[android] How do I get the height and width of the Android Navigation Bar programmatically?

In case of Samsung S8 none of the above provided methods were giving proper height of navigation bar so I used the KeyboardHeightProvider keyboard height provider android. And it gave me height in negative values and for my layout positioning I adjusted that value in calculations.

Here is KeyboardHeightProvider.java :

import android.app.Activity;
import android.content.res.Configuration;
import android.graphics.Point;
import android.graphics.Rect;
import android.graphics.drawable.ColorDrawable;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;
import android.view.WindowManager.LayoutParams;
import android.widget.PopupWindow;


/**
 * The keyboard height provider, this class uses a PopupWindow
 * to calculate the window height when the floating keyboard is opened and closed. 
 */
public class KeyboardHeightProvider extends PopupWindow {

    /** The tag for logging purposes */
    private final static String TAG = "sample_KeyboardHeightProvider";

    /** The keyboard height observer */
    private KeyboardHeightObserver observer;

    /** The cached landscape height of the keyboard */
    private int keyboardLandscapeHeight;

    /** The cached portrait height of the keyboard */
    private int keyboardPortraitHeight;

    /** The view that is used to calculate the keyboard height */
    private View popupView;

    /** The parent view */
    private View parentView;

    /** The root activity that uses this KeyboardHeightProvider */
    private Activity activity;

    /** 
     * Construct a new KeyboardHeightProvider
     * 
     * @param activity The parent activity
     */
    public KeyboardHeightProvider(Activity activity) {
        super(activity);
        this.activity = activity;

        LayoutInflater inflator = (LayoutInflater) activity.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
        this.popupView = inflator.inflate(R.layout.popupwindow, null, false);
        setContentView(popupView);

        setSoftInputMode(LayoutParams.SOFT_INPUT_ADJUST_RESIZE | LayoutParams.SOFT_INPUT_STATE_ALWAYS_VISIBLE);
        setInputMethodMode(PopupWindow.INPUT_METHOD_NEEDED);

        parentView = activity.findViewById(android.R.id.content);

        setWidth(0);
        setHeight(LayoutParams.MATCH_PARENT);

        popupView.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {

                @Override
                public void onGlobalLayout() {
                    if (popupView != null) {
                        handleOnGlobalLayout();
                    }
                }
            });
    }

    /**
     * Start the KeyboardHeightProvider, this must be called after the onResume of the Activity.
     * PopupWindows are not allowed to be registered before the onResume has finished
     * of the Activity.
     */
    public void start() {

        if (!isShowing() && parentView.getWindowToken() != null) {
            setBackgroundDrawable(new ColorDrawable(0));
            showAtLocation(parentView, Gravity.NO_GRAVITY, 0, 0);
        }
    }

    /**
     * Close the keyboard height provider, 
     * this provider will not be used anymore.
     */
    public void close() {
        this.observer = null;
        dismiss();
    }

    /** 
     * Set the keyboard height observer to this provider. The 
     * observer will be notified when the keyboard height has changed. 
     * For example when the keyboard is opened or closed.
     * 
     * @param observer The observer to be added to this provider.
     */
    public void setKeyboardHeightObserver(KeyboardHeightObserver observer) {
        this.observer = observer;
    }

    /**
     * Get the screen orientation
     *
     * @return the screen orientation
     */
    private int getScreenOrientation() {
        return activity.getResources().getConfiguration().orientation;
    }

    /**
     * Popup window itself is as big as the window of the Activity. 
     * The keyboard can then be calculated by extracting the popup view bottom 
     * from the activity window height. 
     */
    private void handleOnGlobalLayout() {

        Point screenSize = new Point();
        activity.getWindowManager().getDefaultDisplay().getSize(screenSize);

        Rect rect = new Rect();
        popupView.getWindowVisibleDisplayFrame(rect);

        // REMIND, you may like to change this using the fullscreen size of the phone
        // and also using the status bar and navigation bar heights of the phone to calculate
        // the keyboard height. But this worked fine on a Nexus.
        int orientation = getScreenOrientation();
        int keyboardHeight = screenSize.y - rect.bottom;

        if (keyboardHeight == 0) {
            notifyKeyboardHeightChanged(0, orientation);
        }
        else if (orientation == Configuration.ORIENTATION_PORTRAIT) {
            this.keyboardPortraitHeight = keyboardHeight; 
            notifyKeyboardHeightChanged(keyboardPortraitHeight, orientation);
        } 
        else {
            this.keyboardLandscapeHeight = keyboardHeight; 
            notifyKeyboardHeightChanged(keyboardLandscapeHeight, orientation);
        }
    }

    /**
     *
     */
    private void notifyKeyboardHeightChanged(int height, int orientation) {
        if (observer != null) {
            observer.onKeyboardHeightChanged(height, orientation);
        }
    }

    public interface KeyboardHeightObserver {
        void onKeyboardHeightChanged(int height, int orientation);
    }
}

popupwindow.xml :

<?xml version="1.0" encoding="utf-8"?>
<View
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/popuplayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/transparent"
    android:orientation="horizontal"/>

Usage in MainActivity

import android.os.Bundle
import android.support.v7.app.AppCompatActivity
import kotlinx.android.synthetic.main.activity_main.*

/**
 * Created by nileshdeokar on 22/02/2018.
 */
class MainActivity : AppCompatActivity() , KeyboardHeightProvider.KeyboardHeightObserver  {

    private lateinit var keyboardHeightProvider : KeyboardHeightProvider


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        keyboardHeightProvider = KeyboardHeightProvider(this)
        parentActivityView.post { keyboardHeightProvider?.start() }
    }

    override fun onKeyboardHeightChanged(height: Int, orientation: Int) {
        // In case of 18:9 - e.g. Samsung S8
        // here you get the height of the navigation bar as negative value when keyboard is closed.
        // and some positive integer when keyboard is opened.
    }

    public override fun onPause() {
        super.onPause()
        keyboardHeightProvider?.setKeyboardHeightObserver(null)
    }

    public override fun onResume() {
        super.onResume()
        keyboardHeightProvider?.setKeyboardHeightObserver(this)
    }

    public override fun onDestroy() {
        super.onDestroy()
        keyboardHeightProvider?.close()
    }
}

For any further help you can have a look at advanced usage of this here.