Only if that bit is set, your widget will receive a WM_CONTROL message with the TTN_NEEDTEXT notification and XCENTER_TOOLTIP as the control's ID.

You will need to include include\helpers\comctl.h from the &xwp; helpers for the definitions of the &xwp; tooltip control.

Again, if you have the full &xwp; source code, see the widgets in src\widgets for how this is done.