Merge pull request #5993 from Textualize/anchor-header

release anchor

Author: willmcgugan

src/textual/widget.py

@@ -1181,6 +1181,7 @@ def _get_style(self, style: VisualStyle | str) -> VisualStyle:
         """
         if isinstance(style, VisualStyle):
             return style
+        visual_style = VisualStyle.null()
         if style.startswith("."):
             for node in self.ancestors_with_self:
                 if not isinstance(node, Widget):
@@ -1196,7 +1197,7 @@ def _get_style(self, style: VisualStyle | str) -> VisualStyle:
         try:
             visual_style = VisualStyle.parse(style)
         except Exception:
-            visual_style = VisualStyle.null()
+            pass
         return visual_style
 
     @overload
@@ -2542,6 +2543,7 @@ def _scroll_to(
         force: bool = False,
         on_complete: CallbackType | None = None,
         level: AnimationLevel = "basic",
+        release_anchor: bool = True,
     ) -> bool:
         """Scroll to a given (absolute) coordinate, optionally animating.
 
@@ -2555,10 +2557,13 @@ def _scroll_to(
             force: Force scrolling even when prohibited by overflow styling.
             on_complete: A callable to invoke when the animation is finished.
             level: Minimum level required for the animation to take place (inclusive).
+            release_anchor: If `True` call `release_anchor`.
 
         Returns:
             `True` if the scroll position changed, otherwise `False`.
         """
+        if release_anchor:
+            self.release_anchor()
         maybe_scroll_x = x is not None and (self.allow_horizontal_scroll or force)
         maybe_scroll_y = y is not None and (self.allow_vertical_scroll or force)
         scrolled_x = scrolled_y = False
@@ -2676,6 +2681,7 @@ def scroll_to(
         on_complete: CallbackType | None = None,
         level: AnimationLevel = "basic",
         immediate: bool = False,
+        release_anchor: bool = True,
     ) -> None:
         """Scroll to a given (absolute) coordinate, optionally animating.
 
@@ -2691,10 +2697,13 @@ def scroll_to(
             level: Minimum level required for the animation to take place (inclusive).
             immediate: If `False` the scroll will be deferred until after a screen refresh,
                 set to `True` to scroll immediately.
+            release_anchor: If `True` call `release_anchor`.
 
         Note:
             The call to scroll is made after the next refresh.
         """
+        if release_anchor:
+            self.release_anchor()
         animator = self.app.animator
         if x is not None:
             animator.force_stop_animation(self, "scroll_x")
@@ -2869,6 +2878,7 @@ def _lazily_scroll_end() -> None:
                 force=force,
                 on_complete=scroll_end_on_complete,
                 level=level,
+                release_anchor=False,
             )
 
         if self._anchored and self._anchor_released:
@@ -4548,54 +4558,45 @@ def _on_blur(self, event: events.Blur) -> None:
     def _on_mouse_scroll_down(self, event: events.MouseScrollDown) -> None:
         if event.ctrl or event.shift:
             if self.allow_horizontal_scroll:
-                self.release_anchor()
                 if self._scroll_right_for_pointer(animate=False):
                     event.stop()
         else:
             if self.allow_vertical_scroll:
-                self.release_anchor()
                 if self._scroll_down_for_pointer(animate=False):
                     event.stop()
 
     def _on_mouse_scroll_up(self, event: events.MouseScrollUp) -> None:
         if event.ctrl or event.shift:
             if self.allow_horizontal_scroll:
-                self.release_anchor()
                 if self._scroll_left_for_pointer(animate=False):
                     event.stop()
         else:
             if self.allow_vertical_scroll:
-                self.release_anchor()
                 if self._scroll_up_for_pointer(animate=False):
                     event.stop()
 
     def _on_scroll_to(self, message: ScrollTo) -> None:
         if self._allow_scroll:
-            self.release_anchor()
             self.scroll_to(message.x, message.y, animate=message.animate, duration=0.1)
             message.stop()
 
     def _on_scroll_up(self, event: ScrollUp) -> None:
         if self.allow_vertical_scroll:
-            self.release_anchor()
             self.scroll_page_up()
             event.stop()
 
     def _on_scroll_down(self, event: ScrollDown) -> None:
         if self.allow_vertical_scroll:
-            self.release_anchor()
             self.scroll_page_down()
             event.stop()
 
     def _on_scroll_left(self, event: ScrollLeft) -> None:
         if self.allow_horizontal_scroll:
-            self.release_anchor()
             self.scroll_page_left()
             event.stop()
 
     def _on_scroll_right(self, event: ScrollRight) -> None:
         if self.allow_horizontal_scroll:
-            self.release_anchor()
             self.scroll_page_right()
             event.stop()
 
@@ -4623,7 +4624,6 @@ def _on_unmount(self) -> None:
     def action_scroll_home(self) -> None:
         if not self._allow_scroll:
             raise SkipAction()
-        self.release_anchor()
         self.scroll_home(x_axis=self.scroll_y == 0)
 
     def action_scroll_end(self) -> None:
@@ -4634,49 +4634,41 @@ def action_scroll_end(self) -> None:
     def action_scroll_left(self) -> None:
         if not self.allow_horizontal_scroll:
             raise SkipAction()
-        self.release_anchor()
         self.scroll_left()
 
     def action_scroll_right(self) -> None:
         if not self.allow_horizontal_scroll:
             raise SkipAction()
-        self.release_anchor()
         self.scroll_right()
 
     def action_scroll_up(self) -> None:
         if not self.allow_vertical_scroll:
             raise SkipAction()
-        self.release_anchor()
         self.scroll_up()
 
     def action_scroll_down(self) -> None:
         if not self.allow_vertical_scroll:
             raise SkipAction()
-        self.release_anchor()
         self.scroll_down()
 
     def action_page_down(self) -> None:
         if not self.allow_vertical_scroll:
             raise SkipAction()
-        self.release_anchor()
         self.scroll_page_down()
 
     def action_page_up(self) -> None:
         if not self.allow_vertical_scroll:
             raise SkipAction()
-        self.release_anchor()
         self.scroll_page_up()
 
     def action_page_left(self) -> None:
         if not self.allow_horizontal_scroll:
             raise SkipAction()
-        self.release_anchor()
         self.scroll_page_left()
 
     def action_page_right(self) -> None:
         if not self.allow_horizontal_scroll:
             raise SkipAction()
-        self.release_anchor()
         self.scroll_page_right()
 
     def notify(

src/textual/widgets/_markdown.py

@@ -999,7 +999,8 @@ def table_of_contents(self) -> TableOfContentsType:
         if self._table_of_contents is None:
             self._table_of_contents = [
                 (header.LEVEL, header._content.plain, header.id)
-                for header in self.query_children(MarkdownHeader)
+                for header in self.children
+                if isinstance(header, MarkdownHeader)
             ]
         return self._table_of_contents
 
@@ -1413,6 +1414,9 @@ async def await_append() -> None:
                         break
 
                 new_blocks = list(self._parse_markdown(tokens))
+                any_headers = any(
+                    isinstance(block, MarkdownHeader) for block in new_blocks
+                )
                 for block in new_blocks:
                     start, end = block.source_range
                     block.source_range = (
@@ -1434,7 +1438,7 @@ async def await_append() -> None:
                     if new_blocks:
                         await self.mount_all(new_blocks)
 
-                if any(isinstance(block, MarkdownHeader) for block in new_blocks):
+                if any_headers:
                     self._table_of_contents = None
                     self.post_message(
                         Markdown.TableOfContentsUpdated(