/** * The observer that will be notified when the height of  * the keyboard has changed */public interface KeyboardHeightObserver { /**   * Called when the keyboard height has changed, 0 means keyboard is closed,  * >= 1 means keyboard is opened.  *   * @param height  The height of the keyboard in pixels  * @param orientation The orientation either: Configuration.ORIENTATION_PORTRAIT or   *      Configuration.ORIENTATION_LANDSCAPE  */ void onKeyboardHeightChanged(int height, int orientation);}

/** * 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.keyboard_popup_window, 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);  } }}

@Overridepublic void onKeyboardHeightChanged(int height, int orientation) { String or = orientation == Configuration.ORIENTATION_PORTRAIT ? "portrait" : "landscape"; Logger.d(TAG, "onKeyboardHeightChanged in pixels: " + height + " " + or);}

private KeyboardHeightProvider mKeyboardHeightProvider;@Overrideprotected void onCreate(@Nullable Bundle savedInstanceState) { ... mKeyboardHeightProvider = new KeyboardHeightProvider(this); new Handler().post(() -> mKeyboardHeightProvider.start());}

@Overrideprotected void onResume() { super.onResume(); mKeyboardHeightProvider.setKeyboardHeightObserver(this);}@Overrideprotected void onPause() { super.onPause(); mKeyboardHeightProvider.setKeyboardHeightObserver(null);}@Overrideprotected void onDestroy() { super.onDestroy(); mKeyboardHeightProvider.close();}