/*******************************************************************************
* Copyright (c) 2000, 2013 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.jdt.core.dom;
import java.util.ArrayList;
import java.util.List;
/**
* If statement AST node type.
* <pre>
* IfStatement:
* <b>if</b> <b>(</b> Expression <b>)</b> Statement [ <b>else</b> Statement]
* </pre>
*
* @since 2.0
* @noinstantiate This class is not intended to be instantiated by clients.
*/
@SuppressWarnings("rawtypes")
public class IfStatement extends Statement {
/**
* The "expression" structural property of this node type (child type: {@link Expression}).
* @since 3.0
*/
public static final ChildPropertyDescriptor EXPRESSION_PROPERTY =
new ChildPropertyDescriptor(IfStatement.class, "expression", Expression.class, MANDATORY, CYCLE_RISK); //$NON-NLS-1$
/**
* The "thenStatement" structural property of this node type (child type: {@link Statement}).
* @since 3.0
*/
public static final ChildPropertyDescriptor THEN_STATEMENT_PROPERTY =
new ChildPropertyDescriptor(IfStatement.class, "thenStatement", Statement.class, MANDATORY, CYCLE_RISK); //$NON-NLS-1$
/**
* The "elseStatement" structural property of this node type (child type: {@link Statement}).
* @since 3.0
*/
public static final ChildPropertyDescriptor ELSE_STATEMENT_PROPERTY =
new ChildPropertyDescriptor(IfStatement.class, "elseStatement", Statement.class, OPTIONAL, 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 properyList = new ArrayList(4);
createPropertyList(IfStatement.class, properyList);
addProperty(EXPRESSION_PROPERTY, properyList);
addProperty(THEN_STATEMENT_PROPERTY, properyList);
addProperty(ELSE_STATEMENT_PROPERTY, properyList);
PROPERTY_DESCRIPTORS = reapPropertyList(properyList);
}
/**
* 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 expression; lazily initialized; defaults to an unspecified, but
* legal, expression.
*/
private Expression expression = null;
/**
* The then statement; lazily initialized; defaults to an unspecified, but
* legal, statement.
*/
private Statement thenStatement = null;
/**
* The else statement; <code>null</code> for none; defaults to none.
*/
private Statement optionalElseStatement = null;
/**
* Creates a new unparented if statement node owned by the given
* AST. By default, the expresssion is unspecified,
* but legal, the then statement is an empty block, and there is no else
* statement.
* <p>
* N.B. This constructor is package-private.
* </p>
*
* @param ast the AST that is to own this node
*/
IfStatement(AST ast) {
super(ast);
}
/* (omit javadoc for this method)
* Method declared on ASTNode.
*/
final List internalStructuralPropertiesForType(int apiLevel) {
return propertyDescriptors(apiLevel);
}
/* (omit javadoc for this method)
* Method declared on ASTNode.
*/
final ASTNode internalGetSetChildProperty(ChildPropertyDescriptor property, boolean get, ASTNode child) {
if (property == EXPRESSION_PROPERTY) {
if (get) {
return getExpression();
} else {
setExpression((Expression) child);
return null;
}
}
if (property == THEN_STATEMENT_PROPERTY) {
if (get) {
return getThenStatement();
} else {
setThenStatement((Statement) child);
return null;
}
}
if (property == ELSE_STATEMENT_PROPERTY) {
if (get) {
return getElseStatement();
} else {
setElseStatement((Statement) child);
return null;
}
}
// allow default implementation to flag the error
return super.internalGetSetChildProperty(property, get, child);
}
/* (omit javadoc for this method)
* Method declared on ASTNode.
*/
final int getNodeType0() {
return IF_STATEMENT;
}
/* (omit javadoc for this method)
* Method declared on ASTNode.
*/
ASTNode clone0(AST target) {
IfStatement result = new IfStatement(target);
result.setSourceRange(getStartPosition(), getLength());
result.copyLeadingComment(this);
result.setExpression((Expression) getExpression().clone(target));
result.setThenStatement(
(Statement) getThenStatement().clone(target));
result.setElseStatement(
(Statement) ASTNode.copySubtree(target, getElseStatement()));
return result;
}
/* (omit javadoc for this method)
* Method declared on ASTNode.
*/
final boolean subtreeMatch0(ASTMatcher matcher, Object other) {
// dispatch to correct overloaded match method
return matcher.match(this, other);
}
/* (omit javadoc for this method)
* Method declared on ASTNode.
*/
void accept0(ASTVisitor visitor) {
boolean visitChildren = visitor.visit(this);
if (visitChildren) {
// visit children in normal left to right reading order
acceptChild(visitor, getExpression());
acceptChild(visitor, getThenStatement());
acceptChild(visitor, getElseStatement());
}
visitor.endVisit(this);
}
/**
* Returns the expression of this if statement.
*
* @return the expression node
*/
public Expression getExpression() {
if (this.expression == null) {
// lazy init must be thread-safe for readers
synchronized (this) {
if (this.expression == null) {
preLazyInit();
this.expression = new SimpleName(this.ast);
postLazyInit(this.expression, EXPRESSION_PROPERTY);
}
}
}
return this.expression;
}
/**
* Sets the condition of this if statement.
*
* @param expression the expression 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 setExpression(Expression expression) {
if (expression == null) {
throw new IllegalArgumentException();
}
ASTNode oldChild = this.expression;
preReplaceChild(oldChild, expression, EXPRESSION_PROPERTY);
this.expression = expression;
postReplaceChild(oldChild, expression, EXPRESSION_PROPERTY);
}
/**
* Returns the "then" part of this if statement.
*
* @return the "then" statement node
*/
public Statement getThenStatement() {
if (this.thenStatement == null) {
// lazy init must be thread-safe for readers
synchronized (this) {
if (this.thenStatement == null) {
preLazyInit();
this.thenStatement = new Block(this.ast);
postLazyInit(this.thenStatement, THEN_STATEMENT_PROPERTY);
}
}
}
return this.thenStatement;
}
/**
* Sets the "then" part of this if statement.
* <p>
* Special note: The Java language does not allow a local variable declaration
* to appear as the "then" part of an if statement (they may only appear within a
* block). However, the AST will allow a <code>VariableDeclarationStatement</code>
* as the thenStatement of a <code>IfStatement</code>. To get something that will
* compile, be sure to embed the <code>VariableDeclarationStatement</code>
* inside a <code>Block</code>.
* </p>
*
* @param statement the "then" 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 setThenStatement(Statement statement) {
if (statement == null) {
throw new IllegalArgumentException();
}
ASTNode oldChild = this.thenStatement;
preReplaceChild(oldChild, statement, THEN_STATEMENT_PROPERTY);
this.thenStatement = statement;
postReplaceChild(oldChild, statement, THEN_STATEMENT_PROPERTY);
}
/**
* Returns the "else" part of this if statement, or <code>null</code> if
* this if statement has <b>no</b> "else" part.
* <p>
* Note that there is a subtle difference between having no else
* statement and having an empty statement ("{}") or null statement (";").
* </p>
*
* @return the "else" statement node, or <code>null</code> if none
*/
public Statement getElseStatement() {
return this.optionalElseStatement;
}
/**
* Sets or clears the "else" part of this if statement.
* <p>
* Note that there is a subtle difference between having no else part
* (as in <code>"if(true){}"</code>) and having an empty block (as in
* "if(true){}else{}") or null statement (as in "if(true){}else;").
* </p>
* <p>
* Special note: The Java language does not allow a local variable declaration
* to appear as the "else" part of an if statement (they may only appear within a
* block). However, the AST will allow a <code>VariableDeclarationStatement</code>
* as the elseStatement of a <code>IfStatement</code>. To get something that will
* compile, be sure to embed the <code>VariableDeclarationStatement</code>
* inside a <code>Block</code>.
* </p>
*
* @param statement the "else" statement 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>
* <li>a cycle in would be created</li>
* </ul>
*/
public void setElseStatement(Statement statement) {
ASTNode oldChild = this.optionalElseStatement;
preReplaceChild(oldChild, statement, ELSE_STATEMENT_PROPERTY);
this.optionalElseStatement = statement;
postReplaceChild(oldChild, statement, ELSE_STATEMENT_PROPERTY);
}
/* (omit javadoc for this method)
* Method declared on ASTNode.
*/
int memSize() {
return super.memSize() + 3 * 4;
}
/* (omit javadoc for this method)
* Method declared on ASTNode.
*/
int treeSize() {
return
memSize()
+ (this.expression == null ? 0 : getExpression().treeSize())
+ (this.thenStatement == null ? 0 : getThenStatement().treeSize())
+ (this.optionalElseStatement == null ? 0 : getElseStatement().treeSize());
}
}