QWidget QMouseEvent position() reporting relative to centralWidget

dabble53

I'm developing a custom widget derived from QWidget. (Linux/Fedora-42/g++/qt 6.9)
class MyWidget : public QWidget
{ ... usual stuff ...
void mousePressEvent(QMouseEvent*) override;
MyWidget(QWidget* parent, QRect geometry) : QWidget(parent)
{
setGeometry(geometry);
setFocusPolicy(Qt::StrongFocus);
};
I create in a MainWindow (button) click event
MyWidget* p = new MyWidget(ui->centralwidget, QRect(40, 40, 100, 100);
p->show();

When I click on the displayed widget, the mouse event is giving me
coordinates relative to centralWidget. E.g., if I click on the upper left
corner, the mouse event position() is reporting (40, 40), not the (0,0)
I would expect.
Or am I reading the documentation wrong that says the coordinates
should be relative to MyWidget?

JonB

@Kent-Dorfman
I was just looking at this, as that is what it sounds like. But see here, the docs https://doc.qt.io/qt-6/qmouseevent.html#details state:

Mouse move events will occur only when a mouse button is pressed down, unless mouse tracking has been enabled with QWidget::setMouseTracking().

So OP is calling mousePressEvent() not mouseMoveEvent(), so why should this apply here?

SGaist

Hi,

Which desktop environment are you using ?
Which window manager ?
Can you provide a minimal compilable example that shows this behavior ?

Kent-Dorfman

Use < QWidget::setMouseTracking()> in your widget class, otherwise the parent will receive the event, not the child.

JonB

@Kent-Dorfman
I was just looking at this, as that is what it sounds like. But see here, the docs https://doc.qt.io/qt-6/qmouseevent.html#details state:

Mouse move events will occur only when a mouse button is pressed down, unless mouse tracking has been enabled with QWidget::setMouseTracking().

So OP is calling mousePressEvent() not mouseMoveEvent(), so why should this apply here?

Pl45m4

@dabble53

Simple:
Your point is in parent coordinates. And parent is the centralWidget to which your widget is located at 40,40... exactly the values to pass to it.

So how do you print these numbers?