ui: don't quit if editing a draft

Ask user to save draft or discard it.

src/bin.rs

@@ -254,8 +254,12 @@ fn main() -> std::result::Result<(), std::io::Error> {
                                 UIMode::Normal => {
                                     match k {
                                         Key::Char('q') | Key::Char('Q') => {
-                                            drop(state);
-                                            break 'main;
+                                            if state.can_quit_cleanly() {
+                                                drop(state);
+                                                break 'main;
+                                            } else {
+                                                state.redraw();
+                                            }
                                         },
                                         Key::Char(' ') => {
                                             state.mode = UIMode::Execute;

ui/src/components.rs

@@ -90,6 +90,9 @@ pub trait Component: Display + Debug + Send {
     fn is_visible(&self) -> bool {
         true
     }
+    fn can_quit_cleanly(&mut self) -> bool {
+        true
+    }
     fn set_dirty(&mut self);
     fn kill(&mut self, _id: ComponentId, _context: &mut Context) {}
     fn set_id(&mut self, _id: ComponentId) {}

ui/src/components/mail/compose.rs

@@ -756,6 +756,13 @@ impl Component for Composer {
     fn set_id(&mut self, id: ComponentId) {
         self.id = id;
     }
+
+    fn can_quit_cleanly(&mut self) -> bool {
+        /* Play it safe and ask user for confirmation */
+        self.mode = ViewMode::Discard(self.id);
+        self.set_dirty();
+        false
+    }
 }
 
 pub fn send_draft(context: &mut Context, account_cursor: usize, draft: Draft) -> bool {

ui/src/components/utilities.rs

@@ -1066,6 +1066,10 @@ impl Component for StatusBar {
     fn set_id(&mut self, id: ComponentId) {
         self.id = id;
     }
+
+    fn can_quit_cleanly(&mut self) -> bool {
+        self.container.can_quit_cleanly()
+    }
 }
 
 #[derive(Debug)]
@@ -1530,6 +1534,17 @@ impl Component for Tabbed {
     fn set_id(&mut self, id: ComponentId) {
         self.id = id;
     }
+
+    fn can_quit_cleanly(&mut self) -> bool {
+        for (i, c) in self.children.iter_mut().enumerate() {
+            if !c.can_quit_cleanly() {
+                self.cursor_pos = i;
+                self.set_dirty();
+                return false;
+            }
+        }
+        true
+    }
 }
 
 type EntryIdentifier = Vec<u8>;

ui/src/state.rs

@@ -514,6 +514,10 @@ impl State {
         }
     }
 
+    pub fn can_quit_cleanly(&mut self) -> bool {
+        self.components.iter_mut().all(|c| c.can_quit_cleanly())
+    }
+
     pub fn register_component(&mut self, component: Box<dyn Component>) {
         self.components.push(component);
     }