How to get value from new android material design Slider

  Slider slider = findViewById(R.id.slider);
  slider.addOnSliderTouchListener(touchListener);

Then

private final OnSliderTouchListener touchListener =
      new OnSliderTouchListener() {
        @Override
        public void onStartTrackingTouch(Slider slider) {

        }

        @Override
        public void onStopTrackingTouch(Slider slider) {

        }
      };

For more details, Check SliderMainDemoFragment.java

You can use the OnChangeListener listener

slider.addOnChangeListener(new Slider.OnChangeListener() {
    @Override
    public void onValueChange(@NonNull Slider slider, float value, boolean fromUser) {
        //Use the value
    }
});

To get value updates you can use Slider.OnChangeListener:

val slider = Slider(requireContext())
slider.addOnChangeListener { slider, value, fromUser -> /* `value` is the argument you need */ }
// the same implementation with interface name
// slider.addOnChangeListener(Slider.OnChangeListener { slider, value, fromUser -> })

Examples of slider implementation from Material Components official repository.

We can get the value of the slider using addOnChangeListener.

The parameter value is of type Float.

    slider.addOnChangeListener { slider, value, fromUser ->                            
              Toast.makeText(baseContext, value.toString(), Toast.LENGTH_LONG).show()    
    }

If I'm right you are trying to get the value of the Slider on the go.

As far as I can see there is no direct method for that, but we can utilize a Labelformatter to do so.

A Labelformatter gets the value of the Slider, modifies it and returns it so that it can be displayed in the label above the Slider. In there you can add you lines of code processing the value.

Create a Labelformatter:

formatter = new LabelFormatter() {
        @NonNull
        @Override
        public String getFormattedValue(float value) {
            //do what you want with the value in here...
            return "" + value;
        }
    };

Afterwards just add the Labelformatter to your Slider with

slider.setLabelFormatter(formatter);

Caution: This only works when you choose to show the label on the Slider

Edit:

If you don't want the label to show up, you will have to create your own style for the label making it invisible.

Create a style in styles.xml:

<style name="LabelStyle" parent="ShapeAppearance.Material3.Tooltip"> //parent might be different for you
    <item name="android:textColor">@color/transparent</item>
    <item name="backgroundTint">@color/transparent</item>
</style>

Finally, add the style to the label in the xml of your layout

<com.google.android.material.slider.Slider
...                                
app:labelStyle="@style/LabelStyle"/>