Kompass exended

public class CompassView extends ImageView {
	private static final AtomicBoolean drawing = new AtomicBoolean(false);
	private static final Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
	
	private static int parentWidth = 0;
	private static int parentHeight = 0;
    private static Matrix matrix = null;
    private static Bitmap bitmap = null;
    private static Bitmap bobbel = null;
    private static Matrix bobbelmatrix = null;
    
    private int bobbelX, bobbelY, bobbelcenterX, bobbelcenterY; 
    

    public CompassView(Context context) {
        super(context);
        
        initialize();
    }    
    
    public CompassView(Context context, AttributeSet attr) {
        super(context,attr);
        
        initialize();
    }
    
    private void initialize() {
        matrix = new Matrix();
        bobbelmatrix = new Matrix();
        bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.grundriss);
        bobbel = BitmapFactory.decodeResource(getResources(), R.drawable.bobbel);

    }
    
    /**
     * {@inheritDoc}
     */
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    	int ausdehnung=0;
    	super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        ausdehnung = bitmap.getWidth();
        if(bitmap.getHeight()>ausdehnung)
        {
        	ausdehnung=bitmap.getHeight();
        }
        parentWidth=ausdehnung;
        parentHeight=ausdehnung;
        /*parentWidth = MeasureSpec.getSize(widthMeasureSpec);
        parentHeight = MeasureSpec.getSize(heightMeasureSpec);*/
        setMeasuredDimension(parentWidth, parentHeight);
    }
    
    /**
     * {@inheritDoc}
     */
    @Override
    protected void onDraw(Canvas canvas) {
    	
    	
    	if (canvas==null) throw new NullPointerException();

        if (!drawing.compareAndSet(false, true)) return; 

        float bearing = GlobalData.getBearing();
       /* if (bitmap.getWidth()>canvasWidth || bitmap.getHeight()>canvasHeight) {        
            //Resize the bitmap to the size of the canvas
            bitmap = Bitmap.createScaledBitmap(bitmap, (int)(bitmapWidth*.9), (int)(bitmapHeight*.9), true);
        }*/
        
       
        int bitmapX = bitmap.getWidth()/2;
        int bitmapY = bitmap.getHeight()/2;
        
        int parentX = parentWidth/2;
        int parentY = parentHeight/2;
        
        int centerX = parentX-bitmapX;
        int centerY = parentY-bitmapY;
        
        int rotation = (int)(360-bearing);
        
        matrix.reset();
        //Rotate the bitmap around it's center point so it's always pointing north
        matrix.setRotate(rotation, bitmapX, bitmapY);
        //Move the bitmap to the center of the canvas
        matrix.postTranslate(centerX, centerY);

        canvas.drawBitmap(bitmap, matrix, paint);
        bobbelX=bobbel.getWidth()/2;
        bobbelY=bobbel.getHeight()/2;
        bobbelcenterX = parentX-bobbelX;
        bobbelcenterY = parentY-bobbelY;

        bobbelmatrix.reset();
        bobbelmatrix.setRotate(rotation,bobbelX,bobbelY);
        bobbelmatrix.postTranslate(bobbelcenterX, bobbelcenterY);
        
        
        canvas.drawBitmap(bobbel, bobbelmatrix, paint);
       
	    drawing.set(false);
    }

        bobbelmatrix.reset();         
bobbelmatrix.setRotate(rotation,bobbelX,bobbelY);         
bobbelmatrix.postTranslate(bobbelcenterX, bobbelcenterY);                           
canvas.drawBitmap(bobbel, bobbelmatrix, paint);