canBeChildOf(proposedParent: Window;
rejectionReason: String output): Boolean;
The canBeChildOf method of the Control class is used by the Painter to determine whether the control can be placed on the form or control specified in the proposedParent parameter.
If a value of false is returned, a message can be returned in the rejectionReason parameter. This message is displayed on the status line of the JADE Painter when dragging an existing control or trying to create a new control on top of a control that does not support this dragged or new control; for example, it controls the fact that a Sheet control can be placed only on a Folder control.
At the Control class level, this method always returns the same as the canControlHaveChildren method on the parent. It is reimplemented in the Sheet and WebHotSpot classes to ensure that sheets are placed only on folders and that Web hotspots are placed only on Picture controls.