1 /*
   2  * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.internal;
  27 
  28 import java.lang.annotation.*;
  29 
  30 /**
  31  * Indicates the API declaration in question is associated with a
  32  * <em>preview feature</em>. See JEP 12: "Preview Language and VM
  33  * Features" (http://openjdk.java.net/jeps/12).
  34  * @since 14
  35  */
  36 // Match the meaningful targets of java.lang.Deprecated, omit local
  37 // variables and parameter declarations
  38 @Target({ElementType.METHOD,
  39          ElementType.CONSTRUCTOR,
  40          ElementType.FIELD,
  41          ElementType.PACKAGE,
  42          ElementType.MODULE,
  43          ElementType.TYPE})
  44  // CLASS retention will hopefully be sufficient for the purposes at hand
  45 @Retention(RetentionPolicy.CLASS)
  46 // *Not* @Documented
  47 public @interface PreviewFeature {
  48     /**
  49      * Name of the preview feature the annotated API is associated
  50      * with.
  51      */
  52     public Feature feature();
  53 
  54     public boolean essentialAPI() default false;
  55 
  56     public enum Feature {
  57         TEXT_BLOCKS;
  58     }
  59 }