BadaboomCollector.java

/*
 * This file is part of LaTeXDraw.
 * Copyright (c) 2005-2017 Arnaud BLOUIN
 * LaTeXDraw is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation; either version 2 of the License, or (at your option) any later version.
 * LaTeXDraw is distributed without any warranty; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 */
package net.sf.latexdraw.badaboom;

import java.lang.Thread.UncaughtExceptionHandler;
import java.util.ArrayList;
import java.util.List;
import javafx.concurrent.WorkerStateEvent;
import javafx.event.EventHandler;
import org.eclipse.jdt.annotation.NonNull;
import org.malai.error.ErrorCatcher;
import org.malai.error.ErrorNotifier;

/**
 * Defines an error collector.
 * @author Arnaud BLOUIN
 * @since 3.0
 */
public final class BadaboomCollector extends ArrayList<Throwable> implements UncaughtExceptionHandler, ErrorNotifier, EventHandler<WorkerStateEvent> {
	private static final long serialVersionUID = 1L;

	/** The singleton. */
	public static final BadaboomCollector INSTANCE = new BadaboomCollector();


	/** Contains objects that want to be aware of the manager activities. */
	private final List<BadaboomHandler> handlers;


	/**
	 * Creates an empty collector.
	 */
	private BadaboomCollector() {
		super();
		handlers = new ArrayList<>();
		ErrorCatcher.INSTANCE.setNotifier(this);
	}


	/**
	 * Adds a handler to the manager.
	 * @param handler The handler to add. Must not be null.
	 * @since 3.0
	 */
	public void addHandler(final @NonNull BadaboomHandler handler) {
		synchronized(handlers){ handlers.add(handler); }

		// If there is events, the handler is notified.
		synchronized(INSTANCE){
			if(!INSTANCE.isEmpty())
				handler.notifyEvents();
		}
	}

	/**
	 * Notifies the handlers that an event occurred.
	 * @since 3.0
	 */
	private void notifyHandlers(final @NonNull Throwable error) {
		synchronized(handlers){
			for(final BadaboomHandler handler : handlers)
				handler.notifyEvent(error);
		}
	}


	@Override
	public boolean add(final Throwable ex) {
		synchronized(INSTANCE){
			if(ex==null || !super.add(ex))
				return false;
		}
		ex.printStackTrace();
		notifyHandlers(ex);
		return true;
	}


	@Override
	public Throwable set(final int pos, final Throwable ex) {
		synchronized(INSTANCE){
			if(ex==null || super.set(pos, ex)==null)
				return null;
		}

		ex.printStackTrace();
		notifyHandlers(ex);
		return ex;
	}


	@Override
	public void add(final int index, final Throwable ex) {
		synchronized(INSTANCE){
			if(ex!=null) {
				super.add(index, ex);
				ex.printStackTrace();
				notifyHandlers(ex);
			}
		}
	}


	@Override
	public void uncaughtException(final Thread thread, final Throwable trowable) {
		add(trowable);
	}


	@Override
	public void onException(final Exception exception) {
		add(exception);
	}


	@Override
	public void handle(final WorkerStateEvent evt) {
		add(evt.getSource().getException());
	}
}