NativeScript/apps/app/ui-tests-app/css/text-decoration.ts

import { EventData, TextBase, TextDecoration } from "ui/text-base";

const possibleValues = [
    TextDecoration.NONE, 
    TextDecoration.UNDERLINE, 
    TextDecoration.LINE_THROUGH, 
    TextDecoration.UNDERLINE_LINE_THROUGH
];

export function butonTap(args: EventData) {
    let page = (<TextBase>args.object).page;
    let lbl = <TextBase>page.getViewById("Label");
    let btn = <TextBase>page.getViewById("Button");
    let textField = <TextBase>page.getViewById("TextField");
    let textView = <TextBase>page.getViewById("TextView");
    
    let currentIndex = possibleValues.indexOf(lbl.textDecoration);
    let newIndex = (currentIndex + 1) % possibleValues.length;
    let newValue = <TextDecoration>possibleValues[newIndex];
    
    lbl.textDecoration = newValue;
    btn.textDecoration = newValue;
    textField.textDecoration = newValue;
    textView.textDecoration = newValue;

    if(lbl.text === "Change text") {
        lbl.text = btn.text = textField.text = textView.text = "Text changed";
    } else {
        lbl.text = btn.text = textField.text = textView.text = "Change text";
    }
}