Save zoom and focused window from layout so that it can be restored

crates/modalkit-ratatui/Cargo.toml

@@ -22,3 +22,4 @@ serde = { version = "^1.0", features = ["derive"] }
 
 [dev-dependencies]
 rand = { workspace = true }
+serde_json = "1.0.122"

crates/modalkit-ratatui/src/screen.rs

@@ -22,7 +22,7 @@ use ratatui::{
 use super::{
     cmdbar::{CommandBar, CommandBarState},
     util::{rect_down, rect_zero_height},
-    windows::{WindowActions, WindowLayout, WindowLayoutDescription, WindowLayoutState},
+    windows::{WindowActions, WindowLayout, WindowLayoutRoot, WindowLayoutState},
     TerminalCursor,
     Window,
     WindowOps,
@@ -244,23 +244,33 @@ fn bold<'a>(s: String) -> Span<'a> {
 #[derive(Clone, Debug, Deserialize, Serialize)]
 #[serde(bound(deserialize = "I::WindowId: Deserialize<'de>"))]
 #[serde(bound(serialize = "I::WindowId: Serialize"))]
-pub struct TabLayoutDescription<I: ApplicationInfo> {
+pub struct TabbedLayoutDescription<I: ApplicationInfo> {
     /// The description of the window layout for each tab.
-    pub tabs: Vec<WindowLayoutDescription<I>>,
+    pub tabs: Vec<WindowLayoutRoot<I>>,
+    /// The index of the last focused tab
+    pub focused: usize,
 }
 
-impl<I: ApplicationInfo> TabLayoutDescription<I> {
+impl<I: ApplicationInfo> TabbedLayoutDescription<I> {
     /// Create a new collection of tabs from this description.
     pub fn to_layout<W: Window<I>>(
         self,
         area: Option<Rect>,
         store: &mut Store<I>,
     ) -> UIResult<FocusList<WindowLayoutState<W, I>>, I> {
-        self.tabs
+        let mut tabs = self
+            .tabs
             .into_iter()
             .map(|desc| desc.to_layout(area, store))
             .collect::<UIResult<Vec<_>, I>>()
-            .map(FocusList::new)
+            .map(FocusList::new)?;
+
+        // Count starts at 1
+        let change = FocusChange::Offset(Count::Exact(self.focused + 1), true);
+        let ctx = EditContext::default();
+        tabs.focus(&change, &ctx);
+
+        Ok(tabs)
     }
 }
 
@@ -314,9 +324,10 @@ where
     }
 
     /// Get a description of the open tabs and their window layouts.
-    pub fn as_description(&self) -> TabLayoutDescription<I> {
-        TabLayoutDescription {
+    pub fn as_description(&self) -> TabbedLayoutDescription<I> {
+        TabbedLayoutDescription {
             tabs: self.tabs.iter().map(WindowLayoutState::as_description).collect(),
+            focused: self.tabs.pos(),
         }
     }
 

crates/modalkit-ratatui/src/windows/layout.rs

@@ -1102,6 +1102,34 @@ where
     }
 }
 
+/// Data structure holding layout description and state
+#[derive(Clone, Debug, Deserialize, Eq, PartialEq, Serialize)]
+#[serde(bound(deserialize = "I::WindowId: Deserialize<'de>"))]
+#[serde(bound(serialize = "I::WindowId: Serialize"))]
+#[serde(rename_all = "lowercase")]
+pub struct WindowLayoutRoot<I: ApplicationInfo> {
+    layout: WindowLayoutDescription<I>,
+    focused: usize,
+    zoomed: bool,
+}
+
+impl<I> WindowLayoutRoot<I>
+where
+    I: ApplicationInfo,
+{
+    /// Restore a layout from a description of windows and splits.
+    pub fn to_layout<W: Window<I>>(
+        self,
+        area: Option<Rect>,
+        store: &mut Store<I>,
+    ) -> UIResult<WindowLayoutState<W, I>, I> {
+        let mut layout = self.layout.to_layout(area, store)?;
+        layout._focus(self.focused);
+        layout.zoom = self.zoomed;
+        Ok(layout)
+    }
+}
+
 /// A description of a window layout.
 #[derive(Clone, Debug, Deserialize, Eq, PartialEq, Serialize)]
 #[serde(bound(deserialize = "I::WindowId: Deserialize<'de>"))]
@@ -1282,18 +1310,28 @@ where
     }
 
     /// Convert this layout to a serializable summary of its windows and splits.
-    pub fn as_description(&self) -> WindowLayoutDescription<I> {
+    pub fn as_description(&self) -> WindowLayoutRoot<I> {
         let mut children = vec![];
+        let focused = self.focused;
+        let zoomed = self.zoom;
 
         let Some(root) = &self.root else {
-            return WindowLayoutDescription::Split { children, length: None };
+            return WindowLayoutRoot {
+                layout: WindowLayoutDescription::Split { children, length: None },
+                focused,
+                zoomed,
+            };
         };
 
         for w in root.iter() {
             children.push(w.into());
         }
 
-        return WindowLayoutDescription::Split { children, length: None };
+        return WindowLayoutRoot {
+            layout: WindowLayoutDescription::Split { children, length: None },
+            focused,
+            zoomed,
+        };
     }
 
     /// Create a new instance containing a single [Window] displaying some content.
@@ -2808,6 +2846,7 @@ mod tests {
         let (mut tree, mut store, _) = three_by_three();
         let mut buffer = Buffer::empty(Rect::new(0, 0, 60, 60));
         let area = Rect::new(0, 0, 60, 60);
+        tree._focus(3);
 
         // Draw so that everything gets an initial area.
         WindowLayout::new(&mut store).render(area, &mut buffer, &mut tree);
@@ -2855,13 +2894,20 @@ mod tests {
             }],
             length: None,
         };
-        assert_eq!(desc1, exp);
+        assert_eq!(desc1.layout, exp);
+        assert_eq!(desc1.focused, 3);
+        assert_eq!(desc1.zoomed, false);
 
         // Turn back into a layout, and then generate a new description to show it's the same.
         let tree = desc1
             .clone()
             .to_layout::<TestWindow>(tree.info.area.into(), &mut store)
             .unwrap();
         assert_eq!(tree.as_description(), desc1);
+
+        // Test against an example JSON serialization to test naming.
+        let serialized = serde_json::to_string_pretty(&desc1).unwrap();
+        let exp = include_str!("../../tests/window-layout.json");
+        assert_eq!(serialized, exp.trim_end());
     }
 }

crates/modalkit-ratatui/src/windows/mod.rs

@@ -30,7 +30,12 @@ mod size;
 mod slot;
 mod tree;
 
-pub use self::layout::{WindowLayout, WindowLayoutDescription, WindowLayoutState};
+pub use self::layout::{
+    WindowLayout,
+    WindowLayoutDescription,
+    WindowLayoutRoot,
+    WindowLayoutState,
+};
 
 struct AxisTreeNode<W, X: AxisT, Y: AxisT> {
     value: Value<W, X, Y>,

crates/modalkit-ratatui/tests/window-layout.json

@@ -0,0 +1,91 @@
+{
+  "layout": {
+    "type": "split",
+    "children": [
+      {
+        "type": "split",
+        "children": [
+          {
+            "type": "split",
+            "children": [
+              {
+                "type": "split",
+                "children": [
+                  {
+                    "type": "window",
+                    "window": 0,
+                    "length": 20
+                  },
+                  {
+                    "type": "window",
+                    "window": 1,
+                    "length": 20
+                  }
+                ],
+                "length": 20
+              },
+              {
+                "type": "split",
+                "children": [
+                  {
+                    "type": "window",
+                    "window": 2,
+                    "length": 20
+                  },
+                  {
+                    "type": "window",
+                    "window": 3,
+                    "length": 20
+                  }
+                ],
+                "length": 20
+              },
+              {
+                "type": "split",
+                "children": [
+                  {
+                    "type": "window",
+                    "window": 4,
+                    "length": 20
+                  },
+                  {
+                    "type": "window",
+                    "window": 5,
+                    "length": 20
+                  }
+                ],
+                "length": 20
+              }
+            ],
+            "length": 40
+          },
+          {
+            "type": "split",
+            "children": [
+              {
+                "type": "window",
+                "window": 6,
+                "length": 20
+              },
+              {
+                "type": "window",
+                "window": 7,
+                "length": 20
+              },
+              {
+                "type": "window",
+                "window": 8,
+                "length": 20
+              }
+            ],
+            "length": 20
+          }
+        ],
+        "length": 60
+      }
+    ],
+    "length": null
+  },
+  "focused": 3,
+  "zoomed": false
+}