Continuously increase integer value as the button is pressed

Question

I\'m new to Android so sorry if the question is easy to answer. I have two buttons, a decrease and an increase button, and in the middle of them a TextView which displays a

Answer 1

For that to work, you need a thread that will update the integer value when you long press on a button.

Create a handler in your activity:

private Handler repeatUpdateHandler = new Handler();

And 2 vars which will state: is it increment or decrement? Only one set at a time.

private boolean mAutoIncrement = false;
private boolean mAutoDecrement = false;

And the present number value

public int mValue;

And a class that will run in another thread:

class RptUpdater implements Runnable {
    public void run() {
        if( mAutoIncrement ){
            increment();
            repeatUpdateHandler.postDelayed( new RptUpdater(), REP_DELAY );
        } else if( mAutoDecrement ){
            decrement();
            repeatUpdateHandler.postDelayed( new RptUpdater(), REP_DELAY );
        }
    }
}

Add a long press listener to your button:

mBTIncrement.setOnLongClickListener( 
            new View.OnLongClickListener(){
                public boolean onLongClick(View arg0) {
                    mAutoIncrement = true;
                    repeatUpdateHandler.post( new RptUpdater() );
                    return false;
                }
            }
    );   

mBTIncrement.setOnTouchListener( new View.OnTouchListener() {
        public boolean onTouch(View v, MotionEvent event) {
            if( (event.getAction()==MotionEvent.ACTION_UP || event.getAction()==MotionEvent.ACTION_CANCEL) 
                    && mAutoIncrement ){
                mAutoIncrement = false;
            }
            return false;
        }
    });  

In the above case the button is the increment one. Create another button which will set mAutoDecrement to true.

And decrement() will be a function, which will set your instance int variable like this:

public void decrement(){
    mValue--;
    _value.setText( ""+mValue );
}

You figure the increment out. Oh and REP_DELAY is a static int variable set to 50.

I see this is an excerpt from Jeffrey Cole's open source NumberPicker available at http://www.technologichron.net/ Proper author's attribution must be added.