Add horizontally scrolling columns to cmux-tui

cmux-tui/README.md

@@ -39,6 +39,8 @@ cargo run -p cmux-tui -- attach --session agents --surface <surface-id>
 
 The default session is `main`. Default sockets live at `$TMPDIR/cmux-tui-<uid>/<session>.sock`; use `--socket <path>` for an explicit path. Detach from an attached TUI with prefix `d`, which is `Ctrl-b d` by default.
 
+Pane layout stays tiled by default. Press `Ctrl-b g` to append a terminal to the right at two-thirds of the viewport width. The existing layout keeps its width, so a continuous horizontal scrollbar appears in the status bar. Focusing a pane reveals it with an animated viewport movement. `Alt-n` reapplies Zellij's automatic layout inside the focused horizontal column. `Ctrl-b U` undoes the latest structural layout action on the focused screen; undoing pane creation asks for confirmation before closing the pane.
+
 `attach --surface <id>` attaches one PTY terminal by numeric or short surface id. It uses the full host terminal without the sidebar, status bar, pane border, or other tabs.
 
 Packaged builds can run as `npx cmux`. The optional machine rail lets that local client switch among the current session, other Unix sockets, and sessions reached through SSH. It is disabled by default and activates when `machine_sidebar.enabled` is true or `machines` contains a valid entry in `cmux-tui.json`. `npx cmux --cloud` composes those local targets with the Cloud catalog and enables temporary machine connections without sending local SSH details to Cloud. The client uses noninteractive SSH with strict host-key checking and the remote `cmux-tui relay --session <name>` transport primitive, so the remote headless session, trusted host key, authentication key, and binary must already exist. See [Machines and remote sessions](docs/machines.md).

cmux-tui/bindings/RELEASING.md

@@ -9,7 +9,7 @@ cmux-sdk-vX.Y.Z
 Historical releases used `mux-sdk-vX.Y.Z`; the publish workflows still accept
 that prefix so old release history remains connected. These tags are separate
 from app release tags such as `vX.Y.Z`. Current SDK package versions are
-`0.3.0`.
+`0.4.0`.
 
 ## One-time registry setup
 

cmux-tui/bindings/conformance/fixtures.json

@@ -183,6 +183,65 @@
         }
       ]
     },
+    {
+      "name": "layout-undo-preview-and-confirm",
+      "requires": { "commands": ["new-pane", "undo-layout"] },
+      "steps": [
+        {
+          "type": "command",
+          "request": { "id": 1, "cmd": "new-workspace", "name": "conf-undo", "cols": 80, "rows": 24 },
+          "expect": { "id": 1, "ok": true },
+          "match": "partial"
+        },
+        {
+          "type": "command",
+          "request": { "id": 2, "cmd": "ids", "kind": "pane" },
+          "expect": { "id": 2, "ok": true },
+          "match": "partial",
+          "bind": { "pane0": "data.ids[-1].id" }
+        },
+        {
+          "type": "command",
+          "request": { "id": 3, "cmd": "new-pane", "pane": "$pane0" },
+          "expect": { "id": 3, "ok": true },
+          "match": "partial"
+        },
+        {
+          "type": "command",
+          "request": { "id": 4, "cmd": "ids", "kind": "pane" },
+          "expect": { "id": 4, "ok": true },
+          "match": "partial",
+          "bind": { "pane1": "data.ids[-1].id" }
+        },
+        {
+          "type": "command",
+          "request": { "id": 5, "cmd": "undo-layout", "pane": "$pane1" },
+          "expect": {
+            "id": 5,
+            "ok": true,
+            "data": {
+              "undone": false,
+              "confirmation_required": true,
+              "closes_panes": ["$pane1"]
+            }
+          },
+          "match": "partial",
+          "bind": { "undo_revision": "data.revision" }
+        },
+        {
+          "type": "command",
+          "request": {
+            "id": 6,
+            "cmd": "undo-layout",
+            "pane": "$pane1",
+            "revision": "$undo_revision",
+            "confirm_close": true
+          },
+          "expect": { "id": 6, "ok": true, "data": { "undone": true } },
+          "match": "partial"
+        }
+      ]
+    },
     {
       "name": "subscribe-tree-changed",
       "steps": [

cmux-tui/bindings/conformance/runner.py

@@ -232,9 +232,15 @@ def dispatch(client: CmuxClient, cmd: str, params: Dict[str, Any]) -> Any:
         "new-browser-tab": client.new_browser_tab,
         "new-workspace": client.new_workspace,
         "new-screen": client.new_screen,
+        "new-pane": client.new_pane,
+        "new-pane-right": client.new_pane_right,
         "split": client.split,
         "set-ratio": client.set_ratio,
         "set-split-ratio": client.set_split_ratio,
+        "set-viewport-pane-width": client.set_viewport_pane_width,
+        "undo-layout": lambda **kw: client.undo_layout(
+            kw["pane"], kw.get("revision") if kw.get("confirm_close") else None
+        ),
         "pane-neighbor": client.pane_neighbor,
         "focus-direction": client.focus_direction,
         "swap-pane": client.swap_pane,
@@ -374,7 +380,7 @@ def wait_contains(client: CmuxClient, request: Dict[str, Any], path: str, needle
 def get_path(value: Any, path: str) -> Any:
     current = value
     for part in path.split("."):
-        match = re.fullmatch(r"([A-Za-z0-9_-]+)(?:\[(\d+)\])?", part)
+        match = re.fullmatch(r"([A-Za-z0-9_-]+)(?:\[(-?\d+)\])?", part)
         if not match:
             raise FixtureFailure(f"bad JSON path segment {part!r}")
         key = match.group(1)
@@ -383,7 +389,7 @@ def get_path(value: Any, path: str) -> Any:
         current = current[key]
         if match.group(2) is not None:
             index = int(match.group(2))
-            if not isinstance(current, list) or index >= len(current):
+            if not isinstance(current, list) or index >= len(current) or index < -len(current):
                 raise FixtureFailure(f"path {path!r} missing index {index}")
             current = current[index]
     return current

cmux-tui/bindings/go/client.go

@@ -8,6 +8,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"math"
 	"net"
 	"os"
 	"path/filepath"
@@ -36,10 +37,62 @@ func validateWorkspaceSelector(workspace *uint64, key *string) error {
 	return nil
 }
 
+func validateViewportPaneWidth(width float32) error {
+	value := float64(width)
+	if math.IsNaN(value) || math.IsInf(value, 0) || value < 0.1 || value > 1.0 {
+		return fmt.Errorf(
+			"%w: viewport pane width must be between 0.1 and 1.0",
+			ErrInvalidArgument,
+		)
+	}
+	return nil
+}
+
+type layoutUndoWire struct {
+	Undone               *bool     `json:"undone"`
+	ConfirmationRequired *bool     `json:"confirmation_required"`
+	Screen               *uint64   `json:"screen"`
+	Revision             *uint64   `json:"revision"`
+	ClosesPanes          *[]uint64 `json:"closes_panes"`
+}
+
+func decodeLayoutUndoResult(wire layoutUndoWire) (LayoutUndoResult, error) {
+	if wire.Screen == nil {
+		return nil, &decodeError{msg: "layout undo response omitted screen"}
+	}
+	if wire.Revision == nil {
+		return nil, &decodeError{msg: "layout undo response omitted revision"}
+	}
+
+	switch {
+	case wire.Undone != nil &&
+		*wire.Undone &&
+		(wire.ConfirmationRequired == nil || !*wire.ConfirmationRequired):
+		return LayoutUndoUndone{Screen: *wire.Screen, Revision: *wire.Revision}, nil
+	case wire.Undone != nil &&
+		!*wire.Undone &&
+		wire.ConfirmationRequired != nil &&
+		*wire.ConfirmationRequired:
+		if wire.ClosesPanes == nil {
+			return nil, &decodeError{
+				msg: "layout undo confirmation closes_panes must be an array of pane IDs",
+			}
+		}
+		return LayoutUndoConfirmationRequired{
+			Screen: *wire.Screen, Revision: *wire.Revision, ClosesPanes: *wire.ClosesPanes,
+		}, nil
+	default:
+		return nil, &decodeError{
+			msg: "layout undo response does not contain exactly one valid outcome",
+		}
+	}
+}
+
 type CommandError struct {
-	Message  string
-	ID       any
-	Delivery ErrorDelivery
+	Message   string
+	ID        any
+	ErrorCode string
+	Delivery  ErrorDelivery
 }
 
 func (e *CommandError) Error() string { return e.Message }
@@ -59,11 +112,13 @@ func commandErrorFromResponse(response map[string]any) *CommandError {
 	if msg == "" {
 		msg = "unknown error"
 	}
+	code, _ := response["error_code"].(string)
 	delivery, _ := response["error_delivery"].(string)
 	return &CommandError{
-		Message:  msg,
-		ID:       response["id"],
-		Delivery: ErrorDelivery(delivery),
+		Message:   msg,
+		ID:        response["id"],
+		ErrorCode: code,
+		Delivery:  ErrorDelivery(delivery),
 	}
 }
 
@@ -440,6 +495,29 @@ func (c *Client) NewPane(ctx context.Context, pane uint64, opts NewPaneOptions)
 	return result, c.request(ctx, "new-pane", params, &result)
 }
 
+func (c *Client) NewPaneRight(ctx context.Context, pane uint64, opts NewPaneRightOptions) (SurfaceResult, error) {
+	if opts.Width != nil {
+		if err := validateViewportPaneWidth(*opts.Width); err != nil {
+			return SurfaceResult{}, err
+		}
+	}
+	if err := c.requireCapability(ctx, "viewport-splits-v1", "viewport panes"); err != nil {
+		return SurfaceResult{}, err
+	}
+	params := map[string]any{"pane": pane}
+	if opts.Width != nil {
+		params["width"] = *opts.Width
+	}
+	if opts.Cols != nil {
+		params["cols"] = *opts.Cols
+	}
+	if opts.Rows != nil {
+		params["rows"] = *opts.Rows
+	}
+	var result SurfaceResult
+	return result, c.request(ctx, "new-pane-right", params, &result)
+}
+
 func (c *Client) Split(ctx context.Context, pane uint64, dir string, opts SplitOptions) (SurfaceResult, error) {
 	params := commandMap(opts)
 	params["pane"] = pane
@@ -453,10 +531,65 @@ func (c *Client) SetRatio(ctx context.Context, pane uint64, dir string, ratio fl
 }
 
 func (c *Client) SetSplitRatio(ctx context.Context, split uint64, ratio float32) error {
+	return c.setSplitRatio(ctx, split, ratio, nil)
+}
+
+// SetSplitRatioInTransaction coalesces samples that share one client-scoped transaction.
+func (c *Client) SetSplitRatioInTransaction(ctx context.Context, split uint64, ratio float32, transaction uint64) error {
+	return c.setSplitRatio(ctx, split, ratio, &transaction)
+}
+
+func (c *Client) setSplitRatio(ctx context.Context, split uint64, ratio float32, transaction *uint64) error {
 	if err := c.requireProtocol(ctx, 8, "set-split-ratio"); err != nil {
 		return err
 	}
-	return c.request(ctx, "set-split-ratio", map[string]any{"split": split, "ratio": ratio}, nil)
+	params := map[string]any{"split": split, "ratio": ratio}
+	if transaction != nil {
+		params["transaction"] = *transaction
+	}
+	return c.request(ctx, "set-split-ratio", params, nil)
+}
+
+func (c *Client) SetViewportPaneWidth(ctx context.Context, pane uint64, width float32) error {
+	return c.setViewportPaneWidth(ctx, pane, width, nil)
+}
+
+// SetViewportPaneWidthInTransaction coalesces samples that share one client-scoped transaction.
+func (c *Client) SetViewportPaneWidthInTransaction(ctx context.Context, pane uint64, width float32, transaction uint64) error {
+	return c.setViewportPaneWidth(ctx, pane, width, &transaction)
+}
+
+func (c *Client) setViewportPaneWidth(ctx context.Context, pane uint64, width float32, transaction *uint64) error {
+	if err := validateViewportPaneWidth(width); err != nil {
+		return err
+	}
+	if err := c.requireCapability(ctx, "viewport-column-resize-v1", "viewport pane resizing"); err != nil {
+		return err
+	}
+	params := map[string]any{"pane": pane, "width": width}
+	if transaction != nil {
+		params["transaction"] = *transaction
+	}
+	return c.request(ctx, "set-viewport-pane-width", params, nil)
+}
+
+// UndoLayout previews the latest layout undo when confirmationRevision is nil.
+// To confirm a pane-closing undo, pass the exact revision returned by
+// LayoutUndoConfirmationRequired.
+func (c *Client) UndoLayout(ctx context.Context, pane uint64, confirmationRevision *uint64) (LayoutUndoResult, error) {
+	if err := c.requireCapability(ctx, "layout-undo-v1", "layout undo"); err != nil {
+		return nil, err
+	}
+	params := map[string]any{"pane": pane}
+	if confirmationRevision != nil {
+		params["revision"] = *confirmationRevision
+		params["confirm_close"] = true
+	}
+	var wire layoutUndoWire
+	if err := c.request(ctx, "undo-layout", params, &wire); err != nil {
+		return nil, err
+	}
+	return decodeLayoutUndoResult(wire)
 }
 
 func (c *Client) SetDefaultColors(ctx context.Context, fg, bg *string) error {