diff options
Diffstat (limited to 'src/ui.rs')
| -rw-r--r-- | src/ui.rs | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/src/ui.rs b/src/ui.rs new file mode 100644 index 0000000..6726e47 --- /dev/null +++ b/src/ui.rs @@ -0,0 +1,195 @@ +use crate::app::App; +use color_eyre::Result; +use ratatui::{ + crossterm::event::{self, Event, KeyCode, KeyEventKind}, + layout::{Constraint, Layout, Position}, + style::{Color, Modifier, Style, Stylize}, + text::{Line, Span, Text}, + widgets::{Block, List, ListItem, Paragraph}, + DefaultTerminal, Frame, +}; + +pub struct Ui { + input: String, + input_mode: InputMode, + character_index: usize, + app: App, +} + +pub enum InputMode { + Normal, + Editing, +} + +impl Ui { + pub fn new(app: App) -> Self { + Self { + input: String::new(), + input_mode: InputMode::Normal, + character_index: 0, + app, + } + } + + fn move_cursor_left(&mut self) { + let cursor_moved_left = self.character_index.saturating_sub(1); + self.character_index = self.clamp_cursor(cursor_moved_left); + } + + fn move_cursor_right(&mut self) { + let cursor_moved_right = self.character_index.saturating_add(1); + self.character_index = self.clamp_cursor(cursor_moved_right); + } + + fn enter_char(&mut self, new_char: char) { + let index = self.byte_index(); + self.input.insert(index, new_char); + self.move_cursor_right(); + } + + fn byte_index(&self) -> usize { + self.input + .char_indices() + .map(|(i, _)| i) + .nth(self.character_index) + .unwrap_or(self.input.len()) + } + + fn delete_char(&mut self) { + let is_not_cursor_leftmost = self.character_index != 0; + if is_not_cursor_leftmost { + // Method "remove" is not used on the saved text for deleting the selected char. + // Reason: Using remove on String works on bytes instead of the chars. + // Using remove would require special care because of char boundaries. + + let current_index = self.character_index; + let from_left_to_current_index = current_index - 1; + + // Getting all characters before the selected character. + let before_char_to_delete = self.input.chars().take(from_left_to_current_index); + // Getting all characters after selected character. + let after_char_to_delete = self.input.chars().skip(current_index); + + // Put all characters together except the selected one. + // By leaving the selected one out, it is forgotten and therefore deleted. + self.input = before_char_to_delete.chain(after_char_to_delete).collect(); + self.move_cursor_left(); + } + } + + fn clamp_cursor(&self, new_cursor_pos: usize) -> usize { + new_cursor_pos.clamp(0, self.input.chars().count()) + } + + fn reset_cursor(&mut self) { + self.character_index = 0; + } + + // Send the message to the LLM API when "enter" pressed + fn submit_message(&mut self) { + self.input_mode = InputMode::Normal; + self.app.send_message(self.input.clone()); + self.input.clear(); + self.reset_cursor(); + + } + + pub fn run(mut self, mut terminal: DefaultTerminal) -> Result<()> { + loop { + terminal.draw(|frame| self.draw(frame))?; + + if let Event::Key(key) = event::read()? { + match self.input_mode { + InputMode::Normal => match key.code { + KeyCode::Char('e') => { + self.input_mode = InputMode::Editing; + } + KeyCode::Char('q') => { + return Ok(()) + } + _ => {} + }, + InputMode::Editing if key.kind == KeyEventKind::Press => match key.code { + KeyCode::Enter => self.submit_message(), + KeyCode::Char(to_insert) => self.enter_char(to_insert), + KeyCode::Backspace => self.delete_char(), + KeyCode::Left => self.move_cursor_left(), + KeyCode::Right => self.move_cursor_right(), + KeyCode::Esc => self.input_mode = InputMode::Normal, + _ => {} + }, + InputMode::Editing => {} + } + } + } + } + + fn draw(&self, frame: &mut Frame) { + let vertical = Layout::vertical([ + Constraint::Length(1), + Constraint::Min(1), + Constraint::Length(3), + ]); + let [help_area, messages_area, input_area] = vertical.areas(frame.area()); + + let (msg, style) = match self.input_mode { + InputMode::Normal => ( + vec![ + "Press ".into(), + "q".bold(), + " to exit, ".into(), + "e".bold(), + " to start editing.".bold(), + ], + Style::default(), + ), + InputMode::Editing => ( + vec![ + "Press ".into(), + "Esc".bold(), + " to stop editing, ".into(), + "Enter".bold(), + " to record the message".into(), + ], + Style::default(), + ), + }; + let text = Text::from(Line::from(msg)).patch_style(style); + let help_message = Paragraph::new(text); + frame.render_widget(help_message, help_area); + + let input = Paragraph::new(self.input.as_str()) + .style(match self.input_mode { + InputMode::Normal => Style::default(), + InputMode::Editing => Style::default().fg(Color::Yellow), + }) + .block(Block::bordered().title("Input")); + frame.render_widget(input, input_area); + match self.input_mode { + // Hide the cursor. `Frame` does this by default, so we don't need to do anything here + InputMode::Normal => {} + + // Make the cursor visible and ask ratatui to put it at the specified coordinates after + // rendering + #[allow(clippy::cast_possible_truncation)] + InputMode::Editing => frame.set_cursor_position(Position::new( + // Draw the cursor at the current position in the input field. + // This position is can be controlled via the left and right arrow key + input_area.x + self.character_index as u16 + 1, + // Move one line down, from the border to the input line + input_area.y + 1, + )), + } + + let messages: Vec<ListItem> = self.app.messages + .iter() + .enumerate() + .map(|(i, m)| { + let content = Line::from(Span::raw(format!("{i}: {m}"))); + ListItem::new(content) + }) + .collect(); + let messages = List::new(messages).block(Block::bordered().title("Messages")); + frame.render_widget(messages, messages_area); + } +} |