MouseScrollUp/MouseScrollDown => plain MousEvent's

... which means they get passesd x, y, etc. In particular,
they are passed the keyboard modifiers. This allows widgets
to use e.g. ctrl-wheel to scroll right/left.

src/textual/_xterm_parser.py

@@ -54,36 +54,35 @@ 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 + 1) & 3
             x = int(_x) - 1
             y = int(_y) - 1
             delta_x = x - self.last_x
             delta_y = y - self.last_y
             self.last_x = x
             self.last_y = y
-            event: events.Event
-            if buttons & 64:
-                event = (
-                    events.MouseScrollUp if button == 1 else events.MouseScrollDown
-                )(sender, x, y)
-            else:
-                event = (
-                    events.MouseMove
-                    if buttons & 32
-                    else (events.MouseDown if state == "M" else events.MouseUp)
-                )(
-                    sender,
-                    x,
-                    y,
-                    delta_x,
-                    delta_y,
-                    button,
-                    bool(buttons & 4),
-                    bool(buttons & 8),
-                    bool(buttons & 16),
-                    screen_x=x,
-                    screen_y=y,
-                )
+            event_cls = (
+                (events.MouseScrollDown if buttons & 1 else events.MouseScrollUp)
+                if buttons & 64
+                else events.MouseMove
+                if buttons & 32
+                else (events.MouseDown if state == "M" else events.MouseUp)
+            )
+            if event_cls in (events.MouseScrollUp, events.MouseScrollDown):
+                buttons &= ~(64 | 3)
+            button = (buttons + 1) & 3
+            event = event_cls(
+                sender,
+                x,
+                y,
+                delta_x,
+                delta_y,
+                button,
+                bool(buttons & 4),
+                bool(buttons & 8),
+                bool(buttons & 16),
+                screen_x=x,
+                screen_y=y,
+            )
             return event
         return None
 

src/textual/events.py

@@ -419,22 +419,14 @@ class MouseUp(MouseEvent, bubble=True, verbose=True):
     pass
 
 
-class MouseScrollDown(InputEvent, bubble=True, verbose=True):
-    __slots__ = ["x", "y"]
-
-    def __init__(self, sender: MessageTarget, x: int, y: int) -> None:
-        super().__init__(sender)
-        self.x = x
-        self.y = y
-
+@rich.repr.auto
+class MouseScrollDown(MouseEvent, bubble=True):
+    pass
 
-class MouseScrollUp(InputEvent, bubble=True, verbose=True):
-    __slots__ = ["x", "y"]
 
-    def __init__(self, sender: MessageTarget, x: int, y: int) -> None:
-        super().__init__(sender)
-        self.x = x
-        self.y = y
+@rich.repr.auto
+class MouseScrollUp(MouseEvent, bubble=True):
+    pass
 
 
 class Click(MouseEvent, bubble=True):

tests/test_xterm_parser.py

@@ -236,14 +236,14 @@ def test_mouse_move(parser, sequence, shift, meta, button):
 
 
 @pytest.mark.parametrize(
-    "sequence",
+    "sequence, shift, meta",
     [
-        "\x1b[<64;18;25M",
-        "\x1b[<68;18;25M",
-        "\x1b[<72;18;25M",
+        ("\x1b[<64;18;25M", False, False),
+        ("\x1b[<68;18;25M", True,  False),
+        ("\x1b[<72;18;25M", False, True),
     ],
 )
-def test_mouse_scroll_up(parser, sequence):
+def test_mouse_scroll_up(parser, sequence, shift, meta):
     """Scrolling the mouse with and without modifiers held down.
     We don't currently capture modifier keys in scroll events.
     """
@@ -256,17 +256,19 @@ def test_mouse_scroll_up(parser, sequence):
     assert isinstance(event, MouseScrollUp)
     assert event.x == 17
     assert event.y == 24
+    assert event.shift is shift
+    assert event.meta is meta
 
 
 @pytest.mark.parametrize(
-    "sequence",
+    "sequence, shift, meta",
     [
-        "\x1b[<65;18;25M",
-        "\x1b[<69;18;25M",
-        "\x1b[<73;18;25M",
+        ("\x1b[<65;18;25M", False, False),
+        ("\x1b[<69;18;25M", True,  False),
+        ("\x1b[<73;18;25M", False, True),
     ],
 )
-def test_mouse_scroll_down(parser, sequence):
+def test_mouse_scroll_down(parser, sequence, shift, meta):
     events = list(parser.feed(sequence))
 
     assert len(events) == 1
@@ -276,6 +278,8 @@ def test_mouse_scroll_down(parser, sequence):
     assert isinstance(event, MouseScrollDown)
     assert event.x == 17
     assert event.y == 24
+    assert event.shift is shift
+    assert event.meta is meta
 
 
 def test_mouse_event_detected_but_info_not_parsed(parser):