ValuePropertyAdapter.java

package fr.lteconsulting.hexa.databinding.gwt.propertyadapters;

import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.user.client.ui.HasValue;

import fr.lteconsulting.hexa.client.tools.Action2;
import fr.lteconsulting.hexa.databinding.propertyadapters.PropertyAdapter;

/**
 * A PropertyAdapter implementation that works with a target
 * implementing the HasValue interface.
 *
 * Typically, this will be a Widget, like a TextBox for example,
 * that will receive and notify its changes
 * 
 * @author Arnaud Tournier
 */
public class ValuePropertyAdapter implements PropertyAdapter, ValueChangeHandler<Object>
{
	HasValue<Object> hasValue;

	Action2<PropertyAdapter, Object> callback;
	Object cookie;

	@SuppressWarnings( "unchecked" )
	public ValuePropertyAdapter(HasValue<?> hasValue)
	{
		this.hasValue = (HasValue<Object>) hasValue;
	}

	@Override
	public Object registerPropertyChanged( Action2<PropertyAdapter, Object> callback, Object cookie )
	{
		this.callback = callback;
		this.cookie = cookie;

		return hasValue.addValueChangeHandler( this );
	}

	@Override
	public void onValueChange( ValueChangeEvent<Object> event )
	{
		if( callback != null )
			callback.exec( this, cookie );
	}

	@Override
	public Object getValue()
	{
		return hasValue.getValue();
	}

	@Override
	public void setValue( Object object )
	{
		hasValue.setValue( object, true );
	}

	@Override
	public void removePropertyChangedHandler( Object handler )
	{
		((HandlerRegistration) handler).removeHandler();
	}
}