Triggering event continuously when Button is pressed down in Android

Question

I have Button and an TextView. Initially on click of button i an incrementing the count value and display in the TextView. The code i have used to do so is.

buttonDayPlus.setOnClickListener(new OnClickListener() 
{               
     @Override
     public void onClick(View v) 
     {
     count = count + 1;
         textView.setText(Integer.toString(count));
     }
}

But now what i want is if the user pressed the Button, then i want to increment the value one after another and display the increment value in the textView and as soon as user move his hand up...the final increment value is shown in textView. So if anyone knows help me to solve this out

Answer 1

You will need to use a Handler object because you have to implement a separate thread for incrementing/decrementing

public class MainActivity extends Activity {

    private boolean autoIncrement = false;
    private boolean autoDecrement = false;
    private final long REPEAT_DELAY = 50;
    private Handler repeatUpdateHandler = new Handler();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.input);

        class RepetitiveUpdater implements Runnable {

            @Override
            public void run() {
                if (autoIncrement) {
                    increment();
                    repeatUpdateHandler.postDelayed(new RepetitiveUpdater(), REPEAT_DELAY);
                } else if (autoDecrement) {
                    decrement();
                    repeatUpdateHandler.postDelayed(new RepetitiveUpdater(), REPEAT_DELAY);
                }
            }

        }

        up.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                increment();
            }
        });

        up.setOnLongClickListener(new OnLongClickListener() {

            @Override
            public boolean onLongClick(View v) {
                autoIncrement = true;
                repeatUpdateHandler.post(new RepetitiveUpdater());
                return false;
            }
        });

        up.setOnTouchListener(new OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                if (event.getAction() == MotionEvent.ACTION_UP && autoIncrement) {
                    autoIncrement = false;
                }
                return false;
            }
        });

    }

    public void increment() {
        if (i < 100) {
            i++;
            TextView no = (TextView) findViewById(R.id.no);
            no.setText(String.valueOf(i));
        }

    }

}

Do the same for decrement.

Courtesy: Github, author: Jeffrey F. Cole

Answer 2

I just answered this question here https://stackoverflow.com/a/41466381/2991628

I created a CounterHandler class to do all the counting and event handling. This is how it works.

 new CounterHandler.Builder()
            .incrementalView(buttonPlus)
            .decrementalView(buttonMinus)
            .minRange(-50) // cant go any less than -50
            .maxRange(50) // cant go any further than 50
            .isCycle(true) // 49,50,-50,-49 and so on
            .counterDelay(200) // speed of counter
            .counterStep(2)  // steps e.g. 0,2,4,6...
            .listener(this) // to listen counter results and show them in app
            .build();

You can find this class from my gist https://gist.github.com/nomanr/d142f4ccaf55ceba22e7f7122b55b9b6