Generalize Joist Buttons with Highlighting

[samreid]

In #177 @pixelzoom pointed out that the new PhetButton could be generalized to support the other highlighting button types. More work will be necessary to handle those cases since they are actually radio buttons, and the home screen buttons also change size. But I'll look into it.

[pixelzoom]

The buttons on the home screen are not part of this generalization. The home button on the navbar is.

[pixelzoom]

@samreid since you said "I'll look into it", I've assigned this to you. Feel free to unassign if you'd rather have someone else look at it.

[samreid]

Sounds good, thanks!

[samreid]

I have 231 open issues assigned to me now: https://github.com/issues?q=is%3Aissue+author%3Asamreid+is%3Aopen

😄

EDIT: The link above is issues I authored. For issues assigned to me it is https://github.com/issues?q=is%3Aissue+assignee%3Asamreid+is%3Aopen and only in the eighties. Whew!

[pixelzoom]

And looks like you opened the majority of them :-)

[samreid]

I created JoistButton and generalized it to support HomeButton and PhetButton above. @pixelzoom can you take a look and give feedback?

[pixelzoom]

This looks good. I changed the order of JoistButton constructor params, seemed like 'content' is most important, so should be first.

Assigning back to @samreid. Proceed with using JoistButton for NavigationBarScreenButton at your convenience.

[samreid]

That is a good move to put content first, thanks! I'll close this issue and create a new issue about the radio buttons.

[samreid]

I created a new issue in #183 and let's close this one.