Merge pull request #3647 from EricWF/fix-terminal-movements

Fix erroneous ButtonDown mouse event reporting.

Author: willmcgugan

CHANGELOG.md

@@ -579,6 +579,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Fixed CSS watcher crash if file becomes unreadable (even temporarily) https://github.com/Textualize/textual/pull/4079
 - Fixed display of keys when used in conjunction with other keys https://github.com/Textualize/textual/pull/3050
 - Fixed double detection of <kbd>Escape</kbd> on Windows https://github.com/Textualize/textual/issues/4038
+- Fixed erroneous mouse 'ButtonDown' reporting for mouse movement when any-event mode is enabled in xterm. https://github.com/Textualize/textual/pull/3647
+
 
 ## [0.47.1] - 2024-01-05
 

src/textual/_xterm_parser.py

@@ -77,13 +77,14 @@ def parse_mouse_code(self, code: str) -> events.Event | None:
                 )
                 button = 0
             else:
-                if buttons & 32:
+                button = (buttons + 1) & 3
+                # XTerm events for mouse movement can look like mouse button down events. But if there is no key pressed,
+                # it's a mouse move event.
+                if buttons & 32 or button == 0:
                     event_class = events.MouseMove
                 else:
                     event_class = events.MouseDown if state == "M" else events.MouseUp
 
-                button = (buttons + 1) & 3
-
             event = event_class(
                 x,
                 y,

tests/test_xterm_parser.py

@@ -218,6 +218,7 @@ def test_mouse_click(parser, sequence, event_type, shift, meta):
         ("\x1b[<35;15;38M", False, False, 0),  # Basic cursor movement
         ("\x1b[<39;15;38M", True, False, 0),  # Shift held down
         ("\x1b[<43;15;38M", False, True, 0),  # Meta held down
+        ("\x1b[<3;15;38M", False, False, 0),
     ],
 )
 def test_mouse_move(parser, sequence, shift, meta, button):