What causes group select when dragging single piece?

[Benkyo]

I have a widely-used module that appears to be bug free, except for one user, who is using a Mac.

He sent me a screencapture of a reproducible problem.

When he tries dragging a piece from a deck, the image of the piece moves with the cursor for some distance, then a rectangular group select box appears from the piece source to the cursor. When he releases the mouse button, the piece is placed, and the piece, the deck it came from, and everything else in the group select is selected.

If he fails to notice this, and tries to drag a second piece from somewhere, everything that was group selected gets moved, which can be disastrous if the first deck was a deck of face-down cards that get drawn face-up.

Apparently he does *not* have this problem in other modules, he can reproduce it on both his Mac devices, but it's not a problem anyone else has been able to reproduce.

Can anyone tell me what is going on?

[tar]

Seems really of that it would be module-specific.

Is it happening with a mouse or a trackpad?

The Mac had gotten notorious for introducing various multi-finger gestures
in the past few years. I expect done of then may also affect the smart
mouse in addition to a trackpad.

One could look at the various mouse settings and also the accessibility
panel, which might have a select lock seeing it something like that.


On Sat, Feb 29, 2020, 10:59 PM Benkyo wrote:

> I have a widely-used module that appears to be bug free, except for one
> user, who is using a Mac.
>
> He sent me a screencapture of a reproducible problem.
>
> When he tries dragging a piece from a deck, the image of the piece moves
> with the cursor for some distance, then a rectangular group select box
> appears from the piece source to the cursor. When he releases the mouse
> button, the piece is placed, and the piece, the deck it came from, and
> everything else in the group select is selected.
>
> If he fails to notice this, and tries to drag a second piece from
> somewhere, everything that was group selected gets moved, which can be
> disastrous if the first deck was a deck of face-down cards that get
> drawn face-up.
>
> Apparently he does *not* have this problem in other modules, he can
> reproduce it on both his Mac devices, but it's not a problem anyone else
> has been able to reproduce.
>
> Can anyone tell me what is going on?
>
> _______________________________________________
> Read this topic online here:
> viewtopic.php?p=58673#p58673
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[Benkyo]

Apparently it is module specific, because he tells me it is, but I don't see how - there's nothing on the user side of Vassal editor that could introduce this bug to a module. So, I figure it must be the underlying engine.

It is also not something anyone else has experienced, so I do think it must be something to do with his setup too. He tells me it occurs on both a laptop and a desktop, both using a mouse (Bluetooth and wired, respectively).

[marktb1961]

I do not believe that this is module specific, nor restricted to Mac.

The sequence described happens frequently for users of the Commands and Colours Napoleonics module but I also observe in others, such as A Study in Emerald. I have been doing some work on the later and, so far, no amount of configuration has prevented the unwanted select behaviour from occuring. It is so common in C&C Nap that regular users have established a habit of clicking on the playing board before interacting with dragged pieces.

I believe that some modules will be more susceptible than others depending on how the module is laid out.

I think it is triggered (sometimes) by dragging a "card" from a "deck", and not by other dragging actions.

It is one of the most irritating mis-behaviours I've come across on vassal so I would love to find an answer.

[Benkyo]

Thank you for the confirmation.

I will have a look into those two modules to see if I can find anything in common between them, but even if I do, I doubt I'll be in any position to do anything about it. I can't even reproduce the bug. Like you, I would love to find an answer.

If you are interested in doing your own comparison, the module that prompted my post is Pax Pamir (Second Edition)

[Brent Easton]

The fact that it is not happening all the time to all users seems to indicate it is something in the modules in question.

I would investigate whether there is an 'Apply key on move to this map' key that is being processed by a Trigger in the pieces that is then doing 'something', but not all the time depending on the trigger.

[Benkyo]

The fact that it is not happening all the time to all users seems to indicate it is something in the modules in question.

Agreed

I would investigate whether there is an 'Apply key on move to this map' key that is being processed by a Trigger in the pieces that is then doing 'something', but not all the time depending on the trigger.

Can you elaborate a little? In my module there is an "apply key on move to this map", and there are a LOT of triggers on some pieces. However, in the video capture I saw of the bug occurring, the piece being dragged does not have any triggers at all.

1 Marker
8 send to location
1 layer
3 report actions
1 return to deck
1 non-rectangular
1 restrict commands

The only traits that seems at all complex are the send to location traits that have X position: $CurrentX$ with additional X offset -389, and another send to location trait that has a complicated destination of another counter, selected by properties, and a long set of If(,,) conditions for the property.

[Brent Easton]

I'm really just guessing. It's where I would look. Since the problem does not occur all the time, then presumably 'something' is different between occurrences and non-occurrences. Triggers and Global Key Commands are the only things that can cause differing behavior when repeating the same movement on similar pieces, via the property expressions.

If the problem was only occurring on Mac's, I would suggest trying a different Java version or implementation.

Are we sure the problem reported on the Macs is 100% exactly the same as the C&C Napoelonics issue? Or just similar?

[shilinski]

You need a strategy for focusing in on the problem. I suggest making a copy of the module. Then strip out of it a bunch of its features, especially the non-essential ones. Give it to your player (assuming you can’t reproduce the problem), and ask them to screw around with it to see if they still have the problem. (They probably should not use it in an ongoing game unless you think it’s safe.) Depending on what they report, you then add or subtract features until you get the precise one that triggers the problem. With that information, the Vassal folk may be able to do something because otherwise it’s pretty hopeless.