Helper class for simple execution of tasks on the UI thread.

UiWorker.java

/**
 * @copyright
 * This code is licensed under the Rekisoft Public License.
 * See http://www.rekisoft.eu/licenses/rkspl.html for more informations.
 */
package eu.rekisoft.android.util;

import android.os.Handler;
import android.os.Looper;

/**
 * Helper class for simple changing UI elements. If this object is created in UI thread the job will be executed immediately, if not the job
 * will be executed on the UI thread delayed.
 * 
 * @author rekire
 * @version 0.8
 * @copyright This code is licensed under the Rekisoft Public License.<br/>
 *            See http://www.rekisoft.eu/licenses/rkspl.html for more informations.
 */
public abstract class UiWorker<T> extends Handler implements Runnable {
	private final boolean isCritical;
	private T data;
	/**
	 * Creates a new UiWoker with the default priority.
	 */
	public UiWorker() {
		this(null, false, true);
	}

	/**
	 * Creates a new UiWoker with the ability to make this job critical.
	 * 
	 * @param isCritical
	 *            true if this job is critical.
	 */
	public UiWorker(boolean isCritical) {
		this(null, isCritical, true);
	}

	/**
	 * Creates a new UiWoker with the default priority and data.
	 * 
	 * @param data
	 *            The data which should be injected to doWork().
	 */
	public UiWorker(T data) {
		this(data, false, true);
	}

	/**
	 * Creates a new UiWoker with the ability to make this job critical and data.
	 * 
	 * @param data
	 *            The data which should be injected to doWork().
	 * @param isCritical
	 *            true if this job is critical.
	 */
	public UiWorker(T data, boolean isCritical) {
		this(null, isCritical, true);
	}

	/**
	 * Base for extension of this UiWorker, you can control if the execution should been done immediately or not.
	 * 
	 * @param data
	 *            The data which should been used in doWork(data).
	 * @param isCritical
	 *            true if this job is critical.
	 * @param runNow
	 *            should been executed right now in the constructor.
	 */
	protected UiWorker(T data, boolean isCritical, boolean runNow) {
		super(Looper.getMainLooper());
		this.isCritical = isCritical;
		this.data = data;
		if(runNow) {
			run();
		}
	}

	/**
	 * Executes the task on the Ui Thread.
	 */
	@Override
	public final void run() {
		if(Thread.currentThread().getId() == getLooper().getThread().getId()) {
			doWork(data);
		} else {
			if(isCritical && postAtFrontOfQueue(this)) {
				return;
			}
			post(this);
		}
	}

	/**
	 * This method is invoked on the UI Thread.
	 * 
	 * @param data
	 *            The data you defined in the constructor of this class.
	 */
	protected abstract void doWork(T data);
}