Qt 4.8: bytearrayclass.cpp Example File (script/customclass/bytearrayclass.cpp)

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# bytearrayclass.cpp Example File

script/customclass/bytearrayclass.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
     ** Contact: http://www.qt-project.org/legal
     **
     ** This file is part of the examples of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:BSD$
     ** You may use this file under the terms of the BSD license as follows:
     **
     ** "Redistribution and use in source and binary forms, with or without
     ** modification, are permitted provided that the following conditions are
     ** met:
     **   * Redistributions of source code must retain the above copyright
     **     notice, this list of conditions and the following disclaimer.
     **   * Redistributions in binary form must reproduce the above copyright
     **     notice, this list of conditions and the following disclaimer in
     **     the documentation and/or other materials provided with the
     **     distribution.
     **   * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
     **     of its contributors may be used to endorse or promote products derived
     **     from this software without specific prior written permission.
     **
     **
     ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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     ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
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     ****************************************************************************/

     #include <QtScript/QScriptClassPropertyIterator>
     #include <QtScript/QScriptEngine>
     #include "bytearrayclass.h"
     #include "bytearrayprototype.h"

     #include <stdlib.h>

     Q_DECLARE_METATYPE(QByteArray*)
     Q_DECLARE_METATYPE(ByteArrayClass*)

     class ByteArrayClassPropertyIterator : public QScriptClassPropertyIterator
     {
     public:
         ByteArrayClassPropertyIterator(const QScriptValue &object);
         ~ByteArrayClassPropertyIterator();

         bool hasNext() const;
         void next();

         bool hasPrevious() const;
         void previous();

         void toFront();
         void toBack();

         QScriptString name() const;
         uint id() const;

     private:
         int m_index;
         int m_last;
     };

     ByteArrayClass::ByteArrayClass(QScriptEngine *engine)
         : QObject(engine), QScriptClass(engine)
     {
         qScriptRegisterMetaType<QByteArray>(engine, toScriptValue, fromScriptValue);

         length = engine->toStringHandle(QLatin1String("length"));

         proto = engine->newQObject(new ByteArrayPrototype(this),
                                    QScriptEngine::QtOwnership,
                                    QScriptEngine::SkipMethodsInEnumeration
                                    | QScriptEngine::ExcludeSuperClassMethods
                                    | QScriptEngine::ExcludeSuperClassProperties);
         QScriptValue global = engine->globalObject();
         proto.setPrototype(global.property("Object").property("prototype"));

         ctor = engine->newFunction(construct, proto);
         ctor.setData(engine->toScriptValue(this));
     }

     ByteArrayClass::~ByteArrayClass()
     {
     }

     QScriptClass::QueryFlags ByteArrayClass::queryProperty(const QScriptValue &object,
                                                            const QScriptString &name,
                                                            QueryFlags flags, uint *id)
     {
         QByteArray *ba = qscriptvalue_cast<QByteArray*>(object.data());
         if (!ba)
             return 0;
         if (name == length) {
             return flags;
         } else {
             bool isArrayIndex;
             qint32 pos = name.toArrayIndex(&isArrayIndex);
             if (!isArrayIndex)
                 return 0;
             *id = pos;
             if ((flags & HandlesReadAccess) && (pos >= ba->size()))
                 flags &= ~HandlesReadAccess;
             return flags;
         }
     }

     QScriptValue ByteArrayClass::property(const QScriptValue &object,
                                           const QScriptString &name, uint id)
     {
         QByteArray *ba = qscriptvalue_cast<QByteArray*>(object.data());
         if (!ba)
             return QScriptValue();
         if (name == length) {
             return ba->length();
         } else {
             qint32 pos = id;
             if ((pos < 0) || (pos >= ba->size()))
                 return QScriptValue();
             return uint(ba->at(pos)) & 255;
         }
         return QScriptValue();
     }

     void ByteArrayClass::setProperty(QScriptValue &object,
                                      const QScriptString &name,
                                      uint id, const QScriptValue &value)
     {
         QByteArray *ba = qscriptvalue_cast<QByteArray*>(object.data());
         if (!ba)
             return;
         if (name == length) {
             resize(*ba, value.toInt32());
         } else {
             qint32 pos = id;
             if (pos < 0)
                 return;
             if (ba->size() <= pos)
                 resize(*ba, pos + 1);
             (*ba)[pos] = char(value.toInt32());
         }
     }

     QScriptValue::PropertyFlags ByteArrayClass::propertyFlags(
         const QScriptValue &/*object*/, const QScriptString &name, uint /*id*/)
     {
         if (name == length) {
             return QScriptValue::Undeletable
                 | QScriptValue::SkipInEnumeration;
         }
         return QScriptValue::Undeletable;
     }

     QScriptClassPropertyIterator *ByteArrayClass::newIterator(const QScriptValue &object)
     {
         return new ByteArrayClassPropertyIterator(object);
     }

     QString ByteArrayClass::name() const
     {
         return QLatin1String("ByteArray");
     }

     QScriptValue ByteArrayClass::prototype() const
     {
         return proto;
     }

     QScriptValue ByteArrayClass::constructor()
     {
         return ctor;
     }

     QScriptValue ByteArrayClass::newInstance(int size)
     {
         engine()->reportAdditionalMemoryCost(size);
         return newInstance(QByteArray(size, /*ch=*/0));
     }

     QScriptValue ByteArrayClass::newInstance(const QByteArray &ba)
     {
         QScriptValue data = engine()->newVariant(QVariant::fromValue(ba));
         return engine()->newObject(this, data);
     }

     QScriptValue ByteArrayClass::construct(QScriptContext *ctx, QScriptEngine *)
     {
         ByteArrayClass *cls = qscriptvalue_cast<ByteArrayClass*>(ctx->callee().data());
         if (!cls)
             return QScriptValue();
         QScriptValue arg = ctx->argument(0);
         if (arg.instanceOf(ctx->callee()))
             return cls->newInstance(qscriptvalue_cast<QByteArray>(arg));
         int size = arg.toInt32();
         return cls->newInstance(size);
     }

     QScriptValue ByteArrayClass::toScriptValue(QScriptEngine *eng, const QByteArray &ba)
     {
         QScriptValue ctor = eng->globalObject().property("ByteArray");
         ByteArrayClass *cls = qscriptvalue_cast<ByteArrayClass*>(ctor.data());
         if (!cls)
             return eng->newVariant(QVariant::fromValue(ba));
         return cls->newInstance(ba);
     }

     void ByteArrayClass::fromScriptValue(const QScriptValue &obj, QByteArray &ba)
     {
         ba = qvariant_cast<QByteArray>(obj.data().toVariant());
     }

     void ByteArrayClass::resize(QByteArray &ba, int newSize)
     {
         int oldSize = ba.size();
         ba.resize(newSize);
         if (newSize > oldSize)
             engine()->reportAdditionalMemoryCost(newSize - oldSize);
     }

     ByteArrayClassPropertyIterator::ByteArrayClassPropertyIterator(const QScriptValue &object)
         : QScriptClassPropertyIterator(object)
     {
         toFront();
     }

     ByteArrayClassPropertyIterator::~ByteArrayClassPropertyIterator()
     {
     }

     bool ByteArrayClassPropertyIterator::hasNext() const
     {
         QByteArray *ba = qscriptvalue_cast<QByteArray*>(object().data());
         return m_index < ba->size();
     }

     void ByteArrayClassPropertyIterator::next()
     {
         m_last = m_index;
         ++m_index;
     }

     bool ByteArrayClassPropertyIterator::hasPrevious() const
     {
         return (m_index > 0);
     }

     void ByteArrayClassPropertyIterator::previous()
     {
         --m_index;
         m_last = m_index;
     }

     void ByteArrayClassPropertyIterator::toFront()
     {
         m_index = 0;
         m_last = -1;
     }

     void ByteArrayClassPropertyIterator::toBack()
     {
         QByteArray *ba = qscriptvalue_cast<QByteArray*>(object().data());
         m_index = ba->size();
         m_last = -1;
     }

     QScriptString ByteArrayClassPropertyIterator::name() const
     {
         return object().engine()->toStringHandle(QString::number(m_last));
     }

     uint ByteArrayClassPropertyIterator::id() const
     {
         return m_last;
     }