Volume 6A: Motif Programming Manual

XmDRAG_UNDER_PIXMAP value specifies that a special pixmap is displayed in the drop site when the drag icon is in

it; the XmN-animationPixmap and XmN-animationMask resources indicate the pixmap that is used. If

XmN-animationStyle is set to XmDRAG_UNDER_NONE, there are no animation effects unless they are provided

by the XmN-dragProc.

Under the dynamic protocol, the drop site can participate in the drag by specifying an XmN-dragProc. This callback

routine is invoked when the drag icon enters or leaves the drop site, when the drag icon moves within the drop site,

and when the operation changes while the icon is in the drop site. The callback receives a callback structure of the

type XmDragProcCallbackStruct, which is defined as follows:

typedef struct {

int reason;

XEvent *event;

Time timeStamp;

Widget dragContext;

Position x;

Position y;

unsigned char dropSiteStatus;

unsigned char operation;

unsigned char operations;

Boolean animate;

} XmDragProcCallbackStruct, *XmDragProcCallback;

The reason field is set to XmCR_DROP_SITE_ENTER_MESSAGE, XmCR_DROP_ SITE_LEAVE_MESSAGE,

XmCR_DRAG_MOTION_MESSAGE, or XmCR_OPERATION_ CHANGED_MESSAGE, depending on the event that

triggered the callback.

The dragContext field specifies the current DragContext object, while dropSiteStatus is set to either

XmDROP_SITE_VALID or XmDROP_SITE_INVALID, based on the values of XmN-importTargets and

XmN-exportTargets for the drop site and the drag source, respectively. The operations and operation

fields are set to the possible ...