Merge pull request #436 from Textualize/bugfix-display-none-is-being-ignored-in-vertical-and-horizontal-layouts

[layout][bugfix] Horizontal & Vertical layouts shouldn't display children that have `display: none`

src/textual/app.py

@@ -521,6 +521,7 @@ class App(DOMNode):
                 mount_event = events.Mount(sender=self)
                 await self.dispatch_message(mount_event)
 
+                # TODO: don't override `self.console` here
                 self.console = Console(file=sys.__stdout__)
                 self.title = self._title
                 self.refresh()

src/textual/css/styles.py

@@ -70,7 +70,7 @@ if TYPE_CHECKING:
 class RulesMap(TypedDict, total=False):
     """A typed dict for CSS rules.
 
-    Any key may be absent, indiciating that rule has not been set.
+    Any key may be absent, indicating that rule has not been set.
 
     Does not define composite rules, that is a rule that is made of a combination of other rules.
 

src/textual/dom.py

@@ -278,6 +278,10 @@ class DOMNode(MessagePump):
         add_children(tree, self)
         return tree
 
+    @property
+    def displayed_children(self) -> list[DOMNode]:
+        return [child for child in self.children if child.display]
+
     def get_pseudo_classes(self) -> Iterable[str]:
         """Get any pseudo classes applicable to this Node, e.g. hover, focus.
 

src/textual/layouts/dock.py

@@ -50,10 +50,9 @@ class DockLayout(Layout):
 
     def get_docks(self, parent: Widget) -> list[Dock]:
         groups: dict[str, list[Widget]] = defaultdict(list)
-        for child in parent.children:
+        for child in parent.displayed_children:
             assert isinstance(child, Widget)
-            if child.display:
+            groups[child.styles.dock].append(child)
-                groups[child.styles.dock].append(child)
         docks: list[Dock] = []
         append_dock = docks.append
         for name, edge, z in parent.styles.docks:

src/textual/layouts/horizontal.py

@@ -39,7 +39,9 @@ class HorizontalLayout(Layout):
 
         x = box_models[0].margin.left if box_models else 0
 
-        for widget, box_model, margin in zip(parent.children, box_models, margins):
+        displayed_children = parent.displayed_children
+
+        for widget, box_model, margin in zip(displayed_children, box_models, margins):
             content_width, content_height = box_model.size
             offset_y = widget.styles.align_height(content_height, parent_size.height)
             region = Region(x, offset_y, content_width, content_height)
@@ -53,4 +55,4 @@ class HorizontalLayout(Layout):
         total_region = Region(0, 0, max_width, max_height)
         add_placement(WidgetPlacement(total_region, None, 0))
 
-        return placements, set(parent.children)
+        return placements, set(displayed_children)

src/textual/layouts/vertical.py

@@ -40,10 +40,13 @@ class VerticalLayout(Layout):
 
         y = box_models[0].margin.top if box_models else 0
 
-        for widget, box_model, margin in zip(parent.children, box_models, margins):
+        displayed_children = parent.displayed_children
+
+        for widget, box_model, margin in zip(displayed_children, box_models, margins):
             content_width, content_height = box_model.size
             offset_x = widget.styles.align_width(content_width, parent_size.width)
             region = Region(offset_x, y, content_width, content_height)
+            # TODO: it seems that `max_height` is not used?
             max_height = max(max_height, content_height)
             add_placement(WidgetPlacement(region, widget, 0))
             y += region.height + margin
@@ -54,4 +57,4 @@ class VerticalLayout(Layout):
         total_region = Region(0, 0, max_width, max_height)
         add_placement(WidgetPlacement(total_region, None, 0))
 
-        return placements, set(parent.children)
+        return placements, set(displayed_children)

tests/layouts/test_common_layout_features.py

@@ -0,0 +1,30 @@
+import pytest
+
+from textual.screen import Screen
+from textual.widget import Widget
+
+
+@pytest.mark.parametrize(
+    "layout,display,expected_in_displayed_children",
+    [
+        ("dock", "block", True),
+        ("horizontal", "block", True),
+        ("vertical", "block", True),
+        ("dock", "none", False),
+        ("horizontal", "none", False),
+        ("vertical", "none", False),
+    ],
+)
+def test_nodes_take_display_property_into_account_when_they_display_their_children(
+    layout: str, display: str, expected_in_displayed_children: bool
+):
+    widget = Widget(name="widget that might not be visible 🥷 ")
+    widget.styles.display = display
+
+    screen = Screen()
+    screen.styles.layout = layout
+    screen.add_child(widget)
+
+    displayed_children = screen.displayed_children
+    assert isinstance(displayed_children, list)
+    assert (widget in screen.displayed_children) is expected_in_displayed_children