Merge pull request #7 from helix-editor/interactive-split-select

File picker/interactive split prompt

1 files changed, 258 insertions, 0 deletions

diff --git a/helix-term/src/ui/picker.rs b/helix-term/src/ui/picker.rs
new file mode 100644
index 00000000..0a12cff9
--- /dev/null
+++ b/helix-term/src/ui/picker.rs
@@ -0,0 +1,258 @@
+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 fuzzy_matcher::skim::SkimMatcherV2 as Matcher;
+use fuzzy_matcher::FuzzyMatcher;
+
+use crate::ui::{Prompt, PromptEvent};
+use helix_core::Position;
+use helix_view::Editor;
+
+pub struct Picker<T> {
+    options: Vec<T>,
+    // filter: String,
+    matcher: Box<Matcher>,
+    /// (index, score)
+    matches: Vec<(usize, i64)>,
+
+    cursor: usize,
+    // pattern: String,
+    prompt: Prompt,
+
+    format_fn: Box<dyn Fn(&T) -> &str>,
+    callback_fn: Box<dyn Fn(&mut Editor, &T)>,
+}
+
+impl<T> Picker<T> {
+    pub fn new(
+        options: Vec<T>,
+        format_fn: impl Fn(&T) -> &str + 'static,
+        callback_fn: impl Fn(&mut Editor, &T) + 'static,
+    ) -> Self {
+        let prompt = Prompt::new(
+            "".to_string(),
+            |pattern: &str| Vec::new(),
+            |editor: &mut Editor, pattern: &str, event: PromptEvent| {
+                //
+            },
+        );
+
+        let mut picker = Self {
+            options,
+            matcher: Box::new(Matcher::default()),
+            matches: Vec::new(),
+            cursor: 0,
+            prompt,
+            format_fn: Box::new(format_fn),
+            callback_fn: Box::new(callback_fn),
+        };
+
+        // TODO: scoring on empty input should just use a fastpath
+        picker.score();
+
+        picker
+    }
+
+    pub fn score(&mut self) {
+        // need to borrow via pattern match otherwise it complains about simultaneous borrow
+        let Self {
+            ref mut options,
+            ref mut matcher,
+            ref mut matches,
+            ref format_fn,
+            ..
+        } = *self;
+
+        let pattern = &self.prompt.line;
+
+        // reuse the matches allocation
+        matches.clear();
+        matches.extend(
+            self.options
+                .iter()
+                .enumerate()
+                .filter_map(|(index, option)| {
+                    // TODO: maybe using format_fn isn't the best idea here
+                    let text = (format_fn)(option);
+                    // TODO: using fuzzy_indices could give us the char idx for match highlighting
+                    matcher
+                        .fuzzy_match(text, pattern)
+                        .map(|score| (index, score))
+                }),
+        );
+        matches.sort_unstable_by_key(|(_, score)| -score);
+
+        // reset cursor position
+        self.cursor = 0;
+    }
+
+    pub fn move_up(&mut self) {
+        self.cursor = self.cursor.saturating_sub(1);
+    }
+
+    pub fn move_down(&mut self) {
+        // TODO: len - 1
+        if self.cursor < self.options.len() {
+            self.cursor += 1;
+        }
+    }
+
+    pub fn selection(&self) -> Option<&T> {
+        self.matches
+            .get(self.cursor)
+            .map(|(index, _score)| &self.options[*index])
+    }
+}
+
+// process:
+// - read all the files into a list, maxed out at a large value
+// - on input change:
+//  - score all the names in relation to input
+
+impl<T> Component for Picker<T> {
+    fn handle_event(&mut self, event: Event, cx: &mut Context) -> EventResult {
+        let key_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 key_event {
+            // KeyEvent {
+            //     code: KeyCode::Char(c),
+            //     modifiers: KeyModifiers::NONE,
+            // } => {
+            //     self.insert_char(c);
+            //     (self.callback_fn)(cx.editor, &self.line, PromptEvent::Update);
+            // }
+            KeyEvent {
+                code: KeyCode::Up, ..
+            }
+            | KeyEvent {
+                code: KeyCode::Char('k'),
+                modifiers: KeyModifiers::CONTROL,
+            } => self.move_up(),
+            KeyEvent {
+                code: KeyCode::Down,
+                ..
+            }
+            | KeyEvent {
+                code: KeyCode::Char('j'),
+                modifiers: KeyModifiers::CONTROL,
+            } => self.move_down(),
+            KeyEvent {
+                code: KeyCode::Esc, ..
+            } => {
+                return close_fn;
+            }
+            KeyEvent {
+                code: KeyCode::Enter,
+                ..
+            } => {
+                if let Some(option) = self.selection() {
+                    (self.callback_fn)(&mut cx.editor, option);
+                }
+                return close_fn;
+            }
+            _ => {
+                match self.prompt.handle_event(event, cx) {
+                    EventResult::Consumed(_) => {
+                        // TODO: recalculate only if pattern changed
+                        self.score();
+                    }
+                    _ => (),
+                }
+            }
+        }
+
+        EventResult::Consumed(None)
+    }
+
+    fn render(&self, area: Rect, surface: &mut Surface, cx: &mut Context) {
+        let padding_vertical = area.height * 20 / 100;
+        let padding_horizontal = area.width * 20 / 100;
+
+        let area = Rect::new(
+            area.x + padding_horizontal,
+            area.y + padding_vertical,
+            area.width - padding_horizontal * 2,
+            area.height - padding_vertical * 2,
+        );
+
+        // -- Render the frame:
+
+        // clear  area
+        for y in area.top()..area.bottom() {
+            for x in area.left()..area.right() {
+                surface.get_mut(x, y).reset()
+            }
+        }
+
+        use tui::widgets::Widget;
+        // don't like this but the lifetime sucks
+        let block = Block::default().borders(Borders::ALL);
+
+        // calculate the inner area inside the box
+        let inner = block.inner(area);
+
+        block.render(area, surface);
+        // TODO: abstract into a clear(area) fn
+        // surface.set_style(inner, Style::default().bg(Color::Rgb(150, 50, 0)));
+
+        // -- Render the input bar:
+
+        let area = Rect::new(inner.x + 1, inner.y, inner.width - 1, 1);
+        self.prompt.render(area, surface, cx);
+
+        // -- Separator
+        use tui::widgets::BorderType;
+        let style = Style::default().fg(Color::Rgb(90, 89, 119));
+        let symbols = BorderType::line_symbols(BorderType::Plain);
+        for x in inner.left()..inner.right() {
+            surface
+                .get_mut(x, inner.y + 1)
+                .set_symbol(symbols.horizontal)
+                .set_style(style);
+        }
+
+        // -- Render the contents:
+
+        let style = Style::default().fg(Color::Rgb(164, 160, 232)); // lavender
+        let selected = Style::default().fg(Color::Rgb(255, 255, 255));
+
+        let rows = inner.height - 2; // -1 for search bar
+
+        let files = self.matches.iter().map(|(index, _score)| {
+            (index, self.options.get(*index).unwrap()) // get_unchecked
+        });
+
+        for (i, (_index, option)) in files.take(rows as usize).enumerate() {
+            if i == self.cursor {
+                surface.set_string(inner.x + 1, inner.y + 2 + i as u16, ">", selected);
+            }
+
+            surface.set_stringn(
+                inner.x + 3,
+                inner.y + 2 + i as u16,
+                (self.format_fn)(option),
+                inner.width as usize - 1,
+                if i == self.cursor { selected } else { style },
+            );
+        }
+    }
+
+    fn cursor_position(&self, area: Rect, ctx: &mut Context) -> Option<Position> {
+        self.prompt.cursor_position(area, ctx)
+    }
+}