Bug 88742 Drop target is not selected in center of target item (all java views) [dnd]
I20050315-1100 + zrh-plugins for I20050322 Highlighting of the drop target is broken in Package Explorer, Type Hierarchy, Outline, ...: The drop target tree item under the cursor is only rendered as selected when the mouse cursor points to the top or bottom quarter of the item label. When the cursor is moved towards the center of the tree item, the item is not rendered as selected (but it should). The drop action seems to work regardless of the missing visual feedback.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/dnd/JdtViewerDropAdapter.java
*/
	public void validateDrop(DropTargetEvent event) {
		validateDrop(fTarget, event, fRequestedOperation);
	}
	
	/**
	 * Checks if the drop on the current target is valid. The method
	 * can alter the <code>currentDataType</code> field and the <code>
	 * detail</code> field to give feedback about drop acceptence.
	 * @param target the drop target in form of a domain element.
	 * @param event the drop traget event
	 * @param operation the operation requested by the user.
	 */
	public void validateDrop(Object target, DropTargetEvent event, int operation) {
	}
	
	public void dragEnter(DropTargetEvent event) {
		dragOperationChanged(event);
	}
	
	public void dragLeave(DropTargetEvent event) {
		fTarget= null;
		fLocation= LOCATION_NONE;
	}
	
	public void dragOperationChanged(DropTargetEvent event) {
		fRequestedOperation= event.detail;
		fTarget= computeTarget(event);
		fLocation= computeLocation(event);
		validateDrop(event);