I am trying to perform basic task of rotating a canvas 20 times a

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Asked: May 20, 20262026-05-20T00:18:47+00:00 2026-05-20T00:18:47+00:00

I am trying to perform basic task of rotating a canvas 20 times a

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I am trying to perform basic task of rotating a canvas 20 times a
second using timer but it doesn’t seem to be working properly and its
lagging. for example, if I rotate rectangle 0.3 degrees per 50 ms it
should rotate 6 degree in on second, but that is not the case. It
really slow in rotation. Here is my sample code:

//Code for update task
class UpdateTimeTask extends TimerTask {

      public void run() {
              hndView.post(new Runnable() {
                   public void run() {
                           hndView.invalidate(); //this code invalidates custom view that calls onDraw to draw rotated hand
                   }
                 });
      }
}


//Code for onDraw method of custom view that needs to be update
@Override 
protected void onDraw(Canvas canvas){

    super.onDraw(canvas);

    //ang is angle to rotate and inc is float value of 0.3 degree to be incremented
    ang = ang + inc;
    if (ang >= 360) ang = ang - 360;
    canvas.rotate(ang, canvas.getWidth()/2, canvas.getHeight()/2);  
    canvas.drawRect((canvas.getWidth()/2 - 2), (canvas.getHeight()/2 - 125), (canvas.getWidth()/2 + 2), (canvas.getHeight()/2 + 10), mTextPaint);
    canvas.restore();

}

//code to schedule task
Timer timer = new Timer();
UpdateTimeTask tt = new UpdateTimeTask();
timer.schedule(tt, 0, 50);

Can anyone please tell me what am I doing wrong here? Should I used
different approach to perform this task? Because its hard to believe
that you cannot have simple smooth rotation of rectangle 20 times in
one second.