Planned Feature: Indicate Currently Selected Key

[epiccoleman]

Currently, the only way that a user of the component can know which key is selected is by managing state in some parent component. (For example, see the current approach in the demo app.)

The CircleOfFifths component should have an internal notion of which key is currently selected. It should also indicate the current selection in some way.

A couple thoughts:

• Simplest - just highlight the currently selected "wedge" with a different color, like we do for hover.
• It might also be nice to put some text in the center indicating the currently selected key.
• it would be cool if there was a "selection wedge," that surrounds the currently selected tonic.
• it might be cool / useful to expand that to surround all the notes in the current key
• it might be cool / useful to color the chords in the currently selected key according to some scheme (like, the tonic is green, the third is blue, the seventh is purple, or something like that).

This is going to require some work because the current rendering logic is blissfully unaware of any internal state like that. We'll need to add IDs to each wedge and write some logic around deciding which wedges should be styled based on the current selection.

[epiccoleman]

The 1.0.0 Release contains a first-pass implementation of selection management. Leaving this issue open for now, as I'd still like to explore some of the more interesting ideas here like indicating the selection with an outline and recoloring diatonic notes in the circle.