Bug 29698 drag and drop of java files between packages in package explorer doesn't work
the <preview> <ok> <cancel> dialog shows up, but <ok> has the same effect as <cancel> and <preview> would only show movements of files and no changes in imports of other java files. on <ok> in the preview it only moves the file(s) (as indicated ) without changing referencing imports.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/SelectionTransferDropAdapter.java
ExceptionHandler.handle(e, PackagesMessages.getString("SelectionTransferDropAdapter.error.title"), PackagesMessages.getString("SelectionTransferDropAdapter.error.message")); 
			event.detail= DND.DROP_NONE;
		}	
	}
	protected void initializeSelection(){
		if (fElements != null)
			return;
		ISelection s= LocalSelectionTransfer.getInstance().getSelection();
		if (!(s instanceof IStructuredSelection))
			return;
		fSelection= s;	
		fElements= ((IStructuredSelection)s).toList();
	}
	
	protected ISelection getSelection(){
		return fSelection;
	}
	
	private boolean tooFast(DropTargetEvent event) {
		return Math.abs(LocalSelectionTransfer.getInstance().getSelectionSetTime() - event.time) < DROP_TIME_DIFF_TRESHOLD;
	}	
	public void drop(Object target, DropTargetEvent event) {
		try{
			if (event.detail == DND.DROP_MOVE) {
				handleDropMove(target, event);
				
				if (! canPasteSourceReferences(target))
					return;
				DeleteSourceReferencesAction delete= ReorgActionFactory.createDeleteSourceReferencesAction(getDragableSourceReferences());
				delete.setAskForDeleteConfirmation(true);