Better_Software_Header_Mobile Better_Software_Header_Web

Find what you need - explore our website and developer resources

Replaying the Drawing of a Qt Widget Step by Step - Video

GammaRay Tutorials for Qt Widgets Applications

David Faure

13 September 2023

Advanced Search

Tags

qttools

To watch this video on our website please or view it directly on YouTube

In this video, you will learn how to debug a painting issue for a QWidget, using the detailed recording by GammaRay of all individual painting operations.

All GammaRay Tutorials - Module 2:
https://www.youtube.com/playlist?list=PL6CJYn40gN6izGNDIH06YXf0UzR_1BVhn

All GammaRay Tutorials - Module 1:
https://www.youtube.com/playlist?list=PL6CJYn40gN6itybeSJb5FvRWOxVW5PCUX

All Qt Widgets and more videos:
https://www.youtube.com/playlist?list=PL6CJYn40gN6gf-G-o6syFwGrtq3kItEqI

Tags:

qttools
DavidFaure

David Faure

Senior Software Engineer

Senior software engineer and Managing Director of KDAB’s French office, David is a Qt user since its beginning. He has made numerous contributions to Qt, including new classes for QtCore in Qt 5. David is well known in the KDE project for his work on the web browser and especially on KDE Frameworks. He has become a specialist in multithreading with Qt, as well as performance optimizations. David holds an MSc in Computer Science.

Sign up for the KDAB Newsletter

Stay on top of the latest news, publications, events and more.

Go to Sign-up

Expertise

Trusted Software Excellence across Desktop and Embedded

Take a glance at the areas of expertise where KDAB excels ranging from swift troubleshooting, ongoing consulting and training to multi-year, large-scale software development projects.

Find out why customers from innovative industries rely on our extensive expertise, including Medical, Biotech, Science, Renewable Energy, Transportation, Mobility, Aviation, Automation, Electronics, Agriculture and Defense.

Embedded Devices Embedded Devices

High-quality Embedded Engineering across the Stack

To successfully develop an embedded device that meets your expectations regarding quality, budget and time to market, all parts of the project need to fit perfectly together.

Learn more about KDAB's expertise in embedded software development.

Read More

Cross-platform Desktop Cross-platform Desktop

Create complex Applications for the Desktop

Where the capabilities of modern mobile devices or web browsers fall short, KDAB engineers help you expertly architect and build high-functioning desktop and workstation applications.

Read More

Modernizing Legacy Software Modernizing Legacy Software

Reduce Technical Debt

Legacy software is a growing but often ignored problem across all industries. KDAB helps you elevate your aging code base to meet the dynamic needs of the future.

Whether you want to migrate from an old to a modern GUI toolkit, update to a more recent version, or modernize your code base, you can rely on over 25 years of modernization experience.

Read More

Medical Medical

Extensible, Safety-compliant Software for the Medical Sector

Create intelligent, patient-focused medical software and devices and stay ahead with technology that adapts to your needs.

KDAB offers you expertise in developing a broad spectrum of clinical and home-healthcare devices, including but not limited to, internal imaging systems, robotic surgery devices, ventilators and non-invasive monitoring systems.

Read More

Industrial Industrial

Build on Advanced Expertise when creating Modern UIs

KDAB assists you in the creation of user-friendly interfaces designed specifically for industrial process control, manufacturing, and fabrication.

Our specialties encompass the custom design and development of HMIs, enabling product accessibility from embedded systems, remote desktops, and mobile devices on the move.

Read More

Vehicle Dashboards Vehicle Dashboards

Fluid animations and gesture-controlled UIs

Building digital dashboards and cockpits with fluid animations and gesture-controlled touchscreens is a big challenge.

In over two decades of developing intricate UI solutions for cars, trucks, tractors, scooters, ships, airplanes and more, the KDAB team has gained market leading expertise in this realm.

Read More

Security and Defense Systems

Reliable software for the public security and defense sector

KDAB is a trusted software partner for authorities and suppliers requiring ever more robust and reliable software in the public security and defense sector. 

Read More

Services

Software Consulting, Development and Training

KDAB offers a wide range of services to address your software needs including consulting, development, workshops and training tailored to your requirements.

Our expertise spans cross-platform desktop, embedded and 3D application development, using the proven technologies for the job.

Software Consulting Software Consulting

Guidance for your Software Project across the Stack

Get expert advice on any phase of your project's journey, from inception to execution, across multiple platforms and hardware.

KDAB provides guidance on architectural approach, UI strategy, development tooling, test infrastructure, deployment model, runtime execution and more.

Read More

Code Modernization

UI Modernization

CI/CD

Performance optimization

Software Architecture

Migration from legacy frameworks

Qt Services Qt Services

Expert Qt Solutions for Your Needs

When working with KDAB, the first-ever Qt consultancy, you benefit from a deep understanding of Qt internals, that allows us to provide effective solutions, irrespective of the depth or scale of your Qt project.

Qt Services include developing applications, building runtimes, mixing native and web technologies, solving performance issues, and porting problems.

Read More

Qt 5 to Qt 6 Migration Services

Embedded Development Embedded Development

Build rich embedded applications for your embedded UI

Turn your vision into reality and unleash the potential of your embedded development projects.

KDAB helps you navigate the complex landscape of embedded development, ensuring your software performs optimally on your chosen hardware.

Read More

Cross-platform Development Cross-platform Development

Get help with all Aspects of Desktop Applications

KDAB helps create commercial, scientific or industrial desktop applications from scratch, or update its code or framework to benefit from modern features.

Discover clean, efficient solutions that precisely meet your requirements.

Read More

3D Software 3D Software

Simplify the complexity of 3D

Creating 3D applications can be overwhelming due to terminology, visual concepts, and advanced math.

KDAB simplifies this task, providing you with the best solution for your 3D project, easing complexities and maximizing efficiency.

Read More

OpenGL Expert Services

Vulkan

Developer Training Developer Training

Professional Developer Training Courses

Boost your team's programming skills with in-depth, constantly updated, hands-on training courses delivered by active software engineers who love to teach and share their knowledge.

Our courses cover Modern C++, Qt/QML, Rust, 3D programming, Debugging, Profiling and more.

Read More

Technologies

Make the right Technology Choices

The collective expertise of KDAB's engineering team is at your disposal to help you choose the software stack for your project or master domain-specific challenges.

Our particular focus is on software technologies you use for cross-platform applications or for embedded devices.

Qt / QML Qt / QML

Leading Qt Expertise

Since 1999, KDAB has been the largest independent Qt consultancy worldwide and today is a Qt Platinum partner. Our experts can help you with any aspect of software development with Qt and QML.

Read More

Modern C++ Modern C++

Deep understanding of Modern C++

KDAB specializes in Modern C++ development, with a focus on desktop applications, GUI, embedded software, and operating systems.

Our experts are industry-recognized contributors and trainers, leveraging C++'s power and relevance across these domains to deliver high-quality software solutions.

Read More

Rust Rust

Integrate Rust into your application

KDAB can guide you incorporating Rust into your project, from as overlapping element to your existing C++ codebase to a complete replacement of your legacy code.

Read More

How to build Hybrid Rust and C++ Applications

Memory-Safety Roadmap for Secure Programming

Platforms Platforms

Unique Expertise for Desktop and Embedded Platforms

Whether you are using Linux, Windows, MacOS, Android, iOS or real-time OS, KDAB helps you create performance optimized applications on your preferred platform.

Read More

Windows

MacOS/iOS

QNX

Unix / X11 (Motif)

Android

Web Engines

Linux

Embedded Linux

Slint Slint

A lightweight GUI toolkit

If you are planning to create projects with Slint, a lightweight alternative to standard GUI frameworks especially on low-end hardware, you can rely on the expertise of KDAB being one of the earliest adopters and official service partner of Slint.

Read More

Flutter Flutter

Flutter for Embedded and Desktop

KDAB has deep expertise in embedded systems, which coupled with Flutter proficiency, allows us to provide comprehensive support throughout the software development lifecycle.

Our engineers are constantly contributing to the Flutter ecosystem, for example by developing flutter-pi, one of the most used embedders.

Read More

3D / OpenGL / Vulkan 3D / OpenGL / Vulkan

Cutting-edge 3D / XR

Incorporating 3D into 2D UIs or creating compelling XR experiences can be challenging.

Create visually stunning, ultra-realistic 3D graphics, dynamic 2D user interfaces, or leveraging the power of hardware-accelerated computation.

The 3D experts at KDAB bring incisive know-how for your project.

Read More

Qt 3D

Vulkan – next generation graphics & compute

OpenGL expert services

Developer Tools Developer Tools

Developer Tools from KDAB

The right tools and libraries can skyrocket developers' productivity.

Take advantage of KDAB's popular open source tools for tasks including profiling, debugging and continuous integration (CI).

Read More

GammaRay

KD Reports

KD Chart

Hotspot

KD SOAP

KDDockWidgets

KDAB Labs KDAB Labs

Research & Development at KDAB

KDAB invests significant time in exploring new software technologies to maintain its position as software authority. Benefit from this research and incorporate it eventually into your own project.

Read More

KDGpu

Resources

Start here to browse information on the KDAB website(s) and take advantage of useful developer resources like blogs, publications and videos about Qt, C++, Rust, 3D technologies like OpenGL and Vulkan, the KDAB developer tools and more.

Blogs Blogs

KDAB engineers and designers constantly share cutting-edge technology insights with regard to Qt, QML, C++, Rust, Linux, Vulkan, OpenGL, Qt 3D, scalable UIs and more topics.

Stay up-to-date and be inspired with their blogs.

Read More

Events Events

Get a quick overview of events relevant to the software industry and with involvement of KDAB, be it as speakers, sponsors, exhibitors or organizer.

Take the opportunity to reach out to our experts directly. See you there!

Read More

Publications Publications

KDAB regularly publishes in-depth papers, brochures and other material on topics relevant to software developers and desicion makers.

Have a look at the list of KDAB publictions.

Read More

Videos Videos

The KDAB Youtube channel has become a go-to source for developers looking for high-quality tutorial and information material around software development with Qt/QML, C++, Rust and other technologies.

Click to navigate the all KDAB videos directly on this website.

Read More

Why KDAB

A software supplier you can rely on

In over 25 years KDAB has served hundreds of customers from various industries, many of them having become long-term customers who value our unique expertise and dedication.

Learn more about KDAB as a company, understand why we are considered a trusted partner by many and explore project examples in which we have proven to be the right supplier.

About KDAB About KDAB

Committed, compassionate, trustworthy

The KDAB Group is a globally recognized provider for software consulting, development and training, specializing in embedded devices and complex cross-platform desktop applications.

Read more about the history, the values, the team and the founder of the company.

Read More

Proven Excellence Proven Excellence

Customer Success Stories

When working with KDAB you can expect quality software and the desired business outcomes thanks to decades of experience gathered in hundreds of projects of different sizes in various industries.

Have a look at selected examples where KDAB has helped customers to succeed with their projects.

Read More

Trusted Partner Trusted Partner

Benefit from a strong partner network

Lasting relationships reduce frictions in software development projects and help to guarantee success.

Benefit from the established relationships KDAB has with well-selected hardware suppliers and specialized domain experts.

Read More

Software Excellence for Texas Instruments

Better Software Better Software

Constantly improving Software Quality

KDAB is committed to developing high-quality and high-performance software, and helping other developers deliver to the same high standards.

We create software with pride to improve your engineering and your business, making your products more resilient and maintainable with better performance.

Read More

ISO 9001 ISO 9001

ISO 9001 certified software services

KDAB has been the first certified Qt consulting and software development company in the world, and continues to deliver quality processes that meet or exceed the highest expectations.

Read More

Working at KDAB Working at KDAB

Looking for a new challenge?

In KDAB we value practical software development experience and skills higher than academic degrees. We strive to ensure equal treatment of all our employees regardless of age, ethnicity, gender, sexual orientation, nationality.

Interested? Read more about working at KDAB and how to apply for a job in software engineering or business administration.

Read More

Contact

Search

CODEBROWSER

KDAB|Training