Use escape key to exit editing

The escape key can now be used to exit edit mode. In writing a todo,
this will also cancel the new todo.

Author: Piturnah

src/main.rs

@@ -337,6 +337,10 @@ fn save_state(todos: &[String], dones: &[String], file_path: &str) {
 fn main() {
     ctrlc::init();
 
+    // On some old terminals ESC was used instead of ALT. So we have to tell ncurses not to wait
+    // for another key when receiving ESC.
+    set_escdelay(0);
+
     let mut args = env::args();
     args.next().unwrap();
 
@@ -410,8 +414,14 @@ fn main() {
                                 if editing {
                                     ui.edit_field(todo, &mut editing_cursor, x / 2);
 
-                                    if let Some('\n') = ui.key.take().map(|x| x as u8 as char) {
-                                        editing = false;
+                                    match ui.key.take().map(|x| x as u8 as char) {
+                                        Some('\n') => editing = false,
+                                        Some('\u{1b}') => {
+                                            editing = false;
+                                            list_delete(&mut todos, &mut todo_curr);
+                                            break;
+                                        }
+                                        _ => {}
                                     }
                                 } else {
                                     ui.label_fixed_width(
@@ -483,7 +493,9 @@ fn main() {
                                 if editing {
                                     ui.edit_field(done, &mut editing_cursor, x / 2);
 
-                                    if let Some('\n') = ui.key.take().map(|x| x as u8 as char) {
+                                    if let Some('\n') | Some('\u{1b}') =
+                                        ui.key.take().map(|x| x as u8 as char)
+                                    {
                                         editing = false;
                                     }
                                 } else {