AppImage: Initial support for wayland (#7704)

Adds opt-in wayland support to the AppImage

.github/workflows/deps-ubuntu-24.04-gcc.txt

@@ -46,6 +46,7 @@ qtbase5-dev
 qtbase5-dev-tools
 qtbase5-private-dev
 qttools5-dev-tools
+qtwayland5
 software-properties-common
 ssh-client
 stk

cmake/linux/LinuxDeploy.cmake

@@ -135,6 +135,10 @@ file(GLOB LADSPA "${APP}/usr/lib/${lmms}/ladspa/*.so")
 # Inform linuxdeploy about remote plugins
 file(GLOB REMOTE_PLUGINS "${APP}/usr/lib/${lmms}/*Remote*")
 
+# Inform linuxdeploy-plugin-qt about wayland plugin
+set(ENV{EXTRA_PLATFORM_PLUGINS} "libqwayland-generic.so")
+set(ENV{EXTRA_QT_MODULES} "waylandcompositor")
+
 # Collect, sort and dedupe all libraries
 list(APPEND LIBS ${LADSPA})
 list(APPEND LIBS ${REMOTE_PLUGINS})

cmake/linux/apprun-hooks/wayland-hook.sh

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+
+# Configure QPlatform Abstraction (qpa) to prefer X-Protocol C-Bindings (xcb) over Wayland 
+ME="$( basename "${BASH_SOURCE[0]}")"
+
+if [ -n "$QT_QPA_PLATFORM" ]; then
+	echo "[$ME] QT_QPA_PLATFORM=\"$QT_QPA_PLATFORM\" was provided, using." >&2
+else
+	export QT_QPA_PLATFORM="xcb"
+	echo "[$ME] Defaulting to QT_QPA_PLATFORM=\"$QT_QPA_PLATFORM\" for compatibility purposes." >&2
+	echo "[$ME] To force wayland, set QT_QPA_PLATFORM=\"wayland\" or call using \"-platform wayland\"." >&2
+fi