Top-Level Window vs Window in QGuiApplication?

[CJha]

The QGuiApplication class has two functions:

QWindowList QGuiApplication::topLevelWindows()

Returns a list of the top-level windows in the application.

and
QWindowList QGuiApplication::allWindows()

Returns a list of all the windows in the application.

Isn't a window a top-level window as well? What is the difference between these two functions?

[JKSH]

@CJha said in Top-Level Window vs Window in QGuiApplication?:

Isn't a window a top-level window as well? What is the difference between these two functions?

A window could be embedded inside another window. That makes it a window that is not top-level.

For example, see https://specifications.freedesktop.org/xembed-spec/xembed-spec-latest.html

[JonB]

@CJha
All topLevelWindows() appear in allWindows(), but not all allWindows() appear in topLevelWindows() :)

In Qt "Any widget without a parent widget is a top-level widget or window. " You should be able to verify this holds for all the windows/widgets in those two lists --- all topLevelWindows() should have no parent, and no other window in allWindows() should have no parent.

[CJha]

This post is deleted!

[CJha]

@JonB Thanks! sounds a little complicated, but I think I get it. The basic distinction being if a window has a parent then I will only find it using allWindows() and not using topLevelWindows()?

[JonB]

@CJha Yes, exactly that.