Move responsibility for writing in to driver (#2273)

* Move responsibility for writing in to driver

* remove driver property

* optimization for segments

* force terminal

* Update src/textual/drivers/_writer_thread.py

Co-authored-by: Rodrigo Girão Serrão <5621605+rodrigogiraoserrao@users.noreply.github.com>

* no safe box

* safe box false

* force null file

---------

Co-authored-by: Rodrigo Girão Serrão <5621605+rodrigogiraoserrao@users.noreply.github.com>

src/textual/_compositor.py

@@ -94,11 +94,15 @@ class LayoutUpdate:
     def __rich_console__(
         self, console: Console, options: ConsoleOptions
     ) -> RenderResult:
+        return self.iter_segments()
+
+    def iter_segments(self) -> Iterable[Segment]:
+        """Get an iterable of segments."""
         x = self.region.x
         new_line = Segment.line()
         move_to = Control.move_to
         for last, (y, line) in loop_last(enumerate(self.strips, self.region.y)):
-            yield move_to(x, y)
+            yield move_to(x, y).segment
             yield from line
             if not last:
                 yield new_line
@@ -131,6 +135,10 @@ class ChopsUpdate:
     def __rich_console__(
         self, console: Console, options: ConsoleOptions
     ) -> RenderResult:
+        return self.iter_segments()
+
+    def iter_segments(self) -> Iterable[Segment]:
+        """Get an iterable of segments."""
         move_to = Control.move_to
         new_line = Segment.line()
         chops = self.chops
@@ -150,7 +158,7 @@ class ChopsUpdate:
                     continue
 
                 if x2 > x >= x1 and end <= x2:
-                    yield move_to(x, y)
+                    yield move_to(x, y).segment
                     yield from strip
                     continue
 
@@ -159,12 +167,12 @@ class ChopsUpdate:
                     for segment in iter_segments:
                         next_x = x + _cell_len(segment.text)
                         if next_x > x1:
-                            yield move_to(x, y)
+                            yield move_to(x, y).segment
                             yield segment
                             break
                         x = next_x
                 else:
-                    yield move_to(x, y)
+                    yield move_to(x, y).segment
                 if end <= x2:
                     yield from iter_segments
                 else:

src/textual/app.py

@@ -95,7 +95,7 @@ from .screen import Screen
 from .widget import AwaitMount, Widget
 
 if TYPE_CHECKING:
-    from typing_extensions import Coroutine, Final, TypeAlias
+    from typing_extensions import Coroutine, TypeAlias
 
     from .devtools.client import DevtoolsClient
     from .pilot import Pilot
@@ -162,6 +162,15 @@ class CssPathError(Exception):
 ReturnType = TypeVar("ReturnType")
 
 
+CSSPathType = Union[
+    str,
+    PurePath,
+    List[Union[str, PurePath]],
+]
+
+CallThreadReturnType = TypeVar("CallThreadReturnType")
+
+
 class _NullFile:
     """A file-like where writes go nowhere."""
 
@@ -171,77 +180,9 @@ class _NullFile:
     def flush(self) -> None:
         pass
 
-
-MAX_QUEUED_WRITES: Final[int] = 30
-
-
-class _WriterThread(threading.Thread):
-    """A thread / file-like to do writes to stdout in the background."""
-
-    def __init__(self) -> None:
-        super().__init__(daemon=True)
-        self._queue: Queue[str | None] = Queue(MAX_QUEUED_WRITES)
-        self._file = sys.__stdout__
-
-    def write(self, text: str) -> None:
-        """Write text. Text will be enqueued for writing.
-
-        Args:
-            text: Text to write to the file.
-        """
-        self._queue.put(text)
-
     def isatty(self) -> bool:
-        """Pretend to be a terminal.
-
-        Returns:
-            True if this is a tty.
-        """
         return True
 
-    def fileno(self) -> int:
-        """Get file handle number.
-
-        Returns:
-            File number of proxied file.
-        """
-        return self._file.fileno()
-
-    def flush(self) -> None:
-        """Flush the file (a no-op, because flush is done in the thread)."""
-        return
-
-    def run(self) -> None:
-        """Run the thread."""
-        write = self._file.write
-        flush = self._file.flush
-        get = self._queue.get
-        qsize = self._queue.qsize
-        # Read from the queue, write to the file.
-        # Flush when there is a break.
-        while True:
-            text: str | None = get()
-            if text is None:
-                break
-            write(text)
-            if qsize() == 0:
-                flush()
-        flush()
-
-    def stop(self) -> None:
-        """Stop the thread, and block until it finished."""
-        self._queue.put(None)
-        self.join()
-
-
-CSSPathType = Union[
-    str,
-    PurePath,
-    List[Union[str, PurePath]],
-]
-
-CallThreadReturnType = TypeVar("CallThreadReturnType")
-
 
 @rich.repr.auto
 class App(Generic[ReturnType], DOMNode):
@@ -324,21 +265,15 @@ class App(Generic[ReturnType], DOMNode):
         if no_color is not None:
             self._filter = Monochrome()
 
-        self._writer_thread: _WriterThread | None = None
-        if sys.__stdout__ is None:
-            file = _NullFile()
-        else:
-            self._writer_thread = _WriterThread()
-            self._writer_thread.start()
-            file = self._writer_thread
-
         self.console = Console(
-            file=file,
+            file=_NullFile(),
             markup=True,
             highlight=False,
             emoji=False,
             legacy_windows=False,
             _environ=environ,
+            force_terminal=True,
+            safe_box=False,
         )
         self._workers = WorkerManager(self)
         self.error_console = Console(markup=False, stderr=True)
@@ -900,6 +835,7 @@ class App(Generic[ReturnType], DOMNode):
         """
         assert self._driver is not None, "App must be running"
         width, height = self.size
+
         console = Console(
             width=width,
             height=height,
@@ -908,6 +844,7 @@ class App(Generic[ReturnType], DOMNode):
             color_system="truecolor",
             record=True,
             legacy_windows=False,
+            safe_box=False,
         )
         screen_render = self.screen._compositor.render_update(
             full=True, screen_stack=self.app._background_screens
@@ -2011,8 +1948,8 @@ class App(Generic[ReturnType], DOMNode):
         if self.devtools is not None and self.devtools.is_connected:
             await self._disconnect_devtools()
 
-        if self._writer_thread is not None:
+        if self._driver is not None:
-            self._writer_thread.stop()
+            self._driver.close()
 
         self._print_error_renderables()
 
@@ -2049,17 +1986,29 @@ class App(Generic[ReturnType], DOMNode):
             if screen is not self.screen or renderable is None:
                 return
 
-            if self._running and not self._closed and not self.is_headless:
+            if (
+                self._running
+                and not self._closed
+                and not self.is_headless
+                and self._driver is not None
+            ):
                 console = self.console
                 self._begin_update()
                 try:
                     try:
-                        console.print(renderable)
+                        segments = (
+                            renderable.iter_segments()
+                            if hasattr(renderable, "iter_segments")
+                            else console.render(renderable)
+                        )
+                        terminal_sequence = console._render_buffer(segments)
                     except Exception as error:
                         self._handle_exception(error)
+                    else:
+                        self._driver.write(terminal_sequence)
                 finally:
                     self._end_update()
-                console.file.flush()
+                self._driver.flush()
         finally:
             self.post_display_hook()
 
@@ -2552,9 +2501,9 @@ class App(Generic[ReturnType], DOMNode):
         self._sync_available = True
 
     def _begin_update(self) -> None:
-        if self._sync_available:
+        if self._sync_available and self._driver is not None:
-            self.console.file.write(SYNC_START)
+            self._driver.write(SYNC_START)
 
     def _end_update(self) -> None:
-        if self._sync_available:
+        if self._sync_available and self._driver is not None:
-            self.console.file.write(SYNC_END)
+            self._driver.write(SYNC_END)

src/textual/driver.py

@@ -128,3 +128,6 @@ class Driver(ABC):
     @abstractmethod
     def stop_application_mode(self) -> None:
         """Stop application mode, restore state."""
+
+    def close(self) -> None:
+        """Perform any final cleanup."""

src/textual/drivers/_writer_thread.py

@@ -0,0 +1,69 @@
+from __future__ import annotations
+
+import sys
+import threading
+from queue import Queue
+from typing import IO
+
+from typing_extensions import Final
+
+MAX_QUEUED_WRITES: Final[int] = 30
+
+
+class WriterThread(threading.Thread):
+    """A thread / file-like to do writes to stdout in the background."""
+
+    def __init__(self, file: IO[str]) -> None:
+        super().__init__(daemon=True)
+        self._queue: Queue[str | None] = Queue(MAX_QUEUED_WRITES)
+        self._file = file
+
+    def write(self, text: str) -> None:
+        """Write text. Text will be enqueued for writing.
+
+        Args:
+            text: Text to write to the file.
+        """
+        self._queue.put(text)
+
+    def isatty(self) -> bool:
+        """Pretend to be a terminal.
+
+        Returns:
+            True.
+        """
+        return True
+
+    def fileno(self) -> int:
+        """Get file handle number.
+
+        Returns:
+            File number of proxied file.
+        """
+        return self._file.fileno()
+
+    def flush(self) -> None:
+        """Flush the file (a no-op, because flush is done in the thread)."""
+        return
+
+    def run(self) -> None:
+        """Run the thread."""
+        write = self._file.write
+        flush = self._file.flush
+        get = self._queue.get
+        qsize = self._queue.qsize
+        # Read from the queue, write to the file.
+        # Flush when there is a break.
+        while True:
+            text: str | None = get()
+            if text is None:
+                break
+            write(text)
+            if qsize() == 0:
+                flush()
+        flush()
+
+    def stop(self) -> None:
+        """Stop the thread, and block until it finished."""
+        self._queue.put(None)
+        self.join()

src/textual/drivers/linux_driver.py

@@ -17,6 +17,7 @@ from .. import events, log
 from .._xterm_parser import XTermParser
 from ..driver import Driver
 from ..geometry import Size
+from ._writer_thread import WriterThread
 
 if TYPE_CHECKING:
     from ..app import App
@@ -41,11 +42,12 @@ class LinuxDriver(Driver):
             size: Initial size of the terminal or `None` to detect.
         """
         super().__init__(app, debug=debug, size=size)
-        self._file = app.console.file
+        self._file = sys.__stdout__
         self.fileno = sys.stdin.fileno()
         self.attrs_before: list[Any] | None = None
         self.exit_event = Event()
         self._key_thread: Thread | None = None
+        self._writer_thread: WriterThread | None = None
 
     def __rich_repr__(self) -> rich.repr.Result:
         yield self._app
@@ -108,7 +110,8 @@ class LinuxDriver(Driver):
         Args:
             data: Raw data.
         """
-        self._file.write(data)
+        assert self._writer_thread is not None, "Driver must be in application mode"
+        self._writer_thread.write(data)
 
     def start_application_mode(self):
         """Start application mode."""
@@ -124,6 +127,9 @@ class LinuxDriver(Driver):
                 loop=loop,
             )
 
+        self._writer_thread = WriterThread(self._file)
+        self._writer_thread.start()
+
         def on_terminal_resize(signum, stack) -> None:
             send_size_event()
 
@@ -222,6 +228,11 @@ class LinuxDriver(Driver):
             self.write("\x1b[?1049l" + "\x1b[?25h")
             self.flush()
 
+    def close(self) -> None:
+        """Perform cleanup."""
+        if self._writer_thread is not None:
+            self._writer_thread.stop()
+
     def run_input_thread(self) -> None:
         """Wait for input and dispatch events."""
         selector = selectors.DefaultSelector()

src/textual/drivers/windows_driver.py

@@ -4,9 +4,9 @@ import asyncio
 from threading import Event, Thread
 from typing import TYPE_CHECKING, Callable
 
-from .._context import active_app
 from ..driver import Driver
 from . import win32
+from ._writer_thread import WriterThread
 
 if TYPE_CHECKING:
     from ..app import App
@@ -34,6 +34,7 @@ class WindowsDriver(Driver):
         self.exit_event = Event()
         self._event_thread: Thread | None = None
         self._restore_console: Callable[[], None] | None = None
+        self._writer_thread: WriterThread | None = None
 
     def write(self, data: str) -> None:
         """Write data to the output device.
@@ -41,7 +42,8 @@ class WindowsDriver(Driver):
         Args:
             data: Raw data.
         """
-        self._file.write(data)
+        assert self._writer_thread is not None, "Driver must be in application mode"
+        self._writer_thread.write(data)
 
     def _enable_mouse_support(self) -> None:
         """Enable reporting of mouse events."""
@@ -73,6 +75,9 @@ class WindowsDriver(Driver):
         """Start application mode."""
         loop = asyncio.get_running_loop()
 
+        self._writer_thread = WriterThread(self._file)
+        self._writer_thread.start()
+
         self._restore_console = win32.enable_application_mode()
 
         self.write("\x1b[?1049h")  # Enable alt screen
@@ -110,3 +115,8 @@ class WindowsDriver(Driver):
         # Disable alt screen, show cursor
         self.write("\x1b[?1049l" + "\x1b[?25h")
         self.flush()
+
+    def close(self) -> None:
+        """Perform cleanup."""
+        if self._writer_thread is not None:
+            self._writer_thread.stop()