SharedStyle

The value of a particular StyleProp.

A mixed style means that in the current selection, there are lots of different values for the same style prop - e.g. a red and a blue shape are selected.

A shared style means that all shapes in the selection share the same value for this style prop.

type SharedStyle<T> =
  | {
      readonly type: 'mixed'
    }
  | {
      readonly type: 'shared'
      readonly value: T
    }