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
/*******************************************************************************
 * 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;

Simple or qualified "this" AST node type.
ThisExpression:
    [ ClassName . ] this


See FieldAccess for guidelines on handling other expressions
that resemble qualified names.

See Also:
FieldAccess
Since:
2.0
@noinstantiate
This class is not intended to be instantiated by clients./**
 * Simple or qualified "this" AST node type.
 *
 * <pre>
 * ThisExpression:
 *     [ ClassName <b>.</b> ] <b>this</b>
 * </pre>
 * <p>
 * See <code>FieldAccess</code> for guidelines on handling other expressions
 * that resemble qualified names.
 * </p>
 *
 * @see FieldAccess
 * @since 2.0
 * @noinstantiate This class is not intended to be instantiated by clients.
 */
@SuppressWarnings("rawtypes")
public class ThisExpression extends Expression {

	
The "qualifier" structural property of this node type (child type: Name). 
Since:
3.0/**
	 * The "qualifier" structural property of this node type (child type: {@link Name}).
	 * @since 3.0
	 */
	public static final ChildPropertyDescriptor QUALIFIER_PROPERTY =
		new ChildPropertyDescriptor(ThisExpression.class, "qualifier", Name.class, OPTIONAL, NO_CYCLE_RISK); //$NON-NLS-1$

	
A list of property descriptors (element type: StructuralPropertyDescriptor), or null if uninitialized. /**
	 * A list of property descriptors (element type:
	 * {@link StructuralPropertyDescriptor}),
	 * or null if uninitialized.
	 */
	private static final List PROPERTY_DESCRIPTORS;

	static {
		List propertyList = new ArrayList(2);
		createPropertyList(ThisExpression.class, propertyList);
		addProperty(QUALIFIER_PROPERTY, propertyList);
		PROPERTY_DESCRIPTORS = reapPropertyList(propertyList);
	}

	
Returns a list of structural property descriptors for this node type.
Clients must not modify the result.
Params:
apiLevel – the API level; one of the
AST.JLS* constants
Returns:
a list of property descriptors (element type: StructuralPropertyDescriptor)
Since:
3.0/**
	 * 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 optional qualifier; null for none; defaults to none.
/**
	 * The optional qualifier; <code>null</code> for none; defaults to none.
	 */
	private Name optionalQualifier = null;

	
Creates a new AST node for a "this" expression owned by the
given AST. By default, there is no qualifier.
Params:
ast – the AST that is to own this node/**
	 * Creates a new AST node for a "this" expression owned by the
	 * given AST. By default, there is no qualifier.
	 *
	 * @param ast the AST that is to own this node
	 */
	ThisExpression(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 == QUALIFIER_PROPERTY) {
			if (get) {
				return getQualifier();
			} else {
				setQualifier((Name) child);
				return null;
			}
		}
		// allow default implementation to flag the error
		return super.internalGetSetChildProperty(property, get, child);
	}

	@Override
	final int getNodeType0() {
		return THIS_EXPRESSION;
	}

	@Override
	ASTNode clone0(AST target) {
		ThisExpression result = new ThisExpression(target);
		result.setSourceRange(getStartPosition(), getLength());
		result.setQualifier((Name) ASTNode.copySubtree(target, getQualifier()));
		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) {
			acceptChild(visitor, getQualifier());
		}
		visitor.endVisit(this);
	}

	
Returns the qualifier of this "this" expression, or
null if there is none.
Returns:
the qualifier name node, or null if there is none/**
	 * Returns the qualifier of this "this" expression, or
	 * <code>null</code> if there is none.
	 *
	 * @return the qualifier name node, or <code>null</code> if there is none
	 */
	public Name getQualifier() {
		return this.optionalQualifier;
	}

	
Sets or clears the qualifier of this "this" expression.
Params:
name – the qualifier name node, or null if
   there is none
Throws:
IllegalArgumentException – if:

the node belongs to a different AST
the node already has a parent
/**
	 * Sets or clears the qualifier of this "this" expression.
	 *
	 * @param name the qualifier name node, or <code>null</code> if
	 *    there is none
	 * @exception IllegalArgumentException if:
	 * <ul>
	 * <li>the node belongs to a different AST</li>
	 * <li>the node already has a parent</li>
	 * </ul>
	 */
	public void setQualifier(Name name) {
		ASTNode oldChild = this.optionalQualifier;
		preReplaceChild(oldChild, name, QUALIFIER_PROPERTY);
		this.optionalQualifier = name;
		postReplaceChild(oldChild, name, QUALIFIER_PROPERTY);
	}

	@Override
	int memSize() {
		// treat Operator as free
		return BASE_NODE_SIZE + 1 * 4;
	}

	@Override
	int treeSize() {
		return
			memSize()
			+ (this.optionalQualifier == null ? 0 : getQualifier().treeSize());
	}
}