Plot

• holds all non-GUI state: Axes, Axis, Traces (via Arc), ...
• does not hold window size, cursor position, etc.
• draw method to draw to cairo context
• methods to query objects/data coordinates for given device coordinatees (for zooming/scrolling the Axes, selecting Trace etc.)
• zoom_fit/zoom_at/zoom_rect methods for changing the view

PlotWidget (Component?)

• Holds the DrawingArea (or inherits from it?)
  • draw function calls plot.draw() -> needs shared access to all state
• Receives mouse/key events and calls Plot methods to query/update state etc.

Things to add:

• legend
• scrollbar?
• snapping cursor
• trace annotation/value marker
• delta (a-b) marker

let plt = Plot::builder()
             .figsize(400,300)
             .rows(3)
             .title("My title")
             .build();

plt.row(1).plot(wfm, Some("Label"));