qobject.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

/****************************************************************************
**
** Copyright (C) 1992-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
** http://www.trolltech.com/products/qt/opensource.html
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://www.trolltech.com/products/qt/licensing.html or contact the
** sales department at [e-mail].
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

#include "qobject.h"
#include "qobject_p.h"

#include "qabstracteventdispatcher.h"
#include "qcoreapplication.h"
#include "qcoreapplication_p.h"
#include "qvariant.h"
#include "qmetaobject.h"
#include <qregexp.h>
#include <qthread.h>
#include <private/qthread_p.h>
#include <qdebug.h>
#include <qhash.h>
#include <qpair.h>
#include <qvarlengtharray.h>
#include <qset.h>

#include <new>

#include <ctype.h>
#include <limits.h>

static int DIRECT_CONNECTION_ONLY = 0;

Q_GLOBAL_STATIC(QReadWriteLock, qt_object_read_write_lock)
QReadWriteLock *QObjectPrivate::readWriteLock() { return qt_object_read_write_lock(); }

static int *queuedConnectionTypes(const QList<QByteArray> &typeNames)
{
    int *types = static_cast<int *>(qMalloc((typeNames.count() + 1) * sizeof(int)));
    for (int i = 0; i < typeNames.count(); ++i) {
        const QByteArray typeName = typeNames.at(i);
        if (typeName.endsWith('*'))
            types[i] = QMetaType::VoidStar;
        else
            types[i] = QMetaType::type(typeName);

        if (!types[i]) {
            qWarning("QObject::connect: Cannot queue arguments of type '%s'", typeName.constData());
            qFree(types);
            return 0;
        }
    }
    types[typeNames.count()] = 0;

    return types;
}

struct QConnection {
    QObject *sender;
    int signal;
    QObject *receiver;
    int method;
    int inUse:1;
    int type:31; // 0 == auto, 1 == direct, 2 == queued
    int *types;
};
Q_DECLARE_TYPEINFO(QConnection, Q_MOVABLE_TYPE);

class QConnectionList
{
public:
    QReadWriteLock lock;

    typedef QMultiHash<const QObject *, int> Hash;
    Hash sendersHash, receiversHash;
    QList<int> unusedConnections;
    typedef QList<QConnection> List;
    List connections;

    void remove(QObject *object);

    void addConnection(QObject *sender, int signal,
                       QObject *receiver, int method,
                       int type = 0, int *types = 0);
    bool removeConnection(QObject *sender, int signal,
                          QObject *receiver, int method);
};

Q_GLOBAL_STATIC(QConnectionList, connectionList)

/*! \internal

    Removes \a object from the connection list completely, i.e. all
    connections containing \a object are removed.
*/
void QConnectionList::remove(QObject *object)
{
    for (int i = 0; i < 2; ++i) {
        Hash &hash1 = i == 0 ? sendersHash : receiversHash;
        Hash &hash2 = i == 0 ? receiversHash : sendersHash;

        Hash::iterator it = hash1.find(object);
        const Hash::iterator end = hash1.end();
        while (it != end && it.key() == object) {
            const int at = it.value();
            QConnection &c = connections[at];
            if (c.sender) {
                if (c.types && c.types != &DIRECT_CONNECTION_ONLY) {
                    qFree(c.types);
                    c.types = 0;
                }
                it = hash1.erase(it);

                const QObject * const partner = i == 0 ? c.receiver : c.sender;
                Hash::iterator x = hash2.find(partner);
                const Hash::iterator xend = hash2.end();
                while (x != xend && x.key() == partner) {
                    if (x.value() == at) {
                        x = hash2.erase(x);
                        break;
                    } else {
                        ++x;
                    }
                }

                int inUse = c.inUse;
                memset(&c, 0, sizeof(c));
                c.inUse = inUse;
                Q_ASSERT(!unusedConnections.contains(at));
                unusedConnections.prepend(at);
            } else {
                ++it;
            }
        }
    }
}

/*! \internal
    Adds the specified connection.
*/
void QConnectionList::addConnection(QObject *sender, int signal,
                                    QObject *receiver, int method,
                                    int type, int *types)
{
    QConnection c = { sender, signal, receiver, method, 0, 0, types };
    c.type = type; // don't warn on VC++6
    int at = -1;
    for (int i = 0; i < unusedConnections.size(); ++i) {
        if (!connections.at(unusedConnections.at(i)).inUse) {
            // reuse an unused connection
            at = unusedConnections.takeAt(i);
            connections[at] = c;
            break;
        }
    }
    if (at == -1) {
        // append new connection
        at = connections.size();
        connections << c;
    }
    sendersHash.insert(sender, at);
    receiversHash.insert(receiver, at);
}

/*! \internal

    Removes the specified connection.  See QObject::disconnect() for
    more information about valid arguments.
 */
bool QConnectionList::removeConnection(QObject *sender, int signal,
                                       QObject *receiver, int method)
{
    bool success = false;
    Hash::iterator it = sendersHash.find(sender);
    while (it != sendersHash.end() && it.key() == sender) {
        const int at = it.value();
        QConnection &c = connections[at];
        if (c.receiver
            && (signal < 0 || signal == c.signal)
            && (receiver == 0
                || (c.receiver == receiver && (method < 0 || method == c.method)))) {
            if (c.types) {
                if (c.types != &DIRECT_CONNECTION_ONLY)
                    qFree(c.types);
                c.types = 0;
            }
            it = sendersHash.erase(it);

            Hash::iterator x = receiversHash.find(c.receiver);
            const Hash::iterator xend = receiversHash.end();
            while (x != xend && x.key() == c.receiver) {
                if (x.value() == at) {
                    x = receiversHash.erase(x);
                    break;
                } else {
                    ++x;
                }
            }

            int inUse = c.inUse;
            memset(&c, 0, sizeof(c));
            c.inUse = inUse;
            unusedConnections << at;
            success = true;
        } else {
            ++it;
        }
    }
    return success;
}

/*
  QObjectSet sets the minimum capacity to 4099 (the first prime number
  after 4096), so that we can speed up QObject destruction.
 */
class QObjectSet : public QSet<QObject *>
{
public:
    QObjectSet()
    { reserve(4099); }
};

Q_GLOBAL_STATIC(QObjectSet, allObjects)

extern "C" Q_CORE_EXPORT void qt_addObject(QObject *object)
{
    QWriteLocker locker(QObjectPrivate::readWriteLock());
    QObjectSet *set = allObjects();
    if (set)
        set->insert(object);
}

extern "C" Q_CORE_EXPORT void qt_removeObject(QObject *object)
{
    QObjectSet *set = allObjects();
    if (set)
        set->remove(object);
}

bool QObjectPrivate::isValidObject(QObject *object)
{
    QObjectSet *set = allObjects();
    return set ? set->contains(object) : false;
}

QObjectPrivate::QObjectPrivate(int version)
    : thread(0), currentSender(0)
{
    if (version != QObjectPrivateVersion)
        qFatal("Cannot mix incompatible Qt libraries");

    // QObjectData initialization
    q_ptr = 0;
    parent = 0;                                 // no parent yet. It is set by setParent()
    isWidget = false;                           // assume not a widget object
    pendTimer = false;                          // no timers yet
    blockSig = false;                           // not blocking signals
    wasDeleted = false;                         // double-delete catcher
    sendChildEvents = true;                     // if we should send ChildInsert and ChildRemove events to parent
    receiveChildEvents = true;
    postedEvents = 0;
#ifdef QT3_SUPPORT
    postedChildInsertedEvents = 0;
#endif
}

QObjectPrivate::~QObjectPrivate()
{
#ifndef QT_NO_USERDATA
    qDeleteAll(userData);
#endif
}

class ConnectionObject : public QObject
{
    Q_DECLARE_PRIVATE(QObject)
public:
    bool isSender(const QObject *receiver, const char *signal) const;
    QList<QObject*> receiverList(const char *signal) const;
    QList<QObject*> senders() const;
};

bool QObjectPrivate::isSender(const QObject *receiver, const char *signal) const
{
    Q_Q(const QObject);
    int signal_index = q->metaObject()->indexOfSignal(signal);
    if (signal_index < 0)
        return false;
    QConnectionList *list = ::connectionList();
    QReadLocker locker(&list->lock);
    QConnectionList::Hash::const_iterator it = list->sendersHash.find(q);
    while (it != list->sendersHash.end() && it.key() == q) {
        const QConnection &c = list->connections.at(it.value());
        if (c.signal == signal_index && c.receiver == receiver)
            return true;
        ++it;
    }
    return false;
}

QObjectList QObjectPrivate::receiverList(const char *signal) const
{
    Q_Q(const QObject);
    QObjectList receivers;
    int signal_index = q->metaObject()->indexOfSignal(signal);
    if (signal_index < 0)
        return receivers;
    QConnectionList *list = ::connectionList();
    QReadLocker locker(&list->lock);
    QConnectionList::Hash::const_iterator it = list->sendersHash.constFind(q);
    while (it != list->sendersHash.constEnd() && it.key() == q) {
        const QConnection &c = list->connections.at(it.value());
        if (c.signal == signal_index)
            receivers << c.receiver;
        ++it;
    }
    return receivers;
}

QObjectList QObjectPrivate::senderList() const
{
    Q_Q(const QObject);
    QObjectList senders;
    QConnectionList *list = ::connectionList();
    QReadLocker locker(&list->lock);
    QConnectionList::Hash::const_iterator it = list->receiversHash.constFind(q);
    while (it != list->receiversHash.constEnd() && it.key() == q) {
        const QConnection &c = list->connections.at(it.value());
        senders << c.sender;
        ++it;
    }
    return senders;
}

typedef QMultiHash<QObject *, QObject **> GuardHash;
Q_GLOBAL_STATIC(GuardHash, guardHash)
Q_GLOBAL_STATIC(QReadWriteLock, guardHashLock)

/*!\internal
 */
void QMetaObject::addGuard(QObject **ptr)
{
    if (!*ptr)
        return;
    GuardHash *hash = guardHash();
    if (!hash) {
        *ptr = 0;
        return;
    }
    QWriteLocker locker(guardHashLock());
    hash->insert(*ptr, ptr);
}

/*!\internal
 */
void QMetaObject::removeGuard(QObject **ptr)
{
    if (!*ptr)
        return;
    GuardHash *hash = guardHash();
    if (!hash)
        return;
    QWriteLocker locker(guardHashLock());
    GuardHash::iterator it = hash->find(*ptr);
    const GuardHash::iterator end = hash->end();
    for (; it.key() == *ptr && it != end; ++it) {
        if (it.value() == ptr) {
            (void) hash->erase(it);
            break;
        }
    }
}

/*!\internal
 */
void QMetaObject::changeGuard(QObject **ptr, QObject *o)
{
    GuardHash *hash = guardHash();
    if (!hash) {
        *ptr = 0;
        return;
    }
    QWriteLocker locker(guardHashLock());
    if (*ptr) {
        GuardHash::iterator it = hash->find(*ptr);
        const GuardHash::iterator end = hash->end();
        for (; it.key() == *ptr && it != end; ++it) {
            if (it.value() == ptr) {
                (void) hash->erase(it);
                break;
            }
        }
    }
    *ptr = o;
    if (*ptr)
        hash->insert(*ptr, ptr);
}