feat!: implement Application API

examples/application/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "application"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+tracing = "0.1.37"
+tracing-subscriber = "0.3.17"
+
+[dependencies.libcosmic]
+path = "../../"
+default-features = false
+features = ["debug", "wayland", "tokio"]

examples/application/src/main.rs

@@ -0,0 +1,131 @@
+// Copyright 2023 System76 <info@system76.com>
+// SPDX-License-Identifier: MPL-2.0
+
+//! Testing ground for improving COSMIC application API ergonomics.
+
+use cosmic::app::{Command, Core, Settings};
+use cosmic::widget::nav_bar;
+use cosmic::{executor, iced, ApplicationExt, Element};
+
+/// Runs application with these settings
+#[rustfmt::skip]
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let input = vec![
+        ("Page 1".into(), "🖖 Hello from libcosmic.".into()),
+        ("Page 2".into(), "🌟 This is an example application.".into()),
+        ("Page 3".into(), "🚧 The libcosmic API is not stable yet.".into()),
+        ("Page 4".into(), "🚀 Copy the source code and experiment today!".into()),
+    ];
+
+    let settings = Settings::default()
+        .antialiasing(true)
+        .client_decorations(true)
+        .debug(false)
+        .default_icon_theme("Pop")
+        .default_text_size(16.0)
+        .scale_factor(1.0)
+        .size((1024, 768))
+        .theme(cosmic::Theme::dark());
+
+    cosmic::app::run::<App>(settings, input)?;
+
+    Ok(())
+}
+
+/// Messages that are used specifically by our [`App`].
+#[derive(Clone, Debug)]
+pub enum Message {}
+
+/// The [`App`] stores application-specific state.
+pub struct App {
+    core: Core,
+    nav_model: nav_bar::Model,
+}
+
+/// Implement [`cosmic::Application`] to integrate with COSMIC.
+impl cosmic::Application for App {
+    /// Default async executor to use with the app.
+    type Executor = executor::Default;
+
+    /// Argument received [`cosmic::Application::new`].
+    type Flags = Vec<(String, String)>;
+
+    /// Message type specific to our [`App`].
+    type Message = Message;
+
+    const APP_ID: &'static str = "org.cosmic.AppDemo";
+
+    fn core(&self) -> &Core {
+        &self.core
+    }
+
+    fn core_mut(&mut self) -> &mut Core {
+        &mut self.core
+    }
+
+    /// Creates the application, and optionally emits command on initialize.
+    fn init(core: Core, input: Self::Flags) -> (Self, Command<Self::Message>) {
+        let mut nav_model = nav_bar::Model::default();
+
+        for (title, content) in input {
+            nav_model.insert().text(title).data(content);
+        }
+
+        nav_model.activate_position(0);
+
+        let mut app = App { core, nav_model };
+
+        let command = app.update_title();
+
+        (app, command)
+    }
+
+    /// Allows COSMIC to integrate with your application's [`nav_bar::Model`].
+    fn nav_model(&self) -> Option<&nav_bar::Model> {
+        Some(&self.nav_model)
+    }
+
+    /// Called when a navigation item is selected.
+    fn on_nav_select(&mut self, id: nav_bar::Id) -> Command<Self::Message> {
+        self.nav_model.activate(id);
+        self.update_title()
+    }
+
+    fn update(&mut self, _message: Self::Message) -> Command<Self::Message> {
+        Command::none()
+    }
+
+    fn view(&self) -> Element<Self::Message> {
+        let page_content = self
+            .nav_model
+            .active_data::<String>()
+            .map(String::as_str)
+            .unwrap_or("No page selected");
+
+        let text = cosmic::widget::text(page_content);
+
+        let centered = iced::widget::container(text)
+            .width(iced::Length::Fill)
+            .height(iced::Length::Fill)
+            .align_x(iced::alignment::Horizontal::Center)
+            .align_y(iced::alignment::Vertical::Center);
+
+        Element::from(centered)
+    }
+}
+
+impl App
+where
+    Self: cosmic::Application,
+{
+    fn active_page_title(&mut self) -> &str {
+        self.nav_model
+            .text(self.nav_model.active())
+            .unwrap_or("Unknown Page")
+    }
+
+    fn update_title(&mut self) -> Command<Message> {
+        let title = self.active_page_title().to_owned();
+        self.set_title(title)
+    }
+}

examples/cosmic-sctk/src/main.rs

@@ -1,14 +1,11 @@
-use cosmic::{
-    iced::{wayland::InitialSurface, Application},
-    settings,
-};
+use cosmic::iced::{wayland::InitialSurface, Application, Settings};
 
 mod window;
 pub use window::Window;
 
 pub fn main() -> cosmic::iced::Result {
-    settings::set_default_icon_theme("Pop");
-    let mut settings = settings();
+    cosmic::icon_theme::set_default("Pop");
+    let mut settings = Settings::default();
     settings.initial_surface = InitialSurface::XdgWindow(Default::default());
     Window::run(settings)
 }

examples/cosmic-sctk/src/window.rs

@@ -6,7 +6,7 @@ use cosmic::{
     iced::{
         wayland::window::{start_drag_window, toggle_maximize},
         widget::{column, container, horizontal_space, pick_list, progress_bar, row, slider},
-        window, Color, Event,
+        window, Color,
     },
     iced_futures::Subscription,
     iced_style::application,
@@ -15,7 +15,7 @@ use cosmic::{
     widget::{
         button, cosmic_container, header_bar, nav_bar, nav_bar_toggle,
         rectangle_tracker::{rectangle_tracker_subscription, RectangleTracker, RectangleUpdate},
-        scrollable, segmented_button, segmented_selection, settings, toggler, IconSource,
+        scrollable, segmented_button, segmented_selection, settings, IconSource,
     },
     Element, ElementExt,
 };
@@ -336,9 +336,8 @@ impl Application for Window {
             .on_drag(Message::Drag)
             .start(
                 nav_bar_toggle()
-                    .on_nav_bar_toggled(nav_bar_message)
-                    .nav_bar_active(nav_bar_toggled)
-                    .into(),
+                    .on_toggle(nav_bar_message)
+                    .active(nav_bar_toggled),
             );
 
         if self.show_maximize {
@@ -509,7 +508,7 @@ impl Application for Window {
         self.theme.clone()
     }
 
-    fn close_requested(&self, id: window::Id) -> Self::Message {
+    fn close_requested(&self, _id: window::Id) -> Self::Message {
         Message::Close
     }
     fn subscription(&self) -> iced::Subscription<Self::Message> {

examples/cosmic/src/main.rs

@@ -1,7 +1,7 @@
 // Copyright 2022 System76 <info@system76.com>
 // SPDX-License-Identifier: MPL-2.0
 
-use cosmic::{iced::Application, settings};
+use cosmic::iced::{Application, Settings};
 
 mod window;
 use env_logger::Env;
@@ -13,8 +13,8 @@ pub fn main() -> cosmic::iced::Result {
         .write_style_or("MY_LOG_STYLE", "always");
 
     env_logger::init_from_env(env);
-    settings::set_default_icon_theme("Pop");
-    let mut settings = settings();
+    cosmic::icon_theme::set_default("Pop");
+    let mut settings = Settings::default();
     settings.window.min_size = Some((600, 300));
     Window::run(settings)
 }

examples/cosmic/src/window.rs

@@ -483,9 +483,8 @@ impl Application for Window {
             .on_drag(Message::Drag)
             .start(
                 nav_bar_toggle()
-                    .on_nav_bar_toggled(nav_bar_message)
-                    .nav_bar_active(nav_bar_toggled)
-                    .into(),
+                    .on_toggle(nav_bar_message)
+                    .active(nav_bar_toggled),
             );
 
         if self.show_maximize {

examples/cosmic/src/window/demo.rs

@@ -184,7 +184,7 @@ impl State {
             Message::IconTheme(key) => {
                 self.icon_themes.activate(key);
                 if let Some(theme) = self.icon_themes.text(key) {
-                    cosmic::settings::set_default_icon_theme(theme);
+                    cosmic::icon_theme::set_default(theme);
                 }
             }
             Message::InputChanged(s) => {