Slider label is read out frequently

[jessegreenberg]

For some reason VoiceOver is repeating the slider label in this sim frequently. See #234 (comment).

I will investigate.

[jessegreenberg]

Before it reads the name again VO makes the sound that indicates focus has moved. So I am wondering if the PDOM is getting redrawn and causing this.

[jessegreenberg]

The slider is not getting redrawn but the screen summary gets redrawn frequently.

[jessegreenberg]

I verified that every time a new element is created and added to the DOM VoiceOver re-reads the slider name.

[jessegreenberg]

HTML Validator at https://validator.w3.org/nu/#textarea is reporting no issues. So this seems to be a problem with updating the PDOM so frequently.

[jessegreenberg]

The reason we are is recreating PDOM elements and re-sorting the DOM so frequenlty in this sim is because we are using accessibleName setter so frequently. And that is why we aren't seeing this issue in any other issues.

[jessegreenberg]

@terracoda just so you know, I discovered that this is a general scenery problem rather than an issue with the slider (phetsims/scenery#1026)

For now, I think I can fix this in molecules-and-light by removing usages of setAccessibleName.

[terracoda]

Ok, I guess it is a new problem because this is the first time I have noticed it.

[jessegreenberg]

Correct, I verified that molecules-and-light is the first sim to have the conditions necessary to cause this bug.

[jessegreenberg]

After the above commits I am no longer seeing this issue. @terracoda can you please confirm?

[terracoda]

The label is only read once now. Sounds good, thanks @jessegreenberg !

[samreid]

There are still TODOs marked for this issue, discovered during phetsims/chipper#946

[terracoda]

@jessegreenberg, I don't this issue was re-opened for me. Assigning to you. Please re-assign me when needed.

[samreid]

The TODO is:

    Property.multilink( summaryProperties, ( photonWavelength, emitterOn, photonTarget, running, slowMotion, returnMoleculeButtonVisible ) => {

      // TODO: Maybe use accessibleName instead if https://github.com/phetsims/molecules-and-light/issues/237 is fixed
      dynamicDescription.innerContent = this.getSummaryString();
    } );

[samreid]

Since #237 was closed, perhaps this should be changed to use accessibleName?

[jessegreenberg]

Thanks @samreid, the real issue that needs to be fixed before the TODO can be removed is phetsims/scenery#1026, so I updated the code comment to reference that open issue instead.