- wm protocol window ?name? ?command?
Use:
Joe English wrote in c.l.t:Q. Is there a way of getting a list of available protocols for wm protocol? The man pages only list the obvious / common ones (WM_DELETE_WINDOW, WM_SAVE_YOURSELF, and WM_TAKE_FOCUS).A. Those are the only three defined by the ICCCM; the freedesktop.org [EWMH] spec also defines _NET_WM_PING.Note that WM_SAVE_YOURSELF is deprecated, and Tk apps can't implement WM_TAKE_FOCUS or _NET_WM_PING correctly, so WM_DELETE_WINDOW is the only one that should be used.DKF: Tk now handles _NET_WM_PING for you by itself in the correct way; you'll never see this one at the script level. (The purpose of the protocol is to let other clients — especially a window manager or session manager — determine positively whether the application is processing events. That puts its implementation correctly buried in the guts of Tk.)
An example of use of WM_DELETE_WINDOW and chk_exit (thanks MG!)
wm protocol <window> WM_DELETE_WINDOW {#}to prevent your window from closing when the [X] button is clicked.More on this subject appears under the title "Catching window managed events".Joe English wrote in c.l.t:Q. Is there a way of getting a list of available protocols for wm protocol? The man pages only list the obvious / common ones (WM_DELETE_WINDOW, WM_SAVE_YOURSELF, and WM_TAKE_FOCUS).A. Those are the only three defined by the ICCCM; the freedesktop.org [EWMH] spec also defines _NET_WM_PING.Note that WM_SAVE_YOURSELF is deprecated, and Tk apps can't implement WM_TAKE_FOCUS or _NET_WM_PING correctly, so WM_DELETE_WINDOW is the only one that should be used.DKF: Tk now handles _NET_WM_PING for you by itself in the correct way; you'll never see this one at the script level. (The purpose of the protocol is to let other clients — especially a window manager or session manager — determine positively whether the application is processing events. That puts its implementation correctly buried in the guts of Tk.)
An example of use of WM_DELETE_WINDOW and chk_exit (thanks MG!)
wm protocol . WM_DELETE_WINDOW chk_exitMG 16th Feb 2005 - What this actually does, as far as I understand it, is set the command that's run when the operating system/window manager asks your Tcl program to destroy the window . (with the default being to just destroy the window and, if the window is . (the main toplevel) and you're running wish not tclsh, to exit the app). This means that you can do something like...
wm protocol . WM_DELETE_WINDOW chk_exit
proc chk_exit {} {
set ans [tk_messageBox -type yesno -icon question -message "Are you sure you want to quit?"]
if { $ans != "no" } {
exit
}
};# chk_exitYou do need to be careful with this, however; if your chk_exit proc (or whatever you call it) never runs the exit command, either because you don't tell it to or because it encounters an error before it reaches it, you cannot exit your app without killing the process.(As for actually making a command/proc behave like another, interp alias {} function {} proc will create an alias called function for the proc command (as long as there isn't a command called function already). And rename proc function will simply change the name of the command, so 'proc' will no longer exist.)MHo 12-Nov-2008: What if I start a long loop including updates inside the chk_exit (or whatever name), and I want to prevent the user from closing the window (=interrupting the loop)? If I use wm protocol . WM_DELETE_WINDOW {#} inside the handler, it seems that the first few clicks on the magic X are ignored, but Pressing Alt+F4 or other methods or further clicks on X do end the program... MHo Solved. Using update instead of update idletasks a little more often leads to the expected behaviour.