com.google.common.css.compiler.ast.CssConditionalRuleNode.java Source code

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Here is the source code for com.google.common.css.compiler.ast.CssConditionalRuleNode.java

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/*
 * Copyright 2008 Google Inc.
 *
 * 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.google.common.css.compiler.ast;

import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;

import javax.annotation.Nullable;

/**
 * A node representing a conditional rule such as @if or @else.
 *
 */
public class CssConditionalRuleNode extends CssAtRuleNode {
    /**
     * Constructor of a conditional rule.
     *
     * @param type Type of the rule
     * @param name Name of the rule
     */
    public CssConditionalRuleNode(Type type, CssLiteralNode name) {
        super(type, name);
        Preconditions.checkArgument(this.getType().isConditional());
    }

    /**
     * Constructor of a conditional rule.
     *
     * @param type Type of the rule
     * @param name Name of the rule
     * @param condition The condition of the rule
     * @param block A block
     */
    public CssConditionalRuleNode(Type type, CssLiteralNode name, @Nullable CssBooleanExpressionNode condition,
            CssBlockNode block) {
        super(type, name, block);
        Preconditions.checkArgument(this.getType().isConditional());
        if (condition != null) {
            setCondition(condition);
        }
    }

    /**
     * Copy constructor.
     *
     * @param node
     */
    public CssConditionalRuleNode(CssConditionalRuleNode node) {
        super(node);
        if (node.getCondition() != null) {
            this.setCondition(node.getCondition().deepCopy());
        }
    }

    @Override
    public CssConditionalRuleNode deepCopy() {
        return new CssConditionalRuleNode(this);
    }

    @Override
    void setParent(CssNode parent) {
        Preconditions.checkArgument(parent instanceof CssConditionalBlockNode);
        super.setParent(parent);
    }

    /**
     * Can only be called after the node is completely built (meaning it has
     * the condition set).
     */
    public CssBooleanExpressionNode getCondition() {
        if (getType() == Type.ELSE) {
            Preconditions.checkState(getParametersCount() == 0);
            return null;
        }
        Preconditions.checkState(getParametersCount() == 1);
        return (CssBooleanExpressionNode) this.getParameters().get(0);
    }

    void setCondition(CssBooleanExpressionNode condition) {
        Preconditions.checkState(getType() != Type.ELSE);
        Preconditions.checkState(getParametersCount() <= 1);
        this.setParameters(ImmutableList.<CssValueNode>of(condition));
    }

    @Override
    public CssBlockNode getBlock() {
        // This type is ensured by the constructor.
        return (CssBlockNode) super.getBlock();
    }

    // TODO(user): Make sure that the parameters list is made up of a single
    //      CssBooleanExpressionNode.
}