Make loading the messages be responsibility of the state itself

src/state.rs

@@ -165,7 +165,7 @@ pub trait MenuItem {
 
 #[derive(Default, Debug, Clone)]
 pub struct Menu<T: MenuItem> {
-    items: Vec<T>,
+    pub items: Vec<T>,
     idx: usize,
     scroll: usize,
 }

src/states.rs

@@ -340,27 +340,7 @@ impl State for MainMenuState {
             match option {
                 MainMenuItem::SendSMS => return Some(Box::new(PhoneNumberState::default())),
                 MainMenuItem::ReadSMS => {
-                    return Some(Box::new(ATCommandState::with(
+                    return Some(Box::new(ListSMSMessagesState::default()));
-                        "Loading\nmessages".to_owned(),
-                        ListSMSMessages {
-                            stat: SMSMessageStat::All,
-                        },
-                        |resp| match resp {
-                            Ok(response) => match response {
-                                ListSMSMessagesResponse::Ok(messages) => {
-                                    Box::new(ListSMSMessagesState::from(messages))
-                                }
-                                ListSMSMessagesResponse::Error(err) => Box::new(TextState {
-                                    text: format!("Error:\n{:?}", err),
-                                    after: MainMenuState::default(),
-                                }),
-                            },
-                            Err(err) => Box::new(TextState {
-                                text: format!("Error:\n{:?}", err),
-                                after: MainMenuState::default(),
-                            }),
-                        },
-                    )));
                 }
             }
         }
@@ -388,24 +368,53 @@ impl MenuItem for MessageListing {
 #[derive(Clone, Default)]
 pub struct ListSMSMessagesState {
     menu: Menu<MessageListing>,
-}
+    promise: Option<ATPromise<ListSMSMessages>>,
-
-impl ListSMSMessagesState {
-    pub fn from(messages: Vec<SMSMessageListing>) -> ListSMSMessagesState {
-        let mut menu = Menu::default();
-        for message in &messages {
-            menu = menu.with_item(MessageListing {
-                from: message.from_addr.clone(),
-                text: message.text.clone(),
-            })
-        }
-
-        ListSMSMessagesState { menu }
-    }
 }
 
 impl State for ListSMSMessagesState {
+    fn init(&mut self, data: &mut StateData) {
+        self.promise = data
+            .io
+            .send_at_command(ListSMSMessages {
+                stat: SMSMessageStat::All,
+            })
+            .ok()
+    }
+
     fn update(&mut self, data: &mut StateData) -> Option<Box<dyn State>> {
+        if let Some(promise) = &self.promise {
+            match promise.poll(&mut data.io) {
+                Some(result) => {
+                    match result {
+                        Ok(response) => match response {
+                            ListSMSMessagesResponse::Ok(messages) => {
+                                for message in messages {
+                                    self.menu = self.menu.clone().with_item(MessageListing {
+                                        from: message.from_addr.clone(),
+                                        text: message.text.clone(),
+                                    })
+                                }
+                            }
+                            ListSMSMessagesResponse::Error(err) => {
+                                return Some(Box::new(TextState {
+                                    text: format!("Error\n{:?}", err),
+                                    after: MainMenuState::default(),
+                                }));
+                            }
+                        },
+                        Err(err) => {
+                            return Some(Box::new(TextState {
+                                text: format!("Error\n{:?}", err),
+                                after: MainMenuState::default(),
+                            }));
+                        }
+                    }
+                    self.promise = None;
+                }
+                None => return None,
+            }
+        }
+
         if let Some(listing) = self.menu.poll(&mut data.io) {
             return Some(Box::new(ReadMessageState {
                 message: listing.clone(),
@@ -419,7 +428,16 @@ impl State for ListSMSMessagesState {
     }
 
     fn draw(&self, data: &mut StateData) {
-        self.menu.draw(data);
+        data.clear_screen(Rgb565::black().as_color());
+        if self.menu.items.len() == 0 {
+            data.draw_text(
+                "Loading\nmessages",
+                Position::new(0, 0),
+                TextSettings::default(),
+            );
+        } else {
+            self.menu.draw(data);
+        }
     }
 }
 
@@ -431,7 +449,7 @@ pub struct ReadMessageState {
 impl State for ReadMessageState {
     fn update(&mut self, data: &mut StateData) -> Option<Box<dyn State>> {
         if data.io.keypad.get_presses(KeypadButton::KeypadB) > 0 {
-            Some(Box::new(MainMenuState::default()))
+            Some(Box::new(ListSMSMessagesState::default()))
         } else {
             None
         }