Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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 org.apache.isis.viewer.wicket.ui.components.widgets; import java.util.Collection; import java.util.List; import java.util.Locale; import com.google.common.base.Function; import com.google.common.collect.Collections2; import com.google.common.collect.Lists; import org.wicketstuff.select2.TextChoiceProvider; import org.apache.wicket.Session; import org.apache.wicket.util.convert.IConverter; import org.apache.wicket.util.string.Strings; import org.apache.isis.core.metamodel.adapter.ObjectAdapter; import org.apache.isis.core.metamodel.adapter.mgr.AdapterManager.ConcurrencyChecking; import org.apache.isis.core.metamodel.adapter.oid.RootOid; import org.apache.isis.viewer.wicket.model.isis.WicketViewerSettings; import org.apache.isis.viewer.wicket.model.mementos.ObjectAdapterMemento; import org.apache.isis.viewer.wicket.model.models.ScalarModel; import org.apache.isis.viewer.wicket.ui.components.scalars.IsisConverterLocator; public abstract class ObjectAdapterMementoProviderAbstract extends TextChoiceProvider<ObjectAdapterMemento> { private static final long serialVersionUID = 1L; protected static final String NULL_PLACEHOLDER = "$$_isis_null_$$"; private static final String NULL_DISPLAY_TEXT = ""; private final ScalarModel scalarModel; private final WicketViewerSettings wicketViewerSettings; public ObjectAdapterMementoProviderAbstract(final ScalarModel scalarModel, final WicketViewerSettings wicketViewerSettings) { this.scalarModel = scalarModel; this.wicketViewerSettings = wicketViewerSettings; } @Override protected String getDisplayText(final ObjectAdapterMemento choice) { if (choice == null) { return NULL_DISPLAY_TEXT; } final ObjectAdapter objectAdapter = choice.getObjectAdapter(ConcurrencyChecking.NO_CHECK); final IConverter<Object> converter = findConverter(objectAdapter); return converter != null ? converter.convertToString(objectAdapter.getObject(), getLocale()) : objectAdapter.titleString(null); } protected Locale getLocale() { return Session.exists() ? Session.get().getLocale() : Locale.ENGLISH; } protected IConverter<Object> findConverter(final ObjectAdapter objectAdapter) { return IsisConverterLocator.findConverter(objectAdapter, wicketViewerSettings); } @Override protected Object getId(final ObjectAdapterMemento choice) { return choice != null ? choice.asString() : NULL_PLACEHOLDER; } @Override public void query(final String term, final int page, final org.wicketstuff.select2.Response<ObjectAdapterMemento> response) { final List<ObjectAdapterMemento> mementos = Lists.newArrayList(obtainMementos(term)); // if not mandatory, and the list doesn't contain null already, then add it in. if (!scalarModel.isRequired() && !mementos.contains(null)) { mementos.add(0, null); } response.addAll(mementos); } protected abstract List<ObjectAdapterMemento> obtainMementos(String term); /** * Filters all choices against a term by using their * {@link org.apache.isis.core.metamodel.adapter.ObjectAdapter#titleString(org.apache.isis.core.metamodel.adapter.ObjectAdapter) title string} * * @param term The term entered by the user * @param choicesMementos The collections of choices to filter * @return A list of all matching choices */ protected List<ObjectAdapterMemento> obtainMementos(String term, Collection<ObjectAdapterMemento> choicesMementos) { List<ObjectAdapterMemento> matches = Lists.newArrayList(); if (Strings.isEmpty(term)) { matches.addAll(choicesMementos); } else { for (ObjectAdapterMemento candidate : choicesMementos) { ObjectAdapter objectAdapter = candidate.getObjectAdapter(ConcurrencyChecking.NO_CHECK); String title = objectAdapter.titleString(objectAdapter); if (title.toLowerCase().contains(term.toLowerCase())) { matches.add(candidate); } } } return matches; } @Override public Collection<ObjectAdapterMemento> toChoices(final Collection<String> ids) { final Function<String, ObjectAdapterMemento> function = new Function<String, ObjectAdapterMemento>() { @Override public ObjectAdapterMemento apply(final String input) { if (NULL_PLACEHOLDER.equals(input)) { return null; } final RootOid oid = RootOid.deString(input, ObjectAdapterMemento.getOidMarshaller()); return ObjectAdapterMemento.createPersistent(oid); } }; return Collections2.transform(ids, function); } protected ScalarModel getScalarModel() { return scalarModel; } }