deactivate hook with qobject

[Jeronimo]

Hi i'm connecting to my external class with qobject to check mouse event's . But when i try to deactivate the hook with emit instance().event(); doesnt seem's to work the problem seem .this dont call signal. Obviously when i do this :

mouseHook = SetWindowsHookEx(WH_MOUSE_LL, mouseProc, hInstance, 0);
UnhookWindowsHookEx(mouseHook);

Stop me the hook. But the signal never is called?¿
Code:
main.cpp:

#include <QCoreApplication>
#include <QDebug>
#include "mouselogger.h"

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    QObject::connect(&MouseLogger::instance(), &MouseLogger::mouseEvent,
                     [](){

    });

    return a.exec();
}

mouse.cpp:

#include "mouselogger.h"
#include <QDebug>

MouseLogger &MouseLogger::instance()
{
    static MouseLogger _instance;
    return _instance;
}

MouseLogger::MouseLogger(QObject *parent) : QObject(parent)
{
    HINSTANCE hInstance = GetModuleHandle(NULL);
    // Set hook
    //mouseHook = SetWindowsHookEx(WH_MOUSE_LL, mouseProc, hInstance, 0);
    // Check hook is correctly
    //if (mouseHook == NULL) {
      //  qWarning() << "Mouse Hook failed";
    //}
}

LRESULT CALLBACK MouseLogger::mouseProc(int Code, WPARAM wParam, LPARAM lParam)
{
    Q_UNUSED(Code)

    // Having an event hook, we nned to cast argument lParam
    // to the structure of the mouse is the hook.
    MOUSEHOOKSTRUCT * pMouseStruct = (MOUSEHOOKSTRUCT *)lParam;

    // Next, we check to see what kind of event occurred,
    // if the structure is not a pointer to nullptr
    if(pMouseStruct != nullptr) {
        switch (wParam) {
        case WM_MOUSEMOVE:
            qDebug() << "WM_MOUSEMOVE";
            break;
        case WM_LBUTTONDOWN:
            qDebug() << "WM_LBUTTONDOWN";
            break;
        case WM_LBUTTONUP:
            qDebug() << "WM_LBUTTONUP";
            break;
        case WM_RBUTTONDOWN:
            qDebug() << "WM_RBUTTONDOWN";
            break;
        case WM_RBUTTONUP:
            qDebug() << "WM_RBUTTONUP";
            break;
        case WM_MBUTTONDOWN:
            qDebug() << "WM_MBUTTONDOWN";
            break;
        case WM_MBUTTONUP:
            qDebug() << "WM_MBUTTONUP";
            break;
        case WM_MOUSEWHEEL:
            qDebug() << "WM_MOUSEWHEEL";
            break;
        default:
            break;
        }
        emit instance().mouseEvent();

    }

    // After that you need to return back to the chain hook event handlers
    return CallNextHookEx(NULL, Code, wParam, lParam);
}

mouse.h:

#ifndef MOUSELOGGER_H
#define MOUSELOGGER_H

#include <QObject>
#include <windows.h>

class MouseLogger : public QObject
{
    Q_OBJECT
    Q_DISABLE_COPY(MouseLogger)
public:
    static MouseLogger &instance();
    explicit MouseLogger(QObject *parent = nullptr);
    virtual ~MouseLogger(){}

    // Static method that will act as a callback-function
    static LRESULT CALLBACK mouseProc(int Code, WPARAM wParam, LPARAM lParam);
signals:
    // The signal, which will report the occurrence of an event
    void mouseEvent();
    void Eventos();

public slots:


private:
    // hook handler
    HHOOK   mouseHook;
};

#endif // MOUSELOGGER_H

[mrjj]

hi
emit instance().event() ---> emit instance().Eventos();

Would emit a signal.

I dont see you have this signal hooked up to any slot ?

[Jeronimo]

@mrjj yeah i didnt include because when i do this:
QObject::connect(&MouseLogger::instance(), &MouseLogger::mouseEvent,
{

});

The signal never is emitted. In other words , i want to call the signal but i think like you say me i need to include some slot first? to be emitted first.
Ok i tried to do this creating slot define the slot:
void MouseLogger::parada(){
qDebug() << "test";
emit instance().mouseEvent();

}
and call with:

QObject::connect(&MouseLogger::instance(), &MouseLogger::mouseEvent,
{

});

Not seem's to show nothing?

[mrjj]

@Jeronimo

Since its your signal. you defined it.
You must also emit it.
and if no slot is connected, nothing happens.

So you did call
MouseLogger::instance().parada() from main?

[Jeronimo]

@mrjj i tried this but not seem's to work i'm trying to use qobject because the class is separated.
But anyways not seem's to stop my hook:
Main.cpp:

#include <QCoreApplication>
#include <QDebug>
#include "mouselogger.h"

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    QObject::connect(&MouseLogger::instance(), &MouseLogger::mouseEvent,
                     [](){

    });
    

    return a.exec();
}

mouse.cpp:

#include "mouselogger.h"
#include <QDebug>

MouseLogger &MouseLogger::instance()
{
    static MouseLogger _instance;
    return _instance;
}

MouseLogger::MouseLogger(QObject *parent) : QObject(parent)
{
    HINSTANCE hInstance = GetModuleHandle(NULL);
     //Set hook
    mouseHook = SetWindowsHookEx(WH_MOUSE_LL, mouseProc, hInstance, 0);
    // Check hook is correctly
    if (mouseHook == NULL) {
        qWarning() << "Mouse Hook failed";
    }
}

void MouseLogger::parada(){
    mouseHook = SetWindowsHookEx(WH_MOUSE_LL, mouseProc, hInstance, 0);
    UnhookWindowsHookEx(mouseHook);
    emit instance().mouseEvent();
}

LRESULT CALLBACK MouseLogger::mouseProc(int Code, WPARAM wParam, LPARAM lParam)
{
    Q_UNUSED(Code)

    // Having an event hook, we nned to cast argument lParam
    // to the structure of the mouse is the hook.
    MOUSEHOOKSTRUCT * pMouseStruct = (MOUSEHOOKSTRUCT *)lParam;

    // Next, we check to see what kind of event occurred,
    // if the structure is not a pointer to nullptr
    if(pMouseStruct != nullptr) {
        switch (wParam) {
        case WM_MOUSEMOVE:
            qDebug() << "WM_MOUSEMOVE";
            break;
        case WM_LBUTTONDOWN:
            qDebug() << "WM_LBUTTONDOWN";
            break;
        case WM_LBUTTONUP:
            qDebug() << "WM_LBUTTONUP";
            break;
        case WM_RBUTTONDOWN:
            qDebug() << "WM_RBUTTONDOWN";
            break;
        case WM_RBUTTONUP:
            qDebug() << "WM_RBUTTONUP";
            break;
        case WM_MBUTTONDOWN:
            qDebug() << "WM_MBUTTONDOWN";
            break;
        case WM_MBUTTONUP:
            qDebug() << "WM_MBUTTONUP";
            break;
        case WM_MOUSEWHEEL:
            qDebug() << "WM_MOUSEWHEEL";
            break;
        default:
            break;

        }


    }

    // After that you need to return back to the chain hook event handlers
    return CallNextHookEx(NULL, Code, wParam, lParam);
}

mouse.h:

#ifndef MOUSELOGGER_H
#define MOUSELOGGER_H

#include <QObject>
#include <windows.h>

class MouseLogger : public QObject
{
    Q_OBJECT
    Q_DISABLE_COPY(MouseLogger)
public:
    static MouseLogger &instance();
    explicit MouseLogger(QObject *parent = nullptr);
    virtual ~MouseLogger(){}
    HINSTANCE hInstance;
    void parada();
    // Static method that will act as a callback-function
    static LRESULT CALLBACK mouseProc(int Code, WPARAM wParam, LPARAM lParam);
signals:
    // The signal, which will report the occurrence of an event
    void mouseEvent();
    void Eventos();

public slots:


private:
    // hook handler
    HHOOK   mouseHook;
};

#endif // MOUSELOGGER_H

[mrjj]

well you seems to create a new ONE and then stop that , not the one you create in constructor

MouseLogger::MouseLogger(QObject *parent) : QObject(parent)
{
HINSTANCE hInstance = GetModuleHandle(NULL);
//Set hook
mouseHook = SetWindowsHookEx(WH_MOUSE_LL, mouseProc, hInstance, 0); <<< the FIRST

void MouseLogger::parada(){
mouseHook = SetWindowsHookEx(WH_MOUSE_LL, mouseProc, hInstance, 0); <<<< NEW ??
UnhookWindowsHookEx(mouseHook);
emit instance().mouseEvent();
}

so I would expect it to be

void MouseLogger::parada(){
UnhookWindowsHookEx(mouseHook);
}

[Jeronimo]

@mrjj ok thx one question i can call with this:
MouseLogger::instance().parada();

But then qobject can't be used to call parada(), only connect me the signal with the instance only so?

[mrjj]

@Jeronimo

Nothing should stop you from doing
MouseLogger::instance().parada(); directly