Files
keydr/src/ui/components/typing_area.rs

329 lines
11 KiB
Rust

use ratatui::buffer::Buffer;
use ratatui::layout::Rect;
use ratatui::style::{Modifier, Style};
use ratatui::text::{Line, Span};
use ratatui::widgets::{Block, Paragraph, Widget, Wrap};
use crate::session::drill::DrillState;
use crate::session::input::CharStatus;
use crate::ui::theme::Theme;
pub struct TypingArea<'a> {
drill: &'a DrillState,
theme: &'a Theme,
}
impl<'a> TypingArea<'a> {
pub fn new(drill: &'a DrillState, theme: &'a Theme) -> Self {
Self { drill, theme }
}
}
/// A render token maps a single target character to its display representation.
struct RenderToken {
target_idx: usize,
display: String,
is_line_break: bool,
}
fn color_to_rgb(color: ratatui::style::Color) -> (u8, u8, u8) {
use ratatui::style::Color;
match color {
Color::Reset => (0, 0, 0),
Color::Black => (0, 0, 0),
Color::Red => (205, 49, 49),
Color::Green => (13, 188, 121),
Color::Yellow => (229, 229, 16),
Color::Blue => (36, 114, 200),
Color::Magenta => (188, 63, 188),
Color::Cyan => (17, 168, 205),
Color::Gray => (229, 229, 229),
Color::DarkGray => (102, 102, 102),
Color::LightRed => (241, 76, 76),
Color::LightGreen => (35, 209, 139),
Color::LightYellow => (245, 245, 67),
Color::LightBlue => (59, 142, 234),
Color::LightMagenta => (214, 112, 214),
Color::LightCyan => (41, 184, 219),
Color::White => (255, 255, 255),
Color::Rgb(r, g, b) => (r, g, b),
Color::Indexed(i) => {
if i < 16 {
const ANSI16: [(u8, u8, u8); 16] = [
(0, 0, 0),
(128, 0, 0),
(0, 128, 0),
(128, 128, 0),
(0, 0, 128),
(128, 0, 128),
(0, 128, 128),
(192, 192, 192),
(128, 128, 128),
(255, 0, 0),
(0, 255, 0),
(255, 255, 0),
(0, 0, 255),
(255, 0, 255),
(0, 255, 255),
(255, 255, 255),
];
ANSI16[i as usize]
} else if i <= 231 {
let idx = i - 16;
let r = idx / 36;
let g = (idx % 36) / 6;
let b = idx % 6;
let cv = |n: u8| if n == 0 { 0 } else { 55 + n * 40 };
(cv(r), cv(g), cv(b))
} else {
let v = 8 + (i - 232) * 10;
(v, v, v)
}
}
}
}
fn relative_luminance(color: ratatui::style::Color) -> f64 {
let (r, g, b) = color_to_rgb(color);
let to_linear = |c: u8| {
let x = c as f64 / 255.0;
if x <= 0.03928 {
x / 12.92
} else {
((x + 0.055) / 1.055).powf(2.4)
}
};
0.2126 * to_linear(r) + 0.7152 * to_linear(g) + 0.0722 * to_linear(b)
}
fn contrast_ratio(a: ratatui::style::Color, b: ratatui::style::Color) -> f64 {
let la = relative_luminance(a);
let lb = relative_luminance(b);
let (hi, lo) = if la >= lb { (la, lb) } else { (lb, la) };
(hi + 0.05) / (lo + 0.05)
}
fn choose_cursor_colors(
colors: &crate::ui::theme::ThemeColors,
) -> (ratatui::style::Color, ratatui::style::Color) {
use ratatui::style::Color;
let base_bg = colors.bg();
let mut cursor_bg = colors.text_cursor_bg();
// Ensure cursor block stands out from the typing area's background.
if contrast_ratio(cursor_bg, base_bg) < 1.8 {
let mut best_bg = cursor_bg;
let mut best_ratio = contrast_ratio(cursor_bg, base_bg);
for candidate in [
colors.accent(),
colors.focused_key(),
colors.warning(),
Color::Black,
Color::White,
] {
let ratio = contrast_ratio(candidate, base_bg);
if ratio > best_ratio {
best_bg = candidate;
best_ratio = ratio;
}
}
cursor_bg = best_bg;
}
// Pick most readable fg on top of chosen cursor background.
let mut cursor_fg = colors.text_cursor_fg();
let mut best_ratio = contrast_ratio(cursor_fg, cursor_bg);
for candidate in [colors.fg(), colors.bg(), Color::Black, Color::White] {
let ratio = contrast_ratio(candidate, cursor_bg);
if ratio > best_ratio {
cursor_fg = candidate;
best_ratio = ratio;
}
}
(cursor_fg, cursor_bg)
}
/// Expand target chars into render tokens, handling whitespace display.
fn build_render_tokens(target: &[char]) -> Vec<RenderToken> {
let mut tokens = Vec::new();
let mut col = 0usize;
for (i, &ch) in target.iter().enumerate() {
match ch {
'\n' => {
tokens.push(RenderToken {
target_idx: i,
display: "\u{21b5}".to_string(), // ↵
is_line_break: true,
});
col = 0;
}
'\t' => {
let tab_width = 4 - (col % 4);
let mut display = String::new();
if tab_width > 1 {
for _ in 0..(tab_width - 1) {
display.push('\u{2500}'); // ─
}
}
display.push('\u{21E5}'); // ⇥
tokens.push(RenderToken {
target_idx: i,
display,
is_line_break: false,
});
col += tab_width;
}
_ => {
tokens.push(RenderToken {
target_idx: i,
display: ch.to_string(),
is_line_break: false,
});
col += 1;
}
}
}
tokens
}
impl Widget for TypingArea<'_> {
fn render(self, area: Rect, buf: &mut Buffer) {
let colors = &self.theme.colors;
let (cursor_fg, cursor_bg) = choose_cursor_colors(colors);
let tokens = build_render_tokens(&self.drill.target);
// Group tokens into lines, splitting on line_break tokens
let mut lines: Vec<Vec<Span>> = vec![Vec::new()];
for token in &tokens {
let idx = token.target_idx;
let target_ch = self.drill.target[idx];
let style = if idx < self.drill.cursor {
match &self.drill.input[idx] {
CharStatus::Correct => Style::default().fg(colors.text_correct()),
CharStatus::Incorrect(_) => Style::default()
.fg(colors.text_incorrect())
.bg(colors.text_incorrect_bg())
.add_modifier(Modifier::UNDERLINED),
}
} else if idx == self.drill.cursor {
Style::default()
.fg(cursor_fg)
.bg(cursor_bg)
.add_modifier(Modifier::BOLD)
} else {
Style::default().fg(colors.text_pending())
};
// For incorrect chars, show the actual typed char for regular chars,
// but always show the token display for whitespace markers
let display = if idx < self.drill.cursor {
if let CharStatus::Incorrect(actual) = &self.drill.input[idx] {
if target_ch == '\n' || target_ch == '\t' {
// Show the whitespace marker even when incorrect
token.display.clone()
} else {
actual.to_string()
}
} else {
token.display.clone()
}
} else if idx == self.drill.cursor && target_ch == ' ' {
// Keep an actual space at cursor position so soft-wrap break opportunities
// remain stable at word boundaries.
" ".to_string()
} else {
token.display.clone()
};
lines.last_mut().unwrap().push(Span::styled(display, style));
if token.is_line_break {
lines.push(Vec::new());
}
}
// Keep cursor visible at end-of-input as an insertion marker.
if self.drill.cursor >= self.drill.target.len() {
lines.last_mut().unwrap().push(Span::styled(
"\u{258f}",
Style::default()
.fg(colors.accent())
.add_modifier(Modifier::BOLD),
));
}
let ratatui_lines: Vec<Line> = lines.into_iter().map(Line::from).collect();
let block = Block::bordered()
.border_style(Style::default().fg(colors.border()))
.style(Style::default().bg(colors.bg()));
let paragraph = Paragraph::new(ratatui_lines)
.block(block)
.wrap(Wrap { trim: false });
paragraph.render(area, buf);
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_render_tokens_basic() {
let target: Vec<char> = "abc".chars().collect();
let tokens = build_render_tokens(&target);
assert_eq!(tokens.len(), 3);
assert_eq!(tokens[0].display, "a");
assert_eq!(tokens[1].display, "b");
assert_eq!(tokens[2].display, "c");
assert!(!tokens[0].is_line_break);
}
#[test]
fn test_render_tokens_newline() {
let target: Vec<char> = "a\nb".chars().collect();
let tokens = build_render_tokens(&target);
assert_eq!(tokens.len(), 3);
assert_eq!(tokens[1].display, "\u{21b5}"); // ↵
assert!(tokens[1].is_line_break);
assert_eq!(tokens[1].target_idx, 1);
}
#[test]
fn test_render_tokens_tab() {
let target: Vec<char> = "\tx".chars().collect();
let tokens = build_render_tokens(&target);
assert_eq!(tokens.len(), 2);
// Tab at col 0: width = 4 - (0 % 4) = 4 => "───⇥"
assert_eq!(tokens[0].display, "\u{2500}\u{2500}\u{2500}\u{21E5}");
assert!(!tokens[0].is_line_break);
assert_eq!(tokens[0].target_idx, 0);
}
#[test]
fn test_render_tokens_tab_alignment() {
// "ab\t" -> col 2, tab_width = 4 - (2 % 4) = 2 => "─⇥"
let target: Vec<char> = "ab\t".chars().collect();
let tokens = build_render_tokens(&target);
assert_eq!(tokens[2].display, "\u{2500}\u{21E5}");
}
#[test]
fn test_render_tokens_newline_resets_column() {
// "\n\tx" -> after newline, col resets to 0, tab_width = 4
let target: Vec<char> = "\n\tx".chars().collect();
let tokens = build_render_tokens(&target);
assert_eq!(tokens.len(), 3);
assert!(tokens[0].is_line_break);
assert_eq!(tokens[1].display, "\u{2500}\u{2500}\u{2500}\u{21E5}");
}
}