Make ToggleButtons respect passed style kwarg

[hinnefe2]

This PR is a (work in progress) attempt to solve #1691.

Things that I've tried so far (which haven't worked) this includes:

• make ToggleButtonStyle inherit from DescriptionStyle in both the .py and .ts definitions.
• modify the styleProperties in the .ts definition.

[jasongrout]

Ah, you'll also need to modify the styleProperties like the int slider:

ipywidgets/packages/controls/src/widget_int.ts

Line 59 in 96aa66b

...DescriptionStyleModel.styleProperties,

[jasongrout]

To explain more: the error is here in the Travis log (which you can find by clicking on the "Details" link above, or on the red X:

lerna ERR! execute src/widget_selection.ts(370,7): error TS2417: Class static side 'typeof ToggleButtonsStyleModel' incorrectly extends base class static side 'typeof DescriptionStyleModel'.
lerna ERR! execute   Types of property 'styleProperties' are incompatible.
lerna ERR! execute     Type '{ button_width: { selector: string; attribute: string; default: any; }; }' is not assignable to type '{ description_width: { selector: string; attribute: string; default: any; }; }'.
lerna ERR! execute       Property 'description_width' is missing in type '{ button_width: { selector: string; attribute: string; default: any; }; }'.

The last line indicates that the styleProperties does not properly include a description_width value, which leads to the above suggestion to augment the styleProperties with the DescriptionStyleModel styleProperties.

Isn't typescript great? In normal javascript, we wouldn't have found out about this omission until we hit a probably hard-to-debug bug where the style properties wouldn't actually update. In this case, the typings force us to fix the bug before things even compile.

[jasongrout]

@hinnefe2 - thanks again for this PR. I should make a release tonight (i.e., in the next 10 hours or so) - please let me know if you have time to look at the above comment, or alternatively I can look into making the change.

[jasongrout]

Also, one more thing: the name/address on the commit is: hinnefe2 <[email protected]>. If you'd like your real name to show up in our changelog and release notes, can you either:

(a) Tell git your name: git config --global user.name "John Doe", then amend your commit to record that new information, OR
(b) add an entry to our .mailmap file which matches git commit information to current names/emails: https://github.com/jupyter-widgets/ipywidgets/blob/master/.mailmap (add a line that looks like:

Correct Name <correct email> hinnefe2 <[email protected]>

I'm happy to help with either of these.

[jasongrout]

(I could also make the release tomorrow morning, i.e., within 24 hours, if the extra time helps...)

[hinnefe2]

Hi @jasongrout - I think this is good to go. On my local machine the description widths for toggle buttons respect the style argument now.

Thanks for helping me through this - java/typescript is a bit outside my wheelhouse but you made it easy to contribute. I'll definitely be back next time I find something that could use fixing.

[jasongrout]

Awesome, thanks!

[jasongrout]

This looks great to me too. I checked it and it works as well. Thanks again!