mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QKeyEvent>
#include <QMouseEvent>
#include <QDebug>

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

    editor = new QTextEdit(this);
    setCentralWidget(editor);

    editor->installEventFilter(this);
}

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

bool MainWindow::eventFilter(QObject *target, QEvent *event)
{
    if (target == editor)
    {
        if (event->type() == QEvent::KeyPress)
        {
            QKeyEvent *keyEvent = static_cast<QKeyEvent*>(event);
            qDebug() << "Ate key press" << keyEvent->key();
            return true;
        }
        else
        {
            return false;
        }
    }
    else if (target == editor->viewport())
    {
        if (event->type() == QEvent::MouseButtonPress)
        {
            QMouseEvent *mouseEvent = static_cast<QMouseEvent*>(event);
            qDebug() << "positon of mouse is" << mouseEvent->pos();
            return true;
        }
    }

    return QMainWindow::eventFilter(target, event);
}