Merge pull request #5052 from Textualize/tree-fix

fix tree issues

CHANGELOG.md

@@ -10,14 +10,17 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ### Add
 
 - Added `x_axis` and `y_axis` parameters to `Widget.scroll_to_region` https://github.com/Textualize/textual/pull/5047
+- Added `Tree.move_cursor_to_line` https://github.com/Textualize/textual/pull/5052
 
 ### Changed
 
 - Tree will no longer scroll the X axis when moving the cursor https://github.com/Textualize/textual/pull/5047
+- DirectoryTree will no longer select the first node https://github.com/Textualize/textual/pull/5052
 
 ### Fixed
 
 - Fixed widgets occasionally not getting Resize events https://github.com/Textualize/textual/pull/5048
+- Fixed tree regression https://github.com/Textualize/textual/pull/5052
 
 ## [0.80.1] - 2024-09-24
 

src/textual/widgets/_directory_tree.py

@@ -362,9 +362,12 @@ async def watch_path(self) -> None:
         If the path is changed the directory tree will be repopulated using
         the new value as the root.
         """
+        has_cursor = self.cursor_node is not None
         self.reset_node(self.root, str(self.path), DirEntry(self.PATH(self.path)))
         await self.reload()
-        self.move_cursor(self.root, animate=False)
+        if has_cursor:
+            self.cursor_line = 0
+        self.scroll_to(0, 0, animate=False)
 
     def process_label(self, label: TextType) -> Text:
         """Process a str or Text into a label. May be overridden in a subclass to modify how labels are rendered.

src/textual/widgets/_tree.py

@@ -654,7 +654,7 @@ class Tree(Generic[TreeDataType], ScrollView, can_focus=True):
     """Show the root of the tree."""
     hover_line = var(-1)
     """The line number under the mouse pointer, or -1 if not under the mouse pointer."""
-    cursor_line = var(-1)
+    cursor_line = var(-1, always_update=True)
     """The line with the cursor, or -1 if no cursor."""
     show_guides = reactive(True)
     """Enable display of tree guide lines."""
@@ -846,7 +846,7 @@ def render_label(
 
         if node._allow_expand:
             prefix = (
-                self.ICON_NODE if node.is_expanded else self.ICON_NODE_EXPANDED,
+                self.ICON_NODE_EXPANDED if node.is_expanded else self.ICON_NODE,
                 base_style + TOGGLE_STYLE,
             )
         else:
@@ -930,6 +930,24 @@ def move_cursor(
                 animate=animate and abs(self.cursor_line - previous_cursor_line) > 1,
             )
 
+    def move_cursor_to_line(self, line: int, animate=False) -> None:
+        """Move the cursor to the given line.
+
+        Args:
+            line: The line number (negative indexes are offsets from the last line).
+            animate: Enable scrolling animation.
+
+        Raises:
+            IndexError: If the line doesn't exist.
+        """
+        if self.cursor_line == line:
+            return
+        try:
+            node = self._tree_lines[line].node
+        except IndexError:
+            raise IndexError(f"No line no. {line} in the tree")
+        self.move_cursor(node, animate=animate)
+
     def select_node(self, node: TreeNode[TreeDataType] | None) -> None:
         """Move the cursor to the given node and select it, or reset cursor.
 
@@ -1079,22 +1097,33 @@ def watch_hover_line(self, previous_hover_line: int, hover_line: int) -> None:
 
     def watch_cursor_line(self, previous_line: int, line: int) -> None:
         previous_node = self._get_node(previous_line)
-        # Refresh previous cursor node
+        node = self._get_node(line)
+
+        if self.cursor_node is not None:
+            self.cursor_node._selected = False
+
         if previous_node is not None:
-            self._refresh_node(previous_node)
             previous_node._selected = False
+
+        if node is not None:
+            node._selected = True
+            self._cursor_node = node
+        else:
             self._cursor_node = None
 
-        node = self._get_node(line)
+        if previous_line == line:
+            # No change, so no need for refresh
+            return
+
+        # Refresh previous cursor node
+        if previous_node is not None:
+            self._refresh_node(previous_node)
+
         # Refresh new node
         if node is not None:
             self._refresh_node(node)
-            node._selected = True
-            self._cursor_node = node
             if previous_node != node:
                 self.post_message(self.NodeHighlighted(node))
-        else:
-            self._cursor_node = None
 
     def watch_guide_depth(self, guide_depth: int) -> None:
         self._invalidate()