/*
* Copyright 2011 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.lang;
import com.google.gwt.core.client.JavaScriptObject;
/**
* Utility class for fetching prototype-seed functions for injection into JsAST.
*/
public class SeedUtil {
/*
* Holds a map of seedId to anonymous Javascript functions (prototypes for class vtables).
*/
private static JavaScriptObject seedTable = JavaScriptObject.createObject();
/**
* If not already created, generates an anonymous function and assigns it a slot in the global
* seedTable. If superSeed is > -1, it creates an instance of the superSeed by invoking
* newSeed() and then assigns it as the prototype of the seed being defined. It also sets up the
* castableTypeMap, as well as any ctors which are passed in via Javascript varargs. Finally, if
* the class literal for this seed id was setup first, which can happen if they are in separate
* code-split fragments, the Class.createFor* methods will have created a placeholder seedTable
* entry containing the Class literal, and this will be copied from the placeholder location
* onto the current prototype.
*/
public static native JavaScriptObject defineSeed(int id, int superSeed,
JavaScriptObject castableTypeMap) /*-{
var seed = @com.google.gwt.lang.SeedUtil::seedTable[id];
if (seed && !seed.@java.lang.Object::___clazz) {
// not a placeholder entry setup by Class.setClassLiteral
_ = seed.prototype;
} else {
if (!seed) {
seed = @com.google.gwt.lang.SeedUtil::seedTable[id] = function() {
};
}
_ = seed.prototype = (superSeed < 0) ? {}
: @com.google.gwt.lang.SeedUtil::newSeed(I)(superSeed);
_.@java.lang.Object::castableTypeMap = castableTypeMap;
}
for (var i = 3; i < arguments.length; ++i) {
arguments[i].prototype = _;
}
if (seed.@java.lang.Object::___clazz) {
_.@java.lang.Object::___clazz = seed.@java.lang.Object::___clazz;
seed.@java.lang.Object::___clazz = null;
}
}-*/;
/**
* Lookup seed function by id and instantiate an object with it.
*/
public static native JavaScriptObject newSeed(int id) /*-{
return new (@com.google.gwt.lang.SeedUtil::seedTable[id]);
}-*/;
}