1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
|
/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
import org.mozilla.javascript.Context;
import org.mozilla.javascript.Function;
import org.mozilla.javascript.Scriptable;
import org.mozilla.javascript.ScriptableObject;
import org.mozilla.javascript.annotations.JSFunction;
import org.mozilla.javascript.annotations.JSGetter;
/**
* An example host object class.
*
* <p>Here's a shell session showing the Foo object in action:
*
* <pre>
* js> defineClass("Foo")
* js> foo = new Foo(); <i>A constructor call, see <a href="#Foo">Foo</a> below.</i>
* [object Foo] <i>The "Foo" here comes from <a href"#getClassName">getClassName</a>.</i>
* js> foo.counter; <i>The counter property is defined by the <code>defineProperty</code></i>
* 0 <i>call below and implemented by the <a href="#getCounter">getCounter</a></i>
* js> foo.counter; <i>method below.</i>
* 1
* js> foo.counter;
* 2
* js> foo.resetCounter(); <i>Results in a call to <a href="#resetCounter">resetCounter</a>.</i>
* js> foo.counter; <i>Now the counter has been reset.</i>
* 0
* js> foo.counter;
* 1
* js> bar = new Foo(37); <i>Create a new instance.</i>
* [object Foo]
* js> bar.counter; <i>This instance's counter is distinct from</i>
* 37 <i>the other instance's counter.</i>
* js> foo.varargs(3, "hi"); <i>Calls <a href="#varargs">varargs</a>.</i>
* this = [object Foo]; args = [3, hi]
* js> foo[7] = 34; <i>Since we extended ScriptableObject, we get</i>
* 34 <i>all the behavior of a JavaScript object</i>
* js> foo.a = 23; <i>for free.</i>
* 23
* js> foo.a + foo[7];
* 57
* js>
* </pre>
*
* @see org.mozilla.javascript.Context
* @see org.mozilla.javascript.Scriptable
* @see org.mozilla.javascript.ScriptableObject
* @author Norris Boyd
*/
public class Foo extends ScriptableObject {
private static final long serialVersionUID = -3833489808933339159L;
/**
* The zero-parameter constructor.
*
* <p>When Context.defineClass is called with this class, it will construct Foo.prototype using
* this constructor.
*/
public Foo() {}
/**
* The Java method defining the JavaScript Foo constructor.
*
* <p>Takes an initial value for the counter property. Note that in the example Shell session
* above, we didn't supply a argument to the Foo constructor. This means that the Undefined
* value is used as the value of the argument, and when the argument is converted to an integer,
* Undefined becomes 0.
*/
public Foo(int counterStart) {
counter = counterStart;
}
/** Returns the name of this JavaScript class, "Foo". */
@Override
public String getClassName() {
return "Foo";
}
/**
* The Java method defining the JavaScript resetCounter function.
*
* <p>Resets the counter to 0.
*/
@JSFunction
public void resetCounter() {
counter = 0;
}
/**
* The Java method implementing the getter for the counter property.
*
* <p>If "setCounter" had been defined in this class, the runtime would call the setter when the
* property is assigned to.
*/
@JSGetter
public int getCounter() {
return counter++;
}
/**
* An example of a variable-arguments method.
*
* <p>All variable arguments methods must have the same number and types of parameters, and must
* be static.
*
* <p>
*
* @param cx the Context of the current thread
* @param thisObj the JavaScript 'this' value.
* @param args the array of arguments for this call
* @param funObj the function object of the invoked JavaScript function This value is useful to
* compute a scope using Context.getTopLevelScope().
* @return computes the string values and types of 'this' and of each of the supplied arguments
* and returns them in a string.
* @see org.mozilla.javascript.ScriptableObject#getTopLevelScope
*/
@JSFunction
public static Object varargs(Context cx, Scriptable thisObj, Object[] args, Function funObj) {
StringBuilder buf = new StringBuilder();
buf.append("this = ");
buf.append(Context.toString(thisObj));
buf.append("; args = [");
for (int i = 0; i < args.length; i++) {
buf.append(Context.toString(args[i]));
if (i + 1 != args.length) buf.append(", ");
}
buf.append("]");
return buf.toString();
}
/** A piece of private data for this class. */
private int counter;
}
|
