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General and Desktop

This is where all the desktop OS and general Qt questions belong.
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  • Reporting inappropriate content on the forums

    Pinned Locked spam
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    A
    Thank you for the report. I have banned the user, which got rid of the spam posting. Not a loss, as this user did not post any other content on the site. Just deleting this one posting was not possible. Thanks for reporting this.
  • Resize VirtualKeyboard ing QWidget

    Solved virtualkeyboard
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    Joe von HabsburgJ
    thanks you @SGaist
  • Qt Desktop app to browser app

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    C
    I wouldn't assume a rewrite yet. If most of the app is already Qt-based, WebAssembly is probably the first thing I'd evaluate. The biggest challenge is usually not Qt itself but the OpenGL requirements and whether all the third-party libraries can be built and run in the browser environment. A small proof-of-concept build is likely the fastest way to see how much work you're actually facing.
  • Building and shipping QT 6.10 on RHEL 8

    Unsolved webengine qt6 building qt
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    jeremy_kJ
    @SGaist Thanks for the clarification. LD_LIBRARY_PATH and other dynamic linker features are great development tools.
  • MariaDB / QMySqlDriver connection without SSL got 2026 error

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    E
    The cleanest cross-version solution that works for both Qt 5.15.2 and Qt 6 is setting the environment variable before QApplication initializes: qputenv("MARIADB_TLS_DISABLE_PEER_VERIFICATION","1"); If you are on Qt 6 only, you can alternatively use the connectOptions approach: MYSQL_OPT_SSL_VERIFY_SERVER_CERT = 0 One thing worth noting for anyone still on LAMPP with MariaDB 10.4.x — the issue only appears on newer LAMPP builds from 2025 onwards. Older installations from 2020 are not affected, so if you recently upgraded your LAMPP stack and suddenly started seeing the 2026 SSL error, this is almost certainly your problem.
  • QMenu is not getting drawn when there is a child doing WA_PaintOnScreen n GNOME

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    Pl45m4P
    @maarten said in QMenu is not getting drawn when there is a child doing WA_PaintOnScreen n GNOME: (I'm new here and assumed I would get a mail when somebody replied). https://forum.qt.io/user/maarten/settings Right side... you can specify what notifications you want to receive and how :))
  • How to create a QOpenGLContext from a GLFW EGL window?

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    S
    Very suspicious code, your first example with GLTF, do you actually have an EGL based context? If you do, are the implementations the same? it's possible that both Qt and GLFW try to load their own EGL and GL ES libraries. Kkeep in mind that its possible to create an ES context without using EGL, so you're looking for an ES context and assuming that it was created via EGL that might a false assumption. In general In my opinion this approach is just too finicky and is not going to work, whenever you have 2 different things that are using the same OpenGL context you're going to run into issues with a) unexpected state changes b) context version mismatch. A much better approach (and the only thing that actually has any chance of working) is to setup a context sharing group and share a render target texture. I.e. you create a shareable texture, setup an FBO, let QML render into the texture and the use that texture to render the result on the GLFW side.
  • 0 Votes
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    Christian EhrlicherC
    @Lan-Friend said in Clang-cl + lld-link + Qt 6.11: undefined symbol QConstIterator<QMetaSequence> when iterating QMetaSequence::Iterable: Is this a known ABI / export issue in Qt 6.11 MSVC builds when using clang-cl + lld-link? No, but clang-cl is not officially supported: https://doc.qt.io/qt-6/supported-platforms.html#windows You might create a bug report about it though.
  • php and c application data exchange .so lib linkage problem

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    SGaistS
    Hi, What do you mean by web interface ?
  • Qt 6.12 build from source

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    JoeCFDJ
    Avoid multi-thread build of webengine which needs about 15GB memory in parallel mode build. export NINJAFLAGS="-j1 -l1" use only one thread to build if webengine is included. if you do not need webengine, take it out of the build.
  • 0 Votes
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    Kent-DorfmanK
    My advise would be to write your own virtual keyboard app using Qt. Since it seems you are writing a kiosk application then consider dropping gnome completely and run the app on a raw X11 session. Well, actually a kiosk application is one of the few places where wayland is actually appropriate since it is a single application (if you integrate the popup keyword)
  • 0 Votes
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    M
    I wrote the email you suggested and no response. I tried to use a duckduck account and that doesnt work either (I don't prefer a gmail account) so perhaps I'll drop the bug quick: ColorPicker "Crosshairs" don't reflect color on drag when BLACK due to isNull() regression here: https://github.com/qt/qtbase/blame/v6.12.0-beta1/src/widgets/dialogs/qcolordialog.cpp#L817 Video "Steps to reproduce" from my Dropbox: https://www.dropbox.com/scl/fi/upl1g7w8mofoli1ew1y1g/QT6bug.mkv?rlkey=u04njublm9si74hptnp3h4y34&st=qxc081uz&dl=0
  • Qgtk3Style Theme engine is it broken?

    Unsolved qt5 theme gtk3
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    No one has replied
  • GTK Style Not Working On Qt5.7+?

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    Y
    So I came here while researching for the problems with qt5 theme. So in the archi wiki it says - QGtk3Style This is a platform theme built into qt5-base starting with version 5.7.0 [2] and qt6-base. It can be used to style Qt5 and Qt6 applications according to current GTK3 style. It can be enabled by setting the following environment variable: QT_QPA_PLATFORMTHEME=gtk3. I am on nixos and while if i set the same envionment variable qt6 apps like pcmanfm-qt, qbittorrent correctly use the same colors as my gtk3 theme, but it seems qt5 apps even though in logs they seem to load the plugin, dont theme accordingly and show the default white color. Its an old thread so I just want to know is the plugin abandoned? Meaning its no use trying to wait for it to update and be fixed or should i just switch to qtstyleplugins for qt5 apps?
  • QWidget in QMainToolBar can not hide ?

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    Christian EhrlicherC
    @sonichy said in QWidget in QMainToolBar can not hide ?: @Pl45m4 QWidget::setVisible() is useless too. This is what he wrote... "Note: You should use QAction::setVisible() to change the visibility of the widget. Using QWidget::setVisible(), QWidget::show() and QWidget::hide() does not work."
  • SVG rendering differently on Linux vs windows.

    Unsolved svg linux desktop icon qtreeview stylesheet
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    J
    I've tested the same code against Qt 6.9.3 and it doesn't seem to be an issue there.
  • Support for Long Names with QCanDbcFileParser?

    Unsolved can serialbus qcanbus dbcfileparser dbc
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    SGaistS
    Hi and welcome to devnet, Which version of Qt are you using ? Can you provide a minimal compilable example that shows this issue ?
  • 2 Votes
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    ansifpiA
    Nice work
  • This topic is deleted!

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  • Performing Calculations with Data from LineEdits

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    Joe von HabsburgJ
    I think you should use a DoubleSpinBox instead of a LineEdit. But I’ll proceed as if you’re still using a LineEdit. You can configure it the same way within the DoubleSpinBox. First of all, I think you want to perform a joint calculation using all the values you have. To do this, you need to add a calculate function to the slots that are connected to the currentIndexChanged signal. As @JonB mentioned above, you can access those values. For example, if you have five parameters and three of them are used in one calculation while two are used in a different calculation , you’ll need to adapt and customize your function accordingly. QString r_text = ui->lineEdit_r->text(); double r_double = r_text.toDouble(); QString gamma_text = ui->lineEdit_gamma->text(); double gamma_double = gamma_text .toDouble(); QString inletP0_text = ui->lineEdit_inletP0->text(); double inletP0_double = inletP0_text .toDouble(); calculate1(r_double, gamma_double, inletP0); ...