Java tutorial
/* * Copyright 2000-2018 Vaadin Ltd. * * 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.vaadin.client.ui.dd; import com.vaadin.client.UIDL; import com.vaadin.ui.dnd.DropTargetExtension; /** * * @author Vaadin Ltd * @deprecated Replaced in 8.1 with * {@link DropTargetExtension#setDropCriteria(String)} * */ @Deprecated public abstract class VAcceptCriterion { /** * Checks if current drag event has valid drop target and target accepts the * transferable. If drop target is valid, callback is used. * * @param drag * @param configuration * @param callback */ public void accept(final VDragEvent drag, UIDL configuration, final VAcceptCallback callback) { if (needsServerSideCheck(drag, configuration)) { VDragEventServerCallback acceptCallback = (accepted, response) -> { if (accepted) { callback.accepted(drag); } }; VDragAndDropManager.get().visitServer(acceptCallback); } else { boolean validates = accept(drag, configuration); if (validates) { callback.accepted(drag); } } } protected abstract boolean accept(VDragEvent drag, UIDL configuration); public boolean needsServerSideCheck(VDragEvent drag, UIDL criterioUIDL) { return false; } }