public class DrawingView extends View {

 //drawing path
 private Path drawPath;
 //drawing and canvas paint
 private Paint drawPaint, canvasPaint;
 //initial color
 private int paintColor = 0xFF660000, paintAlpha = 255;
 //canvas
 private Canvas drawCanvas;
 //canvas bitmap
 private Bitmap canvasBitmap;
 //brush sizes
 private float brushSize, lastBrushSize;
 //erase flag
 private boolean erase=false;

 public DrawingView(Context context, AttributeSet attrs){
  super(context, attrs);
  setupDrawing();
 }

 //setup drawing
 private void setupDrawing(){

  //prepare for drawing and setup paint stroke properties
  brushSize = getResources().getInteger(R.integer.medium_size);
  lastBrushSize = brushSize;
  drawPath = new Path();
  drawPaint = new Paint();
  drawPaint.setColor(paintColor);
  drawPaint.setAntiAlias(true);
  drawPaint.setStrokeWidth(brushSize);
  drawPaint.setStyle(Paint.Style.STROKE);
  drawPaint.setStrokeJoin(Paint.Join.ROUND);
  drawPaint.setStrokeCap(Paint.Cap.ROUND);
  canvasPaint = new Paint(Paint.DITHER_FLAG);
 }

 //size assigned to view
 @Override
 protected void onSizeChanged(int w, int h, int oldw, int oldh) {
  super.onSizeChanged(w, h, oldw, oldh);
  canvasBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
  drawCanvas = new Canvas(canvasBitmap);
 }

 //draw the view - will be called after touch event
 @Override
 protected void onDraw(Canvas canvas) {
  canvas.drawBitmap(canvasBitmap, 0, 0, canvasPaint);
  canvas.drawPath(drawPath, drawPaint);
 }

 //register user touches as drawing action
 @Override
 public boolean onTouchEvent(MotionEvent event) {
 
  if(!MainActivity.zoom) {
   System.out.println("11 Zoom : " + ((MainActivity)getContext()).getZoomFocusX());

   System.out.println("11 Touch X : " + event.getX());
   System.out.println("11 Touch Y : " + event.getY());
   
   float touchX = event.getX();/// ((MainActivity)getContext()).getZoomFocusX();
   float touchY = event.getY();/// ((MainActivity)getContext()).getZoomFocusY();

   System.out.println("11 Draw X : " + touchX);
   System.out.println("11 Draw Y : " + touchY);
   //respond to down, move and up events
   switch (event.getAction()) {
    case MotionEvent.ACTION_DOWN:
     drawPath.moveTo(touchX, touchY);
     break;
    case MotionEvent.ACTION_MOVE:
     drawPath.lineTo(touchX, touchY);
     break;
    case MotionEvent.ACTION_UP:
     drawPath.lineTo(touchX, touchY);
     drawCanvas.drawPath(drawPath, drawPaint);
     drawPath.reset();
     break;
    default:
     return false;
   }
   //redraw
   invalidate();
  }
  return true;

 }

 //update color
 public void setColor(String newColor){
  invalidate();
  //check whether color value or pattern name
  if(newColor.startsWith("#")){
   paintColor = Color.parseColor(newColor);
   drawPaint.setColor(paintColor);
   drawPaint.setShader(null);
  }
  else{
   //pattern
   int patternID = getResources().getIdentifier(
     newColor, "drawable", "com.example.drawingfun");
   //decode
   Bitmap patternBMP = BitmapFactory.decodeResource(getResources(), patternID);
   //create shader
   BitmapShader patternBMPshader = new BitmapShader(patternBMP,
     Shader.TileMode.REPEAT, Shader.TileMode.REPEAT);
   //color and shader
   drawPaint.setColor(0xFFFFFFFF);
   drawPaint.setShader(patternBMPshader);
  }
 }

 //set brush size
 public void setBrushSize(float newSize){
  float pixelAmount = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
    newSize, getResources().getDisplayMetrics());
  brushSize=pixelAmount;
  drawPaint.setStrokeWidth(brushSize);
 }

 //get and set last brush size
 public void setLastBrushSize(float lastSize){
  lastBrushSize=lastSize;
 }
 public float getLastBrushSize(){
  return lastBrushSize;
 }

 //set erase true or false
 public void setErase(boolean isErase){
  erase=isErase;
  if(erase) drawPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
  else drawPaint.setXfermode(null);
 }

 //start new drawing
 public void startNew(){
  drawCanvas.drawColor(0, PorterDuff.Mode.CLEAR);
  invalidate();
 }

 //return current alpha
 public int getPaintAlpha(){
  return Math.round((float)paintAlpha/255*100);
 }

 //set alpha
 public void setPaintAlpha(int newAlpha){
  paintAlpha=Math.round((float)newAlpha/100*255);
  drawPaint.setColor(paintColor);
  drawPaint.setAlpha(paintAlpha);
 }
}