NumberControls should have a "snappy" slider

[zepumph]

In a PhET-iO design meeting for GFL, @kathy-phet mentioned that the number control slider should snap to 10, and the tweakers should be able to fine tune it to the ones place.

@kathy-phet mentioned this is what we are doing in more recent sim designs. @arouinfar and @terracoda what do you think?

[zepumph]

From #76

[arouinfar]

@zepumph I like this suggestion. This is indeed a common design pattern we've used across many sims, particularly when the slider range is large. I believe the relevant option is called constrainValue.

[zepumph]

Does this mean that you will not be able to get at the smaller values? Or that you will snap with the slider, and still be able to access the single digits with the tweakers?

[kathy-phet]

I think we agreed today that we would have a minimum of 0, so no single digits. It also makes the range of the force much better behaved. And we didn’t see a pedagogical reason that we needed to go to a value of 1. K

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Sent from my iPhone On Aug 22, 2019, at 7:16 PM, Michael Kauzmann <[email protected]<mailto:[email protected]>> wrote: Does this mean that you will not be able to get at the smaller values? Or that you will snap with the slider, and still be able to access the single digits with the tweakers? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub<#173?email_source=notifications&email_token=ABG4KZAPJXZCVTOY34N2N3LQF4263A5CNFSM4IN5YBGKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD462WQA#issuecomment-524135232>, or mute the thread<https://github.com/notifications/unsubscribe-auth/ABG4KZAG5DMCJIAQQJ35GADQF4263ANCNFSM4IN5YBGA>.

[terracoda]

I feel this issue is related to #133, and I do indeed agree the sliders should be snappy.

Starting at zero is fine with me if that makes sense for the sim. I would, however, need to double check the described values. As of right now there is no described value of zero.

[zepumph]

I think we agreed today that we would have a minimum of 0, so no single digits.

I thought we agreed to have a minimum of 10.

[zepumph]

The GFL sliders now snap to 10. The current minimum is 10, and the keyboard shift key delta is 10. @arouinfar @terracoda please review.

[kathy-phet]

@zepumph - The tweekers should be set to steps of "1". There is a way to set the snappy different from the tweekers.

[zepumph]

@kathy-phet I implemented that above. The issue is that currently there is no way to make that possible for accessibility. I created phetsims/scenery-phet#528 to fix that. But for now this issue should block a11y publication of this sim (not that was coming up anytime soon).

[zepumph]

@kathy-phet please review. Is this good enough to give to a client today?

[kathy-phet]

I think this looks nice. Good enough for the dev delivery. Marking for review by @arouinfar and @ariel-phet when they are around. Please see what you think of the arrow scaling in GFL and GFLB now.

[ariel-phet]

I looked at both GFL and GFL:B on master

I think the scaling is generally good, and I double checked that it is linear. I think this is good enough for a dev delivery.

@kathy-phet @arouinfar If I were polishing, at "default" I think it would be good for a bit of a tail on the vector arrow. In GLF:B this could be accomplished simply by making the default masses 3 and 6 (billion). That keeps fairly similar goals to using 2 and 4

Again, in GFL, perhaps start with something like 100 kg and 400 kg as the default, that would be a nicer beginning arrow size without have to continue messing with the scaling.

[zepumph]

Review of the arrow scaling can happen over in phetsims/inverse-square-law-common#76.

It seems like the snappy slider is looking good for gravity-force-lab, and there have been no complaints from our clients. Closing this issue.