older versions of Python struggle with the type hints syntax

xpra/client/gl/gl_window_backing_base.py

@@ -276,7 +276,7 @@ def __init__(self, wid : int, window_alpha : bool, pixel_depth : int=0):
         self.pixel_format : str = ""
         self.textures = None # OpenGL texture IDs
         self.shaders = None
-        self.texture_size : Tuple[int,int] = 0, 0
+        self.texture_size : Tuple[int,int] = (0, 0)
         self.gl_setup : bool = False
         self.debug_setup : bool = False
         self.border : WindowBorder = WindowBorder(shown=False)

xpra/client/gui/window_backing_base.py

@@ -117,12 +117,12 @@ def __init__(self, wid : int, window_alpha : bool):
         load_csc_options()
         load_video_decoders()
         self.wid : int = wid
-        self.size : Tuple[int,int] = 0, 0
-        self.render_size : Tuple[int,int] = 0, 0
+        self.size : Tuple[int,int] = (0, 0)
+        self.render_size : Tuple[int,int] = (0, 0)
         #padding between the window contents and where we actually draw the backing
         #(ie: if the window is bigger than the backing,
         # we may be rendering the backing in the center of the window)
-        self.offsets : Tuple[int,int,int,int] = 0, 0, 0, 0       #top,left,bottom,right
+        self.offsets : Tuple[int,int,int,int] = (0, 0, 0, 0)       #top,left,bottom,right
         self.gravity : int = 0
         self._alpha_enabled = window_alpha
         self._backing = None
@@ -152,7 +152,7 @@ def __init__(self, wid : int, window_alpha : bool):
         self.mmap = None
         self.mmap_enabled : bool = False
         self.fps_events : deque = deque(maxlen=120)
-        self.fps_buffer_size : Tuple[int,int] = 0, 0
+        self.fps_buffer_size : Tuple[int,int] = (0, 0)
         self.fps_buffer_update_time : float = 0
         self.fps_value : int = 0
         self.fps_refresh_timer : int = 0

xpra/client/mixins/window_manager.py

@@ -111,8 +111,8 @@ def __init__(self):
         self._id_to_window : Dict[int,Any] = {}
 
         self.auto_refresh_delay : int = -1
-        self.min_window_size : Tuple[int, int] = 0, 0
-        self.max_window_size : Tuple[int, int] = 0, 0
+        self.min_window_size : Tuple[int, int] = (0, 0)
+        self.max_window_size : Tuple[int, int] = (0, 0)
 
         #draw thread:
         self._draw_queue = None

xpra/server/source/windows.py

@@ -81,8 +81,8 @@ def init_state(self) -> None:
         self.send_bell = False
         self.send_windows = True
         self.pointer_grabs = False
-        self.window_min_size : Tuple[int,int] = 0, 0
-        self.window_max_size : Tuple[int,int] = 0, 0
+        self.window_min_size : Tuple[int,int] = (0, 0)
+        self.window_max_size : Tuple[int,int] = (0, 0)
         self.window_restack = False
         self.window_pre_map = False
         self.system_tray = False