Using the Paned widget
The grips allow the panes
to be resized by the user. The semantics of how
these panes resize is somewhat complicated, and warrants further
explanation here. When the mouse pointer is positioned on a grip and
pressed, an arrow is displayed that indicates the pane that is to be to be
resized. While keeping the mouse button down, the user can move the grip
up and down (or left and right). This, in turn, changes the size of the
pane. The size of the Paned widget will not change. Instead, it chooses
another pane (or panes) to resize. For more details on which pane it
chooses to resize, see