ActiveList.java :  » RSS » androidnews » vn » evolus » droidreader » util » Android Open Source

package vn.evolus.droidreader.util;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

public class ActiveList<T> extends ArrayList<T> implements Serializable {
  private static final long serialVersionUID = -2676879815793179223L;  
  transient private List<ActiveListListener<T>> listeners;
  
  public interface ActiveListListener<T> {
    void onAdd(T item);
    void onInsert(int location, T item);
    void onClear();
  }    
  
  public synchronized void clear() {
    super.clear();
    fireChangedEvent();
  }
  
  public synchronized int size() {
    return super.size();
  }
  
  public synchronized T get(int index) {
    return super.get(index);
  }
  
  public synchronized boolean add(T item) {
    boolean success = super.add(item);
    if (success) {
      fireAddEvent(item);
    }
    return success;
  }
  
  public synchronized void add(int location, T item) {
    super.add(location, item);    
    fireInsertEvent(location, item);    
  }
  
  public synchronized void addListener(ActiveListListener<T> listener) {
    if (this.listeners == null) {
      listeners = new ArrayList<ActiveListListener<T>>();
    }
    this.listeners.add(listener);
  }  
  public synchronized void removeListener(ActiveListListener<T> listener) {
    if (this.listeners != null) {
      this.listeners.remove(listener);
    }
  }
  
  private void fireChangedEvent() {
    if (this.listeners == null) return;
    for (ActiveListListener<T> listener : listeners) {
      listener.onClear();
    }
  }
  
  private void fireInsertEvent(int location, T item) {
    if (this.listeners == null) return;    
    for (ActiveListListener<T> listener : listeners) {
      listener.onInsert(location, item);
    }
  }
  
  private void fireAddEvent(T item) {
    if (this.listeners == null) return;    
    for (ActiveListListener<T> listener : listeners) {
      listener.onAdd(item);
    }
  }
}