I'm not glad to say this, but in order to help…
I find that the least useful tools are the DrawTool.ERASER_PENCIL();, the DrawTool.ERASER_RECTANGLE(); and the DrawTool.ERASER_FLOODFILL();, because their functions can be emulated by choosing their not-eraser equivalent and the color 00000000, that is the pure alpha channel.
I really don't want to be sassy, but I found them as the worst tool in the entire apliccations.
Thank you for considering my opinion.