declaration parser

examples/basic.css

@@ -1,4 +1,13 @@
-App > DockView {
+App > View {
+  docks: main=top;
+}
+
+#sidebar {
+  dock-group: main;
+}
+
+/*
+App > View {
   layout: dock;
   docks: side=left/1 header=top footer=bottom;
   layers: base panels;
@@ -37,3 +46,4 @@ App > DockView {
   dock-group: header;
   text: on #20639b;
 }
+*/

examples/basic.py

@@ -6,7 +6,7 @@ class BasicApp(App):
     """A basic app demonstrating CSS"""
 
     def on_load(self):
-        self.bind("t", "toggle_class('#sidebar', '-active')")
+        self.bind("tab", "toggle_class('#sidebar', '-active')")
 
     def on_mount(self):
         """Build layout here."""

src/textual/_ansi_sequences.py

@@ -15,7 +15,7 @@ ANSI_SEQUENCES: Dict[str, Tuple[Keys, ...]] = {
     "\x06": (Keys.ControlF,),  # Control-F (cursor forward)
     "\x07": (Keys.ControlG,),  # Control-G
     "\x08": (Keys.ControlH,),  # Control-H (8) (Identical to '\b')
-    "\x09": (Keys.ControlI,),  # Control-I (9) (Identical to '\t')
+    "\x09": (Keys.Tab,),  # Control-I (9) (Identical to '\t')
     "\x0a": (Keys.ControlJ,),  # Control-J (10) (Identical to '\n')
     "\x0b": (Keys.ControlK,),  # Control-K (delete until end of line; vertical tab)
     "\x0c": (Keys.ControlL,),  # Control-L (clear; form feed)

src/textual/app.py

@@ -498,7 +498,7 @@ class App(DOMNode):
         # Handle input events that haven't been forwarded
         # If the event has been forwarded it may have bubbled up back to the App
         if isinstance(event, events.Mount):
-            view = DockView()
+            view = View()
             self.register(self, view)
             await self.push_view(view)
             await super().on_event(event)

src/textual/css/_style_properties.py

@@ -67,6 +67,7 @@ class ScalarProperty:
         if new_value is not None and new_value.is_percent:
             new_value = Scalar(float(new_value.value), self.percent_unit, Unit.WIDTH)
         setattr(obj, self.internal_name, new_value)
+        obj.refresh()
         return value
 
 
@@ -100,6 +101,7 @@ class BoxProperty:
             else:
                 new_value = (_type, Style.from_color(Color.parse(color)))
         setattr(obj, self.internal_name, new_value)
+        obj.refresh()
         return border
 
 
@@ -151,6 +153,7 @@ class BorderProperty:
         | None,
     ) -> None:
         top, right, bottom, left = self._properties
+        obj.refresh()
         if border is None:
             setattr(obj, top, None)
             setattr(obj, right, None)
@@ -207,6 +210,7 @@ class StyleProperty:
         return style
 
     def __set__(self, obj: Styles, style: Style | str | None) -> Style | str | None:
+        obj.refresh()
         if style is None:
             setattr(obj, self._color_name, None)
             setattr(obj, self._bgcolor_name, None)
@@ -232,6 +236,7 @@ class SpacingProperty:
         return getattr(obj, self._internal_name) or NULL_SPACING
 
     def __set__(self, obj: Styles, spacing: SpacingDimensions) -> Spacing:
+        obj.refresh(True)
         spacing = Spacing.unpack(spacing)
         setattr(obj, self._internal_name, spacing)
         return spacing
@@ -246,6 +251,7 @@ class DocksProperty:
     def __set__(
         self, obj: Styles, docks: Iterable[DockGroup] | None
     ) -> Iterable[DockGroup] | None:
+        obj.refresh(True)
         if docks is None:
             obj._rule_docks = None
         else:
@@ -258,6 +264,7 @@ class DockGroupProperty:
         return obj._rule_dock_group or ""
 
     def __set__(self, obj: Styles, spacing: str | None) -> str | None:
+        obj.refresh(True)
         obj._rule_dock_group = spacing
         return spacing
 
@@ -274,6 +281,7 @@ class OffsetProperty:
     def __set__(
         self, obj: Styles, offset: tuple[int | str, int | str]
     ) -> tuple[int | str, int | str]:
+        obj.refresh(True)
         x, y = offset
         scalar_x = (
             Scalar.parse(x, Unit.WIDTH)
@@ -299,6 +307,7 @@ class IntegerProperty:
         return getattr(obj, self._internal_name, 0)
 
     def __set__(self, obj: Styles, value: int | None) -> int | None:
+        obj.refresh()
         if not isinstance(value, int):
             raise StyleTypeError(f"{self._name} must be a str")
         setattr(obj, self._internal_name, value)
@@ -318,6 +327,7 @@ class StringProperty:
         return getattr(obj, self._internal_name, None) or self._default
 
     def __set__(self, obj: Styles, value: str | None = None) -> str | None:
+        obj.refresh()
         if value is not None:
             if value not in self._valid_values:
                 raise StyleValueError(
@@ -336,6 +346,7 @@ class NameProperty:
         return getattr(obj, self._internal_name) or ""
 
     def __set__(self, obj: Styles, name: str | None) -> str | None:
+        obj.refresh(True)
         if not isinstance(name, str):
             raise StyleTypeError(f"{self._name} must be a str")
         setattr(obj, self._internal_name, name)
@@ -355,6 +366,7 @@ class NameListProperty:
     def __set__(
         self, obj: Styles, names: str | tuple[str] | None = None
     ) -> str | tuple[str] | None:
+        obj.refresh(True)
         names_value: tuple[str, ...] | None = None
         if isinstance(names, str):
             names_value = tuple(name.strip().lower() for name in names.split(" "))
@@ -375,6 +387,7 @@ class ColorProperty:
         return getattr(obj, self._internal_name, None) or Color.default()
 
     def __set__(self, obj: Styles, color: Color | str | None) -> Color | str | None:
+        obj.refresh()
         if color is None:
             setattr(self, self._internal_name, None)
         else:
@@ -409,6 +422,7 @@ class StyleFlagsProperty:
         return getattr(obj, self._internal_name, None) or Style.null()
 
     def __set__(self, obj: Styles, style_flags: str | None) -> str | None:
+        obj.refresh()
         if style_flags is None:
             setattr(self, self._internal_name, None)
         else:

src/textual/css/parse.py

@@ -5,7 +5,8 @@ from rich import print
 from functools import lru_cache
 from typing import Iterator, Iterable
 
-from .tokenize import tokenize, Token
+from .styles import Styles
+from .tokenize import tokenize, tokenize_declarations, Token
 from .tokenizer import EOFError
 
 from .model import (
@@ -157,6 +158,44 @@ def parse_rule_set(tokens: Iterator[Token], token: Token) -> Iterable[RuleSet]:
     yield rule_set
 
 
+def parse_declarations(css: str, path: str) -> Styles:
+
+    tokens = iter(tokenize_declarations(css, path))
+    styles_builder = StylesBuilder()
+
+    declaration: Declaration | None = None
+    errors: list[tuple[Token, str]] = []
+
+    while True:
+        token = next(tokens, None)
+        if token is None:
+            break
+        token_name = token.name
+        if token_name in ("whitespace", "declaration_end", "eof"):
+            continue
+        if token_name == "declaration_name":
+            if declaration and declaration.tokens:
+                try:
+                    styles_builder.add_declaration(declaration)
+                except DeclarationError as error:
+                    errors.append((error.token, error.message))
+            declaration = Declaration(token, "")
+            declaration.name = token.value.rstrip(":")
+        elif token_name == "declaration_set_end":
+            break
+        else:
+            if declaration:
+                declaration.tokens.append(token)
+
+    if declaration and declaration.tokens:
+        try:
+            styles_builder.add_declaration(declaration)
+        except DeclarationError as error:
+            errors.append((error.token, error.message))
+
+    return styles_builder.styles
+
+
 def parse(css: str, path: str) -> Iterable[RuleSet]:
 
     tokens = iter(tokenize(css, path))
@@ -206,3 +245,10 @@ def parse(css: str, path: str) -> Iterable[RuleSet]:
 
 if __name__ == "__main__":
     print(parse_selectors("Foo > Bar.baz { foo: bar"))
+
+    CSS = """
+text: on red;
+docks: main=top;
+    """
+
+    print(parse_declarations(CSS, "foo"))

src/textual/css/styles.py

@@ -91,6 +91,9 @@ class Styles:
 
     _rule_transitions: dict[str, Transition] | None = None
 
+    _layout_required: bool = False
+    _repaint_required: bool = False
+
     important: set[str] = field(default_factory=set)
 
     display = StringProperty(VALID_DISPLAY, "block")
@@ -130,6 +133,15 @@ class Styles:
     layers = NameListProperty()
     transitions = TransitionsProperty()
 
+    def refresh(self, layout: bool = False) -> None:
+        self._repaint_required = True
+        self._layout_required = layout
+
+    def check_refresh(self) -> tuple[bool, bool]:
+        result = (self._repaint_required, self._layout_required)
+        self._repaint_required = self._layout_required = False
+        return result
+
     @property
     def has_border(self) -> bool:
         """Check in a border is present."""

src/textual/css/tokenize.py

@@ -40,6 +40,13 @@ expect_declaration = Expect(
     declaration_set_end=r"\}",
 )
 
+expect_declaration_solo = Expect(
+    whitespace=r"\s+",
+    comment_start=r"\/\*",
+    declaration_name=r"[a-zA-Z_\-]+\:",
+    declaration_set_end=r"\}",
+).expect_eof(True)
+
 expect_declaration_content = Expect(
     declaration_end=r"\n|;",
     whitespace=r"\s+",
@@ -55,34 +62,65 @@ expect_declaration_content = Expect(
 )
 
 
-_STATES = {
-    "selector_start": expect_selector_continue,
-    "selector_start_id": expect_selector_continue,
-    "selector_start_class": expect_selector_continue,
-    "selector_start_universal": expect_selector_continue,
-    "selector_id": expect_selector_continue,
-    "selector_class": expect_selector_continue,
-    "selector_universal": expect_selector_continue,
-    "declaration_set_start": expect_declaration,
-    "declaration_name": expect_declaration_content,
-    "declaration_end": expect_declaration,
-    "declaration_set_end": expect_selector,
-}
+class StateTokenizer:
+    EXPECT = expect_selector
+    STATE_MAP = {
+        "selector_start": expect_selector_continue,
+        "selector_start_id": expect_selector_continue,
+        "selector_start_class": expect_selector_continue,
+        "selector_start_universal": expect_selector_continue,
+        "selector_id": expect_selector_continue,
+        "selector_class": expect_selector_continue,
+        "selector_universal": expect_selector_continue,
+        "declaration_set_start": expect_declaration,
+        "declaration_name": expect_declaration_content,
+        "declaration_end": expect_declaration,
+        "declaration_set_end": expect_selector,
+    }
+
+    def __call__(self, code: str, path: str) -> Iterable[Token]:
+        tokenizer = Tokenizer(code, path=path)
+        expect = self.EXPECT
+        get_token = tokenizer.get_token
+        get_state = self.STATE_MAP.get
+        while True:
+            token = get_token(expect)
+            name = token.name
+            if name == "comment_start":
+                tokenizer.skip_to(expect_comment_end)
+                continue
+            elif name == "eof":
+                break
+            expect = get_state(name, expect)
+            yield token
 
 
-def tokenize(code: str, path: str) -> Iterable[Token]:
-    tokenizer = Tokenizer(code, path=path)
-    expect = expect_selector
-    get_token = tokenizer.get_token
-    get_state = _STATES.get
-    while True:
-        token = get_token(expect)
+class DeclarationStateTokenizer(StateTokenizer):
+    EXPECT = expect_declaration_solo
+    STATE_MAP = {
+        "declaration_name": expect_declaration_content,
+        "declaration_end": expect_declaration_solo,
+    }
 
-        name = token.name
-        if name == "comment_start":
-            tokenizer.skip_to(expect_comment_end)
-            continue
-        elif name == "eof":
-            break
-        expect = get_state(name, expect)
-        yield token
+
+tokenize = StateTokenizer()
+tokenize_declarations = DeclarationStateTokenizer()
+
+
+# def tokenize(
+#     code: str, path: str, *, expect: Expect = expect_selector
+# ) -> Iterable[Token]:
+#     tokenizer = Tokenizer(code, path=path)
+#     # expect = expect_selector
+#     get_token = tokenizer.get_token
+#     get_state = _STATES.get
+#     while True:
+#         token = get_token(expect)
+#         name = token.name
+#         if name == "comment_start":
+#             tokenizer.skip_to(expect_comment_end)
+#             continue
+#         elif name == "eof":
+#             break
+#         expect = get_state(name, expect)
+#         yield token

src/textual/view.py

@@ -39,12 +39,15 @@ class LayoutProperty:
 @rich.repr.auto
 class View(Widget):
 
-    layout_factory: ClassVar[Callable[[], Layout]]
+    CSS = """
+        docks: main=top
+    """
 
-    def __init__(
-        self, layout: Layout = None, name: str | None = None, id: str | None = None
-    ) -> None:
-        self._layout: Layout = layout or self.layout_factory()
+    def __init__(self, name: str | None = None, id: str | None = None) -> None:
+
+        from .layouts.dock import DockLayout
+
+        self._layout: Layout = DockLayout()
 
         self.mouse_over: Widget | None = None
         self.widgets: set[Widget] = set()
@@ -56,7 +59,6 @@ class View(Widget):
             Offset(),
             [],
         )
-
         super().__init__(name=name, id=id)
 
     def __init_subclass__(

src/textual/widget.py

@@ -48,7 +48,7 @@ class RenderCache(NamedTuple):
     @property
     def cursor_line(self) -> int | None:
         for index, line in enumerate(self.lines):
-            for text, style, control in line:
+            for _text, style, _control in line:
                 if style and style._meta and style.meta.get("cursor", False):
                     return index
         return None
@@ -59,6 +59,10 @@ class Widget(DOMNode):
     _counts: ClassVar[dict[str, int]] = {}
     can_focus: bool = False
 
+    CSS = """
+    dock-group: main;
+    """
+
     def __init__(self, name: str | None = None, id: str | None = None) -> None:
         if name is None:
             class_name = self.__class__.__name__
@@ -279,13 +283,14 @@ class Widget(DOMNode):
         self.refresh()
 
     async def on_idle(self, event: events.Idle) -> None:
-        if self.check_layout():
+        repaint, layout = self.styles.check_refresh()
+        if layout or self.check_layout():
             self.log("layout required")
             self.render_cache = None
             self.reset_check_repaint()
             self.reset_check_layout()
             await self.emit(Layout(self))
-        elif self.check_repaint():
+        elif repaint or self.check_repaint():
             self.log("repaint required")
             self.render_cache = None
             self.reset_check_repaint()