Question

I am trying to implement a simple digital clock with second and two colons changing every second. I have thought about using DigitalClock but I want the colons to flash as well as the second and don’t want to show am/pm. So I read the “Updating the UI from a Timer” and it suggests us to use Handler. So i use Handler and can change second and colons every second but the weird thing is that sometimes, it jumps a second (1,2,4,5,6). It seems the clock is a bit lagging. Is there any way to solve this problem? Thanks!

tick_handler = new Handler();
    Runnable updateSecond = new Runnable(){
        @Override
        public void run() {
            second.setText(DataModel.getSeconds());
            if(colon1.getVisibility()== View.VISIBLE){
                colon1.setVisibility(View.INVISIBLE);
                colon2.setVisibility(View.INVISIBLE);
            } else {
                colon1.setVisibility(View.VISIBLE);
                colon2.setVisibility(View.VISIBLE);
            }
            tick_handler.postDelayed(this, 1000);
        }
    };
tick_handler.postDelayed(updateSecond, 0);

Answer 1

I suspect that you see this on the emulator as it is much slower than actual phones. Try changing the tick_handler.postDelayed(this, 1000); to a smaller value than 1 second, for e.g. 500 ms

tick_handler.postDelayed(this, 500); 

and add a global variable to track the differece between each time the thread runs and if the difference is 1 second, update the Views.