python 2.7 - How to keep the window focus on new Toplevel() window in Tkinter?

Question

I am currently writing a win32gui python27 application (I'm running win7). I am wondering if it is possible to create a new window from my mainloop() and KEEPING the focus on it, possibly by stopping the mainloop and deactivating the root window. In a sort of pseudo code example:

root=Tk()
#put in some widgets, such as statusbars, tkfileDialog widgets etc...
O=Toplevel()
OptionMenu(O) #wait for user to make his choices; btw: OptionMenu is a class...
tkFileDialog.askdirectory(...) #THEN interpret this line

Basically, I'd like to achieve what most of the widgets in tkfiledialog and tksimpledialog do:
To steal the focus from the main window (not just the console focus, the wm focus) and to resume the mainloop until AFTER everything in, for example, OptionMenu has been resolved. I hope I could make my goals clear to y'all, I just started Tkinter programming a couple of weeks ago and may confuse and misinterpret some concepts behind it....
That's all, folks!

Answer 1

The concept you are looking for is called a "grab". Tkinter supports grabs with several methods. For example, to set a local grab on a toplevel you would do my_window.grab_set(). A local grab is where this window grabs the focus from all other windows in your app, but only for your app.

You can also do a global grab, which effectively freezes your entire display except for your specific window. This is very dangerous since you can easily lock yourself out of your own computer if you have a bug in your code.

Grabs do not deactivate the mainloop function. This must be running for your window to process events. It simply redirects all events to the window that has the grab.

For more information, read about grab_set and other grab commands here: http://effbot.org/tkinterbook/widget.htm#Tkinter.Widget.grab_set-method