NativeScript/e2e/ui-tests-app/app/action-bar/action-item-position-page.ts

import { EventData } from "tns-core-modules/data/observable";
import { Page } from "tns-core-modules/ui/page";
import * as observable from "tns-core-modules/data/observable";

export function navigatingTo(args: EventData) {
    let page = <Page>args.object;
    page.bindingContext = new ActionItemPostitionView();
}

export class ActionItemPostitionView extends observable.Observable {
    private _values = ["-i---", "---i---", "---i-"];
    private _count: number;
    private _text: string;

    constructor() {
        super();
        this._count = 0;
    }

    get text(): string {
        return this._text;
    }

    set text(value: string) {
        if (this._text !== value) {
            this._text = value;
            this.notifyPropertyChange("text", value);
        }
    }

    public onTap() {
        this.change();
    }

    public change() {
        let index = this._count++ % 3;
        this.text = this._values[index];
    }
}