Allow default symbol theme to be configured

gns3server/controller/symbols.py

@@ -43,7 +43,9 @@ class Symbols:
 
         # Keep a cache of symbols size
         self._symbol_size_cache = {}
-        self._current_theme = "Affinity-square-blue"
+
+        self._server_config = Config.instance().settings.Server
+        self._current_theme = self._server_config.default_symbol_theme
         self._themes = BUILTIN_SYMBOL_THEMES
 
     @property
@@ -66,7 +68,8 @@ class Symbols:
 
         theme = self._themes.get(symbol_theme, None)
         if not theme:
-            raise ControllerNotFoundError(f"Could not find symbol theme '{symbol_theme}'")
+            log.warning(f"Could not find symbol theme '{self._current_theme}'")
+            return None
         symbol_path = theme.get(symbol)
         if symbol_path not in self._symbols_path:
             log.warning(f"Default symbol {symbol} was not found")

gns3server/schemas/config.py

@@ -109,6 +109,17 @@ class ServerProtocol(str, Enum):
     https = "https"
 
 
+class BuiltinSymbolTheme(str, Enum):
+
+    classic = "Classic"
+    affinity_square_blue = "Affinity-square-blue"
+    affinity_square_red = "Affinity-square-red"
+    affinity_square_gray = "Affinity-square-gray"
+    affinity_circle_blue = "Affinity-circle-blue"
+    affinity_circle_red = "Affinity-circle-red"
+    affinity_circle_gray = "Affinity-circle-gray"
+
+
 class ServerSettings(BaseModel):
 
     local: bool = False
@@ -124,6 +135,7 @@ class ServerSettings(BaseModel):
     appliances_path: str = "~/GNS3/appliances"
     symbols_path: str = "~/GNS3/symbols"
     configs_path: str = "~/GNS3/configs"
+    default_symbol_theme: BuiltinSymbolTheme = BuiltinSymbolTheme.affinity_square_blue
     report_errors: bool = True
     additional_images_paths: List[str] = Field(default_factory=list)
     console_start_port_range: int = Field(5000, gt=0, le=65535)