Java tutorial
/* * Copyright 2017 Red Hat, Inc. and/or its affiliates. * * 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 org.kie.workbench.common.stunner.standalone.client.widgets; import java.util.List; import javax.annotation.PostConstruct; import javax.enterprise.context.Dependent; import javax.inject.Inject; import com.google.gwt.cell.client.Cell; import com.google.gwt.cell.client.TextCell; import com.google.gwt.user.cellview.client.ColumnSortEvent; import com.google.gwt.user.client.ui.IsWidget; import com.google.gwt.user.client.ui.Widget; import com.google.gwt.view.client.HasData; import com.google.gwt.view.client.ListDataProvider; import com.google.gwt.view.client.ProvidesKey; import org.kie.workbench.common.stunner.client.widgets.notification.Notification; import org.kie.workbench.common.stunner.client.widgets.notification.NotificationsObserver; import org.uberfire.client.mvp.UberView; @Dependent public class Notifications implements IsWidget { public interface View extends UberView<Notifications> { View setColumnSortHandler(final ColumnSortEvent.ListHandler<Notification> sortHandler); View addColumn(final com.google.gwt.user.cellview.client.Column<Notification, String> column, final String name); View removeColumn(final int index); int getColumnCount(); View redraw(); View clear(); } private final View view; private final NotificationsObserver notificationsObserver; final ListDataProvider<Notification> logsProvider = new ListDataProvider<Notification>(); private boolean notifyErrors = true; @Inject public Notifications(final View view, final NotificationsObserver notificationsObserver) { this.view = view; this.notificationsObserver = notificationsObserver; } @PostConstruct public void init() { view.init(this); notificationsObserver.onNotification(this::add); buildViewColumns(); } public void setNotifyErrors(boolean notifyErrors) { this.notifyErrors = notifyErrors; } @Override public Widget asWidget() { return view.asWidget(); } public void add(final Notification notification) { if (null != notification) { addLogEntry(notification); view.redraw(); } } public void clear() { logsProvider.getList().clear(); view.clear(); } /* ****************************************************************************************************** VIEW CALLBACKS ****************************************************************************************************** */ final ProvidesKey<Notification> KEY_PROVIDER = item -> item == null ? null : item.hashCode(); /** * View callback for getting the list. */ void addDataDisplay(final HasData<Notification> display) { logsProvider.addDataDisplay(display); } protected void buildViewColumns() { int columnCount = view.getColumnCount(); while (columnCount > 0) { view.removeColumn(0); columnCount = view.getColumnCount(); } // Attach a column sort handler to the ListDataProvider to sort the list. ColumnSortEvent.ListHandler<Notification> sortHandler = new ColumnSortEvent.ListHandler<Notification>( logsProvider.getList()); view.setColumnSortHandler(sortHandler); // Log's type. final com.google.gwt.user.cellview.client.Column<Notification, String> typeColumn = createTypeColumn( sortHandler); if (typeColumn != null) { view.addColumn(typeColumn, "Type"); } // Log element's UUID. final com.google.gwt.user.cellview.client.Column<Notification, String> contextColumn = createContextColumn( sortHandler); if (contextColumn != null) { view.addColumn(contextColumn, "Context"); } // Log's message. final com.google.gwt.user.cellview.client.Column<Notification, String> messageColumn = createMessageColumn( sortHandler); if (messageColumn != null) { view.addColumn(messageColumn, "Message"); } } private void addLogEntry(final Notification entry) { List<Notification> logs = logsProvider.getList(); logs.remove(entry); logs.add(entry); } private com.google.gwt.user.cellview.client.Column<Notification, String> createTypeColumn( ColumnSortEvent.ListHandler<Notification> sortHandler) { // Log type.. final Cell<String> typeCell = new TextCell(); final com.google.gwt.user.cellview.client.Column<Notification, String> typeColumn = new com.google.gwt.user.cellview.client.Column<Notification, String>( typeCell) { @Override public String getValue(final Notification object) { return getNotificationTypeMessage(object); } }; typeColumn.setSortable(true); sortHandler.setComparator(typeColumn, (o1, o2) -> o1.getType().compareTo(o2.getType())); return typeColumn; } private com.google.gwt.user.cellview.client.Column<Notification, String> createContextColumn( ColumnSortEvent.ListHandler<Notification> sortHandler) { // Log element's context. final Cell<String> contextCell = new TextCell(); final com.google.gwt.user.cellview.client.Column<Notification, String> contextColumn = new com.google.gwt.user.cellview.client.Column<Notification, String>( contextCell) { @Override public String getValue(final Notification object) { return getNotificationContextMessage(object); } }; contextColumn.setSortable(false); return contextColumn; } private com.google.gwt.user.cellview.client.Column<Notification, String> createMessageColumn( ColumnSortEvent.ListHandler<Notification> sortHandler) { // Log message. final Cell<String> messageCell = new TextCell(); final com.google.gwt.user.cellview.client.Column<Notification, String> messageColumn = new com.google.gwt.user.cellview.client.Column<Notification, String>( messageCell) { @Override public String getValue(final Notification object) { return getNotificationSourceMessage(object); } }; messageColumn.setSortable(false); return messageColumn; } @SuppressWarnings("unchecked") private String getNotificationSourceMessage(final Notification notification) { return notification.getSource().isPresent() ? notification.getSource().toString() : "-- No source --"; } @SuppressWarnings("unchecked") private String getNotificationContextMessage(final Notification notification) { return notification.getContext() != null ? notification.getContext().toString() : "-- No context --"; } @SuppressWarnings("unchecked") private String getNotificationTypeMessage(final Notification notification) { return notification.getType() != null ? notification.getType().name() : "-- No type --"; } }