#6 Column selection menu keeps moving to the right as users pick a new field to plot

[DBPlot]

When users pick a new field to plot, the tool add the field name to the X/Y text so the menu moves to the right. The consequence is that if users click on the edge of menu box, the menu box will be closed because the mouse pointer is outside of the menu box (because the box moves the right while the pointer stays at the same position). The solution is to delay adding the text until the selection is done.