Can "connection" be selectable?

[hoch]

This feature was in the original Canopy visualizer. It is often useful to inspect the source and the destination of a connection.

[chihuahua]

I think this can be implemented straightforwardly.

Here is the listener for clicks on the graph. There's a check for whether the cell's ID matches a node. We'd just add another check for whether the cell's ID matches an edge.
https://github.com/google/audion/blob/master/js/entry-points/panel.js#L225

And then, in this directory, we'd create a new "EdgeMode" for the pane that determines how to render the pane when the focus is on an edge (not a node).
https://github.com/google/audion/tree/master/js/ui/pane

The pane would set its mode to an instance of EdgeMode when an edge is highlighted.