columns: enable toolbar scroll to top

Fixes: https://github.com/damus-io/notedeck/issues/969
Signed-off-by: William Casarin <jb55@jb55.com>

crates/notedeck_columns/src/column.rs

@@ -42,6 +42,18 @@ pub struct Columns {
     pub selected: i32,
 }
 
+/// When selecting columns, return what happened
+pub enum SelectionResult {
+    /// We're already selecting that
+    AlreadySelected(usize),
+
+    /// New selection success!
+    NewSelection(usize),
+
+    /// Failed to make a selection
+    Failed,
+}
+
 impl Columns {
     pub fn new() -> Self {
         Columns::default()
@@ -60,20 +72,25 @@ impl Columns {
     /// Select the column based on the timeline kind.
     ///
     /// TODO: add timeline if missing?
-    pub fn select_by_kind(&mut self, kind: &TimelineKind) {
+    pub fn select_by_kind(&mut self, kind: &TimelineKind) -> SelectionResult {
         for (i, col) in self.columns.iter().enumerate() {
             for route in col.router().routes() {
                 if let Some(timeline) = route.timeline_id() {
                     if timeline == kind {
                         tracing::info!("selecting {kind:?} column");
-                        self.select_column(i as i32);
-                        return;
+                        if self.selected as usize == i {
+                            return SelectionResult::AlreadySelected(i);
+                        } else {
+                            self.select_column(i as i32);
+                            return SelectionResult::NewSelection(i);
+                        }
                     }
                 }
             }
         }
 
         tracing::error!("failed to select {kind:?} column");
+        SelectionResult::Failed
     }
 
     pub fn add_new_timeline_column(

crates/notedeck_columns/src/decks.rs

@@ -40,6 +40,10 @@ impl DecksCache {
         self.active_columns(accounts).and_then(|ad| ad.selected())
     }
 
+    pub fn selected_column_index(&self, accounts: &notedeck::Accounts) -> Option<usize> {
+        self.active_columns(accounts).map(|ad| ad.selected as usize)
+    }
+
     /// Gets a mutable reference to the active columns
     pub fn active_columns_mut(&mut self, accounts: &notedeck::Accounts) -> Option<&mut Columns> {
         let account = accounts.get_selected_account();

crates/notedeck_columns/src/lib.rs

@@ -8,7 +8,7 @@ pub mod actionbar;
 pub mod app_creation;
 mod app_style;
 mod args;
-mod column;
+pub mod column;
 mod deck_state;
 mod decks;
 mod draft;

crates/notedeck_columns/src/nav.rs

@@ -4,6 +4,7 @@ use crate::{
     column::ColumnsAction,
     deck_state::DeckState,
     decks::{Deck, DecksAction, DecksCache},
+    options::AppOptions,
     profile::{ProfileAction, SaveProfileChanges},
     route::{Route, Router, SingletonRouter},
     timeline::{
@@ -496,17 +497,34 @@ fn render_nav_body(
         current_account_has_wallet: get_current_wallet(ctx.accounts, ctx.global_wallet).is_some(),
     };
     match top {
-        Route::Timeline(kind) => render_timeline_route(
-            &mut app.timeline_cache,
-            ctx.accounts,
-            kind,
-            col,
-            app.note_options,
-            depth,
-            ui,
-            &mut note_context,
-            &mut app.jobs,
-        ),
+        Route::Timeline(kind) => {
+            // did something request scroll to top for the selection column?
+            let scroll_to_top = app
+                .decks_cache
+                .selected_column_index(ctx.accounts)
+                .is_some_and(|ind| ind == col)
+                && app.options.contains(AppOptions::ScrollToTop);
+
+            let nav_action = render_timeline_route(
+                &mut app.timeline_cache,
+                ctx.accounts,
+                kind,
+                col,
+                app.note_options,
+                depth,
+                ui,
+                &mut note_context,
+                &mut app.jobs,
+                scroll_to_top,
+            );
+
+            // always clear the scroll_to_top request
+            if scroll_to_top {
+                app.options.remove(AppOptions::ScrollToTop);
+            }
+
+            nav_action
+        }
         Route::Thread(selection) => render_thread_route(
             &mut app.threads,
             ctx.accounts,

crates/notedeck_columns/src/timeline/route.rs

@@ -20,6 +20,7 @@ pub fn render_timeline_route(
     ui: &mut egui::Ui,
     note_context: &mut NoteContext,
     jobs: &mut JobsCache,
+    scroll_to_top: bool,
 ) -> Option<RenderNavAction> {
     match kind {
         TimelineKind::List(_)
@@ -39,6 +40,7 @@ pub fn render_timeline_route(
                 jobs,
                 col,
             )
+            .scroll_to_top(scroll_to_top)
             .ui(ui);
 
             note_action.map(RenderNavAction::NoteAction)
@@ -69,6 +71,7 @@ pub fn render_timeline_route(
                     jobs,
                     col,
                 )
+                .scroll_to_top(scroll_to_top)
                 .ui(ui);
 
                 note_action.map(RenderNavAction::NoteAction)

crates/notedeck_columns/src/ui/timeline.rs

@@ -25,6 +25,7 @@ pub struct TimelineView<'a, 'd> {
     cur_acc: &'a KeypairUnowned<'a>,
     jobs: &'a mut JobsCache,
     col: usize,
+    scroll_to_top: bool,
 }
 
 impl<'a, 'd> TimelineView<'a, 'd> {
@@ -40,6 +41,7 @@ impl<'a, 'd> TimelineView<'a, 'd> {
         col: usize,
     ) -> Self {
         let reverse = false;
+        let scroll_to_top = false;
         TimelineView {
             timeline_id,
             timeline_cache,
@@ -50,6 +52,7 @@ impl<'a, 'd> TimelineView<'a, 'd> {
             cur_acc,
             jobs,
             col,
+            scroll_to_top,
         }
     }
 
@@ -65,9 +68,15 @@ impl<'a, 'd> TimelineView<'a, 'd> {
             self.cur_acc,
             self.jobs,
             self.col,
+            self.scroll_to_top,
         )
     }
 
+    pub fn scroll_to_top(mut self, enable: bool) -> Self {
+        self.scroll_to_top = enable;
+        self
+    }
+
     pub fn reversed(mut self) -> Self {
         self.reverse = true;
         self
@@ -86,6 +95,7 @@ fn timeline_ui(
     cur_acc: &KeypairUnowned,
     jobs: &mut JobsCache,
     col: usize,
+    scroll_to_top: bool,
 ) -> Option<NoteAction> {
     //padding(4.0, ui, |ui| ui.heading("Notifications"));
     /*
@@ -152,6 +162,11 @@ fn timeline_ui(
         }
     }
 
+    // chrome can ask to scroll to top as well via an app option
+    if scroll_to_top {
+        scroll_area = scroll_area.vertical_scroll_offset(0.0);
+    }
+
     let scroll_output = scroll_area.show(ui, |ui| {
         let timeline = if let Some(timeline) = timeline_cache.timelines.get(timeline_id) {
             timeline