T03 layout: stacks, grids, surfaces, scroll, splits, sheets, dock, panes, workspace, viewport

src/layout/workspace.rs

@@ -0,0 +1,105 @@
+use anyhow::Context as _;
+use gpui::{App, Entity};
+use serde::{Deserialize, Serialize};
+
+use super::{Dock, DockLayout, PaneGroup, PaneLayout};
+
+/// Bump when a field changes meaning; never reuse a removed name.
+pub const WORKSPACE_VERSION: u32 = 1;
+
+/// Saved window layout: docks and editor panes, as JSON.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct Workspace {
+    pub version: u32,
+    pub dock: DockLayout,
+    pub panes: PaneLayout,
+}
+
+impl Workspace {
+    pub fn capture(dock: &Dock, panes: &PaneGroup) -> Self {
+        Self {
+            version: WORKSPACE_VERSION,
+            dock: dock.layout(),
+            panes: panes.layout(),
+        }
+    }
+
+    pub fn to_json(&self) -> String {
+        serde_json::to_string_pretty(self).expect("workspace layout always serializes")
+    }
+
+    /// Unknown fields are ignored; a newer version is refused.
+    pub fn from_json(json: &str) -> anyhow::Result<Self> {
+        let workspace: Self = serde_json::from_str(json).context("workspace layout json")?;
+        anyhow::ensure!(
+            workspace.version <= WORKSPACE_VERSION,
+            "workspace version {} is newer than this build ({WORKSPACE_VERSION})",
+            workspace.version
+        );
+        Ok(workspace)
+    }
+
+    /// Applies all of it or none of it.
+    pub fn apply(
+        &self,
+        dock: &Entity<Dock>,
+        panes: &Entity<PaneGroup>,
+        cx: &mut App,
+    ) -> anyhow::Result<()> {
+        self.panes.validate()?;
+        dock.update(cx, |dock, cx| dock.restore(&self.dock, cx))?;
+        panes.update(cx, |group, cx| group.restore(self.panes.clone(), cx))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use gpui::Axis;
+
+    use super::*;
+    use crate::layout::{DockSide, Spot};
+
+    fn sample() -> Workspace {
+        Workspace {
+            version: WORKSPACE_VERSION,
+            dock: DockLayout {
+                spots: vec![
+                    ("files".into(), Spot::Docked(DockSide::Left)),
+                    ("outline".into(), Spot::Floating { x: 40.0, y: 60.0 }),
+                ],
+                active: [Some("files".into()), None, None, None],
+                sizes: [15.0, 17.5, 12.0, 13.75],
+            },
+            panes: PaneLayout::Split {
+                axis: Axis::Horizontal,
+                sizes: vec![0.5, 0.5],
+                children: vec![PaneLayout::Pane(1), PaneLayout::Pane(2)],
+            },
+        }
+    }
+
+    #[test]
+    fn round_trips_through_json() {
+        let saved = sample();
+        assert_eq!(Workspace::from_json(&saved.to_json()).unwrap(), saved);
+    }
+
+    #[test]
+    fn ignores_unknown_fields_but_refuses_newer_versions() {
+        let mut value = serde_json::to_value(sample()).unwrap();
+        value["added_later"] = serde_json::json!(true);
+        assert!(Workspace::from_json(&value.to_string()).is_ok());
+        value["version"] = serde_json::json!(WORKSPACE_VERSION + 1);
+        assert!(Workspace::from_json(&value.to_string()).is_err());
+    }
+
+    #[test]
+    fn invalid_pane_trees_are_refused() {
+        let bad = PaneLayout::Split {
+            axis: Axis::Vertical,
+            sizes: vec![1.0],
+            children: vec![PaneLayout::Pane(1), PaneLayout::Pane(1)],
+        };
+        assert!(bad.validate().is_err());
+    }
+}