Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2013 IBM Corporation and others. * * This program and the accompanying materials * are made available under the terms of the Eclipse Public License 2.0 * which accompanies this distribution, and is available at * https://www.eclipse.org/legal/epl-2.0/ * * SPDX-License-Identifier: EPL-2.0 * * Contributors: * IBM Corporation - initial API and implementation *******************************************************************************/ package org.eclipse.jdt.core.dom; import java.util.ArrayList; import java.util.List; /** * Labeled statement AST node type. * * <pre> * LabeledStatement: * Identifier <b>:</b> Statement * </pre> * * @since 2.0 * @noinstantiate This class is not intended to be instantiated by clients. */ @SuppressWarnings("rawtypes") public class LabeledStatement extends Statement { /** * The "label" structural property of this node type (child type: {@link SimpleName}). * @since 3.0 */ public static final ChildPropertyDescriptor LABEL_PROPERTY = new ChildPropertyDescriptor(LabeledStatement.class, "label", SimpleName.class, MANDATORY, NO_CYCLE_RISK); //$NON-NLS-1$ /** * The "body" structural property of this node type (child type: {@link Statement}). * @since 3.0 */ public static final ChildPropertyDescriptor BODY_PROPERTY = new ChildPropertyDescriptor(LabeledStatement.class, "body", Statement.class, MANDATORY, CYCLE_RISK); //$NON-NLS-1$ /** * A list of property descriptors (element type: * {@link StructuralPropertyDescriptor}), * or null if uninitialized. */ private static final List PROPERTY_DESCRIPTORS; static { List propertyList = new ArrayList(3); createPropertyList(LabeledStatement.class, propertyList); addProperty(LABEL_PROPERTY, propertyList); addProperty(BODY_PROPERTY, propertyList); PROPERTY_DESCRIPTORS = reapPropertyList(propertyList); } /** * Returns a list of structural property descriptors for this node type. * Clients must not modify the result. * * @param apiLevel the API level; one of the * <code>AST.JLS*</code> constants * @return a list of property descriptors (element type: * {@link StructuralPropertyDescriptor}) * @since 3.0 */ public static List propertyDescriptors(int apiLevel) { return PROPERTY_DESCRIPTORS; } /** * The label; lazily initialized; defaults to a unspecified, * legal Java identifier. */ private SimpleName labelName = null; /** * The body statement; lazily initialized; defaults to an unspecified, but * legal, statement. */ private Statement body = null; /** * Creates a new AST node for a labeled statement owned by the given * AST. By default, the statement has an unspecified (but legal) label * and an unspecified (but legal) statement. * <p> * N.B. This constructor is package-private. * </p> * * @param ast the AST that is to own this node */ LabeledStatement(AST ast) { super(ast); } @Override final List internalStructuralPropertiesForType(int apiLevel) { return propertyDescriptors(apiLevel); } @Override final ASTNode internalGetSetChildProperty(ChildPropertyDescriptor property, boolean get, ASTNode child) { if (property == LABEL_PROPERTY) { if (get) { return getLabel(); } else { setLabel((SimpleName) child); return null; } } if (property == BODY_PROPERTY) { if (get) { return getBody(); } else { setBody((Statement) child); return null; } } // allow default implementation to flag the error return super.internalGetSetChildProperty(property, get, child); } @Override final int getNodeType0() { return LABELED_STATEMENT; } @Override ASTNode clone0(AST target) { LabeledStatement result = new LabeledStatement(target); result.setSourceRange(getStartPosition(), getLength()); result.setLabel((SimpleName) ASTNode.copySubtree(target, getLabel())); result.setBody((Statement) ASTNode.copySubtree(target, getBody())); return result; } @Override final boolean subtreeMatch0(ASTMatcher matcher, Object other) { // dispatch to correct overloaded match method return matcher.match(this, other); } @Override void accept0(ASTVisitor visitor) { boolean visitChildren = visitor.visit(this); if (visitChildren) { // visit children in normal left to right reading order acceptChild(visitor, getLabel()); acceptChild(visitor, getBody()); } visitor.endVisit(this); } /** * Returns the label of this labeled statement. * * @return the variable name node */ public SimpleName getLabel() { if (this.labelName == null) { // lazy init must be thread-safe for readers synchronized (this) { if (this.labelName == null) { preLazyInit(); this.labelName = new SimpleName(this.ast); postLazyInit(this.labelName, LABEL_PROPERTY); } } } return this.labelName; } /** * Sets the label of this labeled statement. * * @param label the new label * @exception IllegalArgumentException if: * <ul> * <li>the node belongs to a different AST</li> * <li>the node already has a parent</li> * </ul> */ public void setLabel(SimpleName label) { if (label == null) { throw new IllegalArgumentException(); } ASTNode oldChild = this.labelName; preReplaceChild(oldChild, label, LABEL_PROPERTY); this.labelName = label; postReplaceChild(oldChild, label, LABEL_PROPERTY); } /** * Returns the body of this labeled statement. * * @return the body statement node */ public Statement getBody() { if (this.body == null) { // lazy init must be thread-safe for readers synchronized (this) { if (this.body == null) { preLazyInit(); this.body = new EmptyStatement(this.ast); postLazyInit(this.body, BODY_PROPERTY); } } } return this.body; } /** * Sets the body of this labeled statement. * <p> * Special note: The Java language does not allow a local variable declaration * to appear as the body of a labeled statement (they may only appear within a * block). However, the AST will allow a <code>VariableDeclarationStatement</code> * as the body of a <code>LabeledStatement</code>. To get something that will * compile, be sure to embed the <code>VariableDeclarationStatement</code> * inside a <code>Block</code>. * </p> * * @param statement the body statement node * @exception IllegalArgumentException if: * <ul> * <li>the node belongs to a different AST</li> * <li>the node already has a parent</li> * <li>a cycle in would be created</li> * </ul> */ public void setBody(Statement statement) { if (statement == null) { throw new IllegalArgumentException(); } ASTNode oldChild = this.body; preReplaceChild(oldChild, statement, BODY_PROPERTY); this.body = statement; postReplaceChild(oldChild, statement, BODY_PROPERTY); } @Override int memSize() { return super.memSize() + 2 * 4; } @Override int treeSize() { return memSize() + (this.labelName == null ? 0 : getLabel().treeSize()) + (this.body == null ? 0 : getBody().treeSize()); } }