add-outline-item

Arguments: outline new-item parent-value &key no-redisplay position no-error-p

Adds the outline-item new-item to outline either as a top-level item or as a subitem of the item whose value is parent-value, at position among its siblings. new-item must be an instance of the outline-item class. outline must be an instance of the outline class.

If parent-value is nil, then new-item is added as a top-level item of the outline. Otherwise new-item is added as a subitem of the first item whose value is parent-value, if any. (If parent-value is non-nil and there is no item whose value is the parent-value argument, then an error is signaled if no-error-p is nil, and nothing is done if no-error-p is true.)

The value of position should be a non-negative integer, :end or nil. 0 means above all siblings. :end means below all siblings. nil means position according to the on-sort-predicate (if on-sort-predicate is nil or the function true (which always returns true) new-item is positioned at the top among its siblings.)

If no-redisplay is true, the outline will not be redisplayed by this function to reflect the change. You may wish to delay redisplay when there is more than one modification until all modifications are made.

If no-error-p is true, no error will be signaled if the requested action cannot be performed for any reason. Instead, nothing will be done. (Specifying this argument true does not protect against malformed calls to this function, such as specifying a value for new-item which is not an instance of outline-item.)

To change the whole set of child outline-items of a parent outline-item (or all of the top-level items of an outline control), an alternative is to call (setf range) on the parent outline-item or the outline control, passing a list of outline-items as the new value.

Copyright (c) 1998-2002, Franz Inc. Oakland, CA., USA. All rights reserved.
Documentation for Allegro CL version 6.2. This page has had moderate revisions compared to the 6.1 page.
Created 2002.2.26.