1 /*
   2  * Copyright (c) 2015, 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.nashorn.tools.jjs;
  27 
  28 import java.io.IOException;
  29 import java.util.Collections;
  30 import java.util.HashSet;
  31 import java.util.Set;
  32 import java.util.function.Function;
  33 import java.util.function.Supplier;
  34 import jdk.internal.jline.console.history.FileHistory;
  35 import jdk.internal.jline.console.history.History;
  36 import jdk.nashorn.api.scripting.AbstractJSObject;
  37 import jdk.nashorn.api.scripting.JSObject;
  38 import jdk.nashorn.internal.runtime.JSType;
  39 import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED;
  40 
  41 /*
  42  * A script friendly object that exposes history of commands to scripts.
  43  */
  44 final class HistoryObject extends AbstractJSObject {
  45     private static final Set<String> props;
  46     static {
  47         final HashSet<String> s = new HashSet<>();
  48         s.add("clear");
  49         s.add("forEach");
  50         s.add("print");
  51         s.add("size");
  52         s.add("toString");
  53         props = Collections.unmodifiableSet(s);
  54     }
  55 
  56     private final FileHistory hist;
  57 
  58     HistoryObject(final FileHistory hist) {
  59         this.hist = hist;
  60     }
  61 
  62     @Override
  63     public Object getMember(final String name) {
  64         switch (name) {
  65             case "clear":
  66                 return (Runnable)hist::clear;
  67             case "forEach":
  68                 return (Function<JSObject, Object>)this::iterate;
  69             case "print":
  70                 return (Runnable)this::print;
  71             case "size":
  72                 return hist.size();
  73             case "toString":
  74                 return (Supplier<String>)this::toString;
  75         }
  76         return UNDEFINED;
  77     }
  78 
  79     @Override
  80     public Object getDefaultValue(final Class<?> hint) {
  81         if (hint == String.class) {
  82             return toString();
  83         }
  84         return UNDEFINED;
  85     }
  86 
  87     @Override
  88     public String toString() {
  89         final StringBuilder buf = new StringBuilder();
  90         for (History.Entry e : hist) {
  91             buf.append(e.value()).append('\n');
  92         }
  93         return buf.toString();
  94     }
  95 
  96     @Override
  97     public Set<String> keySet() {
  98         return props;
  99     }
 100 
 101     private void print() {
 102         for (History.Entry e : hist) {
 103             System.out.println(e.value());
 104         }
 105     }
 106 
 107     private Object iterate(final JSObject func) {
 108         for (History.Entry e : hist) {
 109             if (JSType.toBoolean(func.call(this, e.value().toString()))) {
 110                 break; // return true from callback to skip iteration
 111             }
 112         }
 113         return UNDEFINED;
 114     }
 115 }