Add support for Qt 6 alongside Qt 5 #1309
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Time to update the CI to also build a job with Qt6? Line 42 in dd4caea |
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Supersede the following: |
This was referenced Nov 9, 2025
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Ditto. I will do so in the next hour or so. |
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Issue specific to older Qt version using a stricter |
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Similarly to #1309 (comment), additional issues related to |
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Pull Request Overview
This pull request introduces support for Qt 6 while maintaining backward compatibility with Qt 5. The implementation uses the CTK_QT_VERSION variable to conditionally configure CMake for either Qt version, with automatic detection defaulting to Qt 6 when Qt6_DIR is defined.
Key changes:
- Generalized CMake macros to handle both Qt 5 and Qt 6 using
CTK_QT_VERSIONvariable - Added Qt 6-specific components (Core5Compat, StateMachine, OpenGLWidgets, DesignerComponentsPrivate)
- Disabled features that depend on Qt components unavailable in Qt 6 (XmlPatterns, QtSOAP)
Reviewed Changes
Copilot reviewed 12 out of 12 changed files in this pull request and generated 2 comments.
Show a summary per file
| File | Description |
|---|---|
| CMakeLists.txt | Adds Qt version auto-detection, validation, and conditional disabling of Qt 6-incompatible features |
| CMake/ctkMacroSetupQt.cmake | Updates Qt package discovery and component selection for both Qt 5 and Qt 6 |
| CMake/ctkMacroSetupPlugins.cmake | Generalizes Qt library path detection for both versions |
| CMake/ctkMacroBuildQtPlugin.cmake | Updates Qt Designer plugin support and compile definitions for Qt 6 |
| CMake/ctkMacroBuildPlugin.cmake | Replaces Qt5-specific functions with version-agnostic equivalents |
| CMake/ctkFunctionGeneratePluginManifest.cmake | Updates resource compilation to use generic Qt function |
| Libs/Core/CMakeLists.txt | Adds Qt 6-specific dependencies (Core5Compat, StateMachine) |
| Libs/Widgets/CMakeLists.txt | Adds Qt 6-specific OpenGLWidgets component |
| Libs/Widgets/Testing/Cpp/CMakeLists.txt | Generalizes Qt Test and XmlPatterns linking for both versions |
| Libs/Visualization/VTK/Widgets/target_libraries.cmake | Adds Qt 6 network and webkit library references |
| Libs/PluginFramework/Documentation/Snippets/EventAdmin-Intro/files.cmake | Replaces Qt5-specific moc wrapper with generic version |
| .github/workflows/ci.yml | Adds Qt 6 CI matrix testing alongside Qt 5 |
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This change updates various CMake macros to handle Qt6 by using CTK_QT_VERSION. It replaces hardcoded Qt5 references with version-agnostic code where possible.
Qt5’s `Qt5Designer_DEFINITIONS` and related variables may contain generator expressions that are not compatible with direct `add_definitions()` usage. This change documents why we continue using `add_definitions()` and `include_directories()` for Qt5, and relies on target usage requirements for newer Qt versions instead of failing with a fatal error.
Enable building CTK with either Qt 5 or Qt 6 by updating CMake
configuration and Qt component selection:
* Allow `CTK_QT_VERSION` to be 5 or 6 (defaulting to 6 when `Qt6_DIR`
is defined, otherwise 5), and validate its value.
* Use common Qt APIs for both Qt 5 and Qt 6 where available
(e.g. `qt_add_resources`, `qt_create_translation`,
`qt_wrap_cpp`, plugin setup helpers).
* Add required Qt 6 components when building with Qt 6, including
`Core5Compat`, `StateMachine`, and `OpenGLWidgets`, while preserving
existing Qt 5 behavior.
* Restrict use of deprecated or Qt 5–only components:
* Require `XmlPatterns` only with Qt 5.
* Force `CTK_USE_QTTESTING` OFF with Qt 6, since QtTesting depends on
`XmlPatterns`.
* Disable CommandLine Modules components and applications that depend
on `XmlPatterns` for Qt 6 builds.
* Disable DICOM Application Hosting plug-ins and example applications
that depend on QtSOAP for Qt 6 builds.
* Update core, widgets, VTK widgets, and test CMakeLists to link against
the appropriate Qt 5/Qt 6 targets based on `CTK_QT_VERSION`.
Co-authored-by: Stefan Dinkelacker <[email protected]>
Co-authored-by: jporcher <[email protected]>
Co-authored-by: Hans Johnson <[email protected]>
- Extend matrix with qt-major-version (5, 6) to exercise both Qt versions. - Split Qt install into Qt 5 and Qt 6 steps conditioned on qt-major-version. - Keep using system VTK only for Qt 5 builds; disable it for Qt 6 builds. - Derive CTK_QT_VERSION from qt-major-version in the configure step. - Update diagnostic step to print both Qt5_DIR and Qt6_DIR from CMake cache.
This was referenced Nov 11, 2025
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This pull request introduces support for Qt 6 while maintaining compatibility with Qt 5. The changes include:
CTK_QT_VERSIONvariable.Fixes #947
Add CMake configuration for Qt6 alongside Qt5
Enable building CTK with either Qt 5 or Qt 6 by updating CMake configuration and Qt component selection:
CTK_QT_VERSIONto be 5 or 6 (defaulting to 6 whenQt6_DIRis defined, otherwise 5), and validate its value.qt_add_resources,qt_create_translation,qt_wrap_cpp, plugin setup helpers).Core5Compat,StateMachine, andOpenGLWidgets, while preserving existing Qt 5 behavior.XmlPatternsonly with Qt 5.CTK_USE_QTTESTINGOFF with Qt 6, since QtTesting depends onXmlPatterns.XmlPatternsfor Qt 6 builds.CTK_QT_VERSION.Related pull requests:
CTK updates
CTK updates
For future reference, the following pull requests fix deprecation warnings and are step toward supporting Qt6 and beyond:
PythonQt Updates (both upstream and our fork)
PythonQt Updates
commont/PythonQt: commontk/PythonQt@f4769f1...patched-v3.6.1-2025-09-30-f4769f190Upstream:
stdin,stdout, andstderrredirection in PythonQt MeVisLab/pythonqt#286PyInt_*toPyLong_*(Python 3) MeVisLab/pythonqt#310sys.flags(verbose/optimize) on Python >= 3.12; fallback to legacy globals MeVisLab/pythonqt#311Upstream (generator):