Getting MouseMoveEvents in Qt

You can use an event filter on the application.

Define and implement bool MainWindow::eventFilter(QObject*, QEvent*). For example

bool MainWindow::eventFilter(QObject *obj, QEvent *event)
{
  if (event->type() == QEvent::MouseMove)
  {
    QMouseEvent *mouseEvent = static_cast<QMouseEvent*>(event);
    statusBar()->showMessage(QString("Mouse move (%1,%2)").arg(mouseEvent->pos().x()).arg(mouseEvent->pos().y()));
  }
  return false;
}

Install the event filter when the MainWindows is constructed (or somewhere else). For example

MainWindow::MainWindow(...)
{
  ...
  qApp->installEventFilter(this);
  ...
}