Tk Toolkit

Pressing the iconify button on a toplevel window does not
generate an unmap event in Mac Aqua Tk 8.4.1. The window
disappears and an icon is shown on the Mac OS X Dock but no
unmap event is generated.

The following wish8.4 script demonstrates the problem

bind . <Unmap> {puts unmap}

After invoking this command press the iconify button on the
window frame. The word "unmap" should be printed to the
console but is not. Although the window is iconified the "winfo
ismapped ." command returns true.

winfo ismapped .
1

In the Tk molecular graphics application we develop the unmap
event on the main window is used to unmap other dialogs the
application is showing. It is also used to stop updating the
realtime display so the CPU utilization drops when the application
is iconified.