nixos/gnome: enable platform integration for Qt

nixos/doc/manual/from_md/release-notes/rl-2111.section.xml

@@ -1088,6 +1088,15 @@ Superuser created successfully.
           but instead use more of the YAML-specific syntax.
         </para>
       </listitem>
+      <listitem>
+        <para>
+          GNOME desktop environment now enables
+          <literal>QGnomePlatform</literal> as the Qt platform theme,
+          which should avoid crashes when opening file chooser dialogs
+          in Qt apps by using XDG desktop portal. Additionally, it will
+          make the apps fit better visually.
+        </para>
+      </listitem>
     </itemizedlist>
   </section>
 </section>

nixos/doc/manual/release-notes/rl-2111.section.md

@@ -311,3 +311,5 @@ To be able to access the web UI this port needs to be opened in the firewall.
 - Nginx will use the value of `sslTrustedCertificate` if provided for a virtual host, even if `enableACME` is set. This is useful for providers not using the same certificate to sign OCSP responses and server certificates.
 
 - `lib.formats.yaml`'s `generate` will not generate JSON anymore, but instead use more of the YAML-specific syntax.
+
+- GNOME desktop environment now enables `QGnomePlatform` as the Qt platform theme, which should avoid crashes when opening file chooser dialogs in Qt apps by using XDG desktop portal. Additionally, it will make the apps fit better visually.

nixos/modules/services/x11/desktop-managers/gnome.nix

@@ -372,6 +372,13 @@ in
       xdg.portal.enable = true;
       xdg.portal.extraPortals = [ pkgs.xdg-desktop-portal-gtk ];
 
+      # Harmonize Qt5 application style and also make them use the portal for file chooser dialog.
+      qt5 = {
+        enable = mkDefault true;
+        platformTheme = mkDefault "gnome";
+        style = mkDefault "adwaita";
+      };
+
       networking.networkmanager.enable = mkDefault true;
 
       services.xserver.updateDbusEnvironment = true;

pkgs/development/libraries/qgnomeplatform/default.nix

@@ -2,26 +2,26 @@
 , lib
 , fetchFromGitHub
 , nix-update-script
+, cmake
 , pkg-config
-, gtk3
+, adwaita-qt
 , glib
+, gtk3
 , qtbase
-, qmake
-, qtx11extras
 , pantheon
 , substituteAll
 , gsettings-desktop-schemas
 }:
 
 mkDerivation rec {
   pname = "qgnomeplatform";
-  version = "0.6.1";
+  version = "0.8.0";
 
   src = fetchFromGitHub {
     owner = "FedoraQt";
     repo = "QGnomePlatform";
     rev = version;
-    sha256 = "1mwqg2zk0sfjq54vz2jjahbgi5sxw8rb71h6mgg459wp99mhlqi0";
+    sha256 = "C/n8i5j0UWfxhP10c4j89U+LrpPozXnam4fIPYMXZAA=";
   };
 
   patches = [
@@ -33,24 +33,21 @@ mkDerivation rec {
   ];
 
   nativeBuildInputs = [
+    cmake
     pkg-config
-    qmake
   ];
 
   buildInputs = [
+    adwaita-qt
     glib
     gtk3
     qtbase
-    qtx11extras
   ];
 
-  postPatch = ''
-    # Fix plugin dir
-    substituteInPlace decoration/decoration.pro \
-      --replace "\$\$[QT_INSTALL_PLUGINS]" "$out/$qtPluginPrefix"
-    substituteInPlace theme/theme.pro \
-      --replace "\$\$[QT_INSTALL_PLUGINS]" "$out/$qtPluginPrefix"
-  '';
+  cmakeFlags = [
+    "-DGLIB_SCHEMAS_DIR=${glib.getSchemaPath gsettings-desktop-schemas}"
+    "-DQT_PLUGINS_DIR=${placeholder "out"}/${qtbase.qtPluginPrefix}"
+  ];
 
   passthru = {
     updateScript = nix-update-script {

pkgs/development/libraries/qgnomeplatform/hardcode-gsettings.patch

@@ -1,13 +1,14 @@
-diff --git a/common/gnomehintssettings.cpp b/common/gnomehintssettings.cpp
-index 9860e57..40fa6ec 100644
---- a/common/gnomehintssettings.cpp
-+++ b/common/gnomehintssettings.cpp
-@@ -80,9 +80,17 @@ void gtkMessageHandler(const gchar *log_domain,
- GnomeHintsSettings::GnomeHintsSettings()
-     : QObject(0)
+diff --git a/src/common/gnomesettings.cpp b/src/common/gnomesettings.cpp
+index 717cc9b..ee255ea 100644
+--- a/src/common/gnomesettings.cpp
++++ b/src/common/gnomesettings.cpp
+@@ -150,10 +150,18 @@ GnomeSettingsPrivate::GnomeSettingsPrivate(QObject *parent)
+     : GnomeSettings(parent)
      , m_usePortal(checkUsePortalSupport())
+     , m_canUseFileChooserPortal(!m_usePortal)
 -    , m_gnomeDesktopSettings(g_settings_new("org.gnome.desktop.wm.preferences"))
 -    , m_settings(g_settings_new("org.gnome.desktop.interface"))
+     , m_fallbackFont(new QFont(QLatin1String("Sans"), 10))
  {
 +    g_autoptr(GSettingsSchemaSource) schemaSource = nullptr;
 +    g_autoptr(GSettingsSchema) gnomeDesktopSchema = nullptr;

pkgs/top-level/all-packages.nix

@@ -18499,7 +18499,7 @@ with pkgs;
 
   qrupdate = callPackage ../development/libraries/qrupdate { };
 
-  qgnomeplatform =  libsForQt514.callPackage ../development/libraries/qgnomeplatform { };
+  qgnomeplatform = libsForQt5.callPackage ../development/libraries/qgnomeplatform { };
 
   randomx = callPackage ../development/libraries/randomx { };