index.js

var app = require("tns-core-modules/application");
var frameModule = require("tns-core-modules/ui/frame");

/**
 * The time duration for which toast will be displayed on the screen
 * For Android the values will be mapped to Toast.LENGTH_LONG and Toast.LENGTH_SHORT
 * For iOS the values will be mapped to the numeric values of Android enum which are 3.5 for LONG and 2 for SHORT
 */
var DURATION = {
  LONG: "long",
  SHORT: "short"
};
exports.DURATION = DURATION;

var POSITION = {
  TOP: 'top',
  BOTTOM: 'bottom',
  CENTER: 'center'
};
exports.POSITION = POSITION;

/**
 * show - displays the toast for iOS and Android
 *
 * @param  {object} toastObject javascript object with properties text and duration. Duration by default is short for android.
 * @return {void}
 */
exports.show = function (toastObject) {
  var position;
  if (app.ios) {
    switch (toastObject.position) {
      case POSITION.TOP:
        position = "CSToastPositionTop";
        break;
      case POSITION.CENTER:
        position = "CSToastPositionCenter";
        break;
      default:
        position = "CSToastPositionBottom"; //default position = bottom
    }
    frameModule.topmost().ios.controller.view.makeToastDurationPosition(
      toastObject.text,
      toastObject.duration === DURATION.LONG ? 3.5 : 2.0,
      position
    );

  } else if (app.android) {
    switch (toastObject.position) {
      case POSITION.TOP:
        position = android.view.Gravity.TOP;
        break;
      case POSITION.CENTER:
        position = android.view.Gravity.CENTER;
        break;
      default:
        position = android.view.Gravity.BOTTOM; //default position = bottom
    }
    var toast = android.widget.Toast.makeText(
      app.android.context,
      toastObject.text,
      toastObject.duration === DURATION.LONG ? android.widget.Toast.LENGTH_LONG : android.widget.Toast.LENGTH_SHORT
    );
    toast.setGravity(position, 0, 0);
    toast.show();
  }
};