Mostly contains DasCanvasComponents, which are components that live within the DasCanvas, and Renderers which draw on DasPlots. DasCanvas, a subclass of JComponent, is the container for drawing graphics in das2. DasCanvasComponents are added to the DasCanvas to set up the graphic. DasCanvasComponents include objects like DasAxis, DasColorBar, and DasPlot, but are simply objects that occupy a region of the canvas specified with a DasRow (vertical position) and DasColumn (horizontal position). Note too the CanvasComponents can be heirarchitical, for example a DasPlot contains two DasAxes. Each CanvasComponent has a DasMouseInputAdapter that handles mouse and keyboard events for the component.
To add new 2-D plotting capabilities, Renderers are introduced to paint the space defined by an x and y axis. Examples of Renderers are SymbolLineRenderer (line plots) and SpectrogramRenderer (spectrograms).