is ZoomButton over-instrumented?

[pixelzoom]

Related to https://github.com/phetsims/ph-scale/issues (ph-scale instrumentation).

ZoomButton is a common-code UI component. Here's what it looks like in ph-scale. There are 2 of them below the linear graph in the Macro screen:

Here's the Studio tree structure for one of those ZoomButtons:

This looks over-instrumented to me, perhaps vestigial from the "instrument everything" days of PhET-iO. Why are we instrumenting the parts of the icon (glassNode, signNode) separately? If instrumenting the icon is important, why isn't the icon (as a whole) instrumented?

I recommend that we remove instrumentation of the icon, and make the instrumentation similar to ResetAllButton and other push buttons, i.e.:

(EDIT: Note that isFiringProperty is specific to ResetAllButton. According to the doc, it's "Commonly used to disable audio effects during reset".)

Assigning to PhET-iO designers to review. If someone from the PhET-iO dev team knows why the icon is instrumented this way, please chime in.

[samreid]

I agree, it seems like a symptom of the instrument everything approach, and those extraneous instrumentations should be removed.

[pixelzoom]

@arouinfar or @kathy-phet if you agree, I'll proceed with removing instrumentation of the icon.

[pixelzoom]

Not only is this over-instrumented, but the instrumentation is buggy, and was probably not tested. If I set glassNode.visibleProperty to false, it looks like the screenshot below. Only part of the magnifying glass disappears; the handle remains. Since this is not at all useful, I have to believe that it's buggy.

[arouinfar]

It's definitely over instrumented @pixelzoom. I see no reason why the icon would be instrumented, rather than the button as a whole.

[pixelzoom]

Thanks @arouinfar. I'll proceed which changes.

[pixelzoom]

Changes completed, and API files update in the above commits. Here's what the Studio tree looks like for ph-scale:

[pixelzoom]

@arouinfar could you please verify in ph-scale 1.4.0-dev.5 ?

In Studio, navigate to phScale.microScreen.view.graphNode.linearGraphNode.zoomButtonGroup.zoomInButton and inspect the structure. It should match what is shown in #573 (comment). If all looks well, please close.

[arouinfar]

Looks wonderful @pixelzoom