Wallpaper (Linux): improves XFCE wallpaper detection via property enumeration

Author: CarterLi

src/common/settings.c

@@ -250,12 +250,96 @@ FFvariant ffSettingsGetXFConf(const char* channelName, const char* propertyName,
 
     return FF_VARIANT_NULL;
 }
+
+#define FF_DBUS_ITER_CONTINUE(dbus, iterator) \
+    { \
+        if(!(dbus).lib->ffdbus_message_iter_next(iterator)) \
+            break; \
+        continue; \
+    }
+
+FFvariant ffSettingsGetXFConfFirstMatch(const char* channelName, const char* propertyPrefix, FFvarianttype type, void* data, FFTestXfconfPropCallback* cb)
+{
+    FFDBusData dbus;
+    if (ffDBusLoadData(DBUS_BUS_SESSION, &dbus) != NULL)
+        return FF_VARIANT_NULL;
+
+    DBusMessage* reply = ffDBusGetMethodReply(&dbus, "org.xfce.Xfconf", "/org/xfce/Xfconf", "org.xfce.Xfconf", "GetAllProperties", channelName, propertyPrefix);
+    if(!reply)
+        return FF_VARIANT_NULL;
+
+    DBusMessageIter rootIterator;
+    if(!dbus.lib->ffdbus_message_iter_init(reply, &rootIterator))
+    {
+        dbus.lib->ffdbus_message_unref(reply);
+        return FF_VARIANT_NULL;
+    }
+
+    DBusMessageIter arrayIterator;
+    dbus.lib->ffdbus_message_iter_recurse(&rootIterator, &arrayIterator);
+
+    while(true)
+    {
+        if(dbus.lib->ffdbus_message_iter_get_arg_type(&arrayIterator) != DBUS_TYPE_DICT_ENTRY)
+            FF_DBUS_ITER_CONTINUE(dbus, &arrayIterator)
+
+        DBusMessageIter dictIterator;
+        dbus.lib->ffdbus_message_iter_recurse(&arrayIterator, &dictIterator);
+
+        const char* key;
+        dbus.lib->ffdbus_message_iter_get_basic(&dictIterator, &key);
+
+        if (cb(data, key)) FF_DBUS_ITER_CONTINUE(dbus, &arrayIterator)
+        dbus.lib->ffdbus_message_iter_next(&dictIterator);
+
+        if(type == FF_VARIANT_TYPE_INT)
+        {
+            int32_t value;
+            if (ffDBusGetInt(&dbus, &dictIterator, &value))
+            {
+                dbus.lib->ffdbus_message_unref(reply);
+                return (FFvariant) { .intValue = value };
+            }
+            return FF_VARIANT_NULL;
+        }
+
+        if(type == FF_VARIANT_TYPE_STRING)
+        {
+            FFstrbuf value = ffStrbufCreate();
+            if (ffDBusGetString(&dbus, &dictIterator, &value))
+            {
+                dbus.lib->ffdbus_message_unref(reply);
+                return (FFvariant) { .strValue = value.chars }; // Leaks value.chars
+            }
+            return FF_VARIANT_NULL;
+        }
+
+        if(type == FF_VARIANT_TYPE_BOOL)
+        {
+            bool value;
+            if (ffDBusGetBool(&dbus, &dictIterator, &value))
+            {
+                dbus.lib->ffdbus_message_unref(reply);
+                return (FFvariant) { .boolValue = value, .boolValueSet = true };
+            }
+        }
+
+        return FF_VARIANT_NULL;
+    }
+
+    return FF_VARIANT_NULL;
+}
 #else //FF_HAVE_DBUS
 FFvariant ffSettingsGetXFConf(const char* channelName, const char* propertyName, FFvarianttype type)
 {
     FF_UNUSED(channelName, propertyName, type)
     return FF_VARIANT_NULL;
 }
+FFvariant ffSettingsGetXFConfFirstMatch(const char* channelName, const char* propertyPrefix, FFvarianttype type, void* data, FFTestXfconfPropCallback* cb)
+{
+    FF_UNUSED(channelName, propertyPrefix, type, data, cb);
+    return FF_VARIANT_NULL;
+}
 #endif //FF_HAVE_DBUS
 
 #ifdef FF_HAVE_SQLITE3

src/common/settings.h

@@ -26,6 +26,8 @@ FFvariant ffSettingsGetDConf(const char* key, FFvarianttype type);
 FFvariant ffSettingsGetGSettings(const char* schemaName, const char* path, const char* key, FFvarianttype type);
 FFvariant ffSettingsGet(const char* dconfKey, const char* gsettingsSchemaName, const char* gsettingsPath, const char* gsettingsKey, FFvarianttype type);
 FFvariant ffSettingsGetXFConf(const char* channelName, const char* propertyName, FFvarianttype type);
+typedef bool FFTestXfconfPropCallback(void* data, const char* propertyName); // Return false to break loop
+FFvariant ffSettingsGetXFConfFirstMatch(const char* channelName, const char* propertyPrefix, FFvarianttype type, void* data, FFTestXfconfPropCallback* cb);
 
 int ffSettingsGetSQLite3Int(const char* dbPath, const char* query);
 bool ffSettingsGetSQLite3String(const char* dbPath, const char* query, FFstrbuf* result);

src/detection/gtk_qt/gtk.c

@@ -34,6 +34,13 @@ static inline void applyGTKSettings(FFGTKResult* result, const char* themeName,
         ffStrbufAppendS(&result->wallpaper, wallpaper);
 }
 
+static bool testXfconfWallpaperPropKey(FF_MAYBE_UNUSED void* data, const char* key)
+{
+    int count = 0;
+    sscanf(key, "/backdrop/screen0/monitor%*[^/]/workspace0/last-image%n", &count);
+    return count == 0;
+}
+
 static void detectGTKFromSettings(FFGTKResult* result)
 {
     static const char* themeName = NULL;
@@ -62,11 +69,7 @@ static void detectGTKFromSettings(FFGTKResult* result)
         fontName = ffSettingsGetXFConf("xsettings", "/Gtk/FontName", FF_VARIANT_TYPE_STRING).strValue;
         cursorTheme = ffSettingsGetXFConf("xsettings", "/Gtk/CursorThemeName", FF_VARIANT_TYPE_STRING).strValue;
         cursorSize = ffSettingsGetXFConf("xsettings", "/Gtk/CursorThemeSize", FF_VARIANT_TYPE_INT).intValue;
-        wallpaper = ffSettingsGetXFConf("xfce4-desktop", "/backdrop/screen0/monitor0/workspace0/last-image", FF_VARIANT_TYPE_STRING).strValue;
-        if (!wallpaper) // FIXME: find a way to enumerate possible properties
-            wallpaper = ffSettingsGetXFConf("xfce4-desktop", "/backdrop/screen0/monitoreDP-1/workspace0/last-image", FF_VARIANT_TYPE_STRING).strValue;
-        if (!wallpaper)
-            wallpaper = ffSettingsGetXFConf("xfce4-desktop", "/backdrop/screen0/monitorbuiltin/workspace0/last-image", FF_VARIANT_TYPE_STRING).strValue;
+        wallpaper = ffSettingsGetXFConfFirstMatch("xfce4-desktop", "/backdrop/screen0", FF_VARIANT_TYPE_STRING, NULL, testXfconfWallpaperPropKey).strValue;
     }
     else if(ffStrbufIgnCaseCompS(&wmde->dePrettyName, FF_DE_PRETTY_CINNAMON) == 0)
     {