The 'onDragEnter' callback

Event generated under Windows only

Event number: 35
Valid for: Any visible control

The onDragEnter callback is invoked for the target control when a potential drag-and-drop operation begins and the mouse enters the target control. (A potential drag-and-drop operation occurs when the user drags a source control onto a target control and the sourceformats property of the source is compatible with the targetformats property of the target, but before the user releases the mouse to complete the operation).

The callback will typically be followed by onDragOver events as the user moves the mouse, and possibly an onDragLeave event if the mouse leaves the control. It may be followed by an onDragDrop event if the user releases the mouse button over the target control.

The dragsource property will contain the name of the control being dragged.

The event-specific parameters in ⎕EV are (in index origin 1):

    ⎕EV[6]   The 'tie' property value of the source control being dragged