fix props and functions naming in buttonGrp

[OriLev]

No description provided.

[elektronik2k5]

A cleaner way to express props:

const { style, } = buttonHeight
const buttonProps = {
  type: 'button',
  disabled,
  key: index,
  className: classes,
  style,
  onClick,
  children: text,
}
return <Button {...buttonProps} />

This is better in several ways:

1. Instead of using the ugly JSX key={{value}} verbose syntax, you use objects/classes/functions - with the full expressivity of the JS language
2. You separate props (in essence, they are function arguments) from the component structure, so you see your component tree at a glance.

[OriLev]

1. mind blown. so simple and somehow haven't crossed my mind so far.

2. about the key - you used key: index, which raised a question in my mind: I tried giving unique keys to all my elements that were constructed via map(), hence the combination of 'button' + index, unlike 'cell' + y + x. Does the fact that you used only index in your example mean that I can keep the keys not unique BETWEEN different maps?

[elektronik2k5]

1. it's not that obvious. Did you read the react docs and official tutorial? ALL the docs?
2. https://reactjs.org/docs/lists-and-keys.html#keys

[OriLev]

Reading now...

It's quite a lot, so I will be making some progress with the code cleanup as well.