import android.content.Context;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.graphics.Path;

import android.util.AttributeSet;

import android.view.MotionEvent;

import android.view.View;

public class SimpleDrawingView extends View {

   // setup initial color

   private final int paintColor = Color.BLACK;

   // defines paint and canvas

   private Paint drawPaint;

   // stores next circle

   private Path path = new Path();

   public SimpleDrawingView(Context context, AttributeSet attrs) {

       super(context, attrs);

       setFocusable(true);

       setFocusableInTouchMode(true);

       setupPaint();

   }

   private void setupPaint() {

       // Setup paint with color and stroke styles

       drawPaint = new Paint();

       drawPaint.setColor(paintColor);

       drawPaint.setAntiAlias(true);

       drawPaint.setStrokeWidth(5);

       drawPaint.setStyle(Paint.Style.STROKE);

       drawPaint.setStrokeJoin(Paint.Join.ROUND);

       drawPaint.setStrokeCap(Paint.Cap.ROUND);

   }

   @Override

   protected void onDraw(Canvas canvas) {

       canvas.drawPath(path, drawPaint);

   }

   @Override

   public boolean onTouchEvent(MotionEvent event) {

       float pointX = event.getX();

       float pointY = event.getY();

       // Checks for the event that occurs

       switch (event.getAction()) {

           case MotionEvent.ACTION_DOWN:

               path.moveTo(pointX, pointY);

               return true;

           case MotionEvent.ACTION_MOVE:

               path.lineTo(pointX, pointY);

               break;

           default:

               return false;

       }

       // Force a view to draw again

       postInvalidate();

       return true;

   }

}