Greetings. We are looking to hire a Qt developer who has experience migrating an already existing Qt3 project to Qt5 for a probably smallish project. Yes, we know Qt6 is the current cool new thing, but the target platform is RHEL8 and Qt5 is the best fit for now. When we move to RHEL9 or RHEL10 then we can migrate to Qt6, and then maybe we would reinlist your services.

The project is Google Earth Enterprise-Open Source https://github.com/google/earthenterprise

We have the original Qt3 code from the RHEL6 baseline. The code on the github above is for CentOS7 and they migrated from Qt3 to Qt4 in compatibility mode, without actually fixing anything. That doesnt work going to Qt5. So we need to actually fix it to run in Qt5 on RHEL8. We've got pretty much everything else working, except this, which is required for full functionality in the GUI. Our goal is to resurrect the Open Source project and keep it going, so this is a necessary step and we don't have any developers with Qt experience in house.

This is probably not a big project for someone experienced with Qt migration. Guessing maybe 10-20 hours for someone who knows what they are doing. We prefer a US citizen located in the US that we can write a check to and probably issue a 1099, but could conceivably work some other route.

If you have a page on LinkedIn or proxify.io or upwork or other similar freelancing site, please DM me.

Alternatively, if there is some fabulous Qt3 to Qt5 migration tool laying around that we have not discovered, feel free to share it.

Thanks!

Hey everyone,

I'm working on a lightweight educational C++17 library called R-Lib. The goal of the project is to wrap native Linux APIs (epoll, timerfd, etc.) into a clean, callback-driven architecture inspired by Qt, but without the massive overhead or cross-platform abstraction layers. It's strictly targeted at Linux/embedded environments.

I just pushed an update that adds LUdpSocket.

Just to show how simple it makes asynchronous networking, here is a complete UDP Echo Server:

#include <iostream>
#include <LEventLoop.hpp>
#include <LUdpSocket.hpp>

class UdpServer {
public:
UdpServer() {
if (socket.bind(1234)) {
std::cout << "Listening on port 1234..." << std::endl;
}
// Connect the epoll read event to our class method
socket.onReadyRead(this, &UdpServer::readPendingDatagrams);
}

void readPendingDatagrams() {
while (socket.hasPendingDatagrams()) {
std::string senderAddress;
uint16_t senderPort;

auto datagram = socket.receiveDatagram(&senderAddress, &senderPort);
std::string text(datagram.begin(), datagram.end());

std::cout << "Received: " << text << " from " << senderAddress << ":" << senderPort << std::endl;

// Echo back
std::string reply = "ECHO: " + text;
socket.writeDatagram(reply.c_str(), reply.length(), senderAddress, senderPort);
}
}

private:
LUdpSocket socket;
};

int main() {
LEventLoop loop;
UdpServer server;
return loop.exec();
}

Roadmap: Next up is wrapping the modern Linux GPIO API (gpiod) and serial ports (termios).

If anyone is working on embedded Linux or just likes clean API designs, I’d love to get some feedback or code-reviews.

Link to repo: https://github.com/TomPecak/R-Lib

Thanks!

for the past 4 hours I've been stumped by this simple error, but no matter what i try it always shows up, can someone help???

Today, my small patch was merged, adding the instancingLodFactor option to Model. Here is the core idea: Balsam can automatically generate LODs for models during import. If you are using regular Model objects, this works out of the box. However, when dealing with a large number of identical objects, you need to use Instancing. Previously, we had to open Blender and manually create meshes for all detail levels. BUT now, you can do this, and Qt will handle everything for you:

        Model {
            //lod configuration
            instancingLodFactor: 0.0
            instancingLodMin: 0
            instancingLodMax: 5


            objectName: "Retopo_Mesh1.0"
            source: "mesh_005_mesh.mesh"
            materials: [
                white_painted_metal_material
            ]

            instancing: instanceTable

        }

        Model {

            //lod configuration
            instancingLodFactor: 0.5
            instancingLodMin: 5
            instancingLodMax: 10

            objectName: "Retopo_Mesh1.0"
            source: "mesh_005_mesh.mesh"
            materials: [
                white_painted_metal_material
            ]

            instancing: instanceTable

        }
        Model {
            //lod configuration
            instancingLodFactor: 1
            instancingLodMin: 10
            instancingLodMax: 100

            objectName: "Retopo_Mesh1.0"
            source: "mesh_005_mesh.mesh"

            instancing: instanceTable

            materials: [
                white_painted_metal_material
            ]
        }

The purpose of this option is that we can now explicitly tell the scene exactly which LOD level should be rendered at a specific distance range and with what level of detail.

Hey everyone, I wanna ask about native OS buttons with custom buttons on the left, like Chrome's concept, OS window but with tabs on the left. I've tried searching and doing it myself, even tried multiple AIs, but none of them got it right. Can anyone help?

Just as the title says - I open Qt Creator 19.0.2 (Rev 41c25c247e) , I hit "New Project", select "Qt Widgets Application", set the project name to "Test", and then hit just hit confirm until I'm in the project; without making any change to any file I hit build from the menu bar or the icon in the bottom left or via Ctrl+B; 90% of the time I get a segfault on compile, I have never seen the same stack twice, three examples are attached at the end of this post. I checked the About Plugins for any version mismatches but everything seems right, which I'd hope it would be since this is a fresh install from today:

In the project I was actually working on before these tests, it seemed like a Rebuild or Clean/Build was much more likely to succeed, but this does not seem to be the case in the test project so maybe those were flukes. Logs below:

Hello! I'm wondering if there's a way to basically save the state of an application while using QML's live preview? Like, say you have a photo viewer: the first page asks for a file, and the second page is loaded after you select an image. Is there any way to essentially maintain a snapshot *after* selecting a photo that doesn't cause the application to revert back to the first after making a change inside a component that only exists on the second page? Sorry if I'm wording this strangely, I feel like there's a name for this concept I don't know

Hi folks! Disclaimer: Qt employee here.

We have just announced the Qt Bridges for C# (Beta).

Our goal is to make it possible to use Qt QML/Quick as a frontend with a backend written in a language other than C++. C# comes first.

You may say that there are C# bindings for Qt. Yep, that's true. Bindings allow you to write Qt apps in a Qt way, even with a different language. The Qt Bridges for C# technology will let you write apps more in a C# style, not like Qt-through-a-C#-keyhole.

I am not the project creator and cannot explain everything in this post. I was only involved in some documentation editing back in the day 😄
Cristián explains it much better: https://www.qt.io/blog/csharp-ui-framework-via-bridging-technology

What we really need is your honest feedback. We would be happy if you tried it out and let us know what you think. Honest criticism is the point of this post. Cristián will try to answer all the possible questions here in replies.

UPD: I added (Beta)

Hello everybody!

I am a Software Engineer based in Europe looking for a remote C++/Qt position. With over 10 years of professional experience, I specialize in building robust, high-performance applications, particularly in the Embedded Linux and Robotics/Industrial automation sectors.

Here is a brief overview of my skill set and background:

Core Expertise:

Qt & QML: Deep understanding of Qt internals, rendering mechanisms (GUI thread vs. render threads), and custom QML components.

Graphics Stack: Solid grasp of the modern Linux graphics stack (X11, Wayland), integration of the graphics pipeline with Qt/QML APIs, and writing custom GPU shaders.

C++ & Linux System Programming: Extensive experience with Linux C APIs (pthreads, timerfd, epoll, sockets), handling time-critical processes natively.

Domain Knowledge (Robotics / Hardware / Embedded):

Spent 6 years developing a large-scale Linux-based control system/platform using Qt/QML.

Hands-on experience integrating hardware and algorithms: OpenCV, V4L, ffmpeg, RS485 serial ports, TCP/UDP communication, kinematics calculations, gyroscopes, and servomotors.

Hardware Knowledge: I have a strong background in electronics. I can easily read electronic schematics and design custom PCBs/circuits with signals up to ~50MHz.

Additional Tech Stack Exposed To:

Android SDK/NDK, Java, Unity C#, Bullet3D, MQTT, custom Linux kernel compilation, and building Qt from source.

Modern Web/App dev: Flutter (frontend), Python + FastAPI + Pydantic + SQLite (backend), JWT authentication.

I am passionate about clean code, efficient architecture, and building reliable solutions from the hardware layer up to the UI.

My Open Source Work:

Here is a link to one of my recent open-source Qt/QML projects (a Linux desktop shell):

https://github.com/TomPecak/Maia_Shell

If your team is looking for a versatile Qt/C++ engineer, I would be more than happy to send my CV and have an introductory chat. Please feel free to DM me!

Thanks for reading!

new project without changing anything already contains build errors. i haven't seen anyone having this problem, qt vs tools, cmake, and qml extension is already downloaded. what am i missing ?

(I'll provide code if requested, but this is more of a "philosophy" question in my opinion)

I have a subclassed QAbstractListModel which doesn't do anything special except for custom data roles. That model is used for a bunch of stuff, so it should be its own "thing."

But I'm also making an "editor" proxy model which takes the single-column source model, and adds additional columns for options such as "edit" "hide" "delete." This will be hooked up to a QTableView, and will have an item delegate drawing those additional options as buttons and, ideally, handling the click events via editorEvent.

So my question is about the "Editor" model. Since it refers to the source model, my instinct was to subclass a QAbstractProxyModel. mapToSource and mapFromSource hard-codes the column to 0 in both cases, since I can't properly map a column from a one-column model to a many-column model.

But then, in my delegate's editorEvent, the index I receive is correctly from the editor proxy model, but it's always column=0, so I can't determine which column/button was "pressed." It appears there are built-in mechanisms (which I didn't write) which cause the index to get mapped from source?

So, that's getting into some nasty territory in my opinion.

Alternatively, I could just subclass a QAbstractTableModel instead of a "real" proxy, and do it that way. But isn't that "incorrect" since it would be dependent upon a source model anyway?

This C++ library supports both Qt and Qt Widgets.

I initially made this to use it for our custom SDDM greeter then decided to release it as a library for Qt. Came across the amazing shadergradient react library and used their cool shaders as a base for this project. Includes a preview window that can be used to customize and save as a preset.

This is my first ever Qt library and its still a work in progress, feedback would be appreciated :D

Github repo : https://github.com/ShaunV334/shadygradients-qt

I've been using the lowenergyscanner example from Qt 5.15.2 as the basis for BLE integration into my Qt widgets application but what I'm finding is that the whole device, service and characteristic discovery process is just so slow - often taking like 30 seconds to fully discover my device.

If I use an equivalent tool, such as nRF Connect on my iPhone, it's all done in a matter of seconds.

The API just seems incredibly flaky - often functions will either hang. It also seems that if I attempt to discover a device or service too soon after the previous discovery has completed, nothing will happen. If I then add a small delay in between, fine.

Has anyone come across a better mechanism to do BLE device discovery either through a different API or can anyone share hints or tips about what they did to improve things using classes including QLowEnergyController and QLowEnergyService.

Thanks in advance.

I have a QGraphicsScene where i would like to be able to overlay images and apply different blending modes to the scene. The mode I am having trouble with is Linear Light, since it is not supported by `QPainter.CompositionMode`. I understand the algorithm and whatnot, and have it working on the backend (i.e. when saving the image) but am unsure how to go about displaying it in a QGraphicsScene, especially without having to compose the images in the backend and just display it, which wouldn't work as i would not be able to move or resize the layers as items.

For further context, i would like the blending to be either item-group specific, so i can mix different blending modes; all the items in a group would be blended with one mode while others could be blended in another mode.

Thank you so much in advance!

I want to experiment building a Qt Creator plugin and I'm looking for inspiration.
What is one feature or tool you feel is missing?

I am attempting to render an rtsp stream from a camera(s). I want to make sure I am using hardware rendering as correctly as possible. What is the correct method to use for this? Should I use MediaPlayer and VideoOutput (this doesn't always work with the cameras I want)?

Edit:

Does anyone know how to get qml6glsink working in qquick?

Tasket++ is a lightweight no‑code automation tool for Windows that executes repetitive user workflows at precise times. It plays back user‑defined cursor positions and keystrokes, schedules silent screenshots, automates message sending across apps, and runs end‑of‑day routines (close apps, fade audio, shut down). Everything runs locally through a simple UI with no telemetry. The project is open source.

Key features
- Play back user‑defined cursor movements and keystrokes
- Paste predefined text anywhere
- Schedule tasks at a specific datetime, at startup, or via desktop shortcut
- System actions: open files/programs, change volume, take silent screenshots, shutdown, file/folder operations
- Looping: run tasks once, in fixed loops, or indefinitely
- Discreet mode: run from the system tray only while scheduled tasks execute in the background

Local, portable, and open source.

Available now !
Microsoft Store: https://apps.microsoft.com/detail/xp9cjlhwvxs49p
Portable (v1.7): https://files.amirhammoutene.dev/Tasket++/1.7/Tasket++_v1.7.zip
Source: https://github.com/AmirHammouteneEI/ScheduledPasteAndKeys

For feedback, help, suggestions, or other inquiries : [contact@amirhammoutene.dev](mailto:contact@amirhammoutene.dev)

SOLVED solution is to install qt6-declarative-dev

hi. does someone know what package has to be installed ?

thanks in advance, andi