@AnneRanch said:

As usual , I like to get plain English description of the following pointer usage

// QMdiArea is a container of subwindows // Get a list of pointers to those subwindows and assign it to a local list variable named "windows" QList<QMdiSubWindow *> windows = mdiArea->subWindowList(); // Assign i-th element of that list to a local variable "mdiSubWindow" QMdiSubWindow *mdiSubWindow = windows.at(i); // QMdiSubWindow is a container that hosts a widget. // Retrieve a pointer to that widget // Try to cast that pointer to a pointer to type MdiChild and assign the result to local variable "child" // If the cast succeeds then the variable "child" points to the widget hosted by QMdiSubWindow // If the cast fails (widget is not a MdiChild class) then the variable "child" is a nullptr MdiChild *child = qobject_cast<MdiChild *>(mdiSubWindow->widget());

somebody comes up with a way to memorize what is definition and what is a declaration

You can try to remember it by imagining a herald on a town square. He's declaring, or in other words announcing that something exists e.g. "Hello good people. The function x exists! Let's be happy!".
Then someone from the crowd asks "ok, but what is it?" and a local scientist defines it, or in other words explains/describes it in detail, saying that "x is this and that my friends and it does this in that way".
Herald is your header declaration guy.
Scientist is your cpp definition guy.

@mzimmers I confirm the guess of @JonB. If the thread is already marked as solved you have to use the "Topic Tools" button, "Mark as Unsolved" and then you'll be able to select the answer you want.

@mzimmers said in old hacker...low tolerance:

Let's all quit, move to Florida and go golfing.

I retired some years ago (never been busier, though), I would not move to the USA, but the Caribbean looks interesting.
Especially when they are turning their backs on the dollar system (which turned its back on them years ago).
https://www.stvincenttimes.com/st-kitts-nevis-to-make-bitcoin-cash-legal-tender-by-march-2023/

@AnneRanch said in To build bluteooth application in QT .....:

sudo apt install qtconnectivity5-dev and reboot.

qrt@qrt-desktop:~$ sudo apt install libbluetooth-dev

now read again what you wrote in the first line and typed in the second

@JonB OK, I have posted similar subject elsewhere. The discussions went nowhere, so I decided to try the "OS / window event" approach here. Perhaps I need to find how the new process result of bluetoothctl command physically highlights the text.
If I can solve that , I am sure I can find a way to "hook into" whatever event highlights the text.

PS My OS is Linux .

@candy76041820 said in Why cling onto RegEx?:

1a. Well it's just a makeshift & demonstrative snippet to convey my idea of usting something instead of regex, so don't be so picky.

Your point was to demonstrate that a simpler solution was available. However, if you can't demonstrate that the simpler solution does everything required then it isn't a solution and you haven't demonstrated anything. It's hardly being "picky" to point this out!

Yup, that's right.

Hi, welcome to the forum.

Qt's ownership model was created looong before C++ added move semantics and smart pointers. It has its own way of handling it via the parent child mechanism and it works fine. There's absolutely no need to mix those two models just because the standard added it.

Apart from that QObjects are non-copyable and non-movable by design, so things like lineEdit_local = QLineEdit or std::move(QLabel... are out of the question. The library is just not designed around references, so changing it would pretty much mean rewriting entire Qt into something else.

Besides, C++ Core Guidelines are just that, guidelines for designing code. Qt was designed waaaaay before they were and it follows quite a different philosophy. It's wort remembering that Qt's fundamental design and rules were created before even C++98. At that point in time there were different approaches emerging and Qt and std:: went different ways. It doesn't automatically mean one or the other is better or worse. They both accomplish roughly the same idea, just in different ways. Trying to combine them is not a good idea though.

And just to clarify - even if you'd make QObject movable the method you want to write would be QWidget& addWidget(QWidget&& w) and invocation would be addWidget(QLabel(tr("Message:")));. Objects created as in-line parametrs are already r-values, so move is not necessary in that case. The way you wrote it wouldn't compile. You can't use move to turn r-value into a pointer.

@mzimmers said in anyone want to play lawyer (LGPL)?:

users are allowed to modify the Qt libraries (or at least, to overlay them with their own)

yes of course users have to be allowed to modify that, but you only have to give warranty to the product shipped(and tested) as is. If the user decided to modify anything he/she is on their own.

Thats at least the way I have seen most companies, that use GPL, do it.

There is no need to follow Wikipedia. For me it will always be "Kyew Tee"

See https://vizacademy.co.uk/architectural-visualization-portfolio/

Are you using QML? I don't know about widgets, but in QML you can rotate on all 3 axis of an Item. So if you wanted to mirror the text downward you would rotate on the x axis.

This is a forum for Qt Framework, not Unity.

You never have to publish (i.e. making it public to everyone) your code. At least that depends on the mode of distribution.

The GPL only places requirements on you when you give your software to someone else. Everyone who receives your software is also eligible to your source code (under GPL, not under LGPL). So, if you give your software to one or two people you also have to give them the source code. If they decide to further give the software to somebody else, they also have to provide the source code to those people. If you put up your software for everyone to download on the internet, then you need to actually publish your source code. This all only applies to GPL. LGPL only means that this applies to the library (Qt in this particular case) and not your own source code. Also, you can provide a written offer valid for at least three? months to provide the source code to everyone who receives your software instead of giving them the source code directly.

Everything that is private and stays private does not have any requirements on the source code.

I also wanted to show message count and notification count. For which the easiest method is embedding it and accessing it's element.
I don't know how to embed this site because of X-Frame-Options . Is there another way to do it?