UI: Set default theme to Yami

Note that this adds a new CurrentTheme3 config variable to preserve
settings of versions older than 28, making this change safely
backward-compatible.

UI/obs-app.cpp

@@ -474,11 +474,6 @@ bool OBSApp::InitGlobalConfigDefaults()
 	config_set_default_bool(globalConfig, "BasicWindow", "StudioModeLabels",
 				true);
 
-	if (!config_get_bool(globalConfig, "General", "Pre21Defaults")) {
-		config_set_default_string(globalConfig, "General",
-					  "CurrentTheme", DEFAULT_THEME);
-	}
-
 	config_set_default_string(globalConfig, "General", "HotkeyFocusType",
 				  "NeverDisableHotkeys");
 
@@ -1138,19 +1133,9 @@ bool OBSApp::InitTheme()
 	defaultStyleSheet = styleSheet();
 
 	const char *themeName =
-		config_get_string(globalConfig, "General", "CurrentTheme2");
-
-	if (!themeName)
-		/* Use deprecated "CurrentTheme" value if available */
-		themeName = config_get_string(globalConfig, "General",
-					      "CurrentTheme");
-	if (!themeName)
-		/* Use deprecated "Theme" value if available */
-		themeName = config_get_string(globalConfig, "General", "Theme");
+		config_get_string(globalConfig, "General", "CurrentTheme3");
 	if (!themeName)
 		themeName = DEFAULT_THEME;
-	if (!themeName)
-		themeName = "Dark";
 
 	if (strcmp(themeName, "Default") == 0)
 		themeName = "System";

UI/ui-config.h.in

@@ -34,4 +34,4 @@
 #define YOUTUBE_CLIENTID_HASH 0x@YOUTUBE_CLIENTID_HASH@
 #define YOUTUBE_SECRET_HASH   0x@YOUTUBE_SECRET_HASH@
 
-#define DEFAULT_THEME "Dark"
+#define DEFAULT_THEME "Yami"

UI/window-basic-settings.cpp

@@ -3055,7 +3055,7 @@ void OBSBasicSettings::SaveGeneralSettings()
 	QString themeData = ui->theme->itemData(themeIndex).toString();
 
 	if (WidgetChanged(ui->theme))
-		config_set_string(GetGlobalConfig(), "General", "CurrentTheme2",
+		config_set_string(GetGlobalConfig(), "General", "CurrentTheme3",
 				  QT_TO_UTF8(themeData));
 
 #if defined(_WIN32) || defined(__APPLE__)