draw alphabets arabic

I am an Android developer but I do not have experience in graphics in Android and so on I want to help me make this idea in my application I want how to draw alphabets arabic and draw line on it by finger I want to create letters and words dynamically on view and also I want to draw line on it by finger. For example I have letters like A as given in picture: The most important thing when drawing is that you should not go out of line Where the drawing is only available on points *** Work Only android studio