com.google.gerrit.client.rpc.Natives.java Source code

Introduction

Here is the source code for com.google.gerrit.client.rpc.Natives.java

Source

// Copyright (C) 2012 The Android Open Source Project
//
// 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.gerrit.client.rpc;

import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.core.client.JsArray;
import com.google.gwt.json.client.JSONObject;

import java.util.AbstractList;
import java.util.Collections;
import java.util.List;
import java.util.Set;

public class Natives {
    /**
     * Get the names of defined properties on the object. The returned set
     * iterates in the native iteration order, which may match the source order.
     */
    public static Set<String> keys(JavaScriptObject obj) {
        if (obj != null) {
            return new JSONObject(obj).keySet();
        }
        return Collections.emptySet();
    }

    public static <T extends JavaScriptObject> List<T> asList(final JsArray<T> arr) {
        if (arr == null) {
            return null;
        }
        return new AbstractList<T>() {
            @Override
            public T set(int index, T element) {
                T old = arr.get(index);
                arr.set(index, element);
                return old;
            }

            @Override
            public T get(int index) {
                return arr.get(index);
            }

            @Override
            public int size() {
                return arr.length();
            }
        };
    }

    public static <T extends JavaScriptObject> JsArray<T> arrayOf(T element) {
        JsArray<T> arr = JavaScriptObject.createArray().cast();
        arr.push(element);
        return arr;
    }

    @SuppressWarnings("unchecked")
    public static <T extends JavaScriptObject> T parseJSON(String json) {
        if (json.startsWith("\"")) {
            return (T) NativeString.wrap(parseString(parser, json));
        }
        return Natives.<T>parseObject(parser, json); // javac generics bug
    }

    private static native <T extends JavaScriptObject> T parseObject(JavaScriptObject p, String s)
    /*-{ return p(s); }-*/;

    private static native String parseString(JavaScriptObject p, String s)
    /*-{ return p(s); }-*/;

    private static JavaScriptObject parser;

    private static native JavaScriptObject bestJsonParser()
    /*-{
      if ($wnd.JSON && typeof $wnd.JSON.parse === 'function')
        return $wnd.JSON.parse;
      return function(s) { return eval('(' + s + ')'); };
    }-*/;

    static {
        parser = bestJsonParser();
    }

    private Natives() {
    }
}