/*******************************************************************************
* Copyright (c) 2000, 2010 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.che.ide.ext.java.jdt.core.dom;
import java.util.ArrayList;
import java.util.List;
/**
* If statement AST node type.
* <p/>
* <pre>
* IfStatement:
* <b>if</b> <b>(</b> Expression <b>)</b> Statement [ <b>else</b> Statement]
* </pre>
*
* @noinstantiate This class is not intended to be instantiated by clients.
* @since 2.0
*/
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
* @throws 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
* @throws 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
* @throws 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());
}
}