Bug 266699 [CommonNavigator] Remove CommonDropAdapter.setCurrentOperation
This has been replaced by overrideOperation() which does the same thing. Note that setCurrentOperation() was added in M5 so it's never really been API yet.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/navigator/CommonDropAdapter.java
* @return An array of Transfers allowed by the CommonDropAdapter. Includes
	 *         {@link LocalSelectionTransfer#getTransfer()},
	 *         {@link FileTransfer#getInstance()},
	 *         {@link PluginTransfer#getInstance()}.
	 * @see LocalSelectionTransfer
	 * @see FileTransfer
	 * @see PluginTransfer
	 */
	public Transfer[] getSupportedDropTransfers() {
		return SUPPORTED_DROP_TRANSFERS;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.viewers.ViewerDropAdapter#dragEnter(org.eclipse.swt.dnd.DropTargetEvent)
	 */
	public void dragEnter(DropTargetEvent event) {
		if (event.detail == DND.DROP_NONE)
			return;
		
		if (Policy.DEBUG_DND) {
			System.out.println("CommonDropAdapter.dragEnter: " + event); 
		}
		for (int i = 0; i < event.dataTypes.length; i++) {
			if (LocalSelectionTransfer.getTransfer().isSupportedType(
					event.dataTypes[i])) {
				event.currentDataType = event.dataTypes[i]; 
				if (Policy.DEBUG_DND) {
					System.out.println("CommonDropAdapter.dragEnter: local selection: " + event.currentDataType); 
				}