1 /* 2 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * - Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 11 * - Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * - Neither the name of Oracle nor the names of its 16 * contributors may be used to endorse or promote products derived 17 * from this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS 20 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 21 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR 23 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 24 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 26 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 27 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 28 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 29 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 import java.nio.DoubleBuffer; 33 import jdk.nashorn.api.scripting.AbstractJSObject; 34 35 /** 36 * Simple class demonstrating pluggable script object 37 * implementation. By implementing jdk.nashorn.api.scripting.JSObject 38 * (or extending AbstractJSObject which implements it), you 39 * can supply a friendly script object. Nashorn will call 40 * 'magic' methods on such a class on 'obj.foo, obj.foo = 33, 41 * obj.bar()' etc. from script. 42 * 43 * In this example, Java nio DoubleBuffer object is wrapped 44 * as a friendly script object that provides indexed acces 45 * to buffer content and also support array-like "length" 46 * readonly property to retrieve buffer's capacity. This class 47 * also demonstrates a function valued property called "buf". 48 * On 'buf' method, we return the underlying nio buffer object 49 * that is being wrapped. 50 */ 51 public class BufferArray extends AbstractJSObject { 52 // underlying nio buffer 53 private final DoubleBuffer buf; 54 55 /** 56 * Constructor 57 * @param size initial size 58 */ 59 public BufferArray(final int size) { 60 buf = DoubleBuffer.allocate(size); 61 } 62 63 /** 64 * Constructur 65 * @param buf {@link DoubleBuffer} to link to 66 */ 67 public BufferArray(final DoubleBuffer buf) { 68 this.buf = buf; 69 } 70 71 // called to check if indexed property exists 72 @Override 73 public boolean hasSlot(final int index) { 74 return index > 0 && index < buf.capacity(); 75 } 76 77 // get the value from that index 78 @Override 79 public Object getSlot(final int index) { 80 return buf.get(index); 81 } 82 83 // set the value at that index 84 @Override 85 public void setSlot(final int index, final Object value) { 86 buf.put(index, ((Number)value).doubleValue()); 87 } 88 89 // do you have a property of that given name? 90 @Override 91 public boolean hasMember(final String name) { 92 return "length".equals(name) || "buf".equals(name); 93 } 94 95 // get the value of that named property 96 @Override 97 public Object getMember(final String name) { 98 switch (name) { 99 case "length": 100 return buf.capacity(); 101 case "buf": 102 // return a 'function' value for this property 103 return new AbstractJSObject() { 104 @Override 105 public Object call(final Object thiz, final Object... args) { 106 return BufferArray.this.buf; 107 } 108 109 // yes, I'm a function ! 110 @Override 111 public boolean isFunction() { 112 return true; 113 } 114 }; 115 default: 116 break; 117 } 118 return null; 119 } 120 }