| /* |
| * Copyright (c) 2011, 2021 Oracle and/or its affiliates. All rights reserved. |
| * |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Public License v. 2.0 which is available at |
| * http://www.eclipse.org/legal/epl-2.0, |
| * or the Eclipse Distribution License v. 1.0 which is available at |
| * http://www.eclipse.org/org/documents/edl-v10.php. |
| * |
| * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause |
| */ |
| |
| // Contributors: |
| // Oracle - initial API and implementation |
| // |
| package org.eclipse.persistence.jpa.jpql.tools.model.query; |
| |
| import java.io.IOException; |
| import java.util.List; |
| import org.eclipse.persistence.jpa.jpql.parser.EmptyCollectionComparisonExpression; |
| import static org.eclipse.persistence.jpa.jpql.parser.AbstractExpression.*; |
| |
| /** |
| * This expression tests whether or not the collection designated by the collection-valued path |
| * expression is empty (i.e, has no elements). |
| * |
| * <div><p><b>BNF:</b> <code>empty_collection_comparison_expression ::= collection_valued_path_expression IS [NOT] EMPTY</code></p></div> |
| * |
| * @see EmptyCollectionComparisonExpression |
| * |
| * @version 2.4 |
| * @since 2.4 |
| * @author Pascal Filion |
| */ |
| @SuppressWarnings({"nls", "unused"}) // unused used for the import statement: see bug 330740 |
| public class EmptyCollectionComparisonExpressionStateObject extends AbstractStateObject { |
| |
| /** |
| * Determines whether the <code><b>NOT</b></code> identifier is part of the expression or not. |
| */ |
| private boolean not; |
| |
| /** |
| * The {@link StateObject} representing the collection-valued path expression. |
| */ |
| private CollectionValuedPathExpressionStateObject stateObject; |
| |
| /** |
| * Notifies the visibility of the <code><b>NOT</b></code> identifier has changed. |
| */ |
| public static final String NOT_PROPERTY = "not"; |
| |
| /** |
| * Creates a new <code>EmptyCollectionComparisonExpressionStateObject</code>. |
| * |
| * @param parent The parent of this state object, which cannot be <code>null</code> |
| * @exception NullPointerException The given parent cannot be <code>null</code> |
| */ |
| public EmptyCollectionComparisonExpressionStateObject(StateObject parent) { |
| super(parent); |
| } |
| |
| /** |
| * Creates a new <code>EmptyCollectionComparisonExpressionStateObject</code>. |
| * |
| * @param parent The parent of this state object, which cannot be <code>null</code> |
| * @param not Determines whether the <code><b>NOT</b></code> identifier is part of the expression |
| * or not |
| * @param path The collection-valued path expression |
| * @exception NullPointerException The given parent cannot be <code>null</code> |
| */ |
| public EmptyCollectionComparisonExpressionStateObject(StateObject parent, |
| boolean not, |
| String path) { |
| |
| super(parent); |
| this.not = not; |
| this.stateObject.setPath(path); |
| } |
| |
| /** |
| * Creates a new <code>EmptyCollectionComparisonExpressionStateObject</code>. |
| * |
| * @param parent The parent of this state object, which cannot be <code>null</code> |
| * @param path The collection-valued path expression |
| * @exception NullPointerException The given parent cannot be <code>null</code> |
| */ |
| public EmptyCollectionComparisonExpressionStateObject(StateObject parent, String path) { |
| this(parent, false, path); |
| } |
| |
| @Override |
| public void accept(StateObjectVisitor visitor) { |
| visitor.visit(this); |
| } |
| |
| @Override |
| protected void addChildren(List<StateObject> children) { |
| super.addChildren(children); |
| children.add(stateObject); |
| } |
| |
| /** |
| * Makes sure the <code><b>NOT</b></code> identifier is specified. |
| * |
| * @return This object |
| */ |
| public EmptyCollectionComparisonExpressionStateObject addNot() { |
| if (!not) { |
| setNot(true); |
| } |
| return this; |
| } |
| |
| @Override |
| public EmptyCollectionComparisonExpression getExpression() { |
| return (EmptyCollectionComparisonExpression) super.getExpression(); |
| } |
| |
| /** |
| * Returns the {@link CollectionValuedPathExpressionStateObject} representing the collection- |
| * valued path expression. |
| * |
| * @return The {@link CollectionValuedPathExpressionStateObject} representing the collection- |
| * valued path expression, which is never <code>null</code> |
| */ |
| public CollectionValuedPathExpressionStateObject getStateObject() { |
| return stateObject; |
| } |
| |
| /** |
| * Determines whether the <code><b>NOT</b></code> identifier is used or not. |
| * |
| * @return <code>true</code> if the <code><b>NOT</b></code> identifier is part of the expression; |
| * <code>false</code> otherwise |
| */ |
| public boolean hasNot() { |
| return not; |
| } |
| |
| @Override |
| protected void initialize() { |
| super.initialize(); |
| stateObject = new CollectionValuedPathExpressionStateObject(this); |
| } |
| |
| @Override |
| public boolean isEquivalent(StateObject stateObject) { |
| |
| if (super.isEquivalent(stateObject)) { |
| EmptyCollectionComparisonExpressionStateObject collection = (EmptyCollectionComparisonExpressionStateObject) stateObject; |
| return not == collection.not && |
| stateObject.isEquivalent(collection.stateObject); |
| } |
| |
| return false; |
| } |
| |
| /** |
| * Makes sure the <code><b>NOT</b></code> identifier is not specified. |
| */ |
| public void removeNot() { |
| if (not) { |
| setNot(false); |
| } |
| } |
| |
| /** |
| * Keeps a reference of the {@link EmptyCollectionComparisonExpression parsed object} object, |
| * which should only be done when this object is instantiated during the conversion of a parsed |
| * JPQL query into {@link StateObject StateObjects}. |
| * |
| * @param expression The {@link EmptyCollectionComparisonExpression parsed object} representing |
| * an <code><b>EMPTY</b></code> expression |
| */ |
| public void setExpression(EmptyCollectionComparisonExpression expression) { |
| super.setExpression(expression); |
| } |
| |
| /** |
| * Sets whether the <code><b>NOT</b></code> identifier should be part of the expression or not. |
| * |
| * @param not <code>true</code> if the <code><b>NOT</b></code> identifier should be part of the |
| * expression; <code>false</code> otherwise |
| */ |
| public void setNot(boolean not) { |
| boolean oldNot = this.not; |
| this.not = not; |
| firePropertyChanged(NOT_PROPERTY, oldNot, not); |
| } |
| |
| /** |
| * Changes the visibility state of the <code><b>NOT</b></code> identifier. |
| */ |
| public void toggleNot() { |
| setNot(!not); |
| } |
| |
| @Override |
| protected void toTextInternal(Appendable writer) throws IOException { |
| |
| stateObject.toString(writer); |
| writer.append(SPACE); |
| |
| if (not) { |
| writer.append(IS_NOT_EMPTY); |
| } |
| else { |
| writer.append(IS_EMPTY); |
| } |
| } |
| } |