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
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
|
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QtScript module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the Technology Preview License Agreement accompanying
** this package.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain
** additional rights. These rights are described in the Nokia Qt LGPL
** Exception version 1.1, included in the file LGPL_EXCEPTION.txt in this
** package.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "qscriptable.h"
#include "qscriptable_p.h"
#include "qscriptengine.h"
QT_BEGIN_NAMESPACE
/*!
\since 4.3
\class QScriptable
\brief The QScriptable class provides access to the Qt Script environment from Qt C++ member functions.
\ingroup script
With QScriptEngine::newQObject(), you can expose the signals and
slots and properties of any QObject (or subclass) to script
code. QScriptable augments this functionality by giving your C++
members access to the Qt Script environment they are invoked in;
conceptually, it is similar to QObject::sender().
By subclassing QScriptable, you get the following functions in your
class: thisObject(), argumentCount(), argument(), context() and
engine(). With these functions, you have full access to the Qt
Script environment from the slots and property access functions of
your class, when they are invoked from script code.
For example, you can throw a Qt Script exception from a slot;
manipulate the `this' object associated with the function call;
inspect the arguments stored in the QScriptContext to know the
"real" arguments passed to the function from script code; and call
script functions from your slot.
A typical use case of QScriptable is to implement prototype objects
for custom C++ types. You define the scriptable interface of your
custom type in a QScriptable subclass using properties and slots;
then you wrap an instance of your class using
QScriptEngine::newQObject(), and finally pass the result to
QScriptEngine::setDefaultPrototype(). See the \l{Default Prototypes Example}
to see how this can be done.
The following is what subclassing QScriptable typically looks
like:
\snippet doc/src/snippets/code/src_script_qscriptable.cpp 0
The only difference from regular QObject subclassing is that you
also inherit from QScriptable.
In the implementation of your slots, you can then use the functions
inherited from QScriptable:
\snippet doc/src/snippets/code/src_script_qscriptable.cpp 1
\sa {Default Prototypes Example}, QScriptEngine::newFunction()
*/
/*!
\internal
*/
QScriptable::QScriptable()
: d_ptr(new QScriptablePrivate())
{
d_ptr->q_ptr = this;
}
/*!
\internal
*/
QScriptable::~QScriptable()
{
}
/*!
Returns a pointer to the QScriptEngine associated with the current
Qt function call, or 0 if the Qt function was not invoked from
script code.
*/
QScriptEngine *QScriptable::engine() const
{
Q_D(const QScriptable);
return d->engine;
}
/*!
Returns a pointer to the QScriptContext associated with the current
Qt function call, or 0 if the Qt function was not invoked from
script code.
*/
QScriptContext *QScriptable::context() const
{
if (QScriptEngine *e = engine())
return e->currentContext();
return 0;
}
/*!
Returns the `this' object associated with the current Qt function
call, or an invalid QScriptValue if the Qt function was not invoked
from script code.
*/
QScriptValue QScriptable::thisObject() const
{
if (QScriptContext *c = context())
return c->thisObject();
return QScriptValue();
}
/*!
Returns the number of arguments passed to the function in this
invocation, or -1 if the Qt function was not invoked from script
code.
\sa argument()
*/
int QScriptable::argumentCount() const
{
if (QScriptContext *c = context())
return c->argumentCount();
return -1;
}
/*!
Returns the function argument at the given \a index, or an invalid
QScriptValue if the Qt function was not invoked from script code.
\sa argumentCount()
*/
QScriptValue QScriptable::argument(int index) const
{
if (QScriptContext *c = context())
return c->argument(index);
return QScriptValue();
}
QT_END_NAMESPACE
|
