EventActivity

//Below the class
private int currentIndex = 0;

//On button Click

currentIndex++;
EventItem currentItem = EventAdapter.getItem(currentIndex);
drawItem(currentItem);


//drawItem

nameTextView.setText(currentItem.name);
loadImage(currentItem.imageUrl, imageView);
// list goes on...

EventAdapter.java

public class EventAdapter {
  private ArrayList<EventItem> eventList;
  
  public EventAdapter(ArrayList<EventItem> eventList) {
    this.eventList = eventList;
  }
  
  public EventItem getItem(int i) {
    return eventList.get(i);
  }
  
  public void mark(boolean isYes, int i) {
    getItem(i).isYes = isYes;
  }
}

EventItem.java

public class EventItem {
  private String name;
  private String imageUrl;
  // Other fields
  private boolean isYes;
  
  //Getters and setters...
  
}