Send singal in eventFilter

[Knj.Tkm]

Hi.
I want to send signal in eventFilter,but it fail.
Can't send signal in eventFilter?

Event.cpp

bool Event::eventFilter(QObject *, QEvent *ev)
{
    if( ev->type() == QEvent::Enter ){
        qDebug() << "ENTER!";
        emit sigMouse();
        return true;
    }
    if( ev->type() == QEvent::Leave){
        qDebug() << "LEAVE!";
        emit sigMouse();
        return true;
    }
    return false;
}

Connect.cpp

Connect::Connect(QObject *parent) : QObject(parent)
{
    connect( &eve, SIGNAL( sigMouse() ), this, SLOT(slotMouse() ));
}

void Connect::slotMouse()
{
    qDebug() << "HERE";
}

It show "ENTER!" and "LEAVE!", but "HERE” is can't show.

[J.Hilk]

@Knj-Tkm well, there's your problem,

you have 2 Event instances, one in MyWidget and one in Connect,

that in MyWidget is installed, and emits the debug texts, that one in Connect is not, but you connect to those signals.

You expect citrus smell from an apple :D
Fix that

[jsulm]

@Knj-Tkm Please check whether your connect() call succeeded (it returns a bool). Even better is to use new Qt5 connect syntax.
Also, it is not clear what eve is and whether it is the one which actually used.

[Knj.Tkm]

@jsulm
connect is true.
eve is create an object in Header

private :
     Event eve;

[jsulm]

@Knj-Tkm said in Send singal in eventFilter:

eve is create an object in Header

And is this eve really the one which is used and gets the events? Do you have another one somewhere?

[Knj.Tkm]

@jsulm
Yes, It using.
I don't have another.

[J.Hilk]

@Knj-Tkm this

Connect::Connect(QObject *parent) : QObject(parent)
{
    connect( &eve, SIGNAL( sigMouse() ), this, SLOT(slotMouse() ));
}

looks like the constructor, where I would have expected to see the event filter applied to the class, where do you apply it ?

[Knj.Tkm]

@J-Hilk
In Header

#include <QObject>
#include "Event.h"

class Connect: public QObject
{
    Q_OBJECT

public:
    Connect(QObject *parent = nullptr);

public slots:

    void slotMouse(void);

private:
    Event eve;
};

[J.Hilk]

@Knj-Tkm
so, you're missing the installEventFilter call?

[Knj.Tkm]

@J-Hilk
Sorry, I was wrong.

MyWidget.h

namespace Ui {
class MyWidget;
}

class MyWidget: public QWidget
{
    Q_OBJECT

public:
    MyWidget();

private:

    QVBoxLayout* myMainLayout;
    Ui::Chart* myWidget;

    Event event;
};

MyWidget.cpp

MyWidget::MyWidget() : QWidget(), myWidget(new Ui::MyWidget)
{
    myWidget->setupUi(this);
    myMainLayout = new QVBoxLayout;
    myMainLayout->setMargin(0);
    myWidget->frame->setLayout(myMainLayout);
    myWidget->frame->setGeometry(0, 0, 1360, 760);
    myWidget->rectangle->installEventFilter(&event);
}

[J.Hilk]

@Knj-Tkm well, there's your problem,

you have 2 Event instances, one in MyWidget and one in Connect,

that in MyWidget is installed, and emits the debug texts, that one in Connect is not, but you connect to those signals.

You expect citrus smell from an apple :D
Fix that

[Knj.Tkm]

@J-Hilk
I understand the principle, but I don't know how to do it.
What should I do?

Ok, I totally get it now.
You were trying to use it in a different place than where you installed it...
Thanks!

[jsulm]

@Knj-Tkm @J-Hilk said in Send singal in eventFilter:

you have 2 Event instances, one in MyWidget and one in Connect

So, my assumption was correct...