In graphical mode, combining this option with -selection BROWSE will cause three callbacks to happen when the mouse is pressed over one item and dragged to the next item (2 from the first item, when selecting and deselecting, and one from the second). Consequently, this option is normally only used in character mode, (that is, passed as CHARM_autoSelect).
Additional callback keys:
Additional callback keys:
Note that to get a horizontal scrollbar to appear, the option -width or -columns must be set. Otherwise the widget will grow as needed and scrollbars will only appear when the list exceeds the available area.