DragSelectionContains
if (fDropTarget && !DragSelectionContains(fDropTarget, message))
if (DragSelectionContains(targetPose, message)) {
if (targetPose != NULL && DragSelectionContains(targetPose, dragMessage))
if (fDropTarget && !DragSelectionContains(fDropTarget, dragMessage))
static bool DragSelectionContains(const BPose* target, const BMessage* dragMessage);