tiling: Allow orientation of active container to be swapped

src/shell/layout/mod.rs

@@ -14,6 +14,12 @@ pub mod combined;
 pub mod floating;
 pub mod tiling;
 
+#[derive(Debug, serde::Deserialize, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum Orientation {
+    Horizontal,
+    Vertical,
+}
+
 pub trait Layout {
     fn map_window<'a>(
         &mut self,
@@ -25,6 +31,15 @@ pub trait Layout {
     fn refresh(&mut self, space: &mut Space);
     //fn unmap_window(&mut self, space: &mut Space, window: &Window);
 
+    fn update_orientation<'a>(
+        &mut self,
+        orientation: Orientation,
+        seat: &Seat,
+        space: &mut Space,
+        focus_stack: Box<dyn Iterator<Item = &'a Window> + 'a>,
+    ) {
+        let _ = (orientation, seat, space, focus_stack);
+    }
     fn maximize_request(&mut self, space: &mut Space, window: &Window, output: &Output) {
         let _ = (space, window, output);
     }

src/shell/layout/tiling.rs

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-3.0-only
 
-use crate::shell::layout::Layout;
+use crate::shell::layout::{Layout, Orientation};
 use id_tree::{InsertBehavior, MoveBehavior, Node, NodeId, NodeIdError, RemoveBehavior, Tree};
 use smithay::{
     desktop::{layer_map_for_output, Kind, Space, Window},
@@ -16,12 +16,6 @@ pub struct TilingLayout {
     gaps: (i32, i32),
 }
 
-#[derive(Debug)]
-pub enum Orientation {
-    Horizontal,
-    Vertical,
-}
-
 #[derive(Debug)]
 pub enum Data {
     Fork {
@@ -143,6 +137,50 @@ impl Layout for TilingLayout {
         self.refresh(space);
     }
 
+    fn update_orientation<'a>(
+        &mut self,
+        new_orientation: Orientation,
+        seat: &Seat,
+        space: &mut Space,
+        mut focus_stack: Box<dyn Iterator<Item = &'a Window> + 'a>,
+    ) {
+        {
+            let output = super::output_from_seat(seat, space);
+            output
+                .user_data()
+                .insert_if_missing(|| RefCell::new(OutputInfo::default()));
+            let mut output_info = output
+                .user_data()
+                .get::<RefCell<OutputInfo>>()
+                .unwrap()
+                .borrow_mut();
+            let tree = &mut output_info.trees.entry(self.idx).or_insert_with(Tree::new);
+
+            let last_active = focus_stack
+                .find_map(|window| tree.root_node_id()
+                    .and_then(|root| tree.traverse_pre_order_ids(root).unwrap()
+                        .find(|id| matches!(tree.get(id).map(|n| n.data()), Ok(Data::Window(w)) if w == window))
+                    )
+                );
+
+            if let Some(ref node_id) = last_active {
+                let mut node_id = node_id.clone();
+                while let Some(parent_id) = tree.get(&node_id).unwrap().parent().cloned() {
+                    if let &mut Data::Fork {
+                        ref mut orientation,
+                        ..
+                    } = tree.get_mut(&parent_id).unwrap().data_mut()
+                    {
+                        *orientation = new_orientation;
+                        break;
+                    }
+                    node_id = parent_id;
+                }
+            }
+        }
+        self.refresh(space);
+    }
+
     fn refresh(&mut self, space: &mut Space) {
         while let Some(dead_windows) =
             Some(update_space_positions(self.idx, space, self.gaps)).filter(|v| !v.is_empty())