_setspeed(evt):
    wt.text = '{:1.2f}'.format(evt.value)
 
def bind_menu(evt):
    global col, current_object
    op = current_object.opacity
    current_axis = current_object.axis
    current_object.visible = False
     
    val = evt.selected
    if(val == "box")       : current_object = box_object
    elif(val == "cone")    : current_object = cone_object
    elif(val == "cylinder"): current_object = cylinder_object
    elif(val == "pyramid") : current_object = pyramid_object
     
    current_object.color   = col
    current_object.axis    = current_axis
    current_object.visible = True
    current_object.opacity = op
 
def bind_transparency(evt):
    if(evt.checked):
        current_object.opacity = 0.5
    else:
        current_object.opacity = 1
#----------------------------------------------------------------- Interfaccia
scene.title = "Widgets (button, checkbox, menu, radio, slider)\n\n"
button(bind = bind_run,
       text = "Pause",
       pos  = scene.title_anchor)
scene.append_to_title(' ')
cbutton = button(background = color.cyan, 
                 bind       = bind_color_1,
                 color      = color.red,                 
                 name       = None,
                 pos        = scene.title_anchor,
                 text       = '<b>Red</b>')
scene.append_to_title('\n\n')
 
scene.append_to_caption('\n\nObject: ')
menu(bind    = bind_menu,
     choices = ['box', 'cone', 'cylinder', 'pyramid'],
     index   = 0)
scene.append_to_caption('\n\nColor: ')
r1 = radio(bind    = bind_color2,
           checked = True,
           name    = 'rads',
           text    = 'Cyan')
r2 = radio(bind = bind_color2,
           name = 'rads',
           text = 'Red')
scene.append_to_caption('\n\nTransparency: ')
checkbox(bind = bind_transparency,
         text = '')
scene.append_to_caption("\n\nSpeed: ")   
sl = slider(bind   = bind_setspeed,
            max    = 2.0,
            min    = 0.25,
            length = 200,
            right  = 10,
            value  = 1.0)
wt = wtext(text = '{:1.2f}'.format(sl.value))
scene.append_to_caption(' rad/s')
#----------------------------------------------------------------- MAIN
dt = 0.01
while(True):
    rate(50)
    if(running):
        current_object.rotate(angle = sl.value*dt,
                              axis  = vector(0, 1, 0))