package org.csstudio.sds.eventhandling;

import org.csstudio.sds.model.AbstractWidgetModel;
import org.csstudio.sds.model.commands.HidePropertyCommand;
import org.csstudio.sds.model.commands.ShowPropertyCommand;
import org.eclipse.gef.commands.Command;
import org.eclipse.gef.commands.CompoundCommand;

/**
 * Convinience class for the implementation of {@link AbstractWidgetPropertyPostProcessor}s.
 * The command shows or hides the specified properties ({@link AbstractEnsureInvariantsCommand#getPropertyIds()}) depending 
 * on the specified condition {@link AbstractEnsureInvariantsCommand#shouldHideProperties(AbstractWidgetModel, String)}.
 * @author Kai Meyer (C1 WPS)
 *
 * @param <M>
 */
public abstract class AbstractEnsureInvariantsCommand<M extends AbstractWidgetModel> extends Command {
	private String _propertyId;
	private CompoundCommand chain;
	private M _widget;

	public AbstractEnsureInvariantsCommand(M widget,
			String propertyId) {
		_widget = widget;
		_propertyId = propertyId;
	}

	@Override
	public void execute() {
		if (chain == null) {
			chain = new CompoundCommand();

			String[] propertyIds = getPropertyIds();

			if (shouldHideProperties(_widget, _propertyId)) {
				for (String propertyId : propertyIds) {
					chain.add(new HidePropertyCommand(_widget, propertyId, _propertyId));
				}
			} else {
				for (String propertyId : propertyIds) {
					chain.add(new ShowPropertyCommand(_widget, propertyId, _propertyId));
				}
			}
		}

		chain.execute();
	}

	@Override
	public void undo() {
		chain.undo();
	}
	
	protected abstract String[] getPropertyIds();
	protected abstract boolean shouldHideProperties(M widget, String propertyId);
}