Can't catch mouse-click in MainWindow's subclassed child widgets from my MainWindow

[alketi]

I'm unable to successfully capture a mouse click in my QMainWindow for subclassed child widgets, such those that live inside a subclassed QTabWidget, like buttons, QTextEdits, etc.

I install a mousePressEvent() filter on the QMainWindow class.

void MyTool::mousePressEvent(QMouseEvent *event)
{
    qDebug() << "mousePressEvent";
    QMainWindow::mousePressEvent(event);
}

void MyTool::mousePressEvent(QMouseEvent *event)
{
    qDebug() << "mousePressEvent";
    QMainWindow::mousePressEvent(event);
}

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I also pass the QMainWindow parent pointer to the subclassed child QTabWidget.

When I click around in the UI, I get a successful mouse press event if I click on whitespace (such as the tab widget frame). Good.

But I do not get a mouse press event if I click on any QWidget inside the QTabWidget, such as buttons or a text edit. These widgets would (I suppose) be grand-children of the QMainWindow.

Shouldn't I be able to install a mouse event filter on the parent and receive events for a click on any subclassed descendant? Or, do I need event filters at all child levels?