Java tutorial
/* * Copyright 2010 The gwtquery plugins team. * * 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 gwtquery.plugins.droppable.client.gwt; import static com.google.gwt.query.client.GQuery.$; import static gwtquery.plugins.draggable.client.Draggable.Draggable; import static gwtquery.plugins.droppable.client.Droppable.Droppable; import com.google.gwt.dom.client.Element; import com.google.gwt.event.shared.EventBus; import com.google.gwt.query.client.GQuery; import gwtquery.plugins.draggable.client.DraggableHandler; import gwtquery.plugins.draggable.client.DraggableOptions; import gwtquery.plugins.droppable.client.DroppableHandler; import gwtquery.plugins.droppable.client.DroppableOptions; /** * Utils class with all code used in CellWidget to manage * the drag and drop behavior of cells * * @author Julien Dramaix (julien.dramaix@gmail.com) * */ public class DragAndDropCellWidgetUtils { public static final String VALUE_KEY = "__dragAndDropCellAssociatedValue"; private static final DragAndDropCellWidgetUtils INSTANCE = new DragAndDropCellWidgetUtils(); static DragAndDropCellWidgetUtils get() { return INSTANCE; } private DragAndDropCellWidgetUtils() { } void cleanCell(Element cell) { if (cell == null) { return; } GQuery $cell = $(cell); if (DraggableHandler.getInstance(cell) != null) { $cell.as(Draggable).destroy(); } if (DroppableHandler.getInstance(cell) != null) { $cell.as(Droppable).destroy(); } $cell.removeData(VALUE_KEY); } <C> void maybeMakeDraggableOrDroppable(Element cell, C value, CellDragAndDropBehaviour<C> cellDragAndDropBehaviour, DraggableOptions draggableOptions, DroppableOptions droppableOptions, EventBus eventBus) { GQuery $cell = $(cell); if ((cellDragAndDropBehaviour == null || cellDragAndDropBehaviour.isDraggable(value)) && DraggableHandler.getInstance(cell) == null) { $cell.as(Draggable).draggable(draggableOptions, eventBus); } if ((cellDragAndDropBehaviour == null || cellDragAndDropBehaviour.isDroppable(value)) && DroppableHandler.getInstance(cell) == null) { $cell.as(Droppable).droppable(droppableOptions, eventBus); } $cell.data(VALUE_KEY, value); } }