Measurement tools, detector probe, etc need headings

[samreid]

From #328, I saw that measurement tools and things are missing headings. It's not a regression from #328, just something else to address:

[terracoda]

I suggested "Measurement Tools" as a heading for the Checkboxes, over in #322, and it is already implemented.

I don't think I have ever added a headings for the added tools, but I have not worked with this many tools before.

[terracoda]

The added tools should go to the end of the Play Area, or in some cases under an existing sub heading, if that makes sense for the sim. For example, the movable ruler could be literally placed under the Detector screen controls, after the Screen Brightness slider if we wanted to do that. In the case of the Experiment Screen, it may not be necessary because there only one control (the Ruler) that can be added.

Perhaps for a tool set like we have on screens 2 and 3, adding a dynamic heading might make sense, but I am not convinced. I know we did a lot of dynamic headings in CCK, but that sim is quite different.

[terracoda]

For sim with a lot of addable tools, we could generate a heading like "Added Measurement Tools" or "Added Tools" since maybe they are not all for measuring in all sims.

This heading could group the activated tools at the bottom of the Play Area. I don't think is necessary on Screen 1, but to be consistent we could instantiate the movable Ruler under the detector screen controls and indicate that in the context response.

[matthew-blackman]

Discussed with @terracoda and @samreid, and @terracoda would like to look at this and propose a path forward.

[terracoda]

I did suggest a heading, "Detector Probe Controls," for the added Detector Probe.
Looking at the above suggestion as these controls are all quite complex.

[terracoda]

Measurement Tools
Group help text for all 4 checkboxes

• If needed, add lab-like measurement tools to probe and measure different aspects of experiment.

Screen 2 and 3: Measurement Tools
The number (4 measurement tools), and their varied complexity and varied state descriptions complicate the design approach. I am hoping we can make an good example here that others might be able to follow.

Working on this.

Screen 1: Ruler (could change the design or leave as-is)

Change help text.

• From: Add ruler to measure distances on detector screen or graph. Once added, move ruler up or down with keyboard shortcuts.
• To: If needed, add lab-like ruler to probe and measure detector screen or graph.
  Then move help text to added Ruler structure (something I discourage once already, sorry).
• accessibleName: Ruler (no change)

[samreid]

I added group help text for the checkboxes, added "Added Measurement Tools" headings on all 3 screens, added help text to the base of the measuring tape, tried to match convention with what we had already decided. I do not consider this done, but at least wanted to start it. @terracoda feel free to revert my commit if it's not inline with your ideas.

[terracoda]

Looking at this now.