General and Desktop

@PusRob Are you sure? I've tried in my Ubuntu. I copied your code from the top post, only changed one line: QSettings::setPath(QSettings::defaultFormat(), QSettings::UserScope, "/tmp"); And the output is "/tmp/MyAppOrg/MyApp.conf"

@VRonin I can't express how grateful I am for this. I think there's a typo in the validate function (the condition of the third if statement should be numInput > m_max), but otherwise it worked. Thanks!

I did the migration with mysqldump then I edited the dump file. Then I have the resulting file into sqlite and saved it as database. The date columns are now stored in sqlite as TEXT fields. All done on a linux machine. Thank you VRonin for your suggestion. That sounds like a great idea. Can I do this in pyQt5 or do I need to go to C++? I think QSQLiteDriver is a plugin i.e. a shared library. That means I have to do this in C++. Is that right? I wanted to avoid C++ so that my application is more portable. But anyway this solution sounds great. Thanks for you answers guys.

the second solution is better for me because my string contain chars in "abc" and must have a constant position. Thank you @Pl45m4 , thank you @SGaist

@Poonam15 You can, but this was not the OP's question from 2011, he wanted a window to have a close button on its title bar.

@Engelard said in error: LNK1120: 1 unresolved externals: Such bugs of this framework makes me sad. I for the whole day was thinking what's wrong with me... Its not a bug in a technical sense. But it would be nice if qmake would recreate ALL of the make file when you change the .pro file or at least ask.

@JonB So embarrassing. As usual, I was too blind to see that the error code argument was changed from int to QString. Thank you....!

@Christian-Ehrlicher You mean that in future versions, QListWidget may handle this in a different way so it may for example return an invalid or wrong row index for example? So you'd recommend to bether stop sorting for the moment of interaction? As I can't see any disadvantages, I think I'll do that and stop/restart sorting while inserting the row.

STOP PRESS [Including for @SGaist, @mrjj's attention.] I revisited my 10 line program apparently showing leak on plain new QWidget but not on new QWidget; setWindowFlags(Qt::Popup);. If I remove the "test" non-Popup widget and only have the Popup widget then valgrind does report the Popup as a leak. If I reverse the order so that the Popup widget is new-ed first and the non-Popup is new-ed next, then valgrind does report the Popup widget as leaking but the non-Popup widget is not reported as leaking. For whatever reason, this reveals that valgrind sometimes only reports certain leaks but not others [has anyone else encountered this behaviour?]. This is "disappointing", but at least makes sense, showing nothing special about Popup. So going back to @mrjj's situation. I do not leak because my Popup widget is on the stack. In his situation he news on the heap, and I conclude that he does need to delete the Popup window. Problem #1 at least apparently resolved!

@Taytoo said in How to propagate/limit stylesheets through code: It's not doing anything special, just setting stylesheet for QDialog and nowhere else. Then in principle if it works from Designer-generated code you should be able to make it work in manual code? Defining custom classes gets too tricky e.g. with QStackedWidget and QTabWidget, I tried specifying a custom class but for some reason the style just wasn't applying I can only say that I do not find this. I do use custom classes when necessary, and it works for me. If I want to apply stylesheet rules across a variety of elements, I use the "dynamic class" principle described at https://doc.qt.io/Qt-5/stylesheet-syntax.html#selector-types Property Selector & https://doc.qt.io/Qt-5/stylesheet-examples.html#customizing-using-dynamic-properties. I use this against a dynamic class property, so I can have things like: /* stylesheet */ .backgroundColorTransparent { background-color: transparent; } /* code */ widget.setProperty("class", "backgroundColorTransparent"); I can't recall now, but I think you can associate multiple classes with a widget as a space-separated list on the class property. One other thought: if your only problem is with *background color", have a read of https://forum.qt.io/topic/115640/how-to-see-the-area-detected-by-qmouseevent/9.

@J-Hilk Dear @J-Hilk, At the time I accepted your suggestion that my problem was a Qt 5.12.2 issue, as per the bug report. I worked around it by setting the color on the conveniently-available parent widget. However, I now discover that my problem is as per my post at https://forum.qt.io/topic/115640/how-to-see-the-area-detected-by-qmouseevent/9, i.e. I need to add: myDerivedWidget->setAttribute(Qt::WA_StyledBackground, true); and then the background color works at run-time. Your bug report may well apply, but I don't think it's my case here. I trust you will understand if I now mark this post as the solution to my issue here!

@Bonnie, @luciole Well blow me down! This is indeed the problem/solution in my own code! Please see my recent report of this issue in https://forum.qt.io/topic/113109/widget-background-color-at-runtime. There I have a QWidget-derived class, whose background I wish to set, which is the child widget of a QMdiSubWindow. It worked in Designer but not at runtime. At the time I accepted @J-Hilk's reply at https://forum.qt.io/topic/113109/widget-background-color-at-runtime/2 thats a bug in Qt, you have 3 options: upgrade to 5.12.6/7 only set stylesheets in designer only set stylesheets in code Edit: found the related bug report: https://bugreports.qt.io/browse/QTBUG-79545 Maybe there is a Qt 5.12.2 issue, but it does not seem to be my case. Until now I had "solved" this by placing colored background not on my subclassed widget but instead on its parent, which is a QMdiSubWindow. Instead, I now find that all I have to do is add myDerivedWidget->setAttribute(Qt::WA_StyledBackground, true); and the background color works at run-time! FWIW, I tested and I do not have to have the Q_OBJECT macro on the derived class to make this work, though it does no harm. I do have to set the attribute.

You're missing a definition of your static variable. Put that in your .cpp file: SMessenger* SMessenger::instance_ = nullptr; Btw. don't forget to delete your singleton before your application object is destroyed. No QObject should live longer than that. One way to do it is to connect QApplication::aboutToQuit signal to your singleton's deleteLater slot when you're creating it. Btw.2 Don't use NULL. It's an old C style macro. If you need to be that explicit use nullptr or you could just assert(instance_).

I've updated the example project so you can test six different implementations of "focus ring", none of which are 100% successful. The only one that comes close is kTest_PARENT_STYLE, and only on mac. On windows i can't for the LIFE of me make ANY focus ring bigger than 1 pixel, which is just too small. I really need 3 pixels in order to keep the UI appearing the same as the previous (10 year old, 32bit) app. -dave

well. have no idea what the problem it is. recorded the video - https://youtu.be/60Gf27affeM @SGaist

@Christian-Ehrlicher good catch ! I have missed that line. I think it deserves a more prominent styling. I'll see to improve that.

Hi and welcome to devnet, You should rather enumerate the cameras with OpenCV as well so you will be consistent to access them.

@Lior said in Signal inside readyread of QUdpsocket: why the UI main thread stoped to respond ? the msleep is in anthor thread. Because you do it wrong (and I would guess the msleep is not in the thread but in the gui thread) but without code...