fix(tui): keep latest message visible in long chats

index 42b2d69..3126e50 100644 --- a/Cargo.toml +++ b/Cargo.toml @@ -30,7 +30,10 @@ tokio-util = { version = "0.7", features = ["compat"] } futures = "0.3" # TUI (interactive chat mode) -ratatui = "0.29" +# `unstable-rendered-line-info` exposes `Paragraph::line_count`, which we use to +# pin the message view to the bottom using the exact wrapped-row count (the same +# WordWrapper that rendering uses) rather than a hand-rolled estimate. +ratatui = { version = "0.29", features = ["unstable-rendered-line-info"] } crossterm = { version = "0.29", features = ["event-stream"] } # Utilities

index df35406..927212f 100644 --- a/src/chat.rs +++ b/src/chat.rs @@ -163,7 +163,6 @@ mod tui { messages: Vec<ChatMessage>, input: String, cursor: usize, - scroll_offset: u16, stream_rx: Option<mpsc::Receiver<StreamChunk>>, stream_buf: String, inference_rx: Option<mpsc::Receiver<InferenceUpdate>>, @@ -259,7 +258,6 @@ mod tui { messages: Vec::new(), input: String::new(), cursor: 0, - scroll_offset: 0, stream_rx: None, stream_buf: String::new(), inference_rx: None, @@ -433,57 +431,6 @@ mod tui { } self.model_picker_index = (self.model_picker_index + 1) % self.model_picker_items.len(); } - - /// rough line count for scroll math - fn total_message_lines(&self, width: u16) -> u16 { - if width == 0 { - return 0; - } - let w = width.saturating_sub(2) as usize; - let mut lines: u16 = 0; - for msg in &self.messages { - lines += wrapped_line_count(&msg.text, msg.role, w); - } - if !self.stream_buf.is_empty() { - lines += wrapped_line_count(&self.stream_buf, Role::Assistant, w); - } - if self.thinking || self.switching_model { - lines += 1; - } - lines - } - - fn auto_scroll(&mut self, visible_height: u16, width: u16) { - let total = self.total_message_lines(width); - if total > visible_height { - self.scroll_offset = total - visible_height; - } else { - self.scroll_offset = 0; - } - } - } - - fn wrapped_line_count(text: &str, role: Role, width: usize) -> u16 { - let prefix_len = match role { - Role::User => 6, // "you > " - Role::Assistant => 8, // "siGit > " - Role::System | Role::Banner => 0, - }; - let effective = if width > prefix_len { - width - prefix_len - } else { - 1 - }; - - let mut count: u16 = 0; - for line in text.split('\n') { - if line.is_empty() { - count += 1; - } else { - count += ((line.len() as f64) / (effective as f64)).ceil() as u16; - } - } - count.max(1) } // ── Model picker ───────────────────────────────────────────────────────── @@ -832,12 +779,10 @@ mod tui { frame.render_widget(Paragraph::new(line), area); } - fn render_messages(frame: &mut Frame, app: &mut App, area: ratatui::layout::Rect) { + fn render_messages(frame: &mut Frame, app: &App, area: ratatui::layout::Rect) { let inner_width = area.width.saturating_sub(2); let inner_height = area.height.saturating_sub(2); - app.auto_scroll(inner_height, area.width); - let block = Block::default() .borders(Borders::ALL) .border_style(Style::default().fg(Color::DarkGray)); @@ -914,19 +859,17 @@ mod tui { } } - let total_lines = lines.len() as u16; - let scroll = if total_lines > inner_height { - app.scroll_offset.min(total_lines - inner_height) - } else { - 0 - }; - - frame.render_widget( - Paragraph::new(lines) - .scroll((scroll, 0)) - .wrap(Wrap { trim: false }), - inner, - ); + // Always pin to the bottom so the latest message stays visible. There is + // no scrollback, so we just need the exact number of wrapped rows the + // paragraph occupies at this width — `line_count` runs the same + // WordWrapper as rendering, so it never diverges from what's drawn (an + // estimate would, e.g. by forgetting the `<think>` box lines, and scroll + // too little — the bug this fixes). + let paragraph = Paragraph::new(lines).wrap(Wrap { trim: false }); + let total_lines = paragraph.line_count(inner_width) as u16; + let scroll = total_lines.saturating_sub(inner_height); + + frame.render_widget(paragraph.scroll((scroll, 0)), inner); } fn render_chat_message(lines: &mut Vec<Line<'static>>, msg: &ChatMessage, _width: usize) { @@ -1192,7 +1135,6 @@ mod tui { SlashCommand::Clear => { let cleared = engine.clear_history().await; app.messages.clear(); - app.scroll_offset = 0; app.messages.push(ChatMessage::system(format!( "Cleared {cleared} turn(s). History is empty.", )));