Merge pull request #63 from realnc/improve-hook-script

Add gtk3 and xdgdesktopportal in apprun hook

Author: TheAssassin

src/deployment.h

@@ -92,14 +92,21 @@ inline bool createAppRunHook(appdir::AppDir &appDir) {
         return false;
     }
 
+    // Old Qt versions only ship gtk2, new versions only gtk3. No Qt version had both.
+    const bool haveGtk3 = bf::exists(appDir.path() / "usr/plugins/platformthemes" / "libqgtk3.so");
+
     ofs << "# generated by linuxdeploy-plugin-qt" << std::endl
         << std::endl
-        << "# try to make Qt apps more \"native looking\", if possible" << std::endl
-        << "# see also https://github.com/AppImage/AppImageKit/issues/977#issue-462374883" << std::endl
-        << "# and https://github.com/AppImage/AppImageKit/issues/977#issue-462374883" << std::endl
+        << "# try to make Qt apps more \"native looking\" on Gtk-based desktops, if possible" << std::endl
+        << "# on other desktops, use the XDG Desktop Portal plugin instead to get native dialogs" << std::endl
+        << "# see https://github.com/AppImage/AppImageKit/issues/977#issue-462374883" << std::endl
+        << "# and https://github.com/linuxdeploy/linuxdeploy-plugin-qt/pull/63" << std::endl
         << "case \"${XDG_CURRENT_DESKTOP}\" in" << std::endl
         << "    *GNOME*|*gnome*|*XFCE*)" << std::endl
-        << "        export QT_QPA_PLATFORMTHEME=gtk2" << std::endl
+        << "        export QT_QPA_PLATFORMTHEME=" << (haveGtk3 ? "gtk3" : "gtk2") << std::endl
+        << "        ;;" << std::endl
+        << "    *)" << std::endl
+        << "        export QT_QPA_PLATFORMTHEME=xdgdesktopportal" << std::endl
         << "        ;;" << std::endl
         << "esac" << std::endl;