ASTASForStatement.java

/*
 * ASTASForStatement.java
 * 
 * Copyright (c) 2006 David Holroyd
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package uk.co.badgersinfoil.metaas.impl;

import org.asdt.core.internal.antlr.AS3Parser;
import uk.co.badgersinfoil.metaas.dom.Expression;
import uk.co.badgersinfoil.metaas.dom.ASForStatement;
import uk.co.badgersinfoil.metaas.dom.ScriptElement;
import uk.co.badgersinfoil.metaas.dom.StatementContainer;
import uk.co.badgersinfoil.metaas.impl.antlr.LinkedListTree;


public class ASTASForStatement extends ContainerDelegate implements ASForStatement {

	private static final int INDEX_INIT = 0;
	private static final int INDEX_CONDITION = 1;
	private static final int INDEX_UPDATE = 2;
	private static final int INDEX_STATEMENT = 3;

	public ASTASForStatement(LinkedListTree ast) {
		super(ast);
	}

	public String getInitString() {
		if (!hasInit()) {
			return null;
		}
		return ASTUtils.stringifyNode(findInit());
	}

	public ScriptElement getInit() {
		if (!hasInit()) {
			return null;
		}
		LinkedListTree init = findInit().getFirstChild();
		switch (init.getType()) {
		    case AS3Parser.VAR:
		    case AS3Parser.CONST:
			return new ASTASDeclarationStatement(init);
		    default:
			return ExpressionBuilder.build(init);
		}
	}

	public String getConditionString() {
		if (!hasCondition()) {
			return null;
		}
		return ASTUtils.stringifyNode(findCondition().getFirstChild());
	}

	public Expression getCondition() {
		if (!hasCondition()) {
			return null;
		}
		return ExpressionBuilder.build(findCondition().getFirstChild());
	}

	public String getUpdateString() {
		if (!hasUpdate()) {
			return null;
		}
		return ASTUtils.stringifyNode(findUpdate().getFirstChild());
	}

	public Expression getUpdate() {
		if (!hasUpdate()) {
			return null;
		}
		return ExpressionBuilder.build(findUpdate().getFirstChild());
	}

	private boolean hasCondition() {
		return findCondition().getChildCount() > 0;
	}

	private boolean hasInit() {
		return findInit().getChildCount() > 0;
	}

	private boolean hasUpdate() {
		return findUpdate().getChildCount() > 0;
	}

	private LinkedListTree getChild(int index) {
		return (LinkedListTree)ast.getChild(index);
	}

	protected StatementContainer getStatementContainer() {
		return new ASTStatementList(getChild(INDEX_STATEMENT));
	}

	private LinkedListTree findInit() {
		return getChild(INDEX_INIT);
	}

	private LinkedListTree findCondition() {
		return getChild(INDEX_CONDITION);
	}

	private LinkedListTree findUpdate() {
		return getChild(INDEX_UPDATE);
	}

	public void setCondition(String expr) {
		if (expr == null) {
			deleteAnyChild(findCondition());
		} else {
			LinkedListTree cond = AS3FragmentParser.parseForCond(expr);
			ast.setChildWithTokens(INDEX_CONDITION, cond);
		}
	}

	public void setCondition(Expression expr) {
		LinkedListTree cond = findCondition();
		if (expr == null) {
			deleteAnyChild(cond);
		} else {
			setFirstChild(cond, ast(expr));
		}
	}

	public void setInit(String expr) {
		if (expr == null) {
			deleteAnyChild(findInit());
		} else {
			LinkedListTree init = AS3FragmentParser.parseForInit(expr);
			ast.setChildWithTokens(INDEX_INIT, init);
		}
	}

	public void setUpdate(String expr) {
		if (expr == null) {
			deleteAnyChild(findUpdate());
		} else {
			LinkedListTree update = AS3FragmentParser.parseForIter(expr);
			ast.setChildWithTokens(INDEX_UPDATE, update);
		}
	}

	public void setUpdate(Expression expr) {
		if (expr == null) {
			deleteAnyChild(findUpdate());
		} else {
			setFirstChild(findUpdate(), ast(expr));
		}
	}

	private void deleteAnyChild(LinkedListTree tree) {
		if (tree.getChildCount() > 0) {
			tree.deleteChild(0);
		}
	}

	private static void setFirstChild(LinkedListTree parent, LinkedListTree child) {
		if (parent.getChildCount() == 0) {
			parent.addChildWithTokens(child);
		} else {
			parent.setChildWithTokens(0, child);
		}
	}
}