How to properly close a widget

Daniel_Contro

Hi to everyone,
I'm developing an application that has several custom widgets dynamically added/removed and I was wondering which is the proper way to close them, keeping in mind that they contain data that should be saved. I read something in the Qt's documentation but I can't comprehend if I should define a slot e.g. onClose() in each widget connected to QWidget::close() or if I should override QWidget::closeEvent().

Pl45m4

@Daniel_Contro said in How to properly close a widget:

override QWidget::closeEvent()

This is one possible way.

Depends on what QWidget you have and what data you are editing, you could make use of windowModified(click)

Daniel_Contro

It's mostly text, but also the widgets order is important to me (it's a hierarchical data structure); I have my own Controller and Model where I should store the data.

Should I override closeEvent() for every different custom widget that requires saving his data then?

Could this be a reasonable wait to override the method?

MyWidget() {
  connect(this, SIGNAL(closingMyWidget(int)), controller, SLOT(onClosingMyWidget(int)));
}
...
void MyWidget::closeEvent(QCloseEvent*) {
  emit closingMyWidget(_myWidgetId);
}

And what about all the subwidgets (base classes) created on the heap? Should I destroy them manually or does Qt takes care of them?

Bonnie

@Daniel_Contro said in How to properly close a widget:

define a slot e.g. onClose() in each widget connected to QWidget::close()

Just want to say that you cannot connect a slot to another slot / non-signal function...

Pl45m4

@Daniel_Contro said in How to properly close a widget:

Should I destroy them manually or does Qt takes care of them

If they have a parent, Qt takes care and they get cleaned up together with their parent. If you allocate member vars on heap, you need to take care of them (d'tor).
https://doc.qt.io/qt-5/objecttrees.html#construction-destruction-order-of-qobjects

@Daniel_Contro said in How to properly close a widget:

Could this be a reasonable wait to override the method?

Yes.

SGaist

Hi,

How are these widget managed from a data saving point of view ?