FilterSelectionListener.java

package org.sigmah.client.ui.view.project.dashboard;

/*
 * #%L
 * Sigmah
 * %%
 * Copyright (C) 2010 - 2016 URD
 * %%
 * This program 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 3 of the
 * License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but 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.
 * 
 * You should have received a copy of the GNU General Public
 * License along with this program.  If not, see
 * <http://www.gnu.org/licenses/gpl-3.0.html>.
 * #L%
 */

import org.sigmah.shared.dto.base.AbstractModelDataEntityDTO;

import com.extjs.gxt.ui.client.store.Store;
import com.extjs.gxt.ui.client.store.StoreFilter;
import com.extjs.gxt.ui.client.widget.menu.MenuItem;

/**
 * Define a listener to apply a one filter at a time and manage the menu item state.
 * 
 * @author Tom Miette
 * @author Denis Colliot (dcolliot@ideia.fr)
 * @param <E>
 *          Store model type.
 */
final class FilterSelectionListener<E extends AbstractModelDataEntityDTO<?>> {

	private final Store<E> store;
	private MenuItem currentItem;
	private StoreFilter<E> currentFilter;

	public FilterSelectionListener(final Store<E> store) {
		this.store = store;
	}

	public void filter(final MenuItem item, final StoreFilter<E> filter) {
		activate();
		currentItem = item;
		filter(filter);
		desactivate();
	}

	private void activate() {
		if (currentItem != null) {
			currentItem.setEnabled(true);
		}
	}

	private void desactivate() {
		if (currentItem != null) {
			currentItem.setEnabled(false);
		}
	}

	private void filter(final StoreFilter<E> filter) {

		if (store == null) {
			return;
		}

		store.removeFilter(currentFilter);

		if (filter != null) {
			store.addFilter(filter);
		}

		store.applyFilters(null);
		currentFilter = filter;
	}

}