Revert branch state to 354801f (without history rewrite)

codex-rs/tui/src/insert_history.rs

@@ -1,6 +1,107 @@
 use std::fmt;
+use std::io;
+use std::io::Write;
 
+use crate::tui;
 use crossterm::Command;
+use crossterm::cursor::MoveTo;
+use crossterm::queue;
+use crossterm::style::Color as CColor;
+use crossterm::style::Colors;
+use crossterm::style::Print;
+use crossterm::style::SetAttribute;
+use crossterm::style::SetBackgroundColor;
+use crossterm::style::SetColors;
+use crossterm::style::SetForegroundColor;
+use ratatui::layout::Size;
+use ratatui::prelude::Backend;
+use ratatui::style::Color;
+use ratatui::style::Modifier;
+use ratatui::text::Line;
+use ratatui::text::Span;
+
+/// Insert `lines` above the viewport.
+pub(crate) fn insert_history_lines(terminal: &mut tui::Tui, lines: Vec<Line>) {
+    let screen_size = terminal.backend().size().unwrap_or(Size::new(0, 0));
+    let cursor_pos = terminal.get_cursor_position().ok();
+
+    let mut area = terminal.get_frame().area();
+
+    let wrapped_lines = wrapped_line_count(&lines, area.width);
+    let cursor_top = if area.bottom() < screen_size.height {
+        // If the viewport is not at the bottom of the screen, scroll it down to make room.
+        // Don't scroll it past the bottom of the screen.
+        let scroll_amount = wrapped_lines.min(screen_size.height - area.bottom());
+        terminal
+            .backend_mut()
+            .scroll_region_down(area.top()..screen_size.height, scroll_amount)
+            .ok();
+        let cursor_top = area.top().saturating_sub(1);
+        area.y += scroll_amount;
+        terminal.set_viewport_area(area);
+        cursor_top
+    } else {
+        area.top().saturating_sub(1)
+    };
+
+    // Limit the scroll region to the lines from the top of the screen to the
+    // top of the viewport. With this in place, when we add lines inside this
+    // area, only the lines in this area will be scrolled. We place the cursor
+    // at the end of the scroll region, and add lines starting there.
+    //
+    // ┌─Screen───────────────────────┐
+    // │┌╌Scroll region╌╌╌╌╌╌╌╌╌╌╌╌╌╌┐│
+    // │┆                            ┆│
+    // │┆                            ┆│
+    // │┆                            ┆│
+    // │█╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┘│
+    // │╭─Viewport───────────────────╮│
+    // ││                            ││
+    // │╰────────────────────────────╯│
+    // └──────────────────────────────┘
+    queue!(std::io::stdout(), SetScrollRegion(1..area.top())).ok();
+
+    // NB: we are using MoveTo instead of set_cursor_position here to avoid messing with the
+    // terminal's last_known_cursor_position, which hopefully will still be accurate after we
+    // fetch/restore the cursor position. insert_history_lines should be cursor-position-neutral :)
+    queue!(std::io::stdout(), MoveTo(0, cursor_top)).ok();
+
+    for line in lines {
+        queue!(std::io::stdout(), Print("\r\n")).ok();
+        write_spans(&mut std::io::stdout(), line.iter()).ok();
+    }
+
+    queue!(std::io::stdout(), ResetScrollRegion).ok();
+
+    // Restore the cursor position to where it was before we started.
+    if let Some(cursor_pos) = cursor_pos {
+        queue!(std::io::stdout(), MoveTo(cursor_pos.x, cursor_pos.y)).ok();
+    }
+}
+
+fn wrapped_line_count(lines: &[Line], width: u16) -> u16 {
+    let mut count = 0;
+    for line in lines {
+        count += line_height(line, width);
+    }
+    count
+}
+
+fn line_height(line: &Line, width: u16) -> u16 {
+    use unicode_width::UnicodeWidthStr;
+    // get the total display width of the line, accounting for double-width chars
+    let total_width = line
+        .spans
+        .iter()
+        .map(|span| span.content.width())
+        .sum::<usize>();
+    // divide by width to get the number of lines, rounding up
+    if width == 0 {
+        1
+    } else {
+        (total_width as u16).div_ceil(width).max(1)
+    }
+}
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct SetScrollRegion(pub std::ops::Range<u16>);