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39 | |
40 | #include "qscriptable.h" |
41 | #include "qscriptable_p.h" |
42 | #include "qscriptengine.h" |
43 | |
44 | QT_BEGIN_NAMESPACE |
45 | |
46 | /*! |
47 | \since 4.3 |
48 | \class QScriptable |
49 | \inmodule QtScript |
50 | |
51 | \brief The QScriptable class provides access to the Qt Script environment from Qt C++ member functions. |
52 | |
53 | \ingroup script |
54 | |
55 | |
56 | With QScriptEngine::newQObject(), you can expose the signals and |
57 | slots and properties of any QObject (or subclass) to script |
58 | code. QScriptable augments this functionality by giving your C++ |
59 | members access to the Qt Script environment they are invoked in; |
60 | conceptually, it is similar to QObject::sender(). |
61 | |
62 | By subclassing QScriptable, you get the following functions in your |
63 | class: thisObject(), argumentCount(), argument(), context() and |
64 | engine(). With these functions, you have full access to the Qt |
65 | Script environment from the slots and property access functions of |
66 | your class, when they are invoked from script code. |
67 | |
68 | For example, you can throw a Qt Script exception from a slot; |
69 | manipulate the `this' object associated with the function call; |
70 | inspect the arguments stored in the QScriptContext to know the |
71 | "real" arguments passed to the function from script code; and call |
72 | script functions from your slot. |
73 | |
74 | A typical use case of QScriptable is to implement prototype objects |
75 | for custom C++ types. You define the scriptable interface of your |
76 | custom type in a QScriptable subclass using properties and slots; |
77 | then you wrap an instance of your class using |
78 | QScriptEngine::newQObject(), and finally pass the result to |
79 | QScriptEngine::setDefaultPrototype(). See the \l{Default Prototypes Example} |
80 | to see how this can be done. |
81 | |
82 | The following is what subclassing QScriptable typically looks |
83 | like: |
84 | |
85 | \snippet code/src_script_qscriptable.cpp 0 |
86 | |
87 | The only difference from regular QObject subclassing is that you |
88 | also inherit from QScriptable. |
89 | |
90 | In the implementation of your slots, you can then use the functions |
91 | inherited from QScriptable: |
92 | |
93 | \snippet code/src_script_qscriptable.cpp 1 |
94 | |
95 | \sa {Default Prototypes Example}, QScriptEngine::newFunction() |
96 | */ |
97 | |
98 | /*! |
99 | \internal |
100 | */ |
101 | QScriptable::QScriptable() |
102 | : d_ptr(new QScriptablePrivate()) |
103 | { |
104 | d_ptr->q_ptr = this; |
105 | } |
106 | |
107 | /*! |
108 | \internal |
109 | */ |
110 | QScriptable::~QScriptable() |
111 | { |
112 | } |
113 | |
114 | /*! |
115 | Returns a pointer to the QScriptEngine associated with the current |
116 | Qt function call, or 0 if the Qt function was not invoked from |
117 | script code. |
118 | */ |
119 | QScriptEngine *QScriptable::engine() const |
120 | { |
121 | Q_D(const QScriptable); |
122 | return d->engine; |
123 | } |
124 | |
125 | /*! |
126 | Returns a pointer to the QScriptContext associated with the current |
127 | Qt function call, or 0 if the Qt function was not invoked from |
128 | script code. |
129 | */ |
130 | QScriptContext *QScriptable::context() const |
131 | { |
132 | if (QScriptEngine *e = engine()) |
133 | return e->currentContext(); |
134 | |
135 | return 0; |
136 | } |
137 | |
138 | /*! |
139 | Returns the `this' object associated with the current Qt function |
140 | call, or an invalid QScriptValue if the Qt function was not invoked |
141 | from script code. |
142 | */ |
143 | |
144 | QScriptValue QScriptable::thisObject() const |
145 | { |
146 | if (QScriptContext *c = context()) |
147 | return c->thisObject(); |
148 | |
149 | return QScriptValue(); |
150 | } |
151 | |
152 | /*! |
153 | Returns the number of arguments passed to the function in this |
154 | invocation, or -1 if the Qt function was not invoked from script |
155 | code. |
156 | |
157 | \sa argument() |
158 | */ |
159 | int QScriptable::argumentCount() const |
160 | { |
161 | if (QScriptContext *c = context()) |
162 | return c->argumentCount(); |
163 | |
164 | return -1; |
165 | } |
166 | |
167 | /*! |
168 | Returns the function argument at the given \a index, or an invalid |
169 | QScriptValue if the Qt function was not invoked from script code. |
170 | |
171 | \sa argumentCount() |
172 | */ |
173 | QScriptValue QScriptable::argument(int index) const |
174 | { |
175 | if (QScriptContext *c = context()) |
176 | return c->argument(index); |
177 | |
178 | return QScriptValue(); |
179 | } |
180 | |
181 | QT_END_NAMESPACE |
182 | |