Don't allow the same experiment to be opened in multiple instances

[smathot]

Right now, the same experiment file can be opened in multiple instances of OpenSesame. This can be confusing, especially because saving in one instance overrides the saves from the other instance.

To improve this, OpenSesame needs be somehow aware that other instances of the program are running, and which files they have opened.

[PascalKieslich]

I do see why such a feature could be helpful. However, if it is generally not allowed to open multiple instances of the same experiment in OpenSesame, that might be problematic if researchers are using the psynteract plugin for OpenSesame to create interactive experiments and want to test their experiment simulating several participants on the same computer.

[smathot]

That's a very good point actually, which I hadn't considered. What would be the ideal solution here, you think? Perhaps if you open an experiment more than once, all except the first instance are read only?

[PascalKieslich]

This could be a good idea. Or maybe one could just display a warning message if the same experiment is opened again?