The Frame Footer and Busy Indicator

The argument :show-footer T of the frame procedure causes the footer to be created for the frame widget. The footer is a frame window having a width equal to the width of the frame widget and a height of 1 character. It is positioned at the bottom of the frame widget.
The footer widget contains a message window which is used to hold short term information messages from the application. By default the message is left justified by this can be modified by the command

:set footer-position location
executed before the :frame procedure call which creates the footer. The path names generated have the root framename.footer and the item footer. The widget name FOOTER is generated allowing reference to the footer widget in the same way as all other widgets.
Messages are inserted into the footer by the procedure
set-footer [frame] string
where frame is the name of a FRAME widget which may be omitted in which case the main frame for the application is used and string is the text to be inserted into the footer. The text will if necessary be truncated in order to fit the single line of the footer.
Messages are removed by the procedure
clear-footer [frame]
which is equivalent to set-footer [frame] “”.
A binding is made such that clicking mouse button 1 on a footer message causes the message to be cleared.

The busy indicator is normally used by the application to indicate that it is performing some action which may take more than the normal interactive response time. Typically this is used during networked server accesses and when spanning a shell to execute a program in foreground. The indicator is created by configuring the background colour of the footer widget windows. The colour used is taken from the task variable tkfooterbusycolor. It has the default value Pink.
If the footer message is empty at the time that the busy indicator is enabled then the message Busy.... is additionally put into the footer.
The busy indicator is controlled by the command

:modify FRAME :busy T|F
The procedures set-busy, clear-busy and query-busy are also provided.
A binding is made such that clicking mouse button 3 on the footer area causes the busy indicator to be cleared.