#1325 GTK4 migration

[lwindolf]

#1325: Starting on the incompatible migration parts (event controllers / GtkContainer & co)

Open Todos

• complete GUI conversion to GTK4 -> drop stuff where needed get everything to compile
• convert to webkitgtk 6.0
• refactor plugin engine for libpeas 2.0
• convert all plugins
  • add-bookmark-site
  • bold-unread
  • download-manager
  • getfocus
  • gnome-keyring
  • libnotify
  • trayicon (dropped, as there is no lib providing it anymore)
• .ui files fully converted
  • about
  • auth
  • google_source
  • liferea_menu
  • mainwindow
  • mark_read_dialog
  • new_folder
  • new_newsbin
  • new_subscription
  • node_source
  • opml_source
  • plugins
  • prefs
  • properties
  • reedah_source
  • rename_node
  • search_folder
  • search
  • simple_search
  • simple_subscription
  • theoldreader_source
  • ttrss_source
  • update_monitor
• reimplement Drag&Drop
• reimplement window auto layout
• convert context menus to GtkPovoverMenu
• setup meson image installation
• setup meson man page installation
• setup meson doc installation
• setup meson intltool XLST processing
• setup meson GIR binding creation
• cleanup all *.ui files from unsupported properties/widgets

Out-of-scope

• solving GTK4 deprecations

[Copilot]

Pull Request Overview

This PR is focused on the GTK4 migration efforts, updating build instructions, dependencies, and workflows to accommodate GTK4 and related library changes.

• Updated the README with Meson-based build instructions and installation commands.
• Updated the CI workflow to use Ubuntu 24.10 and switch to GTK4/updated dependencies.

Reviewed Changes

Copilot reviewed 295 out of 313 changed files in this pull request and generated no comments.

File	Description
README.md	Updated build instructions and installation commands.
.github/workflows/cb.yml	Updated the container image and dependency installations, while commenting out some test steps for future reimplementation.

Files not reviewed (18)

• INSTALL: Language not supported
• Makefile.am: Language not supported
• autogen.sh: Language not supported
• config.h.in: Language not supported
• configure.ac: Language not supported
• doc/Makefile.am: Language not supported
• doc/html/Makefile.am: Language not supported
• glade/Makefile.am: Language not supported
• glade/auth.ui: Language not supported
• glade/liferea.css: Language not supported
• glade/liferea_toolbar.ui: Language not supported
• glade/mainwindow.ui: Language not supported
• glade/new_folder.ui: Language not supported
• glade/new_newsbin.ui: Language not supported
• glade/new_subscription.ui: Language not supported
• glade/node_source.ui: Language not supported
• glade/opml_source.ui: Language not supported
• glade/reedah_source.ui: Language not supported

Comments suppressed due to low confidence (2)

.github/workflows/cb.yml:34

• The commented-out line for running PO file tests indicates that test coverage for localization files is currently disabled. Consider re-enabling these tests once the migration issues have been addressed.

# FIXME - run: make -C po check

.github/workflows/cb.yml:39

• The commented-out test execution in the tests directory suggests that automated test coverage might be incomplete. Reintegrate these tests when possible to ensure reliable builds after migration.

# FIXME - run: cd src/tests && make test