AValueControl.java

package fr.lteconsulting.hexa.client.interfaces;

import com.google.gwt.user.client.ui.Composite;

public abstract class AValueControl<T> extends Composite implements IValueControl<T>
{
	@Override
	public void addCallback( Callback<T> callback, Object cookie ) // throws
																	// Exception
	{
		assert (this.callback == null);
		// if( this.callback != null )
		// throw new Exception(
		// "AValueControl::addCallback has been called but a callback was already set !"
		// );

		this.callback = callback;
		this.cookie = cookie;
	}

	@Override
	public abstract void setValue( T value );

	@Override
	public abstract T getValue();

	private Callback<T> callback = null;
	private Object cookie = null;

	protected void signalCallbacks()
	{
		if( callback == null )
			return;

		callback.onValueControlChange( cookie );
	}
}