This message is generated when the runtime configuration variable TV_EDITLABELS is true and the user is going to change the text of an item of a tree view control. The user can change the text of an item by clicking onto an item already selected (this behavior is consistent with Window system tree-view).
EVENT-DATA-1 is not used and always set to 0, EVENT-DATA-2 contains the ITEM of the tree view being modified. It is possible to prevent the modification by setting EVENT-DATA to EVENT-DATA-FAIL.