HistoryObject.java revision 1388:105d0051d37b 
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
26package jdk.nashorn.tools.jjs;
27
28import java.io.IOException;
29import java.util.Collections;
30import java.util.HashSet;
31import java.util.Set;
32import java.util.function.Function;
33import java.util.function.Supplier;
34import jdk.internal.jline.console.history.FileHistory;
35import jdk.internal.jline.console.history.History;
36import jdk.nashorn.api.scripting.AbstractJSObject;
37import jdk.nashorn.api.scripting.JSObject;
38import jdk.nashorn.internal.runtime.JSType;
39import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED;
40
41/*
42 * A script friendly object that exposes history of commands to scripts.
43 */
44final 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}
116