feat(tui): scroll long names in every list and page through popups and chat

The sideways keys the results had (h/l, arrows, 0 and $) now scroll a
transfer's file name and a query too, each list on its own. The browse tree
and the room list take Home/End, PgUp/PgDn and the vim jumps like the main
lists, and a chat log, room or private, pages back through its history and
holds its place while new messages arrive; what arrives meanwhile counts as
unread until the reader returns to the end.

soulseek-rs/src/ui/panes/chat_pane.rs

@@ -1,4 +1,4 @@
-use crate::models::{AppState, MessageDirection};
+use crate::models::{AppState, ChatMessage, LogView, MessageDirection};
 use crate::ui::{
     accent_style, border_style, dimmed_style, highlight_style, info_style,
     primary_style, wrap_chat_line,
@@ -17,10 +17,11 @@ use ratatui::{
 pub fn render_chat_pane(
     frame: &mut Frame,
     area: Rect,
-    state: &AppState,
+    state: &mut AppState,
     own_username: &str,
 ) {
-    let peer = state.active_chat_peer();
+    let peer = state.active_chat_peer().map(str::to_string);
+    let peer = peer.as_deref();
     let title = peer.map_or_else(
         || " Messages  (m: compose, i/Esc: close) ".to_string(),
         |peer| format!(" {peer}  (↑↓/Tab: switch, m: to…, i/Esc: close) "),
@@ -51,7 +52,14 @@ pub fn render_chat_pane(
         return;
     };
 
-    render_messages(frame, body[0], state, peer, own_username);
+    render_messages(
+        frame,
+        body[0],
+        &state.messages,
+        &mut state.chat_view,
+        peer,
+        own_username,
+    );
     render_compose(frame, chunks[1], state);
 }
 
@@ -94,13 +102,13 @@ fn render_peers(
 fn render_messages(
     frame: &mut Frame,
     area: Rect,
-    state: &AppState,
+    messages: &[ChatMessage],
+    view: &mut LogView,
     peer: &str,
     own_username: &str,
 ) {
     let width = area.width as usize;
-    let lines: Vec<Line> = state
-        .messages
+    let lines: Vec<Line> = messages
         .iter()
         .filter(|m| m.peer == peer)
         .flat_map(|m| {
@@ -123,9 +131,9 @@ fn render_messages(
         })
         .collect();
 
-    // Auto-scroll: tail by rendered rows so the newest message stays visible.
-    let start = lines.len().saturating_sub((area.height as usize).max(1));
-    frame.render_widget(Paragraph::new(lines[start..].to_vec()), area);
+    // The newest rows, unless the reader is holding a place in the history.
+    let window = view.window(lines.len(), usize::from(area.height));
+    frame.render_widget(Paragraph::new(lines[window].to_vec()), area);
 }
 
 fn render_compose(frame: &mut Frame, area: Rect, state: &AppState) {

soulseek-rs/src/ui/panes/downloads_pane.rs

@@ -1,3 +1,4 @@
+use super::name_scroll::{column_width, end_offset, scroll_text};
 use crate::models::DownloadEntry;
 use crate::ui::{
     GLYPH_ACTIVE, GLYPH_DONE, GLYPH_FAILED, GLYPH_QUEUED, HIGHLIGHT_SYMBOL,
@@ -8,12 +9,43 @@ use crate::ui::{
 };
 use ratatui::{
     Frame,
-    layout::Rect,
+    layout::{Constraint, Rect},
     widgets::{Cell, HighlightSpacing, Paragraph, Row, Table, TableState},
 };
 use soulseek_rs::DownloadStatus;
 use soulseek_rs::types::{UploadInfo, UploadStatus};
 
+// Sized to the widest value each column shows in ordinary use — a
+// three-digit megabyte count on both sides of the progress — so the file
+// name keeps whatever width the pane has beyond that.
+const WIDTHS: [Constraint; 5] = [
+    Constraint::Length(6),
+    Constraint::Fill(1),
+    Constraint::Length(12),
+    Constraint::Length(25),
+    Constraint::Length(10),
+];
+
+/// Filename is the second column.
+const NAME_COLUMN: usize = 1;
+
+/// The offset that brings the end of a transfer's name into view.
+#[must_use]
+pub fn name_end_offset(name: &str, area: Rect) -> usize {
+    end_offset(name, area, &WIDTHS, NAME_COLUMN)
+}
+
+/// What the list shows for an upload: the peer-facing path is ours, so only
+/// the file's own name is worth a column.
+#[must_use]
+pub fn upload_display_name(upload: &UploadInfo) -> &str {
+    upload
+        .filename
+        .rsplit(['\\', '/'])
+        .next()
+        .unwrap_or(&upload.filename)
+}
+
 pub fn render_downloads_pane(
     frame: &mut Frame,
     area: Rect,
@@ -21,6 +53,7 @@ pub fn render_downloads_pane(
     uploads: &[UploadInfo],
     table_state: &mut TableState,
     focused: bool,
+    name_offset: usize,
 ) {
     if downloads.is_empty() && uploads.is_empty() {
         let empty_block = pane_block(focused).title(pane_title(
@@ -47,6 +80,7 @@ pub fn render_downloads_pane(
     ])
     .height(1);
 
+    let name_width = column_width(area, &WIDTHS, NAME_COLUMN);
     let mut rows: Vec<Row> = downloads
         .iter()
         .map(|download_entry| {
@@ -106,7 +140,12 @@ pub fn render_downloads_pane(
 
             Row::new(vec![
                 Cell::from(status_icon).style(status_style),
-                Cell::from(download.filename.clone()).style(body_style()),
+                Cell::from(scroll_text(
+                    &download.filename,
+                    name_offset,
+                    name_width,
+                ))
+                .style(body_style()),
                 Cell::from(download.username.clone()).style(info_style()),
                 Cell::from(progress_text).style(progress_style),
                 Cell::from(speed_text).style(warning_style()),
@@ -149,32 +188,21 @@ pub fn render_downloads_pane(
             }
             _ => "-".to_string(),
         };
-        let basename = upload
-            .filename
-            .rsplit(['\\', '/'])
-            .next()
-            .unwrap_or(&upload.filename);
         Row::new(vec![
             Cell::from(format!("↑ {status_icon}")).style(status_style),
-            Cell::from(basename.to_string()).style(body_style()),
+            Cell::from(scroll_text(
+                upload_display_name(upload),
+                name_offset,
+                name_width,
+            ))
+            .style(body_style()),
             Cell::from(upload.username.clone()).style(info_style()),
             Cell::from(progress_text).style(primary_style()),
             Cell::from(speed_text).style(warning_style()),
         ])
     }));
 
-    // Sized to the widest value each column shows in ordinary use — a
-    // three-digit megabyte count on both sides of the progress — so the file
-    // name keeps whatever width the pane has beyond that.
-    let widths = [
-        ratatui::layout::Constraint::Length(6),
-        ratatui::layout::Constraint::Fill(1),
-        ratatui::layout::Constraint::Length(12),
-        ratatui::layout::Constraint::Length(25),
-        ratatui::layout::Constraint::Length(10),
-    ];
-
-    let table = Table::new(rows, widths)
+    let table = Table::new(rows, WIDTHS)
         .header(header)
         .row_highlight_style(row_highlight_style())
         .highlight_symbol(HIGHLIGHT_SYMBOL)

soulseek-rs/src/ui/panes/mod.rs

@@ -2,6 +2,7 @@ mod browse_pane;
 mod chat_pane;
 mod download_info_pane;
 mod downloads_pane;
+mod name_scroll;
 mod results_pane;
 mod rooms_pane;
 mod searches_pane;
@@ -11,9 +12,12 @@ pub use chat_pane::render_chat_pane;
 pub use download_info_pane::{
     InfoSubject, render_download_info_pane, selected_transfer,
 };
-pub use downloads_pane::render_downloads_pane;
+pub use downloads_pane::{
+    name_end_offset as transfer_name_end_offset, render_downloads_pane,
+    upload_display_name,
+};
 pub use results_pane::{
     ResultsPaneParams, name_end_offset, render_results_pane,
 };
 pub use rooms_pane::render_rooms_pane;
-pub use searches_pane::render_searches_pane;
+pub use searches_pane::{query_end_offset, render_searches_pane};

soulseek-rs/src/ui/panes/name_scroll.rs

@@ -0,0 +1,126 @@
+//! Sideways scrolling for a table column that holds text wider than it is:
+//! a file name, a query. Every list scrolls the same way, so the arithmetic
+//! lives here and each pane only says which of its columns it applies to.
+
+use crate::ui::{HIGHLIGHT_SYMBOL, pane_block};
+use ratatui::{
+    layout::{Constraint, Layout, Rect},
+    text::{Line, Span},
+};
+use unicode_width::UnicodeWidthChar;
+
+/// Cells column `column` of a table laid out with `widths` gets inside a pane
+/// drawn over `area`: what the pane keeps for its border, padding and the
+/// highlight symbol comes off first.
+#[must_use]
+pub fn column_width(area: Rect, widths: &[Constraint], column: usize) -> usize {
+    let inner = pane_block(false).inner(area);
+    let symbol = Line::from(HIGHLIGHT_SYMBOL).width() as u16;
+    let [_, columns] =
+        Layout::horizontal([Constraint::Length(symbol), Constraint::Fill(0)])
+            .areas(inner);
+    usize::from(
+        Layout::horizontal(widths).spacing(1).split(columns)[column].width,
+    )
+}
+
+/// How far a text of `cells` can scroll before its tail is in view, keeping
+/// one cell for the ellipsis that marks the cut.
+const fn overflow(cells: usize, width: usize) -> usize {
+    if cells <= width { 0 } else { cells + 1 - width }
+}
+
+/// The offset that brings the end of `text` into view in the column.
+#[must_use]
+pub fn end_offset(
+    text: &str,
+    area: Rect,
+    widths: &[Constraint],
+    column: usize,
+) -> usize {
+    overflow(Span::raw(text).width(), column_width(area, widths, column))
+}
+
+/// `text` scrolled `offset` cells to the left, with an ellipsis where it was
+/// cut. Scrolls by cells, so a wide glyph counts double, and never starts on
+/// a combining mark. Beyond the end it shows the tail.
+#[must_use]
+pub fn scroll_text(text: &str, offset: usize, width: usize) -> Line<'_> {
+    if offset == 0 {
+        return Line::from(text);
+    }
+    let mut tail_cells = 0;
+    let mut furthest = text.len();
+    for (index, ch) in text.char_indices().rev() {
+        let cells = ch.width().unwrap_or(0);
+        if tail_cells + cells >= width {
+            if index == 0 && tail_cells + cells == width {
+                return Line::from(text);
+            }
+            break;
+        }
+        tail_cells += cells;
+        furthest = index;
+    }
+    if furthest == 0 {
+        return Line::from(text);
+    }
+    let mut skipped = 0;
+    let mut start = furthest;
+    for (index, ch) in text.char_indices() {
+        if index >= furthest || skipped >= offset {
+            start = index;
+            break;
+        }
+        skipped += ch.width().unwrap_or(0);
+    }
+    while let Some(ch) = text[start..].chars().next()
+        && ch.width() == Some(0)
+    {
+        start += ch.len_utf8();
+    }
+    Line::from(vec![Span::raw("…"), Span::raw(&text[start..])])
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn text_of(line: &Line<'_>) -> String {
+        line.spans.iter().map(|s| s.content.as_ref()).collect()
+    }
+
+    #[test]
+    fn a_text_that_fits_never_scrolls() {
+        assert_eq!(text_of(&scroll_text("short", 8, 10)), "short");
+        assert_eq!(
+            end_offset(
+                "short",
+                Rect::new(0, 0, 40, 5),
+                &[Constraint::Fill(1)],
+                0
+            ),
+            0
+        );
+    }
+
+    #[test]
+    fn the_end_offset_leaves_room_for_the_ellipsis() {
+        // Column of 40 - 2 border - 2 padding - 1 symbol = 35 cells.
+        let area = Rect::new(0, 0, 40, 5);
+        let widths = [Constraint::Fill(1)];
+        let fits = "x".repeat(35);
+        let over = "x".repeat(36);
+        assert_eq!(end_offset(&fits, area, &widths, 0), 0);
+        assert_eq!(end_offset(&over, area, &widths, 0), 2);
+        let line = scroll_text(&over, 2, 35);
+        assert_eq!(text_of(&line).chars().count(), 35);
+        assert!(text_of(&line).starts_with('…'));
+    }
+
+    #[test]
+    fn scrolling_past_the_end_shows_the_tail() {
+        let line = scroll_text("abcdefghij", usize::MAX, 5);
+        assert_eq!(text_of(&line), "…ghij");
+    }
+}

soulseek-rs/src/ui/panes/results_pane.rs

@@ -1,3 +1,4 @@
+use super::name_scroll::{column_width, end_offset, scroll_text};
 use crate::models::FileDisplayData;
 use crate::ui::{
     BYTES_PER_MB, HIGHLIGHT_SYMBOL, body_style, dimmed_style, format_bytes,
@@ -6,12 +7,11 @@ use crate::ui::{
 };
 use ratatui::{
     Frame,
-    layout::{Constraint, Layout, Rect},
+    layout::{Constraint, Rect},
     text::{Line, Span},
     widgets::{Cell, HighlightSpacing, Paragraph, Row, Table, TableState},
 };
 use std::collections::HashSet;
-use unicode_width::UnicodeWidthChar;
 
 const VERSION: &str = env!("CARGO_PKG_VERSION");
 
@@ -39,59 +39,12 @@ pub struct ResultsPaneParams<'a> {
     pub name_offset: usize,
 }
 
-fn name_column_width(area: Rect) -> usize {
-    let inner = pane_block(false).inner(area);
-    let symbol = Line::from(HIGHLIGHT_SYMBOL).width() as u16;
-    let [_, columns] =
-        Layout::horizontal([Constraint::Length(symbol), Constraint::Fill(0)])
-            .areas(inner);
-    usize::from(Layout::horizontal(WIDTHS).spacing(1).split(columns)[1].width)
-}
-
-const fn overflow(cells: usize, width: usize) -> usize {
-    if cells <= width { 0 } else { cells + 1 - width }
-}
+/// Filename is the second column.
+const NAME_COLUMN: usize = 1;
 
 #[must_use]
 pub fn name_end_offset(name: &str, area: Rect) -> usize {
-    overflow(Span::raw(name).width(), name_column_width(area))
-}
-
-fn scroll_name(name: &str, offset: usize, width: usize) -> Line<'_> {
-    if offset == 0 {
-        return Line::from(name);
-    }
-    let mut tail_cells = 0;
-    let mut furthest = name.len();
-    for (index, ch) in name.char_indices().rev() {
-        let cells = ch.width().unwrap_or(0);
-        if tail_cells + cells >= width {
-            if index == 0 && tail_cells + cells == width {
-                return Line::from(name);
-            }
-            break;
-        }
-        tail_cells += cells;
-        furthest = index;
-    }
-    if furthest == 0 {
-        return Line::from(name);
-    }
-    let mut skipped = 0;
-    let mut start = furthest;
-    for (index, ch) in name.char_indices() {
-        if index >= furthest || skipped >= offset {
-            start = index;
-            break;
-        }
-        skipped += ch.width().unwrap_or(0);
-    }
-    while let Some(ch) = name[start..].chars().next()
-        && ch.width() == Some(0)
-    {
-        start += ch.len_utf8();
-    }
-    Line::from(vec![Span::raw("…"), Span::raw(&name[start..])])
+    end_offset(name, area, &WIDTHS, NAME_COLUMN)
 }
 
 /// Whether the rendered row `display_idx` is selected. `selected_indices` holds
@@ -173,7 +126,7 @@ pub fn render_results_pane(
     ])
     .height(1);
 
-    let name_width = name_column_width(area);
+    let name_width = column_width(area, &WIDTHS, NAME_COLUMN);
     let rows: Vec<Row> = items
         .iter()
         .enumerate()
@@ -206,7 +159,7 @@ pub fn render_results_pane(
 
             Row::new(vec![
                 Cell::from(checkbox).style(checkbox_style),
-                Cell::from(scroll_name(
+                Cell::from(scroll_text(
                     &file.filename,
                     name_offset,
                     name_width,

soulseek-rs/src/ui/panes/rooms_pane.rs

@@ -1,4 +1,4 @@
-use crate::models::{RoomsState, RoomsView};
+use crate::models::{LogView, RoomsState, RoomsView};
 use crate::ui::{
     HIGHLIGHT_SYMBOL, PANE_PADDING, accent_style, dimmed_style,
     highlight_style, info_style, pane_block, plain_title, primary_style,
@@ -20,7 +20,7 @@ use ratatui::{
 pub fn render_rooms_pane(
     frame: &mut Frame,
     area: Rect,
-    rooms: &RoomsState,
+    rooms: &mut RoomsState,
     list_table_state: &mut TableState,
 ) {
     match rooms.view {
@@ -94,7 +94,7 @@ fn render_list(
     frame.render_stateful_widget(table, area, table_state);
 }
 
-fn render_chat(frame: &mut Frame, area: Rect, rooms: &RoomsState) {
+fn render_chat(frame: &mut Frame, area: Rect, rooms: &mut RoomsState) {
     let block = pane_block(true).title(
         " Chat rooms  (Tab: switch, l: room list, x: leave, Esc: back) ",
     );
@@ -110,7 +110,10 @@ fn render_chat(frame: &mut Frame, area: Rect, rooms: &RoomsState) {
 
     render_tab_bar(frame, chunks[0], rooms);
 
-    let Some(active) = rooms.active_room() else {
+    let user_selected = rooms.user_selected;
+    let composing = rooms.composing;
+    let active_index = rooms.active;
+    let Some(active) = rooms.open.get_mut(active_index) else {
         frame.render_widget(
             Paragraph::new("No open rooms. Press l for the room list.")
                 .style(dimmed_style()),
@@ -124,11 +127,11 @@ fn render_chat(frame: &mut Frame, area: Rect, rooms: &RoomsState) {
         Layout::horizontal([Constraint::Fill(1), Constraint::Length(22)])
             .split(chunks[1]);
 
-    render_messages(frame, body[0], active.lines.as_slice());
-    render_users(frame, body[1], &active.users, rooms.user_selected);
+    render_messages(frame, body[0], active.lines.as_slice(), &mut active.view);
+    render_users(frame, body[1], &active.users, user_selected);
 
     // Compose line or hint.
-    if rooms.composing {
+    if composing {
         let line = Line::from(vec![
             Span::styled("› ", accent_style()),
             Span::styled(active.input.clone(), primary_style()),
@@ -173,9 +176,10 @@ fn render_messages(
     frame: &mut Frame,
     area: Rect,
     lines: &[crate::models::RoomLine],
+    view: &mut LogView,
 ) {
-    // Wrap each message to the pane width, then auto-scroll: tail by rendered
-    // rows so the newest message is always fully visible.
+    // Wrap each message to the pane width, then show the rows the reader is
+    // at: the newest ones, unless they are holding a place in the history.
     let width = area.width as usize;
     let rendered: Vec<Line> = lines
         .iter()
@@ -198,8 +202,8 @@ fn render_messages(
             }
         })
         .collect();
-    let start = rendered.len().saturating_sub((area.height as usize).max(1));
-    frame.render_widget(Paragraph::new(rendered[start..].to_vec()), area);
+    let window = view.window(rendered.len(), usize::from(area.height));
+    frame.render_widget(Paragraph::new(rendered[window].to_vec()), area);
 }
 
 fn render_users(

soulseek-rs/src/ui/panes/searches_pane.rs

@@ -1,3 +1,4 @@
+use super::name_scroll::{column_width, end_offset, scroll_text};
 use crate::models::{SearchEntry, SearchStatus};
 use crate::ui::{
     HIGHLIGHT_SYMBOL, body_style, dimmed_style, header_style, pane_block,
@@ -5,16 +6,34 @@ use crate::ui::{
 };
 use ratatui::{
     Frame,
-    layout::Rect,
+    layout::{Constraint, Rect},
     widgets::{Cell, HighlightSpacing, Row, Table, TableState},
 };
 
+// The pane shares a row with two others, so the fixed columns are as
+// narrow as their widest word: the query gets the rest.
+const WIDTHS: [Constraint; 3] = [
+    Constraint::Length(6),
+    Constraint::Fill(1),
+    Constraint::Length(7),
+];
+
+/// Query is the second column.
+const QUERY_COLUMN: usize = 1;
+
+/// The offset that brings the end of a query into view.
+#[must_use]
+pub fn query_end_offset(query: &str, area: Rect) -> usize {
+    end_offset(query, area, &WIDTHS, QUERY_COLUMN)
+}
+
 pub fn render_searches_pane(
     frame: &mut Frame,
     area: Rect,
     searches: &[SearchEntry],
     table_state: &mut TableState,
     focused: bool,
+    query_offset: usize,
 ) {
     let header = Row::new(vec![
         Cell::from("Status").style(header_style()),
@@ -23,6 +42,7 @@ pub fn render_searches_pane(
     ])
     .height(1);
 
+    let query_width = column_width(area, &WIDTHS, QUERY_COLUMN);
     let rows: Vec<Row> = searches
         .iter()
         .map(|search| {
@@ -55,21 +75,18 @@ pub fn render_searches_pane(
 
             Row::new(vec![
                 status_cell,
-                Cell::from(search.query.clone()).style(body_style()),
+                Cell::from(scroll_text(
+                    &search.query,
+                    query_offset,
+                    query_width,
+                ))
+                .style(body_style()),
                 Cell::from(results_text).style(dimmed_style()),
             ])
         })
         .collect();
 
-    // The pane shares a row with two others, so the fixed columns are as
-    // narrow as their widest word: the query gets the rest.
-    let widths = [
-        ratatui::layout::Constraint::Length(6),
-        ratatui::layout::Constraint::Fill(1),
-        ratatui::layout::Constraint::Length(7),
-    ];
-
-    let table = Table::new(rows, widths)
+    let table = Table::new(rows, WIDTHS)
         .header(header)
         .row_highlight_style(row_highlight_style())
         .highlight_symbol(HIGHLIGHT_SYMBOL)