Creating and Destroying Windows

We've seen that all Tk programs start out with a root toplevel window, and then widgets are created as children of that root window. Creating new toplevel windows works almost exactly the same as creating new widgets.

Toplevel windows are created using the toplevel method:

#![allow(unused)]
fn main() {
let window = parent.add_toplevel(())?;
}

Note: Toplevels are part of the classic Tk widgets, not the themed widgets.

Unlike regular widgets, we don't have to grid a toplevel for it to appear onscreen. Once we've created a new toplevel, we can create other widgets as children of that toplevel, and grid them inside the toplevel. The new toplevel behaves exactly like the automatically created root window.

To destroy a window, use the destroy method:

#![allow(unused)]
fn main() {
tk.destroy( window )?;
}

Note that you can use destroy on any widget, not just a toplevel window. When you destroy a window, all windows (widgets) that are children of that window are also destroyed. Be careful! If you destroy the root window (that all other widgets are descended from), that will terminate your application.

In a typical document-oriented application, we want to be able to close any windows while leaving the others open. In that case, we may want to create a new toplevel for every window, and not put anything directly inside the root window at all. While we can't just destroy the root window, we can remove it entirely from the screen using its withdraw method, which we'll see shortly.