Cannot easily drill down the collapsed subprocess as append element gets focussed

[GeethaParthasarathy]

Describe the bug

When we have a collapsed subprocess with the new context pad hovering on the drill down arrow also focusses on the append element making it difficult click on the drill down arrow

Steps to reproduce

1. Create a collapsed subprocess
2. Try to click on the drill down arrow

Screen.Recording.2024-09-24.at.14.09.41.mov

Expected behavior

Focus on the drill down arrow and make it possible to click

Environment

• OS: [MacOS 10.2]
• Camunda Modeler Version: [5.28.0]
• Execution Platform: [Camunda 8]
• Installed plug-ins: [...]

Additional context

No response

[nikku]

@philippfromme @lmbateman I'd be interested to understand your assessment of this UX challenge. From what the looks of it drilldown is not easily possible using the improved canvas.

[lmbateman]

I thought from Geetha's example that there might be some steps we could take to fix it, like separating the icons a bit more and perhaps decreasing the click target for the append menu, but now I think it will require a bit more than that:

For the context pad issue, I wonder if it makes sense to move the start element down just enough that the context pad can appear above tasks by default. Or actually, I've just noticed that when you append a task, it gets nudged down automatically, so perhaps we can do that with sub-processes as well.

This brings us back to the original problem. I'm not sure why my expand button is in a different spot than Geetha's (directly under vs. off to the right); could that be due to screen size? I think understanding how the positioning works might be helpful in thinking about a solution.

[nikku]

@philippfromme Maybe you can work together with @lmbateman here?

[philippfromme]

I thought about moving it so it's inside the element similar to DMN decision table and literal expression icons:

However, if there's a boundary event it's not ideal:

I also tried moving the overlay slightly will still conflict with the context pad when zoomed in since the overlay scales and the context pad doesn't.

Not scaling it will make it look detached when zoomed in. To fix this we'd need to make the overlay a non-overlay like the context pad is now or change the overlays feature.

If we change the overlay to behave like the context pad and the append icons it would look like this when zoomed in:

This would be my preferred solution but would mean a little more work.

Moving the button to the context pad doesn't make sense because the viewer doesn't have a context pad.

[philippfromme]

@lmbateman Wondering if any of the options you'd approve?

[lmbateman]

I like the idea of moving it into the element, but two thoughts:

• It seems like the collapsed subprocess is mutually exclusive with other task types. In that case, I wonder about putting the icon in the upper left, like the other task type icons. One downside is that this would be the only interactive icon in that position in the BPMN editor, but there is a precedent in the DMN editor.
• There are a lot of blue and white plus signs floating around. Is the plus-sign-inside-a-square part of the BPMN standard? If so, I would keep the separate blue and white arrow and go with the option of moving the overlay slightly (the option that requires more work, sadly).

[philippfromme]

I agree that moving the icon to the upper left corner would be cofusing.

The BPMN spec states:

The Sub-Process marker MUST be a small square with a plus sign (+) inside. The square MUST be
positioned at the bottom center of the shape.

So we cannot change that.

So it seems like we'll keep the general position bottom right of the element but adjust it slightly and make sure it behaves like the context pad in terms of position and scaling when zooming.