Set up app invocation and response handling

fitnesstrax/app/src/main.rs

@@ -40,11 +40,14 @@ const RESOURCE_BASE_PATH: &str = "/com/luminescent-dreams/fitnesstrax/";
 #[derive(Debug)]
 enum AppInvocation {
     OpenDatabase(PathBuf),
+    RequestRecords,
 }
 
 #[derive(Debug)]
 enum AppResponse {
-    DatabaseChanged,
+    NoDatabase,
+    Records,
+    DatabaseChanged(PathBuf),
 }
 
 // Note that I have not yet figured out the communication channel or how the central dispatcher
@@ -53,32 +56,38 @@ enum AppResponse {
 /// The real, headless application. This is where all of the logic will reside.
 #[derive(Clone)]
 struct App {
-    settings: gio::Settings,
     database: Arc<RwLock<Option<Series<TraxRecord>>>>,
 }
 
 impl App {
-    pub fn new(settings: gio::Settings) -> Self {
+    pub fn new(db_path: Option<PathBuf>) -> Self {
+        let database = db_path.map(|path| Series::open(path).unwrap());
         let s = Self {
-            settings,
+            database: Arc::new(RwLock::new(database)),
-            database: Arc::new(RwLock::new(None)),
         };
 
-        if !s.settings.string("series-path").is_empty() {
+        s
-            let path = PathBuf::from(s.settings.string("series-path"));
-            let db = Series::open(path).unwrap();
-            *s.database.write().unwrap() = Some(db);
     }
 
-        s
+    pub async fn process_invocation(&self, invocation: AppInvocation) -> AppResponse {
+        match invocation {
+            AppInvocation::OpenDatabase(db_path) => {
+                self.open_db(&db_path);
+                AppResponse::DatabaseChanged(db_path)
+            }
+            AppInvocation::RequestRecords => {
+                if self.database.read().unwrap().is_none() {
+                    AppResponse::NoDatabase
+                } else {
+                    AppResponse::Records
+                }
+            }
+        }
     }
 
     pub fn open_db(&self, path: &Path) {
         let db = Series::open(path).unwrap();
         *self.database.write().unwrap() = Some(db);
-        self.settings
-            .set_string("series-path", path.to_str().unwrap())
-            .unwrap();
     }
 }
 
@@ -224,6 +233,29 @@ impl HistoricalView {
     }
 }
 
+#[derive(Clone, Debug, PartialEq)]
+enum ViewName {
+    Placeholder,
+    Welcome,
+    Historical,
+}
+
+enum View {
+    Placeholder(gtk::Widget),
+    Welcome(gtk::Widget),
+    Historical(gtk::Widget),
+}
+
+impl View {
+    fn widget<'a>(&'a self) -> &'a gtk::Widget {
+        match self {
+            View::Placeholder(widget) => widget,
+            View::Welcome(widget) => widget,
+            View::Historical(widget) => widget,
+        }
+    }
+}
+
 /// The application window, or the main window, is the main user interface for the app. Almost
 /// everything occurs here.
 #[derive(Clone)]
@@ -231,7 +263,8 @@ struct AppWindow {
     app_tx: Sender<AppInvocation>,
     window: adw::ApplicationWindow,
     layout: gtk::Box,
-    current_view: Rc<RefCell<gtk::Widget>>,
+    current_view: Rc<RefCell<View>>,
+    settings: gio::Settings,
 }
 
 impl AppWindow {
@@ -241,7 +274,7 @@ impl AppWindow {
     /// otherwise we don't use this.
     ///
     /// app is a core [App] object which encapsulates all of the basic logic.
-    fn new(adw_app: &adw::Application, app_tx: Sender<AppInvocation>) -> AppWindow {
+    fn new(app_id: &str, adw_app: &adw::Application, app_tx: Sender<AppInvocation>) -> AppWindow {
         let window = adw::ApplicationWindow::builder()
             .application(adw_app)
             .width_request(800)
@@ -272,10 +305,10 @@ impl AppWindow {
             .orientation(gtk::Orientation::Vertical)
             .build();
 
-        let initial_view = PlaceholderView::new();
+        let initial_view = View::Placeholder(PlaceholderView::new().upcast());
 
         layout.append(&header);
-        layout.append(&initial_view);
+        layout.append(initial_view.widget());
 
         window.set_content(Some(&layout));
         window.present();
@@ -284,58 +317,62 @@ impl AppWindow {
             app_tx,
             window,
             layout,
-            current_view: Rc::new(RefCell::new(initial_view.upcast())),
+            current_view: Rc::new(RefCell::new(initial_view)),
+            settings: gio::Settings::new(app_id),
         };
 
-        let initial_view = if true {
-            WelcomeView::new({
-                let s = s.clone();
-                Box::new(move |path: PathBuf| {
-                    // The user has selected a path. Perhaps the path is new, perhaps it already
-                    // exists.
-                    //
-                    // If the file exists already, attempt to read it. Fail if that doesn't work.
-                    // A should show to the user something that indicates that the file exists but is
-                    // not already a database.
-                    //
-                    // If the file does not exist, create a new one. Again, show the user an error if
-                    // some kind of error occurs.
-                    // app.open_db(&path);
-                    // s.change_view(HistoricalView::new().upcast());
-                    // let s = s.clone();
-                    /*
-                    glib::spawn_future_local(async move {
-                        s.app_tx
-                            .send(AppInvocation::OpenDatabase(path))
-                            .await
-                            .unwrap();
-                    });
-                    */
-                    s.app_tx
-                        .send_blocking(AppInvocation::OpenDatabase(path))
-                        .unwrap();
-                })
-            })
-            .upcast()
-        } else {
-            HistoricalView::new().upcast()
-        };
-
-        s.change_view(initial_view);
-
         s
     }
 
+    pub fn change_view(&self, view: ViewName) {
+        self.swap_main(self.construct_view(view));
+    }
+
+    pub fn process_response(&self, response: AppResponse) {
+        match response {
+            AppResponse::DatabaseChanged(db_path) => {
+                self.settings
+                    .set_string("series-path", db_path.to_str().unwrap())
+                    .unwrap();
+                self.change_view(ViewName::Historical);
+            }
+            AppResponse::NoDatabase => {
+                self.change_view(ViewName::Welcome);
+            }
+            AppResponse::Records => {
+                self.change_view(ViewName::Historical);
+            }
+        }
+    }
+
     // Switch views.
     //
     // This function only replaces the old view with the one which matches the current view state.
     // It is responsible for ensuring that the new view goes into the layout in the correct
     // position.
-    fn change_view(&self, view: gtk::Widget) {
+    fn swap_main(&self, view: View) {
-        let mut current_view = self.current_view.borrow_mut();
+        let mut current_widget = self.current_view.borrow_mut();
-        self.layout.remove(&*current_view);
+        self.layout.remove(&*current_widget.widget());
-        *current_view = view;
+        *current_widget = view;
-        self.layout.append(&*current_view);
+        self.layout.append(&*current_widget.widget());
+    }
+
+    fn construct_view(&self, view: ViewName) -> View {
+        match view {
+            ViewName::Placeholder => View::Placeholder(PlaceholderView::new().upcast()),
+            ViewName::Welcome => View::Welcome(
+                WelcomeView::new({
+                    let s = self.clone();
+                    Box::new(move |path: PathBuf| {
+                        s.app_tx
+                            .send_blocking(AppInvocation::OpenDatabase(path))
+                            .unwrap();
+                    })
+                })
+                .upcast(),
+            ),
+            ViewName::Historical => View::Historical(HistoricalView::new().upcast()),
+        }
     }
 }
 
@@ -354,10 +391,14 @@ fn main() {
     };
 
     let settings = gio::Settings::new(app_id);
-
+    let app = App::new({
-    println!("database path: {}", settings.string("series-path"));
+        let path = settings.string("series-path");
-
+        if path.is_empty() {
-    let app = App::new(settings);
+            None
+        } else {
+            Some(PathBuf::from(path))
+        }
+    });
 
     let adw_app = adw::Application::builder()
         .application_id(app_id)
@@ -373,17 +414,26 @@ fn main() {
         let (gtk_tx, gtk_rx) = async_channel::unbounded::<AppResponse>();
         let (app_tx, app_rx) = async_channel::unbounded::<AppInvocation>();
 
-        AppWindow::new(adw_app, app_tx.clone());
+        let window = AppWindow::new(app_id, adw_app, app_tx.clone());
 
         glib::spawn_future_local(async move {
+            // The app requests data to start with. This kicks everything off. The response from
+            // the app will cause the window to be updated shortly.
+            let _ = app_tx.send(AppInvocation::RequestRecords).await;
+
             while let Ok(response) = gtk_rx.recv().await {
                 println!("response received: {:?}", response);
+                window.process_response(response);
             }
         });
 
-        runtime.spawn(async move {
+        runtime.spawn({
+            let app = app.clone();
+            async move {
                 while let Ok(invocation) = app_rx.recv().await {
-                println!("Received an invocation: {:?}", invocation);
+                    let response = app.process_invocation(invocation).await;
+                    let _ = gtk_tx.send(response).await;
+                }
             }
         });
     });