Merge pull request #3644 from davep/chunk-writes-on-windows

Chunk writes on Windows
Textualize · Nov 7, 2023 · c7cf028 · c7cf028
2 parents f0fd8d4 + 7dcf014
commit c7cf028
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ### Fixed
 
 - Duplicate CSS errors when parsing CSS from a screen https://github.com/Textualize/textual/issues/3581
+- Fixed visual glitched characters on Windows due to Python limitation https://github.com/Textualize/textual/issues/2548
 
 ### Changed
 

diff --git a/src/textual/app.py b/src/textual/app.py
@@ -2526,7 +2526,22 @@ def _display(self, screen: Screen, renderable: RenderableType | None) -> None:
                     except Exception as error:
                         self._handle_exception(error)
                     else:
-                        self._driver.write(terminal_sequence)
+                        if WINDOWS:
+                            # Combat a problem with Python on Windows.
+                            #
+                            # https://github.com/Textualize/textual/issues/2548
+                            # https://github.com/python/cpython/issues/82052
+                            CHUNK_SIZE = 8192
+                            write = self._driver.write
+                            for chunk in (
+                                terminal_sequence[offset : offset + CHUNK_SIZE]
+                                for offset in range(
+                                    0, len(terminal_sequence), CHUNK_SIZE
+                                )
+                            ):
+                                write(chunk)
+                        else:
+                            self._driver.write(terminal_sequence)
                 finally:
                     self._end_update()