use crate::compositor::{Component, Compositor, Context, EventResult}; use crate::ui; use crossterm::event::{Event, KeyCode, KeyEvent, KeyModifiers}; use std::{borrow::Cow, ops::RangeFrom}; use tui::buffer::Buffer as Surface; use helix_core::{ unicode::segmentation::GraphemeCursor, unicode::width::UnicodeWidthStr, Position, }; use helix_view::{ graphics::{CursorKind, Margin, Rect}, Editor, }; pub type Completion = (RangeFrom, Cow<'static, str>); pub struct Prompt { prompt: Cow<'static, str>, pub line: String, cursor: usize, completion: Vec, selection: Option, history_register: Option, history_pos: Option, completion_fn: Box Vec>, callback_fn: Box, pub doc_fn: Box Option<&'static str>>, } #[derive(Clone, Copy, PartialEq)] pub enum PromptEvent { /// The prompt input has been updated. Update, /// Validate and finalize the change. Validate, /// Abort the change, reverting to the initial state. Abort, } pub enum CompletionDirection { Forward, Backward, } #[derive(Debug, Clone, Copy)] pub enum Movement { BackwardChar(usize), BackwardWord(usize), ForwardChar(usize), ForwardWord(usize), StartOfLine, EndOfLine, None, } impl Prompt { pub fn new( prompt: Cow<'static, str>, history_register: Option, mut completion_fn: impl FnMut(&str) -> Vec + 'static, callback_fn: impl FnMut(&mut Context, &str, PromptEvent) + 'static, line: Option, ) -> Self { Self { prompt, line: line.unwrap_or_default(), cursor: 0, completion: completion_fn(""), selection: None, history_register, history_pos: None, completion_fn: Box::new(completion_fn), callback_fn: Box::new(callback_fn), doc_fn: Box::new(|_| None), } } /// Compute the cursor position after applying movement /// Taken from: https://github.com/wez/wezterm/blob/e0b62d07ca9bf8ce69a61e30a3c20e7abc48ce7e/termwiz/src/lineedit/mod.rs#L516-L611 fn eval_movement(&self, movement: Movement) -> usize { match movement { Movement::BackwardChar(rep) => { let mut position = self.cursor; for _ in 0..rep { let mut cursor = GraphemeCursor::new(position, self.line.len(), false); if let Ok(Some(pos)) = cursor.prev_boundary(&self.line, 0) { position = pos; } else { break; } } position } Movement::BackwardWord(rep) => { let char_indices: Vec<(usize, char)> = self.line.char_indices().collect(); if char_indices.is_empty() { return self.cursor; } let mut char_position = char_indices .iter() .position(|(idx, _)| *idx == self.cursor) .unwrap_or(char_indices.len() - 1); for _ in 0..rep { if char_position == 0 { break; } let mut found = None; for prev in (0..char_position - 1).rev() { if char_indices[prev].1.is_whitespace() { found = Some(prev + 1); break; } } char_position = found.unwrap_or(0); } char_indices[char_position].0 } Movement::ForwardWord(rep) => { let char_indices: Vec<(usize, char)> = self.line.char_indices().collect(); if char_indices.is_empty() { return self.cursor; } let mut char_position = char_indices .iter() .position(|(idx, _)| *idx == self.cursor) .unwrap_or_else(|| char_indices.len()); for _ in 0..rep { // Skip any non-whitespace characters while char_position < char_indices.len() && !char_indices[char_position].1.is_whitespace() { char_position += 1; } // Skip any whitespace characters while char_position < char_indices.len() && char_indices[char_position].1.is_whitespace() { char_position += 1; } // We are now on the start of the next word } char_indices .get(char_position) .map(|(i, _)| *i) .unwrap_or_else(|| self.line.len()) } Movement::ForwardChar(rep) => { let mut position = self.cursor; for _ in 0..rep { let mut cursor = GraphemeCursor::new(position, self.line.len(), false); if let Ok(Some(pos)) = cursor.next_boundary(&self.line, 0) { position = pos; } else { break; } } position } Movement::StartOfLine => 0, Movement::EndOfLine => { let mut cursor = GraphemeCursor::new(self.line.len().saturating_sub(1), self.line.len(), false); if let Ok(Some(pos)) = cursor.next_boundary(&self.line, 0) { pos } else { self.cursor } } Movement::None => self.cursor, } } pub fn insert_char(&mut self, c: char) { self.line.insert(self.cursor, c); let mut cursor = GraphemeCursor::new(self.cursor, self.line.len(), false); if let Ok(Some(pos)) = cursor.next_boundary(&self.line, 0) { self.cursor = pos; } self.completion = (self.completion_fn)(&self.line); self.exit_selection(); } pub fn move_cursor(&mut self, movement: Movement) { let pos = self.eval_movement(movement); self.cursor = pos } pub fn move_start(&mut self) { self.cursor = 0; } pub fn move_end(&mut self) { self.cursor = self.line.len(); } pub fn delete_char_backwards(&mut self) { let pos = self.eval_movement(Movement::BackwardChar(1)); self.line.replace_range(pos..self.cursor, ""); self.cursor = pos; self.exit_selection(); self.completion = (self.completion_fn)(&self.line); } pub fn delete_word_backwards(&mut self) { let pos = self.eval_movement(Movement::BackwardWord(1)); self.line.replace_range(pos..self.cursor, ""); self.cursor = pos; self.exit_selection(); self.completion = (self.completion_fn)(&self.line); } pub fn kill_to_end_of_line(&mut self) { let pos = self.eval_movement(Movement::EndOfLine); self.line.replace_range(self.cursor..pos, ""); self.exit_selection(); self.completion = (self.completion_fn)(&self.line); } pub fn clear(&mut self) { self.line.clear(); self.cursor = 0; self.completion = (self.completion_fn)(&self.line); self.exit_selection(); } pub fn change_history(&mut self, register: &[String], direction: CompletionDirection) { if register.is_empty() { return; } let end = register.len().saturating_sub(1); let index = match direction { CompletionDirection::Forward => self.history_pos.map_or(0, |i| i + 1), CompletionDirection::Backward => { self.history_pos.unwrap_or(register.len()).saturating_sub(1) } } .min(end); self.line = register[index].clone(); self.history_pos = Some(index); self.move_end(); } pub fn change_completion_selection(&mut self, direction: CompletionDirection) { if self.completion.is_empty() { return; } let index = match direction { CompletionDirection::Forward => self.selection.map_or(0, |i| i + 1), CompletionDirection::Backward => { self.selection.unwrap_or(0) + self.completion.len() - 1 } } % self.completion.len(); self.selection = Some(index); let (range, item) = &self.completion[index]; self.line.replace_range(range.clone(), item); self.move_end(); } pub fn exit_selection(&mut self) { self.selection = None; } } const BASE_WIDTH: u16 = 30; impl Prompt { pub fn render_prompt(&self, area: Rect, surface: &mut Surface, cx: &mut Context) { let theme = &cx.editor.theme; let prompt_color = theme.get("ui.text"); let completion_color = theme.get("ui.statusline"); let selected_color = theme.get("ui.menu.selected"); // completion let max_len = self .completion .iter() .map(|(_, completion)| completion.len() as u16) .max() .unwrap_or(BASE_WIDTH) .max(BASE_WIDTH); let cols = std::cmp::max(1, area.width / max_len); let col_width = (area.width - (cols)) / cols; let height = ((self.completion.len() as u16 + cols - 1) / cols) .min(10) // at most 10 rows (or less) .min(area.height.saturating_sub(1)); let completion_area = Rect::new( area.x, (area.height - height).saturating_sub(1), area.width, height, ); if !self.completion.is_empty() { let area = completion_area; let background = theme.get("ui.statusline"); let items = height as usize * cols as usize; let offset = self .selection .map(|selection| selection / items * items) .unwrap_or_default(); surface.clear_with(area, background); let mut row = 0; let mut col = 0; for (i, (_range, completion)) in self.completion.iter().enumerate().skip(offset).take(items) { let color = if Some(i) == self.selection { selected_color // TODO: just invert bg } else { completion_color }; surface.set_stringn( area.x + col * (1 + col_width), area.y + row, &completion, col_width.saturating_sub(1) as usize, color, ); row += 1; if row > area.height - 1 { row = 0; col += 1; } } } if let Some(doc) = (self.doc_fn)(&self.line) { let mut text = ui::Text::new(doc.to_string()); let viewport = area; let area = viewport.intersection(Rect::new( completion_area.x, completion_area.y.saturating_sub(3), BASE_WIDTH * 3, 3, )); let background = theme.get("ui.help"); surface.clear_with(area, background); text.render( area.inner(&Margin { vertical: 1, horizontal: 1, }), surface, cx, ); } let line = area.height - 1; // render buffer text surface.set_string(area.x, area.y + line, &self.prompt, prompt_color); surface.set_string( area.x + self.prompt.len() as u16, area.y + line, &self.line, prompt_color, ); } } impl Component for Prompt { fn handle_event(&mut self, event: Event, cx: &mut Context) -> EventResult { let event = match event { Event::Key(event) => event, Event::Resize(..) => return EventResult::Consumed(None), _ => return EventResult::Ignored, }; let close_fn = EventResult::Consumed(Some(Box::new(|compositor: &mut Compositor| { // remove the layer compositor.pop(); }))); match event { KeyEvent { code: KeyCode::Char('c'), modifiers: KeyModifiers::CONTROL, } | KeyEvent { code: KeyCode::Esc, .. } => { (self.callback_fn)(cx, &self.line, PromptEvent::Abort); return close_fn; } KeyEvent { code: KeyCode::Left, modifiers: KeyModifiers::ALT, } | KeyEvent { code: KeyCode::Char('b'), modifiers: KeyModifiers::ALT, } => self.move_cursor(Movement::BackwardWord(1)), KeyEvent { code: KeyCode::Right, modifiers: KeyModifiers::ALT, } | KeyEvent { code: KeyCode::Char('f'), modifiers: KeyModifiers::ALT, } => self.move_cursor(Movement::ForwardWord(1)), KeyEvent { code: KeyCode::Char('f'), modifiers: KeyModifiers::CONTROL, } | KeyEvent { code: KeyCode::Right, .. } => self.move_cursor(Movement::ForwardChar(1)), KeyEvent { code: KeyCode::Char('b'), modifiers: KeyModifiers::CONTROL, } | KeyEvent { code: KeyCode::Left, .. } => self.move_cursor(Movement::BackwardChar(1)), KeyEvent { code: KeyCode::End, modifiers: KeyModifiers::NONE, } | KeyEvent { code: KeyCode::Char('e'), modifiers: KeyModifiers::CONTROL, } => self.move_end(), KeyEvent { code: KeyCode::Home, modifiers: KeyModifiers::NONE, } | KeyEvent { code: KeyCode::Char('a'), modifiers: KeyModifiers::CONTROL, } => self.move_start(), KeyEvent { code: KeyCode::Char('w'), modifiers: KeyModifiers::CONTROL, } => self.delete_word_backwards(), KeyEvent { code: KeyCode::Char('k'), modifiers: KeyModifiers::CONTROL, } => self.kill_to_end_of_line(), KeyEvent { code: KeyCode::Backspace, modifiers: KeyModifiers::NONE, } => { self.delete_char_backwards(); (self.callback_fn)(cx, &self.line, PromptEvent::Update); } KeyEvent { code: KeyCode::Enter, .. } => { if self.selection.is_some() && self.line.ends_with('/') { self.completion = (self.completion_fn)(&self.line); self.exit_selection(); } else { (self.callback_fn)(cx, &self.line, PromptEvent::Validate); if let Some(register) = self.history_register { // store in history let register = cx.editor.registers.get_mut(register); register.push(self.line.clone()); } return close_fn; } } KeyEvent { code: KeyCode::Char('p'), modifiers: KeyModifiers::CONTROL, } | KeyEvent { code: KeyCode::Up, .. } => { if let Some(register) = self.history_register { let register = cx.editor.registers.get_mut(register); self.change_history(register.read(), CompletionDirection::Backward); } } KeyEvent { code: KeyCode::Char('n'), modifiers: KeyModifiers::CONTROL, } | KeyEvent { code: KeyCode::Down, .. } => { if let Some(register) = self.history_register { let register = cx.editor.registers.get_mut(register); self.change_history(register.read(), CompletionDirection::Forward); } } KeyEvent { code: KeyCode::Tab, .. } => self.change_completion_selection(CompletionDirection::Forward), KeyEvent { code: KeyCode::BackTab, .. } => self.change_completion_selection(CompletionDirection::Backward), KeyEvent { code: KeyCode::Char('q'), modifiers: KeyModifiers::CONTROL, } => self.exit_selection(), // any char event that's not combined with control or mapped to any other combo KeyEvent { code: KeyCode::Char(c), modifiers, } if !modifiers.contains(KeyModifiers::CONTROL) => { self.insert_char(c); (self.callback_fn)(cx, &self.line, PromptEvent::Update); } _ => (), }; EventResult::Consumed(None) } fn render(&mut self, area: Rect, surface: &mut Surface, cx: &mut Context) { self.render_prompt(area, surface, cx) } fn cursor(&self, area: Rect, _editor: &Editor) -> (Option, CursorKind) { let line = area.height as usize - 1; ( Some(Position::new( area.y as usize + line, area.x as usize + self.prompt.len() + UnicodeWidthStr::width(&self.line[..self.cursor]), )), CursorKind::Block, ) } }