feat: dynamically load pages when their sections are searched

cosmic-settings/src/app.rs

@@ -49,12 +49,14 @@ use desktop::{
 #[cfg(feature = "wayland")]
 use event::wayland;
 use page::Entity;
+use std::collections::BTreeSet;
 use std::{borrow::Cow, str::FromStr};
 
 #[allow(clippy::struct_excessive_bools)]
 #[allow(clippy::module_name_repetitions)]
 pub struct SettingsApp {
     active_page: page::Entity,
+    loaded_pages: BTreeSet<page::Entity>,
     config: Config,
     core: Core,
     nav_model: nav_bar::Model,
@@ -167,6 +169,7 @@ impl cosmic::Application for SettingsApp {
     fn init(core: Core, flags: Self::Flags) -> (Self, Task<Self::Message>) {
         let mut app = SettingsApp {
             active_page: page::Entity::default(),
+            loaded_pages: BTreeSet::new(),
             config: Config::new(),
             core,
             nav_model: nav_bar::Model::default(),
@@ -337,7 +340,7 @@ impl cosmic::Application for SettingsApp {
             Message::SetWindowTitle => return self.set_title(),
 
             Message::SearchChanged(phrase) => {
-                self.search_changed(phrase);
+                return self.search_changed(phrase);
             }
 
             Message::SearchActivate => {
@@ -781,6 +784,7 @@ impl SettingsApp {
         let mut leave_task = iced::Task::none();
 
         if current_page != page {
+            self.loaded_pages.remove(&current_page);
             leave_task = self
                 .pages
                 .on_leave(current_page)
@@ -801,6 +805,8 @@ impl SettingsApp {
             .clone()
             .expect("sender should be available");
 
+        self.loaded_pages.insert(page);
+
         let page_task = self
             .pages
             .on_enter(page, sender)
@@ -920,13 +926,15 @@ impl SettingsApp {
             .into()
     }
 
-    fn search_changed(&mut self, phrase: String) {
+    fn search_changed(&mut self, phrase: String) -> Task<crate::Message> {
         // If the text was cleared, clear the search results too.
         if phrase.is_empty() {
             self.search_clear();
-            return;
+            return Task::none();
         }
 
+        let mut tasks = Vec::new();
+
         // Create a case-insensitive regular expression for the search function.
         let search_expression = regex::RegexBuilder::new(&phrase)
             .case_insensitive(true)
@@ -942,10 +950,51 @@ impl SettingsApp {
             // Use the results if results were found.
             if !results.is_empty() {
                 self.search_selections = results;
+
+                let mut unload = BTreeSet::new();
+                let mut load = BTreeSet::new();
+
+                'outer: for loaded_page in &self.loaded_pages {
+                    for (page, _) in &self.search_selections {
+                        if loaded_page == page {
+                            continue 'outer;
+                        }
+                    }
+
+                    unload.insert(*loaded_page);
+                }
+
+                for (page, _) in &self.search_selections {
+                    if !self.loaded_pages.contains(page) {
+                        load.insert(*page);
+                    }
+                }
+
+                if let Some(ref sender) = self.page_sender {
+                    for page in load {
+                        eprintln!("loading {page:?}");
+                        self.loaded_pages.insert(page);
+                        tasks.push(self.pages.on_enter(page, sender.clone()));
+                    }
+                }
+
+                for page in unload {
+                    eprintln!("unloading {page:?}");
+                    self.loaded_pages.remove(&page);
+                    self.pages.on_leave(page);
+                }
             }
         }
 
         self.search_input = phrase;
+
+        if tasks.is_empty() {
+            Task::none()
+        } else {
+            cosmic::command::batch(tasks)
+                .map(Message::PageMessage)
+                .map(Into::into)
+        }
     }
 
     /// Clears the search results so that the search page will not be shown.

cosmic-settings/src/pages/desktop/appearance/mod.rs

@@ -62,6 +62,7 @@ enum ContextView {
 }
 
 pub struct Page {
+    on_enter_handle: Option<cosmic::iced::task::Handle>,
     can_reset: bool,
     no_custom_window_hint: bool,
     context_view: Option<ContextView>,
@@ -152,6 +153,7 @@ impl
         });
 
         Self {
+            on_enter_handle: None,
             can_reset: if theme_mode.is_dark {
                 theme_builder == ThemeBuilder::dark()
             } else {
@@ -1431,7 +1433,7 @@ impl page::Page<crate::pages::Message> for Page {
         _: page::Entity,
         _sender: tokio::sync::mpsc::Sender<crate::pages::Message>,
     ) -> Task<crate::pages::Message> {
-        cosmic::command::batch(vec![
+        let (task, handle) = cosmic::command::batch(vec![
             // Load icon themes
             cosmic::command::future(icon_themes::fetch()).map(crate::pages::Message::Appearance),
             // Load font families
@@ -1441,9 +1443,17 @@ impl page::Page<crate::pages::Message> for Page {
             })
             .map(crate::pages::Message::Appearance),
         ])
+        .abortable();
+
+        self.on_enter_handle = Some(handle);
+        task
     }
 
     fn on_leave(&mut self) -> Task<crate::pages::Message> {
+        if let Some(handle) = self.on_enter_handle.take() {
+            handle.abort();
+        }
+
         cosmic::command::message(crate::pages::Message::Appearance(Message::Left))
     }
 

cosmic-settings/src/pages/desktop/wallpaper/mod.rs

@@ -137,6 +137,9 @@ enum ContextView {
 
 /// The page struct for the wallpaper view.
 pub struct Page {
+    /// Abort handle to the on_enter task.
+    on_enter_handle: Option<cosmic::iced::task::Handle>,
+
     /// Whether to show a context drawer.
     context_view: Option<ContextView>,
 
@@ -207,11 +210,16 @@ impl page::Page<crate::pages::Message> for Page {
         _page: page::Entity,
         _sender: tokio::sync::mpsc::Sender<crate::pages::Message>,
     ) -> Task<crate::pages::Message> {
+        // Check if the page is already being loaded.
+        if self.on_enter_handle.is_some() {
+            return Task::none();
+        }
+
         let current_folder = self.config.current_folder().to_owned();
 
         let recurse = self.categories.selected == Some(Category::Wallpapers);
 
-        Task::future(async move {
+        let (task, on_enter_handle) = Task::future(async move {
             let (service_config, displays) = wallpaper::config().await;
 
             let mut selection = change_folder(current_folder, recurse).await;
@@ -245,6 +253,19 @@ impl page::Page<crate::pages::Message> for Page {
                 selection,
             })))
         })
+        .abortable();
+
+        self.on_enter_handle = Some(on_enter_handle);
+        task
+    }
+
+    fn on_leave(&mut self) -> Task<crate::pages::Message> {
+        // Cancel the on_enter task if it was running.
+        if let Some(handle) = self.on_enter_handle.take() {
+            handle.abort();
+        }
+
+        Task::none()
     }
 
     fn context_drawer(&self) -> Option<Element<'_, crate::pages::Message>> {
@@ -265,6 +286,7 @@ impl page::AutoBind<crate::pages::Message> for Page {}
 impl Default for Page {
     fn default() -> Self {
         let mut page = Page {
+            on_enter_handle: None,
             context_view: None,
             show_tab_bar: false,
             active_output: None,

cosmic-settings/src/pages/networking/vpn/mod.rs

@@ -194,7 +194,6 @@ pub struct Page {
     dialog: Option<VpnDialog>,
     view_more_popup: Option<ConnectionId>,
     known_connections: IndexMap<UUID, ConnectionSettings>,
-    wireguard_connections: IndexMap<UUID, String>,
     /// Withhold device update if the view more popup is shown.
     withheld_devices: Option<Vec<network_manager::devices::DeviceInfo>>,
     /// Withhold active connections update if the view more popup is shown.

cosmic-settings/src/pages/power/mod.rs

@@ -18,6 +18,7 @@ use slotmap::SlotMap;
 pub struct Page {
     battery: Battery,
     connected_devices: Vec<ConnectedDevice>,
+    on_enter_handle: Option<cosmic::iced::task::Handle>,
 }
 
 impl page::Page<crate::pages::Message> for Page {
@@ -54,7 +55,20 @@ impl page::Page<crate::pages::Message> for Page {
             }),
         ];
 
-        cosmic::Task::batch(futures).map(crate::pages::Message::Power)
+        let (task, handle) = cosmic::Task::batch(futures)
+            .map(crate::pages::Message::Power)
+            .abortable();
+
+        self.on_enter_handle = Some(handle);
+        task
+    }
+
+    fn on_leave(&mut self) -> Task<crate::pages::Message> {
+        if let Some(handle) = self.on_enter_handle.take() {
+            handle.abort();
+        }
+
+        Task::none()
     }
 }
 

cosmic-settings/src/pages/system/about.rs

@@ -21,6 +21,7 @@ pub enum Message {
 pub struct Page {
     editing_device_name: bool,
     info: Info,
+    on_enter_handle: Option<cosmic::iced::task::Handle>,
 }
 
 impl page::AutoBind<crate::pages::Message> for Page {}
@@ -48,9 +49,21 @@ impl page::Page<crate::pages::Message> for Page {
         _page: page::Entity,
         _sender: tokio::sync::mpsc::Sender<crate::pages::Message>,
     ) -> Task<crate::pages::Message> {
-        Task::future(
-            async move { crate::pages::Message::About(Message::Info(Box::new(Info::load()))) },
-        )
+        let (task, handle) = Task::future(async move {
+            crate::pages::Message::About(Message::Info(Box::new(Info::load())))
+        })
+        .abortable();
+
+        self.on_enter_handle = Some(handle);
+        task
+    }
+
+    fn on_leave(&mut self) -> Task<crate::pages::Message> {
+        if let Some(handle) = self.on_enter_handle.take() {
+            handle.abort();
+        }
+
+        Task::none()
     }
 }