/*
* Copyright (c) 2011 Google Inc.
*
* 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
*/
package com.google.eclipse.protobuf.model.util;
import static org.eclipse.xtext.nodemodel.util.NodeModelUtils.findNodesForFeature;
import java.util.List;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.ecore.EStructuralFeature;
import org.eclipse.xtext.AbstractRule;
import org.eclipse.xtext.RuleCall;
import org.eclipse.xtext.TerminalRule;
import org.eclipse.xtext.nodemodel.ILeafNode;
import org.eclipse.xtext.nodemodel.INode;
import com.google.inject.Singleton;
/**
* Utility methods related to <code>{@link INode}</code>s.
*
* @author alruiz@google.com (Alex Ruiz)
*/
@Singleton public class INodes {
/**
* Returns the first node that was used to assign values to the given feature for the given object.
* @param o the given object.
* @param feature the given feature.
* @return the first node that was used to assign values to the given feature for the given object, or {@code null} if
* a node cannot be found.
*/
public INode firstNodeForFeature(EObject o, EStructuralFeature feature) {
List<INode> nodes = findNodesForFeature(o, feature);
if (nodes.isEmpty()) {
return null;
}
return nodes.get(0);
}
/**
* Indicates whether the given node belongs to a string, or a single- or multi-line comment.
* @param node the node to check.
* @return {@code true} if the given node belongs to a string, or a single- or multi-line comment; {@code false}
* otherwise.
*/
public boolean isCommentOrString(INode node) {
return isComment(node) || isString(node);
}
/**
* Indicates whether the given node belongs to a single- or multiple-line comment.
* @param node the node to check.
* @return {@code true} if the given node belongs to a single- or multiple-line comment; {@code false} otherwise.
*/
public boolean isComment(INode node) {
return isSingleLineComment(node) || isMultipleLineComment(node);
}
/**
* Indicates whether the given node belongs to a single-line comment.
* @param node the node to check.
* @return {@code true} if the given node belongs to a single-line comment; {@code false} otherwise.
*/
public boolean isSingleLineComment(INode node) {
return isComment(node, "SL_COMMENT");
}
/**
* Indicates whether the given node belongs to a multiple-line comment.
* @param node the node to check.
* @return {@code true} if the given node belongs to a multiple-line comment; {@code false} otherwise.
*/
public boolean isMultipleLineComment(INode node) {
return isComment(node, "ML_COMMENT");
}
private static boolean isComment(INode node, String commentRuleName) {
if (!(node instanceof ILeafNode)) {
return false;
}
EObject o = node.getGrammarElement();
if (!(o instanceof TerminalRule)) {
return false;
}
TerminalRule rule = (TerminalRule) o;
return commentRuleName.equals(rule.getName());
}
/**
* Indicates whether the given node belongs to a string.
* @param node the node to check.
* @return {@code true} if the given node belongs to a string; {@code false} otherwise.
*/
public boolean isString(INode node) {
EObject grammarElement = node.getGrammarElement();
if (!(grammarElement instanceof RuleCall)) {
return false;
}
AbstractRule rule = ((RuleCall) grammarElement).getRule();
if (!(rule instanceof TerminalRule)) {
return false;
}
TerminalRule terminalRule = (TerminalRule) rule;
return "STRING".equals(terminalRule.getName());
}
/**
* Indicates whether the given node is a hidden leaf node.
* @param node the node to check.
* @return {@code true} if the given node is a hidden leaf node; {@code false} otherwise.
*/
public boolean isHiddenLeafNode(INode node) {
if (node instanceof ILeafNode) {
return ((ILeafNode) node).isHidden();
}
return false;
}
/**
* Returns the text of the given node, with leading and trailing whitespace omitted.
* @param node the given node, may be {@code null}.
* @return the text of the given node, with leading and trailing whitespace omitted.
*/
public String textOf(INode node) {
if (node == null) {
return null;
}
String text = node.getText();
return (text == null) ? null : text.trim();
}
}