From Xojo Documentation
Used to add a disclosure triangle to a window. A DisclosureTriangle can face either left or right in its "closed" position. When the user clicks a DisclosureTriangle control, the value of Value is toggled automatically.
|Action||The DisclosureTriangle has been clicked.|
|The DisclosureTriangle has received the focus and has a selection rectangle (Windows only).
The AcceptFocus property must be set to True for the DisclosureTriangle to be capable of getting the focus.
|The control has lost the focus (Windows only).|
|Boolean||If True, the DisclosureTriangle will be included in the Tab order and can accept the focus. The GotFocus and LostFocus events will fire at the appropriate times.
When the DisclosureTriangle has the focus, it has a selection rectangle. If the user clicks the DisclosureTriangle or presses either the Space bar or the Enter key, the Action event will fire. The ability of the DisclosureTriangle to accept the focus is Windows-only. The default value is False.
|Facing||Integer||Controls whether the triangle is pointed to the left or right. The default is the right.
It can take on either of the following values: 0 - Right facing 1 - Left facing
|Value||Boolean||The orientation of the triangle.|