Clicking on the outline triangle causes it to change position. It also causes the item to be expanded or collapsed, depending on the new state of the outline triangle. An item can be expanded even if it contains no items. Items inside an expanded item are indented. By default, as a user expands or collapses nested items, the width of the column is resized so that it is just wide enough to display the widest item, based on the width of the items and their indentation in the hierarchy.
Justification follows the current system justification.
To turn off automatic resizing, use setAutoResizesOutlineColumn . Note that an item may consist of text, an image, or anything else that can be drawn by a subclass of NSCell. An NSOutlineView is typically displayed in an NSScrollView, as shown below. Inc. All rights reserved.