RelativeLayout onDraw wird nicht aufgerufen

public class DrawView extends RelativeLayout {
	private ArrayList<Rectangle> rectangles = new ArrayList<Rectangle>();
	private int rectId = 0;
	private int width;
	private int height;
	
	public DrawView(Context context) {
		super(context);		
		
		//RelativeLayout layout = new RelativeLayout(context);
		this.setLayoutParams(new RelativeLayout.LayoutParams(width, height));		
		
		Rectangle rect1 = new Rectangle(this.getContext());
		rect1.setId(1);
		rectangles.add(rect1);
		this.addView(rect1);
		
		RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
		params.setMargins(0, 10, 0, 0);
		Rectangle rect2 = new Rectangle(this.getContext());
		rect2.setId(2);
		params.addRule(RelativeLayout.BELOW, rect1.getId());    
		rect2.setLayoutParams(params);	
		rectangles.add(rect2);
		this.addView(rect2);

		
		
	}

	@Override
	protected void onDraw(Canvas canvas) {
		Log.i("ondraw","yes"+rectangles.size());
		
		for(Rectangle v: rectangles){
			Paint paint = new Paint();
			paint.setColor(Color.GREEN);
			Log.i("draw", ""+v.getTop());
			Log.i("draw", ""+v.getLeft());
			canvas.drawRect((float)v.getX(),(float) v.getY(),(float) v.getX()+150, (float)v.getY()+50, paint);
		}
	}

	@Override
	public boolean onTouchEvent(MotionEvent event) {
		
		int x = (int) event.getX();
		int y = (int) event.getY();	
		
		switch(event.getAction()){
			case MotionEvent.ACTION_DOWN:
						
				rectId = 0;
				
				for(int i=0; i < rectangles.size(); i++){
					View child = rectangles.get(i);
					if(x > child.getLeft() && x < child.getLeft()+150 && y > child.getTop() && y < child.getTop()+50){
						rectId = child.getId();
						rectangles.get(rectId-1).setTop(child.getTop());
						rectangles.get(rectId-1).setLeft(child.getLeft());
						break;
					}				
				}
				break;
			case MotionEvent.ACTION_MOVE:
				
				if(rectId > 0){
					rectangles.get(rectId-1).setBackgroundRessource(true);
					rectangles.get(rectId-1).setTop(y-25);
					rectangles.get(rectId-1).setLeft(x-25);
					Log.i("MOVE X", rectId+" "+rectangles.get(rectId-1).getX());
					Log.i("MOVE Y", rectId+" "+rectangles.get(rectId-1).getY());
				}
				
				break;
			case MotionEvent.ACTION_UP:
				Log.i("rectid Cancel", ""+rectId);
				if(rectId > 0){
					rectangles.get(rectId-1).setBackgroundRessource(true);
				}
				
				break;
		}

		invalidate();
		
		return true;
		
	}

	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
		super.onMeasure(widthMeasureSpec, heightMeasureSpec);

		width = View.MeasureSpec.getSize(widthMeasureSpec);
		height = View.MeasureSpec.getSize(heightMeasureSpec);
		
		setMeasuredDimension(width, height);
	}

}