com.vaadin.sass.internal.visitor.IfElseNodeHandler Maven / Gradle / Ivy

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A pure Java implementation of the http://sass-lang.com compiler

There is a newer version: 0.9.13

/*
 * Copyright 2000-2014 Vaadin Ltd.
 * 
 * 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 com.vaadin.sass.internal.visitor;

import java.util.ArrayList;
import java.util.List;

import org.w3c.flute.parser.ParseException;

import com.vaadin.sass.internal.ScssStylesheet;
import com.vaadin.sass.internal.expression.BinaryOperator;
import com.vaadin.sass.internal.parser.SassListItem;
import com.vaadin.sass.internal.tree.Node;
import com.vaadin.sass.internal.tree.controldirective.ElseNode;
import com.vaadin.sass.internal.tree.controldirective.IfElseDefNode;
import com.vaadin.sass.internal.tree.controldirective.IfNode;

public class IfElseNodeHandler {

    public static void traverse(IfElseDefNode node) throws Exception {
        for (final Node child : node.getChildren()) {
            if (child instanceof IfNode) {
                SassListItem expression = ((IfNode) child).getExpression();
                expression = expression.replaceVariables(ScssStylesheet
                        .getVariables());
                expression = expression.evaluateFunctionsAndExpressions(true);

                if (BinaryOperator.isTrue(expression)) {
                    replaceDefNodeWithCorrectChild(node, child);
                    break;
                }
            } else {
                if (!(child instanceof ElseNode)
                        && node.getChildren().indexOf(child) == node
                                .getChildren().size() - 1) {
                    throw new ParseException(
                            "Invalid @if/@else in scss file for " + node);
                } else {
                    replaceDefNodeWithCorrectChild(node, child);
                    break;
                }
            }
        }
        // in case the node hasn't been removed already
        node.removeFromParent();
    }

    private static void replaceDefNodeWithCorrectChild(
            IfElseDefNode ifElseNode, final Node child) {
        List nodesToAdd = new ArrayList(child.getChildren());
        ifElseNode.getParentNode().replaceNode(ifElseNode, nodesToAdd);
        for (Node node : nodesToAdd) {
            node.traverse();
        }
    }
}