Sets the width of %GTK_TEXT_WINDOW_LEFT or %GTK_TEXT_WINDOW_RIGHT,
or the height of %GTK_TEXT_WINDOW_TOP or %GTK_TEXT_WINDOW_BOTTOM.
Automatically destroys the corresponding window if the size is set
to 0, and creates the window if the size is set to non-zero. This
function can only be used for the “border windows”, and it won’t
work with %GTK_TEXT_WINDOW_WIDGET, %GTK_TEXT_WINDOW_TEXT, or
%GTK_TEXT_WINDOW_PRIVATE.
Sets the width of %GTK_TEXT_WINDOW_LEFT or %GTK_TEXT_WINDOW_RIGHT, or the height of %GTK_TEXT_WINDOW_TOP or %GTK_TEXT_WINDOW_BOTTOM. Automatically destroys the corresponding window if the size is set to 0, and creates the window if the size is set to non-zero. This function can only be used for the “border windows”, and it won’t work with %GTK_TEXT_WINDOW_WIDGET, %GTK_TEXT_WINDOW_TEXT, or %GTK_TEXT_WINDOW_PRIVATE.