When a signal is emitted, the slots connected to it are usually executed immediately, just like a normal function call. Study our incredible collection of slots reviews and educate yourself about the amazing array of choices all waiting for you at Slotu today. Christophe Weis 1, 4 18 They are completely type safe. Introduction In GUI programming, when we change one widget, we often want another widget to be notified.
Clicking on a particular button zooms in on an image that is displayed. Is it correct that such slots are private? Would it be of any use to make such public slots? What is expected standard in these cases? Well, slots are basically normal routines of your class, sicne you may use them also directly.
Therefore, I would consider the private and public declaration as a matter of use and philosphy. If private is sufficient, I would use private slots. However, I am using slots across different classes and therefore, most of my slots are public. Also if you are trying to call the slots from QML environment, then slots need to be public only.
With the new syntax you actually do no longer need to specify a function as a SLOT, that part is now totaly ignored. Use public slots or private slots? This topic has been deleted. Only users with topic management privileges can see it. Join Stack Overflow to learn, share knowledge, and build your career.
I have never seen something between the private keyword and the: It only compiles after sending the code through Qt's preprocessor, the Meta-Object Compiler moc. As Frank points out, moc is only required for linking.
The extra keywords are defined away with the standard preprocessor. The keywords such as public , private are ignored for Qt slots. All slots are actually public and can be connected. Declaring slots as private means that you won't be able to reference them from context in which they are private, like any other method. Consequently you won't be able to pass private slots address to connect. If you declare signal and slot as private you are saying that only this class can manage then but function member pointers do not have access restrictions:.
Christophe Weis 1, 4 18 Russell Davis 5, 3 30 Thanks, Qt's preprocessor is what I was missing in my mental model of what was going on. Not correct, the code compiles all the time as "signals" and "slots" are empty defines so the compiler never sees them. These macros are hints for moc, which generates additional code.
What would fail is linking, as the moc-generated definitions signal definitions, metaobject, etc. Is the slots keyword necessary?