Java tutorial
/******************************************************************************* * Copyright (c) 2004, 2019 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; /** * Member value pair node (added in JLS3 API). Member value pairs appear in annotations. * <pre> * MemberValuePair: * SimpleName <b>=</b> Expression * </pre> * <p> * Within annotations, only certain kinds of expressions are meaningful, * including other annotations. * </p> * * @see NormalAnnotation * @since 3.1 * @noinstantiate This class is not intended to be instantiated by clients. */ @SuppressWarnings("rawtypes") public class MemberValuePair extends ASTNode { /** * The "name" structural property of this node type (child type: {@link SimpleName}). */ public static final ChildPropertyDescriptor NAME_PROPERTY = new ChildPropertyDescriptor(MemberValuePair.class, "name", SimpleName.class, MANDATORY, NO_CYCLE_RISK); //$NON-NLS-1$ /** * The "value" structural property of this node type (child type: {@link Expression}). */ public static final ChildPropertyDescriptor VALUE_PROPERTY = new ChildPropertyDescriptor(MemberValuePair.class, "value", Expression.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(MemberValuePair.class, propertyList); addProperty(NAME_PROPERTY, propertyList); addProperty(VALUE_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 AST.JLS* constants * @return a list of property descriptors (element type: * {@link StructuralPropertyDescriptor}) */ public static List propertyDescriptors(int apiLevel) { return PROPERTY_DESCRIPTORS; } /** * The member name; lazily initialized; defaults to a unspecified, * legal name. */ private SimpleName name = null; /** * The value; lazily initialized; defaults to a unspecified, * legal expression. */ private Expression value = null; /** * Creates a new AST node for a member value pair owned by the given * AST. By default, the node has an unspecified (but legal) member * name and value. * <p> * N.B. This constructor is package-private. * </p> * * @param ast the AST that is to own this node */ MemberValuePair(AST ast) { super(ast); unsupportedIn2(); } @Override final List internalStructuralPropertiesForType(int apiLevel) { return propertyDescriptors(apiLevel); } @Override final ASTNode internalGetSetChildProperty(ChildPropertyDescriptor property, boolean get, ASTNode child) { if (property == NAME_PROPERTY) { if (get) { return getName(); } else { setName((SimpleName) child); return null; } } if (property == VALUE_PROPERTY) { if (get) { return getValue(); } else { setValue((Expression) child); return null; } } // allow default implementation to flag the error return super.internalGetSetChildProperty(property, get, child); } @Override final int getNodeType0() { return MEMBER_VALUE_PAIR; } @Override ASTNode clone0(AST target) { MemberValuePair result = new MemberValuePair(target); result.setSourceRange(getStartPosition(), getLength()); result.setName((SimpleName) ASTNode.copySubtree(target, getName())); result.setValue((Expression) ASTNode.copySubtree(target, getValue())); 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, getName()); acceptChild(visitor, getValue()); } visitor.endVisit(this); } /** * Returns the member name. * * @return the member name node */ public SimpleName getName() { if (this.name == null) { // lazy init must be thread-safe for readers synchronized (this) { if (this.name == null) { preLazyInit(); this.name = new SimpleName(this.ast); postLazyInit(this.name, NAME_PROPERTY); } } } return this.name; } /** * Resolves and returns the member value pair binding for this member value pair. * <p> * Note that bindings are generally unavailable unless requested when the * AST is being built. * </p> * * @return the binding, or <code>null</code> if the binding cannot be * resolved * @since 3.2 */ public final IMemberValuePairBinding resolveMemberValuePairBinding() { return this.ast.getBindingResolver().resolveMemberValuePair(this); } /** * Sets the member name. * * @param name the member name node * @exception IllegalArgumentException if: * <ul> * <li>the node belongs to a different AST</li> * <li>the node already has a parent</li> * </ul> */ public void setName(SimpleName name) { if (name == null) { throw new IllegalArgumentException(); } ASTNode oldChild = this.name; preReplaceChild(oldChild, name, NAME_PROPERTY); this.name = name; postReplaceChild(oldChild, name, NAME_PROPERTY); } /** * Returns the value expression. * * @return the value expression */ public Expression getValue() { if (this.value == null) { // lazy init must be thread-safe for readers synchronized (this) { if (this.value == null) { preLazyInit(); this.value = new SimpleName(this.ast); postLazyInit(this.value, VALUE_PROPERTY); } } } return this.value; } /** * Sets the value of this pair. * * @param value the new value * @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 setValue(Expression value) { if (value == null) { throw new IllegalArgumentException(); } ASTNode oldChild = this.value; preReplaceChild(oldChild, value, VALUE_PROPERTY); this.value = value; postReplaceChild(oldChild, value, VALUE_PROPERTY); } @Override int memSize() { return BASE_NODE_SIZE + 2 * 4; } @Override int treeSize() { return memSize() + (this.name == null ? 0 : getName().treeSize()) + (this.value == null ? 0 : getValue().treeSize()); } }