src/script/api/qscriptable.cpp
changeset 0 1918ee327afb
child 3 41300fa6a67c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/script/api/qscriptable.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,182 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** 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