Multiple seekbars - set listeneners more efficiently?

Question

I have 12 seekbars in an activity. Each seekbar needs a listener. At the moment I am manually setting a listener for each seekbar, this doesnt seem particularly efficient.

Can anyone recommend a more efficient practice to set the seekbars???

Answer 1

If your SeekBars all require different interaction logic then obviously you will need to provide unique code to each of the objects. However, you can re-use listeners if each SeekBar is doing the same thing. For example:

public class SeekBarTest extends Activity{

    private Context myContext;
    public SeekBarTest(Context c){
        myContext = c;
    }

    private void initialize(){

        SeekBar seekbar1 = new SeekBar(myContext);
        SeekBar seekbar2 = new SeekBar(myContext);
        SeekBar seekbar3 = new SeekBar(myContext);

        SeekBar.OnSeekBarChangeListener myListener = new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onProgressChanged(SeekBar seekBar, int i, boolean b) {
                //logic
            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {
                //logic
            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
                //logic
            }
        };

        seekbar1.setOnSeekBarChangeListener(myListener);
        seekbar2.setOnSeekBarChangeListener(myListener);
        seekbar3.setOnSeekBarChangeListener(myListener);
    }
}

Answer 2

Try something like this:

public class MainActivity extends AppCompatActivity {

SeekBar seekBar1;
SeekBar seekBar2;
SeekBar.OnSeekBarChangeListener mlistener;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    seekBar1 = findViewById(R.id.seekBar_1);
    seekBar2 = findViewById(R.id.seekBar_2);

    mlistener = new SeekBar.OnSeekBarChangeListener() {
        @Override
        public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
            switch (seekBar.getId()) {
                case R.id.seekBar_1:
                    //do something
                    break;
                case R.id.seekBar_2:
                    //do something else
                    break;
            }
        }

        @Override
        public void onStartTrackingTouch(SeekBar seekBar) {

        }

        @Override
        public void onStopTrackingTouch(SeekBar seekBar) {

        }
    }; 

    seekBar1.setOnSeekBarChangeListener(mlistener);
    seekBar2.setOnSeekBarChangeListener(mlistener);
}

Answer 3

Instead of creating switch in onProgressChanged method you can send variables to SeekBar initiating method.

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_options);

    SeekBar volBar = initiateSeekBar(R.id.volume,R.id.volumeValue,0,1,"%");
    SeekBar playSpeedBar = initiateSeekBar(R.id.autoPlay,R.id.autoPlayValue,100, 100,"ms");
}

 private SeekBar initiateSeekBar(int barId, int textId, final int min, final int step, final String unit) {
    SeekBar bar = findViewById(barId);
    final TextView text = findViewById(textId);

    bar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
        @Override
        public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
            int value = min + progress * step;
            text.setText(value + " " + unit);
            autoPlayDelayTime = value;
        }

        @Override
        public void onStartTrackingTouch(SeekBar seekBar) {

        }

        @Override
        public void onStopTrackingTouch(SeekBar seekBar) {

        }
    });
    return bar;
}

Answer 4

You can just make a reference equality, like this:

override fun onProgressChanged(seekBar: SeekBar?, progress: Int, fromUser: Boolean) {
    seekBar?. let {
        if (this.seekBar1 === it) {
            ...
        }
        if (this.seekBar2 === it) {
            ...
        }}
    ...
}

and call outside:

seekBar1.setOnSeekBarChangeListener(this)
seekBar2.setOnSeekBarChangeListener(this)