How to implemement undo features in painting application in Android?

Question

i want to do undo features in in my application.. for this i searched i net found that take arraylist of x,y points which i have done below code i am unable for undo the drawing

Answer 1

I didn't try, but i think use two canvas and bitmaps is helpful, on draw the current state, one is still former state, only need to restore the former one. But it only can restore on step.