Track tab sort keys

crates/ely_browser_core/src/state.rs

@@ -20,6 +20,7 @@ mod reading_list;
 mod site_permissions;
 mod splits;
 mod sync;
+mod tab_order;
 mod tabs;
 
 pub use plugins::{InstalledPlugin, PluginAuditAction, PluginAuditEvent};
@@ -125,7 +126,8 @@ impl BrowserCore {
             active_profile_id.clone(),
             new_tab_title,
             new_tab_url.clone(),
-        );
+        )
+        .with_sort_key(0);
         let active_tab_id = tab.id().clone();
         let mut active_tabs_by_space = BTreeMap::new();
         let mut active_tabs_by_space_profile = BTreeMap::new();
@@ -406,16 +408,18 @@ impl BrowserCore {
     }
 
     fn pinned_tabs(&self) -> Vec<BrowserTab> {
-        self.tabs
-            .iter()
-            .filter(|tab| tab.space_id() == &self.active_space_id)
-            .filter(|tab| tab.flags().pinned && !tab.flags().favorite)
-            .cloned()
-            .collect()
+        tab_order::sorted_tabs(
+            self.tabs
+                .iter()
+                .filter(|tab| tab.space_id() == &self.active_space_id)
+                .filter(|tab| tab.flags().pinned && !tab.flags().favorite),
+        )
     }
 
     fn visible_tabs(&self) -> Vec<BrowserTab> {
-        self.tabs.iter().filter(|tab| tab.space_id() == &self.active_space_id).cloned().collect()
+        tab_order::sorted_tabs(
+            self.tabs.iter().filter(|tab| tab.space_id() == &self.active_space_id),
+        )
     }
 
     fn record_tab_activity(&mut self, tab_id: &TabId, active_at: SystemTime) {

crates/ely_browser_core/src/state/tab_order.rs

@@ -0,0 +1,47 @@
+use ely_domain::{BrowserTab, SpaceId};
+
+use super::BrowserCore;
+
+impl BrowserCore {
+    pub(super) fn next_tab_sort_key(&self, space_id: &SpaceId) -> u64 {
+        self.tabs
+            .iter()
+            .filter(|tab| tab.space_id() == space_id)
+            .map(BrowserTab::sort_key)
+            .max()
+            .map_or(0, |sort_key| sort_key.saturating_add(1))
+    }
+
+    pub(super) fn normalize_tab_sort_keys(&mut self, space_id: &SpaceId) {
+        let mut sort_key = 0;
+        for tab in self.tabs.iter_mut().filter(|tab| tab.space_id() == space_id) {
+            tab.set_sort_key(sort_key);
+            sort_key = sort_key.saturating_add(1);
+        }
+    }
+
+    pub(super) fn sort_tabs_within_space(&mut self, space_id: &SpaceId) {
+        let indices = self
+            .tabs
+            .iter()
+            .enumerate()
+            .filter_map(|(index, tab)| (tab.space_id() == space_id).then_some(index))
+            .collect::<Vec<_>>();
+        let mut tabs = indices.iter().map(|index| self.tabs[*index].clone()).collect::<Vec<_>>();
+        tabs.sort_by(compare_tabs);
+
+        for (index, tab) in indices.into_iter().zip(tabs) {
+            self.tabs[index] = tab;
+        }
+    }
+}
+
+pub(super) fn sorted_tabs<'a>(tabs: impl Iterator<Item = &'a BrowserTab>) -> Vec<BrowserTab> {
+    let mut tabs = tabs.cloned().collect::<Vec<_>>();
+    tabs.sort_by(compare_tabs);
+    tabs
+}
+
+fn compare_tabs(left: &BrowserTab, right: &BrowserTab) -> std::cmp::Ordering {
+    left.sort_key().cmp(&right.sort_key()).then_with(|| left.id().cmp(right.id()))
+}

crates/ely_browser_core/src/state/tabs.rs

@@ -20,6 +20,7 @@ impl BrowserCore {
     pub fn open_tab(&mut self, url: UrlText) -> TabId {
         let tab = self.build_tab(url);
         let tab_id = tab.id().clone();
+        let space_id = tab.space_id().clone();
         let insert_index = self
             .tabs
             .iter()
@@ -27,6 +28,7 @@ impl BrowserCore {
             .map_or(self.tabs.len(), |index| index + 1);
         self.record_history_entry(&tab);
         self.tabs.insert(insert_index, tab);
+        self.normalize_tab_sort_keys(&space_id);
         self.active_tab_id = tab_id.clone();
         self.active_tabs_by_space.insert(self.active_space_id.clone(), tab_id.clone());
         self.active_tabs_by_space_profile
@@ -49,7 +51,10 @@ impl BrowserCore {
 
         self.detach_tab_from_split(&tab_id);
         let tab_index = self.active_tab_index()?;
+        let target_sort_key = self.next_tab_sort_key(space_id);
         self.tabs[tab_index].move_to_space(space_id.clone());
+        self.tabs[tab_index].set_sort_key(target_sort_key);
+        self.sort_tabs_within_space(space_id);
         self.active_tabs_by_space.insert(space_id.clone(), tab_id.clone());
         self.active_tabs_by_space_profile.remove(&(source_space_id.clone(), profile_id.clone()));
 
@@ -257,6 +262,18 @@ impl BrowserCore {
         Ok(())
     }
 
+    pub fn set_tab_sort_key(&mut self, tab_id: &TabId, sort_key: u64) -> Result<(), CoreError> {
+        let tab = self
+            .tabs
+            .iter_mut()
+            .find(|tab| tab.id() == tab_id)
+            .ok_or_else(|| CoreError::TabNotFound { id: tab_id.clone() })?;
+        let space_id = tab.space_id().clone();
+        tab.set_sort_key(sort_key);
+        self.sort_tabs_within_space(&space_id);
+        Ok(())
+    }
+
     pub fn active_tab(&self) -> Result<&BrowserTab, CoreError> {
         self.tabs
             .iter()
@@ -279,7 +296,8 @@ impl BrowserCore {
         url: UrlText,
     ) -> BrowserTab {
         let title = tab_title(&url);
-        BrowserTab::new(TabId::new(), space_id, profile_id, title, url)
+        let sort_key = self.next_tab_sort_key(&space_id);
+        BrowserTab::new(TabId::new(), space_id, profile_id, title, url).with_sort_key(sort_key)
     }
 
     pub(super) fn tab_belongs_to_space(&self, tab_id: &TabId, space_id: &SpaceId) -> bool {
@@ -294,7 +312,9 @@ impl BrowserCore {
             .position(|existing| existing.id() == &self.active_tab_id)
             .map_or(self.tabs.len(), |index| index + 1);
 
+        let space_id = tab.space_id().clone();
         self.tabs.insert(insert_index, tab);
+        self.normalize_tab_sort_keys(&space_id);
         self.select_tab(&tab_id)?;
         Ok(tab_id)
     }

crates/ely_browser_core/tests/tabs.rs

@@ -22,6 +22,39 @@ fn opens_new_tab_below_active_tab() -> Result<(), Box<dyn Error>> {
     Ok(())
 }
 
+#[test]
+fn opened_tabs_receive_visible_sort_keys() -> Result<(), Box<dyn Error>> {
+    let mut core = BrowserCore::new(InitialBrowserConfig::ely_defaults()?)?;
+    let first_tab_id = core.active_tab()?.id().clone();
+    let second_tab_id = core.open_tab(UrlText::parse("https://example.com")?);
+
+    core.select_tab(&first_tab_id)?;
+    let third_tab_id = core.open_tab(UrlText::parse("https://servo.org")?);
+    let snapshot = core.snapshot()?;
+    let ordered =
+        snapshot.tabs.iter().map(|tab| (tab.id().clone(), tab.sort_key())).collect::<Vec<_>>();
+
+    assert_eq!(ordered, vec![(first_tab_id, 0), (third_tab_id, 1), (second_tab_id, 2)]);
+    Ok(())
+}
+
+#[test]
+fn snapshot_orders_tabs_by_sort_key() -> Result<(), Box<dyn Error>> {
+    let mut core = BrowserCore::new(InitialBrowserConfig::ely_defaults()?)?;
+    let first_tab_id = core.active_tab()?.id().clone();
+    let second_tab_id = core.open_tab(UrlText::parse("https://example.com")?);
+    let third_tab_id = core.open_tab(UrlText::parse("https://servo.org")?);
+
+    core.set_tab_sort_key(&second_tab_id, 30)?;
+    core.set_tab_sort_key(&third_tab_id, 10)?;
+    core.set_tab_sort_key(&first_tab_id, 20)?;
+    let snapshot = core.snapshot()?;
+    let ordered_ids = snapshot.tabs.iter().map(|tab| tab.id().clone()).collect::<Vec<_>>();
+
+    assert_eq!(ordered_ids, vec![third_tab_id, first_tab_id, second_tab_id]);
+    Ok(())
+}
+
 #[test]
 fn opened_tabs_record_active_tab_as_parent() -> Result<(), Box<dyn Error>> {
     let mut core = BrowserCore::new(InitialBrowserConfig::ely_defaults()?)?;