fix is_odd bug

Author: willmcgugan

src/textual/_compositor.py

@@ -1132,6 +1132,8 @@ def render_full_update(self, simplify: bool = False) -> LayoutUpdate:
         crop = screen_region
         chops = self._render_chops(crop, lambda y: True)
         if simplify:
+            # Simplify is done when exporting to SVG
+            # It doesn't make things faster
             render_strips = [
                 Strip.join(chop.values()).simplify().discard_meta() for chop in chops
             ]

src/textual/_node_list.py

@@ -3,7 +3,7 @@
 import sys
 import weakref
 from operator import attrgetter
-from typing import TYPE_CHECKING, Any, Callable, Iterable, Iterator, Sequence, overload
+from typing import TYPE_CHECKING, Any, Callable, Iterator, Sequence, overload
 
 import rich.repr
 
@@ -41,6 +41,8 @@ def __init__(self, parent: DOMNode | None = None) -> None:
         # The nodes in the list
         self._nodes: list[Widget] = []
         self._nodes_set: set[Widget] = set()
+        self._displayed_nodes: tuple[int, list[Widget]] = (-1, [])
+        self._displayed_visible_nodes: tuple[int, list[Widget]] = (-1, [])
 
         # We cache widgets by their IDs too for a quick lookup
         # Note that only widgets with IDs are cached like this, so
@@ -187,18 +189,29 @@ def __reversed__(self) -> Iterator[Widget]:
         return reversed(self._nodes)
 
     @property
-    def displayed(self) -> Iterable[Widget]:
+    def displayed(self) -> Sequence[Widget]:
         """Just the nodes where `display==True`."""
-        for node in self._nodes:
-            if node.display:
-                yield node
+        if self._displayed_nodes[0] != self._updates:
+            self._displayed_nodes = (
+                self._updates,
+                [node for node in self._nodes if node.display],
+            )
+        return self._displayed_nodes[1]
+
+    @property
+    def displayed_and_visible(self) -> Sequence[Widget]:
+        """Nodes with both `display==True` and `visible==True`."""
+        if self._displayed_visible_nodes[0] != self._updates:
+            self._displayed_nodes = (
+                self._updates,
+                [node for node in self.displayed if node.visible],
+            )
+        return self._displayed_nodes[1]
 
     @property
-    def displayed_reverse(self) -> Iterable[Widget]:
+    def displayed_reverse(self) -> Iterator[Widget]:
         """Just the nodes where `display==True`, in reverse order."""
-        for node in reversed(self._nodes):
-            if node.display:
-                yield node
+        return reversed(self.displayed)
 
     if TYPE_CHECKING:
 

src/textual/content.py

@@ -405,13 +405,12 @@ def simplify(self) -> Content:
         Returns:
             Self.
         """
-        spans = self.spans
-        if not spans:
+        if not (spans := self._spans):
             return self
-        last_span = Span(0, 0, Style())
+        last_span = Span(-1, -1, "")
         new_spans: list[Span] = []
         changed: bool = False
-        for span in self._spans:
+        for span in spans:
             if span.start == last_span.end and span.style == last_span.style:
                 last_span = new_spans[-1] = Span(last_span.start, span.end, span.style)
                 changed = True
@@ -422,6 +421,24 @@ def simplify(self) -> Content:
             self._spans[:] = new_spans
         return self
 
+    def add_spans(self, spans: Sequence[Span]) -> Content:
+        """Adds spans to this Content instance.
+
+        Args:
+            spans: A sequence of spans.
+
+        Returns:
+            A Content instance.
+        """
+        if spans:
+            return Content(
+                self.plain,
+                [*self._spans, *spans],
+                None if self._cell_length is None else self.cell_length,
+            )
+        else:
+            return self
+
     def __eq__(self, other: object) -> bool:
         """Compares text only, so that markup doesn't effect sorting."""
         if isinstance(other, str):
@@ -741,11 +758,7 @@ def __add__(self, other: Content | str) -> Content:
                         for start, end, style in other._spans
                     ],
                 ],
-                (
-                    self.cell_length + other._cell_length
-                    if other._cell_length is not None
-                    else None
-                ),
+                (self.cell_length + other.cell_length),
             )
             return content
         return NotImplemented
@@ -1470,7 +1483,7 @@ def highlight_regex(
         self,
         highlight_regex: re.Pattern[str] | str,
         *,
-        style: Style,
+        style: Style | str,
         maximum_highlights: int | None = None,
     ) -> Content:
         """Apply a style to text that matches a regular expression.

src/textual/dom.py

@@ -10,7 +10,6 @@
 import threading
 from functools import lru_cache, partial
 from inspect import getfile
-from operator import attrgetter
 from typing import (
     TYPE_CHECKING,
     Any,
@@ -408,6 +407,15 @@ def children(self) -> Sequence["Widget"]:
         """
         return self._nodes
 
+    @property
+    def displayed_children(self) -> Sequence[Widget]:
+        """The displayed children (where node.display==True).
+
+        Returns:
+            A sequence of widgets.
+        """
+        return self._nodes.displayed
+
     @property
     def is_empty(self) -> bool:
         """Are there no displayed children?"""
@@ -1215,15 +1223,6 @@ def ancestors(self) -> list[DOMNode]:
             add_node(node)
         return cast("list[DOMNode]", nodes)
 
-    @property
-    def displayed_children(self) -> list[Widget]:
-        """The child nodes which will be displayed.
-
-        Returns:
-            A list of nodes.
-        """
-        return list(filter(attrgetter("display"), self._nodes))
-
     def watch(
         self,
         obj: DOMNode,