basehookinterconnector.cpp

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/**********************************************************************
 * LeechCraft - modular cross-platform feature rich internet client.
 * Copyright (C) 2006-2014  Georg Rudoy
 *
 * Boost Software License - Version 1.0 - August 17th, 2003
 *
 * Permission is hereby granted, free of charge, to any person or organization
 * obtaining a copy of the software and accompanying documentation covered by
 * this license (the "Software") to use, reproduce, display, distribute,
 * execute, and transmit the Software, and to prepare derivative works of the
 * Software, and to permit third-parties to whom the Software is furnished to
 * do so, all subject to the following:
 *
 * The copyright notices in the Software and this entire statement, including
 * the above license grant, this restriction and the following disclaimer,
 * must be included in all copies of the Software, in whole or in part, and
 * all derivative works of the Software, unless such copies or derivative
 * works are solely in the form of machine-executable object code generated by
 * a source language processor.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
 * SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
 * FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 **********************************************************************/

#include "basehookinterconnector.h"
#include <QMetaMethod>
#include <QtDebug>

namespace LeechCraft
{
namespace Util
{
    BaseHookInterconnector::BaseHookInterconnector (QObject *parent)
    : QObject (parent)
    {
    }

    BaseHookInterconnector::~BaseHookInterconnector ()
    {
    }

    namespace
    {
        bool IsHookMethod (const QMetaMethod& method)
        {
            return method.parameterTypes ().value (0) == "LeechCraft::IHookProxy_ptr";
        }

#if QT_VERSION >= 0x050000
        auto BuildHookSlots (const QObject *obj)
        {
            const auto objMo = obj->metaObject ();

            QHash<QByteArray, QList<QMetaMethod>> hookSlots;
            for (int i = 0, size = objMo->methodCount (); i < size; ++i)
            {
                const auto& method = objMo->method (i);
                if (IsHookMethod (method))
                    hookSlots [method.name ()] << method;
            }

            return hookSlots;
        }
#endif

        void CheckMatchingSigs (const QObject *snd, const QObject *rcv)
        {
#if QT_VERSION >= 0x050000
            if (!qEnvironmentVariableIsSet ("LC_VERBOSE_HOOK_CHECKS"))
                return;

            const auto& hookSlots = BuildHookSlots (snd);

            const auto rcvMo = rcv->metaObject ();

            for (int i = 0, size = rcvMo->methodCount (); i < size; ++i)
            {
                const auto& rcvMethod = rcvMo->method (i);
                if (!IsHookMethod (rcvMethod))
                    continue;

                const auto& rcvName = rcvMethod.name ();
                if (!hookSlots.contains (rcvName))
                {
                    qWarning () << Q_FUNC_INFO
                            << "no method matching method"
                            << rcvName
                            << "(receiver"
                            << rcv
                            << ") in sender object"
                            << snd;
                    continue;
                }

                const auto& sndMethods = hookSlots [rcvName];
                if (std::none_of (sndMethods.begin (), sndMethods.end (),
                            [&rcvMethod] (const QMetaMethod& sndMethod)
                            {
                                return QMetaObject::checkConnectArgs (sndMethod, rcvMethod);
                            }))
                    qWarning () << Q_FUNC_INFO
                            << "incompatible signatures for hook"
                            << rcvName
                            << "in"
                            << snd
                            << "and"
                            << rcv;
            }
#else
            Q_UNUSED (snd)
            Q_UNUSED (rcv)
#endif
        }

#define LC_N(a) (QMetaObject::normalizedSignature(a))
#define LC_TOSLOT(a) ('1' + QByteArray(a))
#define LC_TOSIGNAL(a) ('2' + QByteArray(a))
        void ConnectHookSignals (QObject *sender, QObject *receiver, bool destSlot)
        {
            if (destSlot)
                CheckMatchingSigs (sender, receiver);

            const QMetaObject *mo = sender->metaObject ();
            for (int i = 0, size = mo->methodCount (); i < size; ++i)
            {
                QMetaMethod method = mo->method (i);
                if (method.methodType () != QMetaMethod::Signal)
                    continue;

                if (!IsHookMethod (method))
                    continue;

#if QT_VERSION >= 0x050000
                const auto& signature = method.methodSignature ();
#else
                const auto& signature = method.signature ();
#endif

                if (receiver->metaObject ()->indexOfMethod (LC_N (signature)) == -1)
                {
                    if (!destSlot)
                    {
                        qWarning () << Q_FUNC_INFO
                                << "not found meta method for"
                                << signature
                                << "in receiver object"
                                << receiver;
                    }
                    continue;
                }

                if (!QObject::connect (sender,
                        LC_TOSIGNAL (signature),
                        receiver,
                        destSlot ? LC_TOSLOT (signature) : LC_TOSIGNAL (signature),
                        Qt::UniqueConnection))
                {
                    qWarning () << Q_FUNC_INFO
                            << "connect for"
                            << sender
                            << "->"
                            << receiver
                            << ":"
                            << signature
                            << "failed";
                }
            }
        }
#undef LC_N
    };

    void BaseHookInterconnector::AddPlugin (QObject *plugin)
    {
        Plugins_.push_back (plugin);

        ConnectHookSignals (this, plugin, true);
    }

    void BaseHookInterconnector::RegisterHookable (QObject *object)
    {
        ConnectHookSignals (object, this, false);
    }
}
}