Ioannis Tziakos

The error is coming from the Save method of IPersistFile which expects two arguments ```python COMMETHOD( [], HRESULT, 'Save', (['in'], LPCOLESTR, 'pszFileName'), (['in'], BOOL, 'fRemember')), ```

> the example you gave is working on my Windows 7 VM: I am running Windows 10. I think it did not matter let me check.

> It does indeed fail on my Win10 VM, with the error you posted. :/ That sounds fun

I found the issue. For some reason the Save method needs the absolute path for the filename on Windows 10 and python 3 **This fails** ```python pf = shortcut.QueryInterface(IPersistFile) pf.Save("foo.lnk",...

I would be good to have basic testing for the new overlay (see example using `EnableTestsAssistant` in [DragToolTestCase](https://github.com/enthought/enable/blob/master/enable/tests/drag_tool_test_case.py))

I would also like to note that activating the Tool at mouse_up without marking the position of the mouse_down can cause unexpected behaviour since the mouse_down -> mouse_up can take...

> (3) any attempt to change the trait value will produce an exception. This feature is currently possible using the `Readonly` trait but it would be nice if `Readonly` supported...

sorry @corranwebster and @mdickinson I thought that I had the PR ready but it looks I am still missing something

@mdickinson and @corranwebster this pr is ready for review.

> Many preference systems (notably on Mac and Gnome) do not have "Apply/OK" action, and the preferences are live and the ui (preference panes) is expected to not let the...