Enable Xwayland only for Winamp interface. Closes: #1754

- Add a configuration setting with a checkbox to enable Xwayland
- Enable it by default though for older systems (Qt <= 6.7),
  window docking for example only works well with newer Qt 6 versions
- Allow using Wayland for the GTK and Qt interface by keeping it disabled
- Enforce it for the Winamp interface, it does not support Wayland

See also: #1664, #1656

---------

Co-authored-by: Thomas Lange <thomas-lange2@gmx.de>

Author: jlindgren90

config.h.meson

@@ -25,5 +25,6 @@
 #mesondefine USE_GTK
 #mesondefine USE_GTK3
 #mesondefine USE_LIBARCHIVE
+#mesondefine USE_XWAYLAND
 
 #mesondefine GLIB_VERSION_MIN_REQUIRED

meson.build

@@ -176,6 +176,9 @@ endif
 
 if get_option('qt')
   conf.set10('USE_QT', true)
+  if qt_dep.version().version_compare('<= 6.7')
+    conf.set10('USE_XWAYLAND', true)
+  endif
 endif
 
 

src/libaudcore/config.cc

@@ -43,6 +43,11 @@ static const char * const core_defaults[] = {
     "resume_playback_on_startup", "TRUE",
     "show_interface", "TRUE",
     "use_qt", "TRUE",
+#ifdef USE_XWAYLAND
+    "use_xwayland", "TRUE",
+#else
+    "use_xwayland", "FALSE",
+#endif
 
     /* equalizer */
     "eqpreset_default_file", "",

src/libaudgui/init.cc

@@ -18,12 +18,10 @@
  */
 
 #include <assert.h>
-#include <stdlib.h>
 
 #include <libaudcore/audstrings.h>
 #include <libaudcore/hook.h>
 #include <libaudcore/playlist.h>
-#include <libaudcore/plugins.h>
 #include <libaudcore/runtime.h>
 
 #include "internal.h"
@@ -343,15 +341,9 @@ EXPORT void audgui_init ()
         return;
 
 #if defined(GDK_WINDOWING_WAYLAND) && defined(GDK_WINDOWING_X11)
-    // Use X11/XWayland by default, but allow to overwrite it.
-    // Especially the Winamp interface is not usable yet on Wayland
-    // due to limitations regarding application-side window positioning.
-    auto backend = g_getenv ("GDK_BACKEND");
-    if (! backend && g_getenv ("DISPLAY"))
-        g_setenv ("GDK_BACKEND", "x11", false);
-    else if (g_strcmp0 (backend, "x11"))
-        AUDWARN ("X11/XWayland was not detected. This is unsupported, "
-                 "please do not report bugs.\n");
+    // Force Xwayland if requested and potentially available
+    if (aud_get_bool ("use_xwayland") && g_getenv ("DISPLAY"))
+        g_setenv ("GDK_BACKEND", "x11", true);
 #endif
 
     static char app_name[] = "audacious";

src/libaudgui/prefs-window.cc

@@ -369,6 +369,10 @@ static const PreferencesWidget song_info_page_widgets[] = {
 
 static const PreferencesWidget advanced_page_widgets[] = {
     WidgetLabel (N_("<b>Compatibility</b>")),
+#if defined(GDK_WINDOWING_WAYLAND) && defined(GDK_WINDOWING_X11)
+    WidgetCheck (N_("Use Xwayland (requires a restart to take effect)"),
+        WidgetBool (0, "use_xwayland")),
+#endif
     WidgetCheck (N_("Interpret \\ (backward slash) as a folder delimiter"),
         WidgetBool (0, "convert_backslash")),
     WidgetTable ({{chardet_elements}}),

src/libaudqt/audqt.cc

@@ -131,15 +131,9 @@ EXPORT void init()
 #endif
 
 #if defined(Q_OS_UNIX) && !defined(Q_OS_MAC)
-    // Use X11/XWayland by default, but allow to overwrite it.
-    // Especially the Winamp interface is not usable yet on Wayland
-    // due to limitations regarding application-side window positioning.
-    auto platform = qgetenv("QT_QPA_PLATFORM");
-    if (platform.isEmpty() && qEnvironmentVariableIsSet("DISPLAY"))
+    // Force Xwayland if requested and potentially available
+    if (aud_get_bool("use_xwayland") && qEnvironmentVariableIsSet("DISPLAY"))
         qputenv("QT_QPA_PLATFORM", "xcb");
-    else if (platform != "xcb")
-        AUDWARN("X11/XWayland was not detected. This is unsupported, "
-                "please do not report bugs.\n");
 #endif
 
     static char app_name[] = "audacious";

src/libaudqt/prefs-window-qt.cc

@@ -401,6 +401,10 @@ static const PreferencesWidget song_info_page_widgets[] = {
 
 static const PreferencesWidget advanced_page_widgets[] = {
     WidgetLabel(N_("<b>Compatibility</b>")),
+#if defined(Q_OS_UNIX) && !defined(Q_OS_MAC)
+    WidgetCheck(N_("Use Xwayland (requires a restart to take effect)"),
+                WidgetBool(0, "use_xwayland")),
+#endif
     WidgetCheck(N_("Interpret \\ (backward slash) as a folder delimiter"),
                 WidgetBool(0, "convert_backslash")),
     WidgetTable({{chardet_elements}}),