From 27418eed88c25124118485bd0d2daa2fcb1b881b Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Thu, 6 Oct 2022 21:51:21 +0530
Subject: [PATCH] Beep when action could not be performed

---
 tools/tui/readline/api.go  | 7 ++++++-
 tools/tui/readline/keys.go | 7 ++++++-
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/tools/tui/readline/api.go b/tools/tui/readline/api.go
index 4ed4fe062..062498765 100644
--- a/tools/tui/readline/api.go
+++ b/tools/tui/readline/api.go
@@ -104,7 +104,12 @@ func (self *Readline) End() {
 }
 
 func (self *Readline) OnKeyEvent(event *loop.KeyEvent) error {
-	return self.handle_key_event(event)
+	err := self.handle_key_event(event)
+	if err == ErrCouldNotPerformAction {
+		err = nil
+		self.loop.Beep()
+	}
+	return err
 }
 
 func (self *Readline) OnText(text string, from_key_event bool, in_bracketed_paste bool) error {
diff --git a/tools/tui/readline/keys.go b/tools/tui/readline/keys.go
index 9cbd90a73..e6dbcf4de 100644
--- a/tools/tui/readline/keys.go
+++ b/tools/tui/readline/keys.go
@@ -3,6 +3,7 @@
 package readline
 
 import (
+	"errors"
 	"fmt"
 
 	"kitty/tools/tui/loop"
@@ -30,6 +31,8 @@ func action_for_key_event(event *loop.KeyEvent, shortcuts map[string]Action) Act
 	return ActionNil
 }
 
+var ErrCouldNotPerformAction = errors.New("Could not perform the specified action")
+
 func (self *Readline) handle_key_event(event *loop.KeyEvent) error {
 	if event.Text != "" {
 		return nil
@@ -37,7 +40,9 @@ func (self *Readline) handle_key_event(event *loop.KeyEvent) error {
 	ac := action_for_key_event(event, default_shortcuts)
 	if ac != ActionNil {
 		event.Handled = true
-		self.perform_action(ac, 1)
+		if !self.perform_action(ac, 1) {
+			return ErrCouldNotPerformAction
+		}
 	}
 	return nil
 }