add scroll and scroll bar indicator to members list

3 files changed, 44 insertions, 9 deletions

diff --git a/src/main.rs b/src/main.rs
index b87ee8d..b81eff8 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -105,6 +105,8 @@ async fn run(
                     (KeyModifiers::NONE | KeyModifiers::SHIFT, KeyCode::Char(c)) => {
                         app.input_insert(c);
                     }
+                    (KeyModifiers::SHIFT, KeyCode::Up) => app.members_scroll_up(),
+                    (KeyModifiers::SHIFT, KeyCode::Down) => app.members_scroll_down(),
                     (_, KeyCode::Backspace) => app.input_backspace(),
                     (_, KeyCode::Left) => app.cursor_left(),
                     (_, KeyCode::Right) => app.cursor_right(),
diff --git a/src/tui/app.rs b/src/tui/app.rs
index 879d762..52fc85a 100644
--- a/src/tui/app.rs
+++ b/src/tui/app.rs
@@ -1,3 +1,5 @@
+use ratatui::widgets::{ListState, ScrollbarState};
+
 /// A single chat message in the log
 #[derive(Clone)]
 pub struct ChatLine {
@@ -15,7 +17,9 @@ pub struct AppState {
     pub members: Vec<String>,
     pub input: String,
     pub cursor: usize,
-    pub scroll_offset: usize,
+    pub chat_scroll: usize,
+    pub members_scroll: ScrollbarState,
+    pub members_list_state: ListState,
     pub status: String,
     pub connected: bool,
 }
@@ -29,7 +33,9 @@ impl AppState {
             members: Vec::new(),
             input: String::new(),
             cursor: 0,
-            scroll_offset: 0,
+            chat_scroll: 0,
+            members_scroll: ScrollbarState::new(0),
+            members_list_state: ListState::default(),
             status: "Set nick with /nick to connect.".into(),
             connected: false,
         }
@@ -88,11 +94,24 @@ impl AppState {
     }
 
     pub fn scroll_up(&mut self) {
-        self.scroll_offset += 1;
+        self.chat_scroll = self.chat_scroll.saturating_add(1);
     }
 
     pub fn scroll_down(&mut self) {
-        self.scroll_offset = self.scroll_offset.saturating_sub(1);
+        self.chat_scroll = self.chat_scroll.saturating_sub(1);
+    }
+
+    pub fn members_scroll_up(&mut self) {
+        let pos = self.members_scroll.get_position().saturating_sub(5);
+        self.members_scroll = self.members_scroll.position(pos);
+        *self.members_list_state.offset_mut() = pos;
+    }
+
+    pub fn members_scroll_down(&mut self) {
+        let max = self.members.len().saturating_sub(1);
+        let pos = (self.members_scroll.get_position().saturating_add(5)).min(max);
+        self.members_scroll = self.members_scroll.position(pos);
+        *self.members_list_state.offset_mut() = pos;
     }
 
     pub fn take_input(&mut self) -> String {
diff --git a/src/tui/ui.rs b/src/tui/ui.rs
index b026c34..05b3c9f 100644
--- a/src/tui/ui.rs
+++ b/src/tui/ui.rs
@@ -4,7 +4,10 @@ use ratatui::{
     layout::{Constraint, Direction, Layout, Rect},
     style::{Color, Modifier, Style},
     text::{Line, Span, Text},
-    widgets::{Block, BorderType, Borders, List, ListItem, Paragraph, Wrap},
+    widgets::{
+        Block, BorderType, Borders, List, ListItem, Paragraph, Scrollbar, ScrollbarOrientation,
+        Wrap,
+    },
 };
 use unicode_width::UnicodeWidthStr;
 
@@ -113,8 +116,8 @@ fn draw_chat_log(f: &mut Frame, area: Rect, state: &mut AppState) {
     let max_offset = base_scroll as usize;
 
     // Clamp the offset and write it back so app.rs stays in sync
-    state.scroll_offset = state.scroll_offset.clamp(0, max_offset);
-    let final_scroll = (base_scroll as i32 - state.scroll_offset as i32) as u16;
+    state.chat_scroll = state.chat_scroll.clamp(0, max_offset);
+    let final_scroll = (base_scroll as i32 - state.chat_scroll as i32) as u16;
 
     f.render_widget(
         Paragraph::new(Text::from(padded_lines))
@@ -246,7 +249,7 @@ fn draw_input(f: &mut Frame, area: Rect, state: &AppState) {
     );
 }
 
-fn draw_members_panel(f: &mut Frame, area: Rect, state: &AppState) {
+fn draw_members_panel(f: &mut Frame, area: Rect, state: &mut AppState) {
     let items: Vec<ListItem> = state
         .members
         .iter()
@@ -281,7 +284,18 @@ fn draw_members_panel(f: &mut Frame, area: Rect, state: &AppState) {
     let title = format!(" users ({}) ", state.members.len());
     let block = panel_block(&title);
 
-    f.render_widget(List::new(items).block(block), area);
+    state.members_scroll = state.members_scroll.content_length(state.members.len());
+
+    f.render_stateful_widget(
+        List::new(items).block(block),
+        area,
+        &mut state.members_list_state,
+    );
+    f.render_stateful_widget(
+        Scrollbar::new(ScrollbarOrientation::VerticalRight),
+        area,
+        &mut state.members_scroll,
+    );
 }
 
 fn draw_statusbar(f: &mut Frame, area: Rect, state: &AppState) {