org.apache.abdera2.common.templates.DefaultingContext.java Source code

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Here is the source code for org.apache.abdera2.common.templates.DefaultingContext.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  The ASF licenses this file to You
 * 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.  For additional information regarding
 * copyright in this work, please see the NOTICE file in the top level
 * directory of this distribution.
 */
package org.apache.abdera2.common.templates;

import static com.google.common.base.Preconditions.*;
import java.util.Iterator;

import org.apache.abdera2.common.misc.MoreFunctions;

import com.google.common.collect.ImmutableSet;

@SuppressWarnings("unchecked")
public class DefaultingContext extends DelegatingContext {

    private static final long serialVersionUID = 3395776996994628136L;
    private final Context defaults;

    public DefaultingContext(Context main, Context defaults) {
        super(main);
        checkNotNull(defaults);
        this.defaults = defaults;
    }

    public <T> T resolve(String var) {
        T t = (T) super.resolve(var);
        return t != null ? t : (T) defaults.resolve(var);
    }

    public Iterator<String> iterator() {
        ImmutableSet.Builder<String> set = ImmutableSet.builder();
        for (String name : subcontext)
            set.add(name);
        for (String name : defaults)
            set.add(name);
        return set.build().iterator();
    }

    public boolean contains(String var) {
        boolean a = subcontext.contains(var);
        return a ? a : defaults.contains(var);
    }

    public String toString() {
        StringBuilder buf = new StringBuilder();
        buf.append("Subcontext: " + subcontext);
        buf.append("\n");
        buf.append("Default Context: " + defaults);
        return buf.toString();
    }

    @Override
    public int hashCode() {
        return MoreFunctions.genHashCode(1, defaults);
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        DefaultingContext other = (DefaultingContext) obj;
        if (defaults == null) {
            if (other.defaults != null)
                return false;
        } else if (!defaults.equals(other.defaults))
            return false;
        return true;
    }

}