Platform Wranglers Meeting Notes

Agenda

• Roundtable
  • New versions/changes in the underlying platform?
  • Current focus areas
  • Known problem areas
  • Features on the horizon
• Topics

2024

8. August 2024

• Roundtable
  • Windows
    • 6.8 looking good
    • ARM64EC still no progress
    • 6.9 features: customizable title bar
      • Might require MS App SDK (needed for other things)
  • Android
    • Getting QML embedding for Java ready for release
    • 6.9: Aim to get support for Android 15 / NDK 27
      • Might also get backport to earlier Qt versions
        • (bigger discussion)
  • macOS
    • Prepared to launch 6.8.0 with support for macOS 15
    • Investigating AI integration (Writing Tools, Genmoji)
  • iOS
    • Prepared to launch 6.8.0 with support for macOS 18
    • Investigating AI integration (Writing Tools, Genmoji)
  • Wayland
    • 6.8 good to go
    • Work going on in Wayland on HDR and color spaces
    • Improving subwindow support

13. June 2024

• Roundtable
  • WASM
    • Improvements to 64-bit builds (Chrome only so far) (https://webassembly.org/features/)
  • Android
    • Bumped minimum version to Android 9
    • Some improvements to QML embedding via Gradle plugin
    • Moving Android builds on macOS to ARM, possible Android ARM testing as well
  • iOS
    • iOS 18 beta released
    • Device control for iOS devices improvement in Xcode 16
  • macOS
    • macOS 15 beta released, tested and working well. Next step CI
    • New features related to generative emojis and AI text tooling, via IM
  • Windows
    • Frameless window improvements in review
    • ARM64 EC, function pointer address is broken
    • Modernizing backends for Bluetooth
    • Removed legacy mouse handling
  • X11
    • No updates
  • Wayland
    • Web engine issue with DPR picked up from screen instead of window
• Topics
  • Toolchain upgrades for older branches
    • All platforms have "frozen" toolchains per release
  • Platform testing
    • Need system level integration to e.g. test Aero snapping on Windows
    • WASM and KDE uses selenium

16. April 2024

• Roundtable
  • WASM
    • About to upgrade Emscripten SDK
      • Comes with fix for not exporting everything to JS from dynamic libraries
    • Continued work on dynamic linking, including Qt Quick (QML plugins)
    • Investigating local file access APIs
      • File engine backend, might be opportunities for co-work with iOS work for sandboxed apps down the line
  • Android
    • Raising minimum version to Android 9
    • Still work ongoing for QML embedding into Android apps
    • Java/C++ code generator might not make it for 6.8
  • Windows
    • Keeping an eye on what's happening on Windows on ARM
    • Investigating compile time solution for mixing arm64 and x86_64 (ARM64EC)
  • macOS
    • Continued move to Tart VMs
    • Resize patch, possible input to other platforms
    • WWDC in June for new versions
  • iOS
    • Window management improvements
    • Still investigating full top level window support
  • visionOS
    • Support for the platform in dev as tech preview, including immersive spaces
  • Wayland
    • Lots of work going on upstream on input methods
      • AP: Need to discuss how this matches Qt's expectations
    • Investigating synchronous expose
    • Investigating resizing issues
  • X11
    • Ubuntu 22.04 in CI now (ARM only, x86_64 still needs work)
• PM update
  • rPI 5 new reference platform
  • Ubuntu 24.04 and Debian 12
  • "Supported" platform brainstorming
  • Cycber security act
• Topics
  • Safe area margins https://bugreports.qt.io/browse/QTBUG-125345

11. April 2024

• Roundtable
  • WASM
    • Adding Qt positioning and sensors backend
  • Windows
    • Working on bordered window fixes
    • 6.8: Discussions around MSCS2019. First 20222
    • Looking into CI for Windows on ARM
  • X11
    • Support for GCC12
    • Working on upgrading our distros in CI
  • macOS
    • Pushing minimum versions
  • iOS
    • Pushing minimum versions
    • Modernizing window management
  • Android
    • Bumping to Android 10 for 6.8
    • QML embedding APIs released, with Android studio plugin
    • Planning C++->java codegen
  • Wayland
    • No major changes upstream
    • 6.8:
      • Refactoring winID
• Other topics
  • Screen rotation
    • Qt 5 -> Qt6 bahvior change in QScreen::orientation()
  • Fancy window backgrounds
    • https://bugreports.qt.io/browse/QTBUG-124282

14. March 2024

• Roundtable
  • WASM
    • Dynamic linking main priority going forward
    • Investigating differences between WebGL and OpenGL
  • Android
    • QML embedding content in place
  • macOS
    • Updating support for macOS 14 / Xcode 15 in stable branches
    • Improving testing via Tart VMs
  • iOS
    • Updating support for iOS 17 / Xcode 15 in stable branches
  • X11
    • Investigating build issues on Linux ARM
      • https://bugreports.qt.io/browse/QTBUG-123153
  • Wayland
    • Some issues in input methods
    • Next KDE 6.1 likely use 6.7
  • Windows
    • Adding support for manifest files
• Other topics
  • Platform support granularity discussion
    • https://codereview.qt-project.org/c/qt/qtdoc/+/542499

8. February 2024

• Roundtable
  • WASM
    • Working on upgrading emscripten SDK for 6.7
    • Investigating how to handle older hardware without good WebGL support
  • Android
    • Embedding of Qt into native apps landed (mostly)
    • Bumping Android 6 to 8 in dev
  • macOS
    • Bumping minimum to 12 or 13 for dev
  • iOS
    • Workarounds for iOS 17 in creator taking shape
    • Started investigating improved window management
  • X11
    • Investigating updating CI distributions we use to test
  • Wayland
    • New protocol in work for modal windows, matches Qt
    • GTK rewriting their a11y on top of AccessKit or using similar protocol
      • https://gnome.pages.gitlab.gnome.org/at-spi2-core/devel-docs/new-protocol.html
    • Might require changes on the Qt side if AT-SPI is no longer an option
• Topics
  • AccessKit
    • Cross platform a11y layer with backends for AT-SPI/Cocoa/Windows
    • Potential replacement for our custom a11y backends on each platform
    • Missing backends for iOS/Android/Web

11. January 2024

• Roundtable
  • WASM
    • Considering using C++ coruitines for the internal plumbing
  • Windows
    • Considering moving off COM and using winrt for plumbing
  • XCB
    • Plan to statically link in xcb-cursor into Qt to solve deployment issues
  • Wayland
    • Some work on client side decorations and possible generic solution
    • Might need new QWSI API for updating cursor position after move
  • Android
    • NDK 26 in Qt 6.7
    • Working on QML in native Android apps
    • Considering bumping minimum version from Android 8 to 10
  • macOS
    • Work on improving save dialogs
    • Might support making child windows fullscreen (videos e.g.)
  • iOS
    • iOS 17 devices supported in 6.7, but workarounds for Qt Creator
• KDE
  • RC1 out
  • Testing building for WASM, everything was very easy, good experience!

2023

21. December 2023

• Roundtable
  • New versions/changes in the underlying platform?
    • macOS, iOS:
      • nothing new
      • continued collaboration with Apple
    • Windows:
      • nothing new
      • maybe win12 next year, we should be prepared
        • Out of the box experience with Qt apps
        • Features that can/should be supported
    • x11:
      • Customer bug about menu handling
      • Mouse grabbing behavior different across platforms
        • might need some coordination
    • Wayland:
      • Not much activity upstream
      • One big issue in 6.7 (application crash)
        • Fix is available, but needs help to make it through CI
    • Android
      • Problems getting the latest NDK into qt5.git
        • Feature freeze exception
        • "Getting there"
      • Android code generator work
      • CI fixes for Androidtestrunner
• Topics

16. November 2023

• Roundtable
  • Windows
    • Trying to get ARM VMs for our CI
    • Windows 12 on the horizon, no details yet, but no likely major changes
    • Finishing up Windows 11 style
    • Improvements to high-DPI
  • X11
    • Gnome and KDE moving to Wayland
  • WASM
    • Updating to WebGL 2 (GLES 3)
  • Android
    • Android 14 in CI, now supported for 6.7
    • Some issues with emulator in CI
    • QPA refactoring making good progress
    • Child window support in review
    • JNI improvements by Volker merged
  • macOS
    • macOS 14 significant in CI now
  • iOS
    • iOS 17 issues due to libmobiledevice no longer being supported
  • Wayland
    • Discussion around behavior when window minimum size is larger than available size (tiling window manager e.g.)
      • Killing app in response is not a good behavior
• Topics
  • Window states for child windows
    • Always use NoWindowState
  • Internal platform window handle changes
    • Only on XCB, exposed as winId
    • on macOS and Wayland, changes, but not exposed as winId
  • Synchronous mouse/touch
    • Many platforms already do this

12. October 2023

• Roundtable
  • X11
    • Looking into a11y improvements
      • Object creation and destruction not supported in Qt
        • Needed for testing tools. Unclear if Squish needs it
  • Android
    • Android 14 released
      • Problems getting into CI
    • QPA refactoring getting into shape
    • Improvements to JNI APIs
  • macOS
    • Sonoma (macOS 14) released
    • Problems with Xcode 15's new linker not providing default linker paths
      • Breaks qmake in all Qt versions. Patch submitted.
  • iOS
    • iOS 17 released
    • New protocol for device management (deploying, running)
      • Breaks Qt Creator integration.
  • Wayland
    • New discussions about windows being able to absolutely position
      • Clients want positioning, compositors don’t
    • XDG session, tying window to tag/id for restoring
      • Not clear if useful as cross platform API, but can be QWaylandWindow API
    • Synchronizing window flushes during resizing
      • Similar issues on other platforms
      • Need to figure out which parts are Wayland quirks and which parts are Qt
    • Window capturing is actually possible on Wayland via pipewire
  • WASM
    • 64 bit mode getting traction and fixes
    • Improvements to locale integration
• Topics
  • Version support
    • Android range of versions, testing min and max
    • macOS, support 3-4 latest version, test full range in CI
    • WASM, latest browser needed.
      • Runtime check features between browsers
      • EM SDK locked per Qt release
    • Wayland
      • Every protocol individually versioned
      • Supporting both desktop compositors and embedded compositors
        • Mutter, Plasma, Qt Compositor
    • X11
      • Rely on XCB
        • Must verify that distros have any new XCB libraries we depend on
  • Application startup / lifecycle
    • Event loop might already be running
      • WASM
      • iOS
      • Plugins
    • Need some kind of callback based API
      • One for startup
      • One for shutdown
    • Should QApp be created automatically for the user?
    • Can no longer create windows and other things on the stack
    • If we move to a new paradigm it should replace the main one
      • Ie the user shouldn’t need to provide both
    • Requires updating of QtC templates, examples, etc
    • Effort should be compared against fixing the main case for the platforms where this is an issue
      • E.g. running main on secondary thread on WASM

13. September 2023

• Introductions
  • Tor Arne - macOS,iOS,QPA
  • Morten - WASM
  • Oliver - Windows
  • Liang - X11
  • Assam - Android
  • David - Wayand
• Ways of working
  • Monthly meeting
  • Desktop/mobile platforms
• Roundtable
  • iOS
    • iOS 17 end of September
      • Things mostly work as before
    • Moving to FFMpeg for Qt Multimedia
    • Technical debt in window management, modern iOS has more advanced window/screen management
    • Exposing safe area margins properly as public Qt Quick API (anchors, etc)
  • macOS
    • macOS Sonoma end of September
      • No major changes, doing nightly builds, weeding out issues
      • One regression in Xcode 15, causing build failures with qmake
        • https://codereview.qt-project.org/c/qt/qtbase/+/503172
    • Key/text input, complex text, shortcut handling
    • Modern window look, blurred/effect windows, etc
  • WASM
    • Emscripten is the SDK
      • Follows Chrome release model (4-6 weeks)
      • No versions are “more stable” than others
      • Upgrade close to feature freeze to get latest fixes
    • 32-bit platform (one of our few)
    • Has a no-thread build option
    • Uses static linking
    • WASM64 is coming, looking at that
    • Dynamic linking is in the works
    • Major challenge is web platform is async, but Qt expects synchronous APIs
    • Complex text difficult
    • Accessibility difficult
  • X11
    • Not much underlying changes on X11
      • Ubuntu 22.04 in CI
      • Updating RedHat and OpenSuse
    • Increased requests for more XDG support
      • Use XDG services more, file dialogs, drag and drop, etc
      • Harald Sitter (?) knows about KDE drag and drop
  • Windows
    • New OS updates every 6 months
      • But usually no new major features
      • CI updates, doesn’t change much
    • Focus areas
      • Finalising Windows 11 style for widgets
      • Modern look of apps
        • Window decorations
      • Windows on ARM
    • Problem areas
      • Windows on ARM, hard to virtualise in CI
  • Android
    • Android 14 coming up
      • Been tested in CI
      • Some new permissions we need to deal with
        • Storage permissions deprecated
    • Bumped minimum from Android 6 to Android 8
    • Focus areas
      • Safe area margins for short edges
      • Refactoring QPA plugin
        • Modernize
        • Remove layers
        • Make more maintainable
      • Generator for JNI APIs
        • Making it easier to invoke Android APIs
  • Wayland
    • A set of generated wire protocols
      • Some core protocols, fairly stable, can be expected everywhere (all compositors/servers)
      • Standard body maintains additional extension protocols
        • Some more essential, eg XDG shell
        • Some more esoteric, for car manufacturers etc
    • Some DEs use Wayland nowadays, but also with XWayland for X11 support
      • Gnome
      • Plasma (KDE), switching soon
    • Deadline for Qt adopting a protocol is in practice when a big bistro adopts a DE version that has support for the protocol
    • Focus areas
      • Fractional scaling
      • Support for clients outliving crashing compositors
      • Support for minimised windows
    • Problem areas
      • Popups
        • Windows don’t know their own screen positions
        • Can not control screen positions
        • Popups need to declare intent about where to be placed
        • Possible solutions
          • Turn window geometry into hints to Wayland
          • Expose placement-intent-based API as public Qt API
            • https://codereview.qt-project.org/c/qt/qtbase/+/491545
      • Qt Quick threaded render out of sync with window resize
        • Needs graphics team attention
      • QWindow setGeometry not emitting geometryChanged
        • We wait until GeometryChangeEvent
      • QWidget updates not going through QWindow::requestUpdate
• Topics
  • Keyboard input and shortcut handling
    • Investigated at https://bugreports.qt.io/browse/QTBUG-116873
  • Custom window decorations
    • Frameless windows on Windows not usable for the use-cases people have
      • Need to figure out if it's a Windows bug fix, or a missing feature in QWindow
      • Olli to write up summary in JIRA task