com.google.gwt.coreext.client.JsIntegerDoubleMap.java Source code

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Here is the source code for com.google.gwt.coreext.client.JsIntegerDoubleMap.java

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/*
 * Copyright 2010 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.gwt.coreext.client;

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

/**
 * Overlay type to deal strictly with double primitives and int keys. We can use
 * this instead of JsIntegerMap<T> in scenarios where we do not want to pay the
 * penalty of Double<->double autoboxing semantics. Since Java generics do not
 * support primitive types, JsIntegerMap can only hold values of type Double.
 * Additionally, pulling Doubles out of maps require that we need to do nullity
 * checks, and thus the GWT compiler must compile this to something that is a
 * Class wrapper for a double primitive, when what we really want is just a
 * plain double.
 */
public class JsIntegerDoubleMap extends JavaScriptObject {

    /**
     * Callback interface for int,double key value pairs.
     */
    public interface IterationCallBack {
        void onIteration(int key, double val);
    }

    /**
     * Create a new empty map.
     * 
     * @return an empty map
     */
    public static JsIntegerDoubleMap create() {
        return JavaScriptObject.createObject().cast();
    }

    protected JsIntegerDoubleMap() {
    }

    /**
     * Removes the mapping for this key from the map.
     * 
     * @param key
     */
    public final native void erase(int key) /*-{
                                            delete this[key];
                                            }-*/;

    /**
     * Returns the value associated with the specified key.
     * 
     * @param key
     * @return the value associated with the key
     */
    public final native double get(int key) /*-{
                                            return this[key];
                                            }-*/;

    /**
     * Returns an array containing all the values in this map.
     * 
     * @return a snapshot of the values contained in the map
     */
    public final native JsArrayNumber getValues() /*-{
                                                  var data = [];
                                                  for (var i in this) {
                                                  if (this.hasOwnProperty(i)) {
                                                  data.push(this[i]);
                                                  }
                                                  }
                                                  return data;
                                                  }-*/;

    /**
     * Returns true if this map has an entry for the specified key.
     * 
     * @param key
     * @return true if this map has an entry for the given key
     */
    public final native boolean hasKey(int key) /*-{
                                                return this.hasOwnProperty(key);
                                                }-*/;

    /**
     * Iterates through the elements and calls back with the proper key value
     * pair.
     * 
     * @param callback
     */
    public final native void iterate(IterationCallBack callback) /*-{
                                                                 for (key in this) {
                                                                 if (this.hasOwnProperty(key)) {
                                                                 callback.
                                                                 @com.google.gwt.coreext.client.JsIntegerDoubleMap.IterationCallBack::onIteration(ID)
                                                                 (parseInt(key), this[key]);
                                                                 }
                                                                 }
                                                                 }-*/;

    /**
     * Associates the specified value with the specified key in this map.
     * 
     * @param key key with which the value will be associated
     * @param val value to be associated with key
     */
    public final native void put(int key, double val) /*-{
                                                      this[key] = val;
                                                      }-*/;
}