Current situation:
If you do not provide a column name in the plot options, and hit the refresh button, a NullPointerException error is raised.
What I would propose:
Catch the exception and instead of showing it in the console, generate a pop-up window stating 'please select a column to be plotted'
Current situation: If you do not provide a column name in the plot options, and hit the refresh button, a NullPointerException error is raised.
What I would propose: Catch the exception and instead of showing it in the console, generate a pop-up window stating 'please select a column to be plotted'
Screenshots: