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helix-plus/helix-term/src/ui/prompt.rs

565 lines
18 KiB
Rust

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<usize>, Cow<'static, str>);
pub struct Prompt {
prompt: String,
pub line: String,
cursor: usize,
completion: Vec<Completion>,
selection: Option<usize>,
history_register: Option<char>,
history_pos: Option<usize>,
completion_fn: Box<dyn FnMut(&str) -> Vec<Completion>>,
callback_fn: Box<dyn FnMut(&mut Context, &str, PromptEvent)>,
pub doc_fn: Box<dyn Fn(&str) -> 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: String,
history_register: Option<char>,
mut completion_fn: impl FnMut(&str) -> Vec<Completion> + 'static,
callback_fn: impl FnMut(&mut Context, &str, PromptEvent) + 'static,
) -> Self {
Self {
prompt,
line: String::new(),
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 {
// char or shift char
KeyEvent {
code: KeyCode::Char(c),
modifiers: KeyModifiers::NONE,
}
| KeyEvent {
code: KeyCode::Char(c),
modifiers: KeyModifiers::SHIFT,
} => {
self.insert_char(c);
(self.callback_fn)(cx, &self.line, PromptEvent::Update);
}
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(),
_ => (),
};
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<Position>, 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,
)
}
}