Get Android Navigation bar height NativeScript

getNavBarHeight.js

function getNavBarHeight() {
  const app = require("application");
  if (app.android) {
    let navBarHeight = 0;
    let windowManager = app.android.context
      .getSystemService(android.content.Context.WINDOW_SERVICE);
    let d = windowManager.getDefaultDisplay();

    let realDisplayMetrics = new android.util.DisplayMetrics();
    d.getRealMetrics(realDisplayMetrics);

    let realHeight = realDisplayMetrics.heightPixels;
    let realWidth = realDisplayMetrics.widthPixels;

    let displayMetrics = new android.util.DisplayMetrics();
    d.getMetrics(displayMetrics);

    let displayHeight = displayMetrics.heightPixels;
    let displayWidth = displayMetrics.widthPixels;

    if ((realHeight - displayHeight) > 0) { // Portrait
      navBarHeight = realHeight - displayHeight;
    } else if ((realWidth - displayWidth) > 0) { // Landscape
      navBarHeight = realWidth - displayWidth;
    }

    // Convert to device independent pixels and return
    return (navBarHeight
      / app.android.currentContext
        .getResources().getDisplayMetrics().density);
  }
  return 0;
}