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
result.add(each);
		}
		return (ISourceReference[])result.toArray(new ISourceReference[result.size()]);
	}
	
	private static boolean isDragableSourceReferences(Object element) {
		if (!(element instanceof ISourceReference))
			return false;
		if (!(element instanceof IJavaElement))
			return false;
		if (element instanceof ICompilationUnit)
			return false;
		
		return true;	
	}
			
	private boolean canCopyElements() {
		if (fCanCopyElements == 0) {
			fCanCopyElements= 2;
			if (!canActivate(fCopyRefactoring))
				fCanCopyElements= 1;
		}
		return fCanCopyElements == 2;
	}		
	
	private void handleDropCopy(final Object target, DropTargetEvent event) throws JavaModelException{
		if (canPasteSourceReferences(target)){
			pasteSourceReferences(target, event);
			return;
		}