Java tutorial
/* * Copyright (c) 2010-2013 Evolveum * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.evolveum.midpoint.web.component; import org.apache.commons.lang.Validate; import org.apache.wicket.markup.html.form.DropDownChoice; import org.apache.wicket.markup.html.form.IChoiceRenderer; import org.apache.wicket.model.AbstractReadOnlyModel; import org.apache.wicket.model.IModel; import org.apache.wicket.model.Model; import org.apache.wicket.model.StringResourceModel; import java.util.ArrayList; import java.util.List; import java.util.concurrent.Callable; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.Future; /** * @author lazyman */ public class GuiComponents { private static ExecutorService EXECUTOR; private static final String KEY_BOOLEAN_NULL = "Boolean.NULL"; private static final String KEY_BOOLEAN_TRUE = "Boolean.TRUE"; private static final String KEY_BOOLEAN_FALSE = "Boolean.FALSE"; public static void destroy() { EXECUTOR.shutdownNow(); } public static void init() { EXECUTOR = Executors.newFixedThreadPool(10); } public static <T> Future<T> submitCallable(Callable<T> callable) { Validate.notNull(callable, "Callable must not be null."); return EXECUTOR.submit(callable); } public static DropDownChoice createTriStateCombo(String id, IModel<Boolean> model) { final IChoiceRenderer renderer = new IChoiceRenderer() { @Override public Object getDisplayValue(Object object) { String key; if (object == null) { key = KEY_BOOLEAN_NULL; } else { Boolean b = (Boolean) object; key = b ? KEY_BOOLEAN_TRUE : KEY_BOOLEAN_FALSE; } StringResourceModel model = new StringResourceModel(key, new Model<String>(), key); return model.getString(); } @Override public String getIdValue(Object object, int index) { return Integer.toString(index); } }; DropDownChoice dropDown = new DropDownChoice(id, model, createChoices(), renderer) { @Override protected CharSequence getDefaultChoice(String selectedValue) { StringResourceModel model = new StringResourceModel(KEY_BOOLEAN_NULL, new Model<String>(), KEY_BOOLEAN_NULL); return model.getString(); } }; dropDown.setNullValid(true); return dropDown; } private static IModel<List<Boolean>> createChoices() { return new AbstractReadOnlyModel<List<Boolean>>() { @Override public List<Boolean> getObject() { List<Boolean> list = new ArrayList<Boolean>(); list.add(null); list.add(Boolean.TRUE); list.add(Boolean.FALSE); return list; } }; } }