Signals and slots are loosely coupled: A class which emits a signal neither knows nor cares which slots receive the signal. Qt's signals and slots mechanism ensures that if you connect a signal to a slot, the slot will be called with the signal's parameters at the right time. Signals and slots can take any number of arguments of any type.
The QObject QObject is the base class to most Qt classes. Examples of exceptions are: Classes that need to be lightweight such as graphical primitives Data containers (QString, QList, QChar, etc)Classes that needs to be copyable, as QObject s cannot be copied.

There are certain QObject macros and conventions that are for use in private Qt APIs only. This page describes them.

Qt public slots vs private slots This means qt public slots vs private slots that, in essence, the slot machine game takes all the money played into it and pays it out to some lucky winners.Evening Sunday bingo session will follow with warm ups at 3:15pm and the regular session starting at 4pm. The QObject QObject is the base class to most Qt classes. Examples of exceptions are: Classes that need to be lightweight such as graphical primitives Data containers (QString, QList, QChar, etc)Classes that needs to be copyable, as QObject s cannot be copied.

Q_PRIVATE_PROPERTY

Introduced here.

This macro is used when you have a C++ class that is public that exposes a property whose type is not public. For example, QQuickItem is a public C++ class that exposes an anchors property, whose type is the private QQuickAnchors class:

In this case, the macro expects there to be a getter named anchors() in the type returned by QQuickItem::d_func(), which there is:

When using this macro, it's necessary to include the generated moc file at the end of the corresponding .cpp file:

If you don't do this, you may see an error like the following (example taken from another class -- replace popup with item and it's the same error):

Private Slots

Q_PRIVATE_SLOT

Qt Private Slots Vs Public Slots

Similar to Q_PRIVATE_PROPERTY, Q_PRIVATE_SLOT is used when you have a slot in a private class that you want to be considered part of the API of the corresponding public class, without affecting the interface (and hence binary compatibility) of that public class. Using QQuickItem as an example again, Q_PRIVATE_SLOT is used to declare this private slot in qquickitem.h:

The slot itself is declared in qquickitem_p.h:

Qt Public Slots

Retrieved from 'https://wiki.qt.io/index.php?title=Private_QObject_API&oldid=33035'

Qt Private Slot Vs Public Slot