Improve search in large diagrams

[philippfromme]

Proposed Changes

• do not set zoom to 1
• reduce padding below search
• add custom marker to preselected element

Related to bpmn-io/bpmn-js#2233
Related to camunda/camunda-modeler#4538

Checklist

To ensure you provided everything we need to look at your PR:

• Brief textual description of the changes present
• Visual demo attached
• Steps to try out present, i.e. using the @bpmn-io/sr tool
• Related issue linked via Closes {LINK_TO_ISSUE} or Related to {LINK_TO_ISSUE}

[nikku]

Try out via

npx @bpmn-io/sr bpmn-io/bpmn-js -l bpmn-io/diagram-js#search-improvements-next

[nikku]

Works well. Thanks for following up.

[nikku]

What is the issue here, could you elaborate? To me this looks like a hack. The cached viewbox, after all, should not be fiddled with.

[philippfromme]

The problem is when you return a reference to the viewbox to the caller of viewbox() they will assume that it's not going to be mutated. This is an issue I ran into. I called viewbox() to then used the viewbox at a later point just to realize it had been changed.

[barmac]

BTW there is a dedicated API for deep cloning: https://developer.mozilla.org/en-US/docs/Web/API/Window/structuredClone

[philippfromme]

Could be a follow-up improvement.

[nikku]

Simple clone:

{ ...viewbox }

[barmac]

If this needs to return a copy, a shallow clone won't work due to nested objects (inner and friends).

[nikku]

I'll need to figure why this needs a copy in the first place. We always construct a fresh viewbox., and the cached viewbox is not to be fiddled with.

@philippfromme Still looking for a concrete scenario where users would mutate the viewbox, and would love to see that as a test.

To prevent mutation (which does not make sense anyway), we can freeze the object, too.

[nikku]

I don't understand the test either 🙈. If we want the to verify "no identity", why don't we test for "not equal"?

[philippfromme]

I'm testing whether the viewbox I got from calling viewbox() has been changed. If you remove the JSON.parse(JSON.stringify()) part you'll see the test failing.

[nikku]

A much simpler test would be:

// mind the "strict object equality"
expect(canvas.viewbox()).not.to.equal(canvas.viewbox())

But

// mind the loose object comparison
expect(canvas.viewbox()).to.eql(canvas.viewbox());

?

[nikku]

@GeethaParthasarathy FYI :)