java.lang.Enum.java Source code

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Here is the source code for java.lang.Enum.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 java.lang;

import com.google.gwt.core.client.JavaScriptObject;

import java.io.Serializable;

/**
 * The first-class representation of an enumeration.
 * 
 * @param <E>
 */
public abstract class Enum<E extends Enum<E>> implements Comparable<E>, Serializable {

    public static <T extends Enum<T>> T valueOf(Class<T> enumType, String name) {
        JavaScriptObject enumValueOfFunc = enumType.enumValueOfFunc;
        if (enumValueOfFunc == null) {
            throw new IllegalArgumentException();
        }
        return invokeValueOf(enumValueOfFunc, name);
    }

    protected static <T extends Enum<T>> JavaScriptObject createValueOfMap(T[] enumConstants) {
        JavaScriptObject result = JavaScriptObject.createObject();
        for (T value : enumConstants) {
            put0(result, ":" + value.name(), value);
        }
        return result;
    }

    protected static <T extends Enum<T>> T valueOf(JavaScriptObject map, String name) {
        T result = Enum.<T>get0(map, ":" + name);
        if (result != null) {
            return result;
        }
        if (name == null) {
            throw new NullPointerException();
        }
        throw new IllegalArgumentException();
    }

    private static native <T extends Enum<T>> T get0(JavaScriptObject map, String name) /*-{
                                                                                        return map[name];
                                                                                        }-*/;

    private static native <T extends Enum<T>> T invokeValueOf(JavaScriptObject enumValueOfFunc, String name) /*-{
                                                                                                             return enumValueOfFunc(name);
                                                                                                             }-*/;

    private static native <T extends Enum<T>> void put0(JavaScriptObject map, String name, T value) /*-{
                                                                                                    map[name] = value;
                                                                                                    }-*/;

    private final String name;

    private final int ordinal;

    protected Enum(String name, int ordinal) {
        this.name = name;
        this.ordinal = ordinal;
    }

    public final int compareTo(E other) {
        // TODO: will a bridge method do the cast for us?
        // if (this.getDeclaringClass() != other.getDeclaringClass()) {
        // throw new ClassCastException();
        // }
        return this.ordinal - other.ordinal;
    }

    @Override
    public final boolean equals(Object other) {
        return this == other;
    }

    @SuppressWarnings("unchecked")
    public final Class<E> getDeclaringClass() {
        Class clazz = getClass();
        assert clazz != null : "clazz";

        // Don't use getSuperclass() to allow that method to be pruned for most
        // class types
        Class superclass = clazz.getEnumSuperclass();
        assert superclass != null : "superclass";

        return (superclass == Enum.class) ? clazz : superclass;
    }

    @Override
    public final int hashCode() {
        return super.hashCode();
    }

    public final String name() {
        return name;
    }

    public final String obfuscatedName() {
        return "" + ordinal;
    }

    public final int ordinal() {
        return ordinal;
    }

    @Override
    public String toString() {
        return name();
    }
}