ABL allows you to obtain the identities of both the ActiveX control that generates an event and the associated control-frame widget from within an OCX event procedure. The COM-SELF system handle returns the component handle of the ActiveX control and the SELF system handle returns the widget handle of the control-frame. This is especially useful in generic event procedures where the source of an event cannot be known.
Unlike for ABL ON triggers, the RETURN NO-APPLY statement has no affect in an OCX event procedure. Some COM object events provide a similar mechanism using output parameters. For example, the standard KeyPress event passes a key code as an INPUT-OUTPUT parameter. If you set this parameter to 0 in the event handler, the key is discarded.
Note: To trigger an ABL widget event from ABL, you use the APPLY statement. However, to trigger an ActiveX control event in ABL, you execute its OCX event procedure as a standard internal procedure, passing any required parameters.
