How to install an event filter on all components inside a QWidget

Question

I have my software with a lot of components ( textbox, checkbox, slider, ...). What i need to do is to install a filter to record all events done by the user ( click on checkbox, slide sliders, ...) save them and replay them later.

I first tryed to install the filter on all component, exemple :

MainGui::MainGui( QWidget* parent ) :
QMainWindow( parent ),
ui( new Ui::MainWindow ),
m_console( new Console( this ) ),
m_serial( &port_qt::get() ),
m_status( new QLabel( "Bienvenue sur STEG.", this ) ),
m_mainLayout( new QHBoxLayout() ){

ui->setupUi( this );
QWidget* centralWidget = new QWidget();
centralWidget->setLayout( m_mainLayout );
setCentralWidget( centralWidget );


addAction( m_console->action() );

statusBar()->addWidget( m_status );
statusBar()->layout()->setMargin( 9 );

QCheckBox *checkbox_1 = new QCheckBox("check 1");
checkbox_1->setChecked (true);

addWidgetToColumn(1,checkbox_1);
m_recorder.setObj(checkbox_1); // Install filter here

.......;}

This code works fine and i can succesfully record and replay a click on this checkbox. Unfortunatly, i need to install a filter which will work on ALL components inside the "centralWidget" and when i put the filter on it, i don't get any event related to the checkbox.

So i'm looking for a solution to install a general filter. Thanks you.

Edit:

Using qApp, i can succesfully get all events, but my problem now is to replay those events. I'm using qApp->postEvent(m_App, clonedEvent); (m_App is qApp). Events are sent but doesn't change Checkbox check status as it should.

Answer 1

I've tested this code and it should do what you want

file mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

protected:
    bool eventFilter(QObject *obj, QEvent *event);

private:
    Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H


file mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"

#include <QApplication>
#include <QEvent>
#include <QDebug>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    qApp->installEventFilter(this);
}

MainWindow::~MainWindow()
{
    delete ui;
}

bool MainWindow::eventFilter(QObject *obj, QEvent *event)
{

    const QObjectList& list = ui->centralwidget->children(); // or centralwidget->children();
    if(list.contains(obj))
    {
        if(event->type() == QEvent::MouseButtonPress)
        {
            qDebug() << "QEvent::MouseButtonPress";
            if(obj == ui->pushButton)
                qDebug() << "pushButton";
            else if(obj == ui->checkBox)
                qDebug() << "checkBox";
        }
    }

    return QObject::eventFilter(obj, event);
}

Tell me if you have any problems with it.