Add to Selection When Using Lasso Tool with Shift Key

[philippfromme]

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Related to bpmn-io/bpmn-js#2053

[nikku]

Nit-pick: If I start the tool without SHIFT I'd expect the existing selection to go away:

Observation: We break existing SHIFT + drag flow for lasso tool activation, it will always add to existing selection. I'd be fine with that.

[barmac]

Let's fix what @nikku pointed out above.

[philippfromme]

Observation: We break existing SHIFT + drag flow for lasso tool activation, it will always add to existing selection. I'd be fine with that.

I've noticed that and checked how Miro does it. Works the same there.

[philippfromme]

Nit-pick: If I start the tool without SHIFT I'd expect the existing selection to go away:

I'm not sure what you mean. What isn't working as expected?

[nikku]

I'm not sure what you mean. What isn't working as expected?

The moment I start the lasso tool without SHIFT the old selection will vanish (new one will not be added to old one); hence I propose to remove it once the tool is started. Cf. attached screen capture.

[philippfromme]

The moment I start the lasso tool without SHIFT the old selection will vanish (new one will not be added to old one); hence I propose to remove it once the tool is started. Cf. attached screen capture.

So you mean you press L and expect the existing selection to go away?

[nikku]

Yes. Sorry if my explanation was misleading.

[philippfromme]

Yes. Sorry if my explanation was misleading.

But that's the same as clicking the palette icon. I wouldn't expect the selection to go away immediately after just activating the tool. I would expect the selection to go away after selecting the recangular area without pressing SHIFT.

[nikku]

I would expect the selection to go away after selecting the recangular area without pressing SHIFT.

I'd expect the opposite 🙃. Let's do a quick poll to resolve this, and proceed afterwards.

[philippfromme]

I'd expect the opposite 🙃. Let's do a quick poll to resolve this, and proceed afterwards.

But that would mean you must press SHIFT while activating the lasso through click or L before even selecting anything.

[nikku]

To clarify, this is the interaction I'd expect (recorded from excalidraw):

[philippfromme]

I had to keep keepSelection: true; for both #activateLasso and #activateSelection, otherwise the selection is lost even if I just want to hide it during the selection phase. Therefore, the only way of hiding the selection is to use CSS so I added a djs-lasso-selection class.

[nikku]

I had to keep keepSelection: true; for both #activateLasso and #activateSelection, otherwise the selection is lost even if I just want to hide it during the selection phase. Therefore, the only way of hiding the selection is to use CSS so I added a djs-lasso-selection class.

Why is it lost?

[philippfromme]

I had to keep keepSelection: true; for both #activateLasso and #activateSelection, otherwise the selection is lost even if I just want to hide it during the selection phase. Therefore, the only way of hiding the selection is to use CSS so I added a djs-lasso-selection class.

Why is it lost?

I've checked again and it's actually restored so there's a different issue. I'll fix that. 😓

[philippfromme]

@nikku I found a different solution. Unfortunately, calling Selection#select with add = true on lasso.end isn't possible since the restoring of the selection that Dragging attempts is done only after cleanup has already been fired so there is no way to first let Dragging restore the selection and then add elements to the selection.

[barmac]

Perhaps Dragging could be even more low-level. It is the selection who should handle selection and not dragging as it is in:

https://github.com/bpmn-io/diagram-js/blob/develop/lib/features/dragging/Dragging.js#L235

[barmac]

After rebase, I cannot run this with bpmn-js due to missing touch support module.

[nikku]

We'd want to wrap up the touch removal to unblock @philippfromme. I can take that over, or you do it.

[barmac]

I can look into this on Monday, otherwise feel free to wrap it up.

[nikku]

@barmac Happy if you take this over 🤞

[barmac]

Let's ship it, and we can improve on the visuals in the future. Better provide value early and we can also collect feedback on the next steps if necessary.