MyViewController.java

package com.some.ios;

import org.robovm.apple.coregraphics.CGRect;
import org.robovm.apple.foundation.NSIndexPath;
import org.robovm.apple.uikit.*;


public class MyViewController extends UIViewController {

    private final UIButton button;
    private final UILabel label;
    private final UICollectionView collectionView;
    private final UICollectionViewDataSource dataSource;

    public MyViewController() {

        // Get the view of this view controller.
        UIView view = getView();

        // Setup background.
        view.setBackgroundColor(UIColor.white());

        // Setup label.
        label = new UILabel(new CGRect(10, 100, 300, 100));
        label.setFont(UIFont.getSystemFont(24));
        label.setTextAlignment(NSTextAlignment.Center);
        label.setNumberOfLines(2);
        view.addSubview(label);

        // Setup button.
        button = UIButton.create(UIButtonType.RoundedRect);
        button.setFrame(new CGRect(110, 50, 100, 40));
        button.setTitle("Start test", UIControlState.Normal);
        button.getTitleLabel().setFont(UIFont.getBoldSystemFont(22));

        button.addOnTouchUpInsideListener(new UIControl.OnTouchUpInsideListener() {
            @Override
            public void onTouchUpInside (UIControl control, UIEvent event) {
               
                 //...doing smth
              
            }
        });
        view.addSubview(button);


        collectionView = new UICollectionView(new CGRect(10, 215, 300, 250),
                           new UICollectionViewFlowLayout());
        dataSource = new UICollectionViewDataSource() {
            @Override
            public long getNumberOfItemsInSection(UICollectionView collectionView, long section) {
                return 5;
            }

            @Override
            public UICollectionViewCell getCellForItem(UICollectionView collectionView, NSIndexPath indexPath) {
                return null;
            }

            @Override
            public long getNumberOfSections(UICollectionView collectionView) {
                return 0;
            }

            @Override
            public UICollectionReusableView getViewForSupplementaryElement(UICollectionView collectionView, String kind, NSIndexPath indexPath) {
                return null;
            }
        };
        collectionView.setDataSource(dataSource);
        view.addSubview(collectionView);


    }
}