source: trunk/src/script/api/qscriptable.cpp@ 1168

Last change on this file since 1168 was 846, checked in by Dmitry A. Kuminov, 14 years ago

trunk: Merged in qt 4.7.2 sources from branches/vendor/nokia/qt.
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1/****************************************************************************
2**
3** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
4** All rights reserved.
5** Contact: Nokia Corporation ([email protected])
6**
7** This file is part of the QtScript module of the Qt Toolkit.
8**
9** $QT_BEGIN_LICENSE:LGPL-ONLY$
10** GNU Lesser General Public License Usage
11** This file may be used under the terms of the GNU Lesser
12** General Public License version 2.1 as published by the Free Software
13** Foundation and appearing in the file LICENSE.LGPL included in the
14** packaging of this file. Please review the following information to
15** ensure the GNU Lesser General Public License version 2.1 requirements
16** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
17**
18** If you have questions regarding the use of this file, please contact
19** Nokia at [email protected].
20** $QT_END_LICENSE$
21**
22****************************************************************************/
23
24#include "qscriptable.h"
25#include "qscriptable_p.h"
26#include "qscriptengine.h"
27
28QT_BEGIN_NAMESPACE
29
30/*!
31 \since 4.3
32 \class QScriptable
33
34 \brief The QScriptable class provides access to the Qt Script environment from Qt C++ member functions.
35
36 \ingroup script
37
38
39 With QScriptEngine::newQObject(), you can expose the signals and
40 slots and properties of any QObject (or subclass) to script
41 code. QScriptable augments this functionality by giving your C++
42 members access to the Qt Script environment they are invoked in;
43 conceptually, it is similar to QObject::sender().
44
45 By subclassing QScriptable, you get the following functions in your
46 class: thisObject(), argumentCount(), argument(), context() and
47 engine(). With these functions, you have full access to the Qt
48 Script environment from the slots and property access functions of
49 your class, when they are invoked from script code.
50
51 For example, you can throw a Qt Script exception from a slot;
52 manipulate the `this' object associated with the function call;
53 inspect the arguments stored in the QScriptContext to know the
54 "real" arguments passed to the function from script code; and call
55 script functions from your slot.
56
57 A typical use case of QScriptable is to implement prototype objects
58 for custom C++ types. You define the scriptable interface of your
59 custom type in a QScriptable subclass using properties and slots;
60 then you wrap an instance of your class using
61 QScriptEngine::newQObject(), and finally pass the result to
62 QScriptEngine::setDefaultPrototype(). See the \l{Default Prototypes Example}
63 to see how this can be done.
64
65 The following is what subclassing QScriptable typically looks
66 like:
67
68 \snippet doc/src/snippets/code/src_script_qscriptable.cpp 0
69
70 The only difference from regular QObject subclassing is that you
71 also inherit from QScriptable.
72
73 In the implementation of your slots, you can then use the functions
74 inherited from QScriptable:
75
76 \snippet doc/src/snippets/code/src_script_qscriptable.cpp 1
77
78 \sa {Default Prototypes Example}, QScriptEngine::newFunction()
79*/
80
81/*!
82 \internal
83*/
84QScriptable::QScriptable()
85 : d_ptr(new QScriptablePrivate())
86{
87 d_ptr->q_ptr = this;
88}
89
90/*!
91 \internal
92*/
93QScriptable::~QScriptable()
94{
95}
96
97/*!
98 Returns a pointer to the QScriptEngine associated with the current
99 Qt function call, or 0 if the Qt function was not invoked from
100 script code.
101*/
102QScriptEngine *QScriptable::engine() const
103{
104 Q_D(const QScriptable);
105 return d->engine;
106}
107
108/*!
109 Returns a pointer to the QScriptContext associated with the current
110 Qt function call, or 0 if the Qt function was not invoked from
111 script code.
112*/
113QScriptContext *QScriptable::context() const
114{
115 if (QScriptEngine *e = engine())
116 return e->currentContext();
117
118 return 0;
119}
120
121/*!
122 Returns the `this' object associated with the current Qt function
123 call, or an invalid QScriptValue if the Qt function was not invoked
124 from script code.
125*/
126
127QScriptValue QScriptable::thisObject() const
128{
129 if (QScriptContext *c = context())
130 return c->thisObject();
131
132 return QScriptValue();
133}
134
135/*!
136 Returns the number of arguments passed to the function in this
137 invocation, or -1 if the Qt function was not invoked from script
138 code.
139
140 \sa argument()
141*/
142int QScriptable::argumentCount() const
143{
144 if (QScriptContext *c = context())
145 return c->argumentCount();
146
147 return -1;
148}
149
150/*!
151 Returns the function argument at the given \a index, or an invalid
152 QScriptValue if the Qt function was not invoked from script code.
153
154 \sa argumentCount()
155*/
156QScriptValue QScriptable::argument(int index) const
157{
158 if (QScriptContext *c = context())
159 return c->argument(index);
160
161 return QScriptValue();
162}
163
164QT_END_NAMESPACE
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