Label moves twice when using space tool

[nikku]

Describe the Bug

When using the space tool along with the sequence flow the labels will move twice.

Steps to Reproduce

The following reproduces the bug on demo.bpmn.io.

Expected Behavior

The label is only moved once.

Environment

• Browser: Any
• OS: Any
• Library version: 2.5.2

[nikku]

The problem underlying this bug is that the LabelBehavior moves the label after the space tool already moved it.

[nikku]

I added a test case that reproduces the issue on the 878-space-moves-label-twice branch.

[philippfromme]

Came across this bug again while working on #1019. The problem is that a couple of behaviors kick in after moving and resizing shapes. In the case of using the space tool we don't want that as we're explicitly moving and resizing elements.

[nikku]

Hints could be a way to to disallow the post-move behavior(s).

[philippfromme]

Was thinking about that. Otherwise, the space tool has to be aware of all those behaviors. 💩

[philippfromme]

@nikku something like this?

this._modeling.moveElements(shapes, delta, null, {
    allowPreExecutionBehavior: true,
    allowPostExecutionBehavior: false
  });

[nikku]

Who performs the pre-execution behavior? Can't we be a bit more explicit?

[philippfromme]

Attach support is doing stuff before and afterward. We also have a nice fix for the space tool inside attach support. 💩 It would become obsolete with the new hints. Label support also does stuff before. So we'd actually need to suppress both pre and post behavior. The only thing that would still mess everything up would be label adjustment that moves labels afterward.

[philippfromme]

Of course we can also do

this._modeling.moveElements(shapes, delta, null, {
  attachSupport: false,
  labelSupport: false,
  ...
});

But that would also mean tighter coupling.

[nikku]

So the question is: Why do we sometimes do stuff pre and post and sometimes don't?

If we cannot find a distinguishing hint name based on that, what about this: Add a generic hint that describes the source of the move operation (i.e. source = spaceTool). Lower level components may interpret that hint and do stuff they like.

[nikku]

The whole space tool / attach support / label support thing is a bit of a mess, I know 👀.

[philippfromme]

Yeah, it's quite shaky. Didn't expect to open a can of worms. 🐛

[nikku]

We could lookie lookie into dat thing together some day 👓 🏖️ 🌆.

[philippfromme]

That would be nicey nicey. 🌞

[BelindaBecker]

Dear all,
is there any update on this?

We are facing this issue when modeling large diagrams and changing the layout afterwards. Especially, when moving elements with the space tool over a larger distance, the labels get lost and hard to recover.

Appreciate any info. Thanks!

[nikku]

Unfortunately we could not follow up on this bug to date.

[nikku]

Closed via #1269