Arjen Markus (20 april 2013) Here is a little script to create a window that slowly fades and then vanishes. Some e-mail programs (Thunderbird) for instance use this type of window when a new e-mail arrives.
(Note: the fading window appears in the lower-right corner)
# fading.tcl --
# Create a transient window that slowly fades away
#
toplevel .fading
wm overrideredirect .fading 1
wm geometry .fading -0-0
raise .fading
pack [label .fading.label -text "Slowly fade away ..."]
tkwait visibility .fading
proc fade {w degree} {
wm attributes $w -alpha $degree
if { $degree > 0 } {
after 200 [list fade $w [expr {$degree-0.05}]]
} else {
destroy $w
}
}
after 1000 {fade .fading 1.0}
Kevin Walzer: The fading alogrithm is useful for other things also, such as a
Cocoa-style popover on Mac.