TimeControlNode PhET-iO API revision

[arouinfar]

TimeControlNode contains a combination of these components, and the exact combination is variable sim-to-sim. Within a sim, there is sometimes variation between screens.

• PlayPauseStepButtonGroup
  • PlayPauseButton
  • StepForwardButton
  • StepBackwardButton
• SpeedRadioButtonGroup
  • FastRadioButton
  • NormalRadioButton
  • SlowRadioButton
• FastForwardButton (e.g. Natural Selection)
• RestartButton (e.g. Gravity and Orbits)

It’s unclear if FastForwardButton and RestartButton are actually part of TimeControlNode, or if they have been artificially inserted into the tree structure of TimeControlNode. I assumed the latter and therefore did not review these buttons in detail. If I am incorrect, please let me know and I will review.

The goals of the TimeControlNode are highly sim-dependent, so there needs to be flexibility to allow for developers to opt-out of subcomponent instrumentation, see #826. This issue also documents a variety of dynamic layout issues currently present.

In general:

• Address TimeControlNode needs work for PhET-iO dynamic layout #826 (dynamic layout & opting-out of instrumentation)
• Add warnings/documentation/whatever appropriate to the code to remind devs that regardless of what view elements may have been opted-out, isPlayingProperty and timeSpeedProperty should still always be instrumented.
• If it’s not possible to handle LinkedProperties in common code as requested below, add documentation to remind devs that there should be a LinkedProperty to isPlayingProperty and timeSpeedProperty if the corresponding view elements are instrumented.
• Review the listeners and emitters to determine if there are redundancies.
• Determine what migration rules will be necessary.

PlayPauseStepButtonGroup

• Verify that visibleProperty and enabledProperty are instrumented in common code and that they are phetioFeatured: true.

PlayPauseButton

• Uninstrument ToggleNode.
  • Optional: There is no need to ever instrument a ToggleButton’s ToggleNode, so it might be worth searching through common code for other instances of this instrumentation and ripping it out.
• Verify there is a LinkedProperty to isPlayingProperty, and if not, add it.
• Verify that these are the only associated elements that are featured:
  • isPlayingProperty
  • visibleProperty
  • enabledProperty

Step Buttons

• Uninstrument enabledProperty. It depends on isPlayingProperty and should never be client-controlled. (Nor should clients care to ask the sim if the button is enabled or not.)
• The only featured element should be visibleProperty.

SpeedRadioButtonGroup

• Verify there is a LinkedProperty to timeSpeedProperty, and if not, add it.
• Verify that these are the only elements associated with the GROUP that are featured:
  • timeSpeedProperty
  • visibleProperty
  • enabledProperty
• The individual radio buttons are a bit over-instrumented (no need for enabledProperty, for example), but RadioButtonGroup is on the docket for API cleanup and will be tracked in a separate issue.

[samreid]

On hold until #826 is complete.