Can't drag multiple items due to automatic deselection

[Metalfusion]

Repro steps:

1. Have at least 2 classes in a C# class diagram.
2. Select both classes with marquee or shift-click.
3. Click and drag from one of the selected classes.

Expectation: Both classes remain selected and get dragged around.
Reality: The second class gets deselected and only the one where dragging started gets moved.

This can be worked around by holding shift when starting drag on unselected item, but this is quite cumbersome.
I believe this is a regression from original NClass.

[gbaychev]

Thank you for reporting this, it could be that it is a regression. I'm going to check it after the holidays.

[gbaychev]

So, it is indeed a regression from the original version. I broke it when I tried to implement the usual 'add/remove to/from selection when holding ctrl and/or shift' logic, which you can find in the most desktop apps today.

The ctrl/shift thing should work now, the only caveat is, that if you have multiple elements selecting, click one of them won't remove the rest from the selection (if they get removed, then the regression happens). But this is also the behavior in the original NClass.