/*
* Copyright 2015 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 jsinterop.annotations;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* JsType is used to describe the JavaScript API of an object, either one that already exists from
* the external JavaScript environment, or one that will be accessible from the external JavaScript
* environment.
*
* <p>Marking an object with JsType is similar to marking each public member of the class with
* {@link JsProperty}/{@link JsMethod}/{@link JsConstructor} respectively. In order for this to work
* correctly the JavaScript name needs to be unique for each member. Some unobvious ways to cause
* name collisions are:
*
* <ul>
* <li>having method or constructor overloads
* <li>using the same name for a method and a field
* <li>shadowing a field from parent
* </ul>
*
* <p>Name collisions must be avoided by providing custom names (e.g. {@link JsProperty#name}) or by
* ignoring members using {@link JsIgnore}.
*
* <p>If the JsType is marked as "native" via {@link #isNative}, then the type is considered a stub
* for an existing class that is available in native JavaScript. Unlike non-native JsTypes, all
* members are considered {@link JsProperty}/{@link JsMethod}/{@link JsConstructor} unless they are
* explicitly marked with {@link JsOverlay}.
*
* <p> For native interfaces with no particular JavaScript type associated with them (e.g.
* structural types) it is recommeded to use {@code namespace = JsPackage.GLOBAL} and
* {@code name = '?'}.
*
* <p><b>Instanceof and Castability:</b>
*
* <p>If the JsType is native, the generated code will try to mimic Javascript semantics.
*
* <p>All non-native JsTypes will follow regular Java semantics in terms of castability.
*
* <ul>
* <li>For concrete native JsTypes, cast checks and instanceof checks will be delegated to the
* native JavaScript instanceof operator.
* <li>For interface native JsTypes, instanceof is forbidden and casts to them always succeed.
* </ul>
*/
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
@Documented
public @interface JsType {
/**
* Customizes the name of the type in generated JavaScript. If not provided, the simple Java name
* will be used.
*/
String name() default "<auto>";
/**
* Customizes the namespace of the type in generated JavaScript.
*/
String namespace() default "<auto>";
/**
* Set to {@code true}, this JsType is a native JavaScript type.
*/
boolean isNative() default false;
}