jsinterop.annotations.JsType Maven / Gradle / Ivy
/*
* 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.
*
* 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;
*
*
Having method or constructor overloads.
* Using the same name for a method and a field.
* Shadowing a field from parent.
*
* A name collision needs to be avoided by providing a custom name (e.g. {@link JsProperty#name}) or
* by completely ignoring the member using {@link JsIgnore}.
*
* If the JsType is marked as "native", then the type is considered as stub for an existing class
* that is available in native JavaScript. If it is concrete type, the subclass will use the
* designated type as super type opposed to the ordinary one (e.g. java.lang.Object).
*
* Instanceof and Castability:
*
* If the JsTypes is native then the generated code will try to mimic Javascript semantics.
*
If it is concrete native JsType then cast checks and instanceof checks will be delegated to
* the native JavaScript instanceof operator.
* If it is an interface and marked as native, no checks will be performed.
*
* All non-native JsTypes will follow regular Java semantics in terms of castability.
*/
@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 "";
/**
* Customizes the namespace of the type in generated JavaScript.
*/
String namespace() default "";
/**
* Set to {@code true}, this JsType is a native JavaScript type.
*/
boolean isNative() default false;
}