got some very basic stuff working, can add simple LineGraphics to the legend

Changing label and auto-update of colors and thickness works

I should determine a way to make a sorting method for LegendItems in space (based on the size of each) and then organize into an optimal column, row or grid of items. Get the bbox for all LegendItems and set the Legend mesh to the bbox.

If legend is placed in the main plot area scale the text size and spacing based on current scene bbox.

I see here you provided images exemplifying use, I think we should add a legends.ipynb.

@kushalkolar thoughts?

Interesting functionality, if I don't specify a dock to put the legend in, it places it in the middle of the plot. Should we have a default dock to use ("top" or "right") if someone just passes the plot?

I see you can pass a Plot, Dock, or Subplot. My only worry is that when I just passed the same plot that my data is in it put the legend over the graphic. Guess maybe it is up to the user to know that you can put legend in a plot or subplot by itself, or you can put it in a dock.

Is there a plan to have something like plot.add_legend(), that would take a plot_area and auto generate a legend based on existing graphics in the plot?

We can think about this later once we have all the legend functionality we want.

1. Interesting functionality, if I don't specify a dock to put the legend in, it places it in the middle of the plot. Should we have a default dock to use ("top" or "right") if someone just passes the plot?

Nope, it can make sense to put the legend in the main plot area too, the user can move them out of the way of existing graphics if required.

1. Also, if I don't change the size of the dock before adding the legend, it doesn't appear? Should we automatically change the size of the dock area that the legend is being added to?

Done

1. Legend location: it appears like the legend is not centered in the middle of the plot.

We can fix this later XD

I see here you provided images exemplifying use, I think we should add a legends.ipynb.

We can do this after implementing all legend functionality that we want, basically when we fully resolve #403

it is up to the user to know that you can put legend in a plot or subplot by itself, or you can put it in a dock.

Yup!

Is there a plan to have something like plot.add_legend(),

Now after the recent References refactor I realize this is probably the best way to do it, keep the API uniform. Can properly look into it after or during axes.