Merge pull request #448 from Textualize/features-env

Add TEXTUAL features env var

sandbox/uber.css

@@ -7,5 +7,5 @@
 
 .list-item {
   height: 8;
-  background: dark_blue;
+  background: darkblue;
 }

src/textual/_xterm_parser.py

@@ -19,15 +19,15 @@ class XTermParser(Parser[events.Event]):
 
     _re_sgr_mouse = re.compile(r"\x1b\[<(\d+);(\d+);(\d+)([Mm])")
 
-    def __init__(self, sender: MessageTarget, more_data: Callable[[], bool]) -> None:
+    def __init__(
+        self, sender: MessageTarget, more_data: Callable[[], bool], debug: bool = False
+    ) -> None:
         self.sender = sender
         self.more_data = more_data
         self.last_x = 0
         self.last_y = 0
 
-        self._debug_log_file = (
-            open("keys.log", "wt") if "TEXTUAL_DEBUG" in os.environ else None
-        )
+        self._debug_log_file = open("keys.log", "wt") if debug else None
 
         super().__init__()
 

src/textual/app.py

@@ -36,6 +36,7 @@ from .devtools.client import DevtoolsClient, DevtoolsConnectionError, DevtoolsLo
 from .devtools.redirect_output import StdoutRedirector
 from .dom import DOMNode
 from .driver import Driver
+from .features import parse_features, FeatureFlag
 from .file_monitor import FileMonitor
 from .geometry import Offset, Region, Size
 from .layouts.dock import Dock
@@ -89,7 +90,6 @@ class App(Generic[ReturnType], DOMNode):
 
     def __init__(
         self,
-        screen: bool = True,
         driver_class: Type[Driver] | None = None,
         log: str = "",
         log_verbosity: int = 1,
@@ -98,19 +98,21 @@ class App(Generic[ReturnType], DOMNode):
         css: str | None = None,
         watch_css: bool = True,
     ):
-        """The Textual Application base class
+        """Textual application base class
 
         Args:
-            console (Console, optional): A Rich Console. Defaults to None.
-            screen (bool, optional): Enable full-screen application mode. Defaults to True.
-            driver_class (Type[Driver], optional): Driver class, or None to use default. Defaults to None.
-            title (str, optional): Title of the application. Defaults to "Textual Application".
+            driver_class (Type[Driver] | None, optional): Driver class or ``None`` to auto-detect. Defaults to None.
+            log (str, optional): Path to log file, or "" to disable. Defaults to "".
+            log_verbosity (int, optional): Log verbosity from 0-3. Defaults to 1.
+            title (str, optional): Default title of the application. Defaults to "Textual Application".
+            css_file (str | None, optional): Path to CSS or ``None`` for no CSS file. Defaults to None.
+            css (str | None, optional): CSS code to parse, or ``None`` for no literal CSS. Defaults to None.
+            watch_css (bool, optional): Watch CSS for changes. Defaults to True.
         """
         self.console = Console(
             file=sys.__stdout__, markup=False, highlight=False, emoji=False
         )
         self.error_console = Console(markup=False, stderr=True)
-        self._screen = screen
         self.driver_class = driver_class or self.get_driver_class()
         self._title = title
         self._screen_stack: list[Screen] = []
@@ -160,6 +162,8 @@ class App(Generic[ReturnType], DOMNode):
         if css is not None:
             self.css = css
 
+        self.features: frozenset[FeatureFlag] = parse_features(os.getenv("TEXTUAL", ""))
+
         self.registry: set[MessagePump] = set()
 
         self.devtools = DevtoolsClient()
@@ -173,6 +177,16 @@ class App(Generic[ReturnType], DOMNode):
     background: Reactive[str] = Reactive("black")
     dark = Reactive(False)
 
+    @property
+    def devtools_enabled(self) -> bool:
+        """Check if devtools are enabled."""
+        return "devtools" in self.features
+
+    @property
+    def debug(self) -> bool:
+        """Check if debug mode is enabled."""
+        return "debug" in self.features
+
     def exit(self, result: ReturnType | None = None) -> None:
         """Exit the app, and return the supplied result.
 
@@ -495,7 +509,7 @@ class App(Generic[ReturnType], DOMNode):
         log("---")
         log(f"driver={self.driver_class}")
 
-        if os.getenv("TEXTUAL_DEVTOOLS") == "1":
+        if self.devtools_enabled:
             try:
                 await self.devtools.connect()
                 self.log(f"Connected to devtools ({self.devtools.url})")
@@ -504,7 +518,6 @@ class App(Generic[ReturnType], DOMNode):
         try:
             if self.css_file is not None:
                 self.stylesheet.read(self.css_file)
-                self.stylesheet.parse()
             if self.css is not None:
                 self.stylesheet.add_source(
                     self.css, path=f"<{self.__class__.__name__}>"

src/textual/driver.py

@@ -15,9 +15,12 @@ if TYPE_CHECKING:
 
 
 class Driver(ABC):
-    def __init__(self, console: "Console", target: "MessageTarget") -> None:
+    def __init__(
+        self, console: "Console", target: "MessageTarget", debug: bool = False
+    ) -> None:
         self.console = console
         self._target = target
+        self._debug = debug
         self._loop = asyncio.get_event_loop()
         self._mouse_down_time = time()
 

src/textual/drivers/linux_driver.py

@@ -27,8 +27,10 @@ from .._profile import timer
 class LinuxDriver(Driver):
     """Powers display and input for Linux / MacOS"""
 
-    def __init__(self, console: "Console", target: "MessageTarget") -> None:
-        super().__init__(console, target)
+    def __init__(
+        self, console: "Console", target: "MessageTarget", debug: bool = False
+    ) -> None:
+        super().__init__(console, target, debug)
         self.fileno = sys.stdin.fileno()
         self.attrs_before: list[Any] | None = None
         self.exit_event = Event()
@@ -189,7 +191,7 @@ class LinuxDriver(Driver):
                     return True
             return False
 
-        parser = XTermParser(self._target, more_data)
+        parser = XTermParser(self._target, more_data, self._debug)
         feed = parser.feed
 
         utf8_decoder = getincrementaldecoder("utf-8")().decode

src/textual/drivers/windows_driver.py

@@ -17,8 +17,10 @@ if TYPE_CHECKING:
 class WindowsDriver(Driver):
     """Powers display and input for Windows."""
 
-    def __init__(self, console: "Console", target: "MessageTarget") -> None:
-        super().__init__(console, target)
+    def __init__(
+        self, console: "Console", target: "MessageTarget", debug: bool = False
+    ) -> None:
+        super().__init__(console, target, debug)
         self.in_fileno = sys.stdin.fileno()
         self.out_fileno = sys.stdout.fileno()
 

src/textual/features.py

@@ -0,0 +1,34 @@
+from __future__ import annotations
+
+import sys
+
+from typing import cast
+
+if sys.version_info >= (3, 8):
+    from typing import Final, Literal
+else:
+    from typing_extensions import Final, Literal
+
+FEATURES: Final = {"devtools", "debug"}
+
+FeatureFlag = Literal["devtools", "debug"]
+
+
+def parse_features(features: str) -> frozenset[FeatureFlag]:
+    """Parse features env var
+
+    Args:
+        features (str): Comma seprated feature flags
+
+    Returns:
+        frozenset[FeatureFlag]: A frozen set of known features.
+    """
+
+    features_set = frozenset(
+        set(
+            feature.strip().lower()
+            for feature in features.split(",")
+            if feature.strip()
+        ).intersection(FEATURES)
+    )
+    return cast("frozenset[FeatureFlag]", features_set)

tests/test_features.py

@@ -0,0 +1,29 @@
+from __future__ import annotations
+
+from textual.app import App
+
+
+def test_textual_env_var(monkeypatch):
+    monkeypatch.setenv("TEXTUAL", "")
+    app = App()
+    assert app.features == set()
+    assert app.devtools_enabled is False
+    assert app.debug is False
+
+    monkeypatch.setenv("TEXTUAL", "devtools")
+    app = App()
+    assert app.features == {"devtools"}
+    assert app.devtools_enabled is True
+    assert app.debug is False
+
+    monkeypatch.setenv("TEXTUAL", "devtools,debug")
+    app = App()
+    assert app.features == {"devtools", "debug"}
+    assert app.devtools_enabled is True
+    assert app.debug is True
+
+    monkeypatch.setenv("TEXTUAL", "devtools, debug")
+    app = App()
+    assert app.features == {"devtools", "debug"}
+    assert app.devtools_enabled is True
+    assert app.debug is True