fixed button issue

Author: willmcgugan

src/textual/_xterm_parser.py

@@ -31,7 +31,7 @@ def parse_mouse_code(self, code: str, sender: MessageTarget) -> events.Event | N
         if sgr_match:
             _buttons, _x, _y, state = sgr_match.groups()
             buttons = int(_buttons)
-            button = buttons & 3
+            button = (buttons + 1) & 3
             x = int(_x) - 1
             y = int(_y) - 1
             delta_x = x - self.last_x

src/textual/events.py

@@ -25,13 +25,8 @@ def __init_subclass__(cls, bubble: bool = False) -> None:
 
 
 class Null(Event):
-    def can_batch(self, event: Event) -> bool:
-        return isinstance(event, Null)
-
-
-class Repaint(Event):
-    def can_batch(self, event: Event) -> bool:
-        return isinstance(event, Repaint)
+    def can_batch(self, message: Message) -> bool:
+        return isinstance(message, Null)
 
 
 class ShutdownRequest(Event):
@@ -96,6 +91,14 @@ class Unmount(Event):
     pass
 
 
+class Show(Event):
+    """Widget has become visible."""
+
+
+class Hide(Event):
+    """Widget has been hidden."""
+
+
 class InputEvent(Event, bubble=True):
     pass