feat: add an Equalize Splits command to even every split in the tab

crates/herdr-commands/src/lib.rs

@@ -113,6 +113,8 @@ pub enum Command {
     ResizeUp,
     ResizeDown,
     ResizeMode,
+    /// Evens every split in the focused tab, as a double-click on a border does.
+    EqualizeSplits,
     RenamePane,
     MovePane,
     PreviousWorkspace,
@@ -374,6 +376,11 @@ pub const COMMANDS: &[CommandInfo] = &[
         name: "resize_mode",
         label: "Resize Mode",
     },
+    CommandInfo {
+        command: Command::EqualizeSplits,
+        name: "equalize_splits",
+        label: "Equalize Splits",
+    },
     CommandInfo {
         command: Command::RenamePane,
         name: "rename_pane",
@@ -911,6 +918,7 @@ pub fn request(command: Command, snapshot: &ClientShellSnapshot) -> Option<(Meth
         | Command::Back
         | Command::Forward
         | Command::ResizeMode
+        | Command::EqualizeSplits
         | Command::RenamePane
         | Command::MovePane
         | Command::PreviousWorkspace

crates/herdr-commands/src/tests.rs

@@ -59,6 +59,7 @@ fn catalog_has_all_native_commands_and_gpui_shortcuts() {
         (ResizeUp, &[]),
         (ResizeDown, &[]),
         (ResizeMode, &[]),
+        (EqualizeSplits, &[]),
         (RenamePane, &[]),
         (MovePane, &[]),
         (Zoom, &["cmd-shift-enter"]),
@@ -217,6 +218,7 @@ fn gui_commands_never_send_daemon_requests() {
         Command::Back,
         Command::Forward,
         Command::ResizeMode,
+        Command::EqualizeSplits,
         Command::RenamePane,
         Command::MovePane,
         Command::PreviousWorkspace,

crates/herdr-gpui/README.md

@@ -4289,7 +4289,9 @@ Ctrl+Shift+U is left unbound for
   `[pane_keys]` entry on the symbol, keeps its key even when a custom
   command is bound to the shifted key. `resize_mode` (`prefix+r`)
   makes h, j, k, l or the arrows resize the focused pane until Escape, Enter,
-  or the shortcut again; the status bar shows it. Renames and
+  or the shortcut again; the status bar shows it. `equalize_splits` evens
+  every split in the focused tab, as a double-click on a border between
+  panes does; it has no default shortcut. Renames and
   `close_workspace` open the same dialogs as their menus, and `reload_config`
   reloads both the daemon's config and this one. The daemon's
   `[[keys.command]]` shortcuts, prefix chords or direct keys, run their

crates/herdr-gpui/src/endpoint/lifecycle_tests/split_equalize.rs

@@ -357,3 +357,5 @@ fn a_tab_switch_drops_the_rest_of_an_even_queue(cx: &mut gpui::TestAppContext) {
     assert_eq!(path, serde_json::json!([]));
     assert!((ratio - 0.25).abs() < 1e-5, "ratio was {ratio}");
 }
+
+mod command;

crates/herdr-gpui/src/endpoint/lifecycle_tests/split_equalize/command.rs

@@ -0,0 +1,61 @@
+use super::*;
+
+fn run(view: &gpui::Entity<HerdrWindow>, cx: &mut gpui::VisualTestContext) {
+    cx.update(|window, cx| {
+        view.update(cx, |view, cx| {
+            view.command(Command::EqualizeSplits, window, cx);
+        });
+    });
+}
+
+#[gpui::test]
+fn the_command_evens_every_split_in_the_tab(cx: &mut gpui::TestAppContext) {
+    let (view, mut server, cx) = with_borders(cx, "ssh:even-command");
+    run(&view, cx);
+    assert!(cx.update(|_, cx| view.read(cx).live.drag_request.is_some()));
+    assert_even(&evened(&view, &mut server, cx));
+    // Nothing is left held, so the next border press starts fresh.
+    cx.update(|_, cx| {
+        view.update(cx, |view, cx| view.flush_split(cx));
+        assert!(view.read(cx).split_drag.is_none());
+    });
+}
+
+#[gpui::test]
+fn the_command_leaves_a_zoomed_tab_alone(cx: &mut gpui::TestAppContext) {
+    let (view, _server, cx) = with_borders(cx, "ssh:even-zoomed");
+    cx.update(|_, cx| view.update(cx, |view, _| set_zoomed(view, true)));
+    run(&view, cx);
+    cx.update(|_, cx| {
+        let view = view.read(cx);
+        assert!(view.split_drag.is_none());
+        assert!(view.live.drag_request.is_none());
+    });
+}
+
+#[gpui::test]
+fn the_command_leaves_a_held_border_drag_alone(cx: &mut gpui::TestAppContext) {
+    let (view, _server, cx) = with_borders(cx, "ssh:even-held");
+    cx.update(|_, cx| {
+        view.update(cx, |view, cx| assert!(down(view, 40.5, 5., 1, cx)));
+    });
+    run(&view, cx);
+    // Evening would have sent its first ratio at once; the held drag sends
+    // nothing until the pointer moves.
+    cx.update(|_, cx| {
+        view.update(cx, |view, cx| {
+            assert!(view.split_drag.is_some());
+            assert!(view.live.drag_request.is_none());
+            release(view, 40.5, 5., cx);
+        });
+    });
+}
+
+#[gpui::test]
+fn running_it_again_mid_way_does_not_restart_the_queue(cx: &mut gpui::TestAppContext) {
+    let (view, mut server, cx) = with_borders(cx, "ssh:even-twice");
+    run(&view, cx);
+    run(&view, cx);
+    // One ratio per split, not a second round on top of the first.
+    assert_even(&evened(&view, &mut server, cx));
+}

crates/herdr-gpui/src/menu/settings.rs

@@ -345,6 +345,7 @@ impl HerdrWindow {
                 | Command::ResizeUp
                 | Command::ResizeDown
                 | Command::ResizeMode
+                | Command::EqualizeSplits
                 | Command::RenamePane
                 | Command::MovePane
                 | Command::RenameWorkspace

crates/herdr-gpui/src/window/commands.rs

@@ -639,6 +639,10 @@ impl HerdrWindow {
                 cx.notify();
                 return;
             }
+            Command::EqualizeSplits => {
+                self.equalize_splits(cx);
+                return;
+            }
             Command::ResizeMode => {
                 self.prefix_armed = false;
                 self.resize_mode = true;

crates/herdr-gpui/src/window/mouse.rs

@@ -771,6 +771,40 @@ impl HerdrWindow {
         true
     }
 
+    /// Evens every split in the focused tab, as a double-click on a border
+    /// does, from a command. A zoomed tab, or one with a border still being
+    /// dragged or evened, is left alone.
+    pub(crate) fn equalize_splits(&mut self, cx: &mut Context<Self>) {
+        if self.split_drag.is_some() {
+            return;
+        }
+        let (Some(snapshot), Some(surface)) = (&self.live.snapshot, self.live.surface.as_deref())
+        else {
+            return;
+        };
+        let Some(tab) = snapshot.focused_tab_id.clone() else {
+            return;
+        };
+        let zoomed = snapshot
+            .tabs
+            .iter()
+            .any(|item| item.tab_id == tab && item.zoomed);
+        // Only a pointer drag moves this split; evening sends every ratio.
+        let Some(split) = surface.splits.first().cloned().filter(|_| !zoomed) else {
+            return;
+        };
+        self.split_drag = Some(SplitDrag {
+            boot: snapshot.boot_id.clone(),
+            tab,
+            topology: splits::topology(surface),
+            split,
+            held: false,
+            motion: SplitMotion::Even(splits::even_targets(&surface.splits)),
+        });
+        self.flush_split(cx);
+        cx.notify();
+    }
+
     pub(crate) fn split_mouse_move(
         &mut self,
         event: &MouseMoveEvent,