Changing layer visibility

Changing layer visibility
 1# This script changes the visibility of certain layers
 2# in the current drawing, if they exist
 3
 4ad = impact.active_drawing
 5if not ad.isNone():
 6    layer_a = ad.layers.item("A")
 7    layer_b = ad.layers.item("B")
 8    layer_c = ad.layers.item("C")
 9
10    # make layer "A" visible
11    if not layer_a.isNone():
12        layer_a.visible = ipBoolean.bTrue
13
14    # toggle the visibility of layer "B"
15    if not layer_b.isNone():
16        layer_b.visible = not layer_b.visible
17
18    # make layer C invisible
19    if not layer_c.isNone():
20        layer_c.visible = ipBoolean.bFalse