qdbusmisc.cpp

QT 开发环境里面一个很重要的文件

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**
** Copyright (C) 1992-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the tools applications of the Qt Toolkit.
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** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
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#include <string.h>

#include <QtCore/qvariant.h>
#include <QtCore/qmetaobject.h>

#include "qdbusutil_p.h"
#include "qdbusconnection_p.h"
#include "qdbusmetatype_p.h"

bool qDBusCheckAsyncTag(const char *tag)
{
    static const char noReplyTag[] = "Q_NOREPLY";
    if (!tag || !*tag)
        return false;

    const char *p = strstr(tag, noReplyTag);
    if (p != NULL &&
        (p == tag || *(p-1) == ' ') &&
        (p[sizeof noReplyTag] == '\0' || p[sizeof noReplyTag] == ' '))
        return true;

    return false;
}

int qDBusNameToTypeId(const char *name)
{
    int id = static_cast<int>( QVariant::nameToType(name) );
    if (id == QVariant::UserType)
        id = QMetaType::type(name);
    return id;
}

// calculates the metatypes for the method
// the slot must have the parameters in the following form:
//  - zero or more value or const-ref parameters of any kind
//  - zero or one const ref of QDBusMessage
//  - zero or more non-const ref parameters
// No parameter may be a template.
// this function returns -1 if the parameters don't match the above form
// this function returns the number of *input* parameters, including the QDBusMessage one if any
// this function does not check the return type, so metaTypes[0] is always 0 and always present
// metaTypes.count() >= retval + 1 in all cases
//
// sig must be the normalised signature for the method
int qDBusParametersForMethod(const QMetaMethod &mm, QList<int>& metaTypes)
{
    QDBusMetaTypeId::init();

    QList<QByteArray> parameterTypes = mm.parameterTypes();
    metaTypes.clear();

    metaTypes.append(0);        // return type
    int inputCount = 0;
    bool seenMessage = false;
    QList<QByteArray>::ConstIterator it = parameterTypes.constBegin();
    QList<QByteArray>::ConstIterator end = parameterTypes.constEnd();
    for ( ; it != end; ++it) {
        const QByteArray &type = *it;
        if (type.endsWith('*')) {
            //qWarning("Could not parse the method '%s'", mm.signature());
            // pointer?
            return -1;
        }

        if (type.endsWith('&')) {
            QByteArray basictype = type;
            basictype.truncate(type.length() - 1);

            int id = qDBusNameToTypeId(basictype);
            if (id == 0) {
                //qWarning("Could not parse the method '%s'", mm.signature());
                // invalid type in method parameter list
                return -1;
            } else if (QDBusMetaType::typeToSignature(id) == 0)
                return -1;

            metaTypes.append( id );
            seenMessage = true; // it cannot appear anymore anyways
            continue;
        }

        if (seenMessage) {      // && !type.endsWith('&')
            //qWarning("Could not parse the method '%s'", mm.signature());
            // non-output parameters after message or after output params
            return -1;          // not allowed
        }

        int id = qDBusNameToTypeId(type);
        if (id == 0) {
            //qWarning("Could not parse the method '%s'", mm.signature());
            // invalid type in method parameter list
            return -1;
        }

        if (id == QDBusMetaTypeId::message)
            seenMessage = true;
        else if (QDBusMetaType::typeToSignature(id) == 0)
            return -1;

        metaTypes.append(id);
        ++inputCount;
    }

    return inputCount;
}