The set-button-panel-enabled-items generic function sets the enabled state of the items in a button panel.
This function sets the enabled state of the items in a button panel. If set is t , then enable is ignored and all items are enabled except those in the disable list. If set is nil , disable is ignored and all items are disabled except those in the enable list. If set is not given, the items in the enable list are enabled and the items in the disable list are disabled. If an item is in both lists, it is enabled. A button is in a list when the data of the button matches one of the items in the list. A match is defined as a non- nil return value from the test function. The default test function is equal .