Text justify initial work, help text

sandbox/darren/text_justify.py

@@ -0,0 +1,43 @@
+from __future__ import annotations
+
+from rich.text import Text
+
+from textual.app import App, ComposeResult
+from textual.widgets import Static
+
+TEXT = """I must not fear.
+Fear is the mind-killer.
+Fear is the little-death that brings total obliteration.
+I will face my fear.
+I will permit it to pass over me and through me.
+And when it has gone past, I will turn the inner eye to see its path.
+Where the fear has gone there will be nothing. Only I will remain."""
+
+
+class TextJustify(App):
+    def compose(self) -> ComposeResult:
+        left = Static(Text(TEXT))
+        left.styles.text_justify = "left"
+        yield left
+
+        right = Static(TEXT)
+        right.styles.text_justify = "right"
+        yield right
+
+        center = Static(TEXT)
+        center.styles.text_justify = "center"
+        yield center
+
+        full = Static(TEXT)
+        full.styles.text_justify = "full"
+        yield full
+
+
+app = TextJustify(css_path="text_justify.scss", watch_css=True)
+
+if __name__ == "__main__":
+    from rich.console import Console
+
+    console = Console()
+    text = Text(TEXT)
+    console.print(TEXT, justify="full")

src/textual/css/_help_text.py

@@ -13,6 +13,7 @@ from textual.css.constants import (
     VALID_ALIGN_HORIZONTAL,
     VALID_ALIGN_VERTICAL,
     VALID_STYLE_FLAGS,
+    VALID_JUSTIFY,
 )
 
 if sys.version_info >= (3, 8):
@@ -648,6 +649,39 @@ def align_help_text() -> HelpText:
     )
 
 
+def text_justify_help_text(context: str) -> HelpText:
+    """Help text to show when the user supplies an invalid value for the text-justify property
+
+    Returns:
+        HelpText: Renderable for displaying the help text for this property.
+    """
+    return HelpText(
+        summary="Invalid value for the [i]text-justify[/] property.",
+        bullets=[
+            *ContextSpecificBullets(
+                css=[
+                    Bullet(
+                        f"The [i]text-justify[/] property must be one of {friendly_list(VALID_JUSTIFY)}",
+                        examples=[
+                            Example("text-justify: center;"),
+                            Example("text-justify: right;"),
+                        ],
+                    )
+                ],
+                inline=[
+                    Bullet(
+                        f"The [i]text_justify[/] property must be one of {friendly_list(VALID_JUSTIFY)}",
+                        examples=[
+                            Example("widget.styles.text_justify = 'center'"),
+                            Example("widget.styles.text_justify = 'right'"),
+                        ],
+                    )
+                ],
+            ).get_by_context(context)
+        ],
+    )
+
+
 def offset_single_axis_help_text(property_name: str) -> HelpText:
     """Help text to show when the user supplies an invalid value for an offset-* property.
 

src/textual/css/_styles_builder.py

@@ -24,6 +24,7 @@ from ._help_text import (
     property_invalid_value_help_text,
     scrollbar_size_property_help_text,
     scrollbar_size_single_axis_help_text,
+    text_justify_help_text,
 )
 from .constants import (
     VALID_ALIGN_HORIZONTAL,
@@ -36,6 +37,7 @@ from .constants import (
     VALID_VISIBILITY,
     VALID_STYLE_FLAGS,
     VALID_SCROLLBAR_GUTTER,
+    VALID_JUSTIFY,
 )
 from .errors import DeclarationError, StyleValueError
 from .model import Declaration
@@ -618,6 +620,19 @@ class StylesBuilder:
         style_definition = " ".join(token.value for token in tokens)
         self.styles.text_style = style_definition
 
+    def process_text_justify(self, name: str, tokens: list[Token]) -> None:
+        if not tokens:
+            return
+
+        if len(tokens) > 1 or tokens[0].value not in VALID_JUSTIFY:
+            self.error(
+                name,
+                tokens[0],
+                text_justify_help_text("css"),
+            )
+
+        self.styles._rules["text_justify"] = tokens[0].value
+
     def process_dock(self, name: str, tokens: list[Token]) -> None:
         if not tokens:
             return

src/textual/css/constants.py

@@ -38,6 +38,7 @@ VALID_BOX_SIZING: Final = {"border-box", "content-box"}
 VALID_OVERFLOW: Final = {"scroll", "hidden", "auto"}
 VALID_ALIGN_HORIZONTAL: Final = {"left", "center", "right"}
 VALID_ALIGN_VERTICAL: Final = {"top", "middle", "bottom"}
+VALID_JUSTIFY: Final = {"left", "center", "right", "full"}
 VALID_SCROLLBAR_GUTTER: Final = {"auto", "stable"}
 VALID_STYLE_FLAGS: Final = {
     "none",

src/textual/css/styles.py

@@ -41,6 +41,7 @@ from .constants import (
     VALID_OVERFLOW,
     VALID_SCROLLBAR_GUTTER,
     VALID_VISIBILITY,
+    VALID_JUSTIFY,
 )
 from .scalar import Scalar, ScalarOffset, Unit
 from .scalar_animation import ScalarAnimation
@@ -56,6 +57,7 @@ from .types import (
     Specificity3,
     Specificity6,
     Visibility,
+    TextJustify,
 )
 
 if sys.version_info >= (3, 8):
@@ -142,6 +144,8 @@ class RulesMap(TypedDict, total=False):
     content_align_horizontal: AlignHorizontal
     content_align_vertical: AlignVertical
 
+    text_justify: TextJustify
+
 
 RULE_NAMES = list(RulesMap.__annotations__.keys())
 RULE_NAMES_SET = frozenset(RULE_NAMES)
@@ -249,6 +253,8 @@ class StylesBase(ABC):
     content_align_vertical = StringEnumProperty(VALID_ALIGN_VERTICAL, "top")
     content_align = AlignProperty()
 
+    text_justify = StringEnumProperty(VALID_JUSTIFY, "left")
+
     def __eq__(self, styles: object) -> bool:
         """Check that Styles contains the same rules."""
         if not isinstance(styles, StylesBase):
@@ -458,7 +464,6 @@ class StylesBase(ABC):
 @rich.repr.auto
 @dataclass
 class Styles(StylesBase):
-
     node: DOMNode | None = None
     _rules: RulesMap = field(default_factory=dict)
 

src/textual/css/types.py

@@ -39,6 +39,7 @@ ScrollbarGutter = Literal["auto", "stable"]
 BoxSizing = Literal["border-box", "content-box"]
 Overflow = Literal["scroll", "hidden", "auto"]
 EdgeStyle = Tuple[EdgeType, Color]
+TextJustify = Literal["left", "center", "right", "full"]
 
 Specificity3 = Tuple[int, int, int]
 Specificity4 = Tuple[int, int, int, int]

src/textual/widget.py

@@ -982,11 +982,12 @@ class Widget(DOMNode):
         """
 
         if isinstance(renderable, str):
-            renderable = Text.from_markup(renderable)
+            renderable = Text.from_markup(renderable, justify=self.styles.text_justify)
 
         rich_style = self.rich_style
         if isinstance(renderable, Text):
             renderable.stylize(rich_style)
+            renderable.justify = self.styles.text_justify
         else:
             renderable = Styled(renderable, rich_style)