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use crate::compositor::{Component, Compositor, Context, EventResult};
use crossterm::event::{Event, KeyCode, KeyEvent, KeyModifiers};
use tui::buffer::Buffer as Surface;
use tui::{
layout::Rect,
style::{Color, Style},
widgets::{Block, Borders},
};
use std::borrow::Cow;
use helix_core::Position;
use helix_view::Editor;
pub struct Menu<T> {
options: Vec<T>,
cursor: Option<usize>,
format_fn: Box<dyn Fn(&T) -> Cow<str>>,
callback_fn: Box<dyn Fn(&mut Editor, Option<&T>, MenuEvent)>,
scroll: usize,
size: (u16, u16),
}
impl<T> Menu<T> {
// TODO: it's like a slimmed down picker, share code? (picker = menu + prompt with different
// rendering)
pub fn new(
options: Vec<T>,
format_fn: impl Fn(&T) -> Cow<str> + 'static,
callback_fn: impl Fn(&mut Editor, Option<&T>, MenuEvent) + 'static,
) -> Self {
Self {
options,
cursor: None,
format_fn: Box::new(format_fn),
callback_fn: Box::new(callback_fn),
scroll: 0,
size: (0, 0),
}
}
pub fn move_up(&mut self) {
// TODO: wrap around to end
let pos = self.cursor.map(|i| i.saturating_sub(1)).unwrap_or(0) % self.options.len();
self.cursor = Some(pos);
self.adjust_scroll();
}
pub fn move_down(&mut self) {
let pos = self.cursor.map(|i| i + 1).unwrap_or(0) % self.options.len();
self.cursor = Some(pos);
self.adjust_scroll();
}
fn adjust_scroll(&mut self) {
let win_height = self.size.1 as usize;
if let Some(cursor) = self.cursor {
let mut scroll = self.scroll;
if cursor > (win_height + scroll).saturating_sub(1) {
// scroll down
scroll += cursor - (win_height + scroll).saturating_sub(1)
} else if cursor < scroll {
// scroll up
scroll = cursor
}
self.scroll = scroll;
}
}
pub fn selection(&self) -> Option<&T> {
self.cursor.and_then(|cursor| self.options.get(cursor))
}
}
use super::PromptEvent as MenuEvent;
impl<T> Component for Menu<T> {
fn handle_event(&mut self, event: Event, cx: &mut Context) -> EventResult {
let event = match event {
Event::Key(event) => event,
_ => return EventResult::Ignored,
};
let close_fn = EventResult::Consumed(Some(Box::new(
|compositor: &mut Compositor, editor: &mut Editor| {
// remove the layer
compositor.pop();
},
)));
match event {
// esc or ctrl-c aborts the completion and closes the menu
KeyEvent {
code: KeyCode::Esc, ..
}
| KeyEvent {
code: KeyCode::Char('c'),
modifiers: KeyModifiers::CONTROL,
} => {
(self.callback_fn)(cx.editor, self.selection(), MenuEvent::Abort);
return close_fn;
}
// arrow up/ctrl-p/shift-tab prev completion choice (including updating the doc)
KeyEvent {
code: KeyCode::Tab,
modifiers: KeyModifiers::SHIFT,
}
| KeyEvent {
code: KeyCode::Up, ..
}
| KeyEvent {
code: KeyCode::Char('p'),
modifiers: KeyModifiers::CONTROL,
} => {
self.move_up();
(self.callback_fn)(cx.editor, self.selection(), MenuEvent::Update);
return EventResult::Consumed(None);
}
// arrow down/ctrl-n/tab advances completion choice (including updating the doc)
KeyEvent {
code: KeyCode::Tab,
modifiers: KeyModifiers::NONE,
}
| KeyEvent {
code: KeyCode::Down,
..
}
| KeyEvent {
code: KeyCode::Char('n'),
modifiers: KeyModifiers::CONTROL,
} => {
self.move_down();
(self.callback_fn)(cx.editor, self.selection(), MenuEvent::Update);
return EventResult::Consumed(None);
}
KeyEvent {
code: KeyCode::Enter,
..
} => {
(self.callback_fn)(cx.editor, self.selection(), MenuEvent::Validate);
return close_fn;
}
// KeyEvent {
// code: KeyCode::Char(c),
// modifiers: KeyModifiers::NONE,
// } => {
// self.insert_char(c);
// (self.callback_fn)(cx.editor, &self.line, MenuEvent::Update);
// }
// / -> edit_filter?
//
// enter confirms the match and closes the menu
// typing filters the menu
// if we run out of options the menu closes itself
_ => (),
}
// for some events, we want to process them but send ignore, specifically all input except
// tab/enter/ctrl-k or whatever will confirm the selection/ ctrl-n/ctrl-p for scroll.
// EventResult::Consumed(None)
EventResult::Ignored
}
fn required_size(&mut self, viewport: (u16, u16)) -> Option<(u16, u16)> {
let width = std::cmp::min(30, viewport.0);
const MAX: usize = 5;
let height = std::cmp::min(self.options.len(), MAX);
let height = std::cmp::min(height, viewport.1 as usize);
self.size = (width as u16, height as u16);
// adjust scroll offsets if size changed
self.adjust_scroll();
Some(self.size)
}
fn render(&self, area: Rect, surface: &mut Surface, cx: &mut Context) {
let style = Style::default().fg(Color::Rgb(164, 160, 232)); // lavender
let selected = Style::default().fg(Color::Rgb(255, 255, 255));
let scroll = self.scroll;
let len = self.options.len();
let win_height = area.height as usize;
fn div_ceil(a: usize, b: usize) -> usize {
(a + b - 1) / a
}
let scroll_height = std::cmp::min(div_ceil(win_height.pow(2), len), win_height as usize);
let scroll_line = (win_height - scroll_height) * scroll
/ std::cmp::max(1, len.saturating_sub(win_height));
for (i, option) in self.options[scroll..(scroll + win_height).min(len)]
.iter()
.enumerate()
{
let line = Some(i + scroll);
// TODO: set bg for the whole row if selected
surface.set_stringn(
area.x,
area.y + i as u16,
(self.format_fn)(option),
area.width as usize - 1,
if line == self.cursor { selected } else { style },
);
let is_marked = i >= scroll_line && i < scroll_line + scroll_height;
if is_marked {
let cell = surface.get_mut(area.x + area.width - 2, area.y + i as u16);
cell.set_symbol("▐ ");
cell.set_style(selected);
// cell.set_style(if is_marked { selected } else { style });
}
}
}
}
|
