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

File picker/interactive split prompt

9 files changed, 422 insertions, 25 deletions

diff --git a/helix-term/Cargo.toml b/helix-term/Cargo.toml
index b8eea7c2..645ed155 100644
--- a/helix-term/Cargo.toml
+++ b/helix-term/Cargo.toml
@@ -32,3 +32,7 @@ futures-util = "0.3"
 fern = "0.6"
 chrono = "0.4"
 log = "0.4"
+
+# File picker
+fuzzy-matcher = "0.3"
+ignore = "0.4"
diff --git a/helix-term/src/commands.rs b/helix-term/src/commands.rs
index b345d2e8..5f8f63f1 100644
--- a/helix-term/src/commands.rs
+++ b/helix-term/src/commands.rs
@@ -10,7 +10,7 @@ use helix_core::{
 use once_cell::sync::Lazy;
 
 use crate::compositor::Compositor;
-use crate::ui::Prompt;
+use crate::ui::{self, Prompt, PromptEvent};
 
 use helix_view::{
     document::Mode,
@@ -248,6 +248,60 @@ pub fn extend_line_down(cx: &mut Context) {
     cx.view.doc.set_selection(selection);
 }
 
+pub fn split_selection(cx: &mut Context) {
+    // TODO: this needs to store initial selection state, revert on esc, confirm on enter
+    // needs to also call the callback function per input change, not just final time.
+    // could cheat and put it into completion_fn
+    //
+    // kakoune does it like this:
+    // # save state to register
+    // {
+    //  # restore state from register
+    //  # if event == abort, return early
+    //  # add to history if enabled
+    //  # update state
+    // }
+
+    let snapshot = cx.view.doc.state.clone();
+
+    let prompt = Prompt::new(
+        "split:".to_string(),
+        |input: &str| Vec::new(), // this is fine because Vec::new() doesn't allocate
+        move |editor: &mut Editor, input: &str, event: PromptEvent| {
+            match event {
+                PromptEvent::Abort => {
+                    // revert state
+                    let view = editor.view_mut().unwrap();
+                    view.doc.state = snapshot.clone();
+                }
+                PromptEvent::Validate => {
+                    //
+                }
+                PromptEvent::Update => {
+                    match Regex::new(input) {
+                        Ok(regex) => {
+                            let view = editor.view_mut().unwrap();
+
+                            // revert state to what it was before the last update
+                            view.doc.state = snapshot.clone();
+
+                            let text = &view.doc.text().slice(..);
+                            let selection =
+                                selection::split_on_matches(text, view.doc.selection(), &regex);
+                            view.doc.set_selection(selection);
+                        }
+                        Err(_) => (), // TODO: mark command line as error
+                    }
+                }
+            }
+        },
+    );
+
+    cx.callback = Some(Box::new(move |compositor: &mut Compositor| {
+        compositor.push(Box::new(prompt));
+    }));
+}
+
 pub fn split_selection_on_newline(cx: &mut Context) {
     let text = &cx.view.doc.text().slice(..);
     // only compile the regex once
@@ -381,14 +435,33 @@ pub fn command_mode(cx: &mut Context) {
                     .filter(|command| command.contains(_input))
                     .collect()
             }, // completion
-            |editor: &mut Editor, input: &str| match input {
-                "q" => editor.should_close = true,
-                _ => (),
+            |editor: &mut Editor, input: &str, event: PromptEvent| {
+                if event != PromptEvent::Validate {
+                    return;
+                }
+
+                let parts = input.split_ascii_whitespace().collect::<Vec<&str>>();
+
+                match parts.as_slice() {
+                    &["q"] => editor.should_close = true,
+                    &["o", path] => {
+                        // TODO: make view()/view_mut() always contain a view.
+                        let size = editor.view().unwrap().size;
+                        editor.open(path.into(), size);
+                    }
+                    _ => (),
+                }
             },
         );
         compositor.push(Box::new(prompt));
     }));
 }
+pub fn file_picker(cx: &mut Context) {
+    cx.callback = Some(Box::new(|compositor: &mut Compositor| {
+        let picker = ui::file_picker("./");
+        compositor.push(Box::new(picker));
+    }));
+}
 
 // calculate line numbers for each selection range
 fn selection_lines(state: &State) -> Vec<usize> {
diff --git a/helix-term/src/compositor.rs b/helix-term/src/compositor.rs
index 2e65f02a..f0d94dbc 100644
--- a/helix-term/src/compositor.rs
+++ b/helix-term/src/compositor.rs
@@ -19,7 +19,7 @@ use smol::Executor;
 use tui::buffer::Buffer as Surface;
 use tui::layout::Rect;
 
-pub type Callback = Box<dyn Fn(&mut Compositor)>;
+pub type Callback = Box<dyn FnOnce(&mut Compositor)>;
 
 // --> EventResult should have a callback that takes a context with methods like .popup(),
 // .prompt() etc. That way we can abstract it from the renderer.
diff --git a/helix-term/src/keymap.rs b/helix-term/src/keymap.rs
index af46f7a4..a31676e4 100644
--- a/helix-term/src/keymap.rs
+++ b/helix-term/src/keymap.rs
@@ -157,6 +157,7 @@ pub fn default() -> Keymaps {
                 vec![key!('d')] => commands::delete_selection,
                 vec![key!('c')] => commands::change_selection,
                 vec![key!('s')] => commands::split_selection_on_newline,
+                vec![shift!('S')] => commands::split_selection,
                 vec![key!(';')] => commands::collapse_selection,
                 // TODO should be alt(;)
                 vec![key!('%')] => commands::flip_selections,
@@ -182,6 +183,8 @@ pub fn default() -> Keymaps {
                 }] => commands::page_down,
                 vec![ctrl!('u')] => commands::half_page_up,
                 vec![ctrl!('d')] => commands::half_page_down,
+
+                vec![ctrl!('p')] => commands::file_picker,
             ),
             Mode::Insert => hashmap!(
                 vec![Key {
diff --git a/helix-term/src/ui/editor.rs b/helix-term/src/ui/editor.rs
index ceb5a442..996e182f 100644
--- a/helix-term/src/ui/editor.rs
+++ b/helix-term/src/ui/editor.rs
@@ -226,7 +226,7 @@ impl EditorView {
         );
         surface.set_string(1, viewport.y, mode, text_color);
 
-        if let Some(path) = view.doc.path() {
+        if let Some(path) = view.doc.relative_path() {
             surface.set_string(6, viewport.y, path.to_string_lossy(), text_color);
         }
 
diff --git a/helix-term/src/ui/helix.log b/helix-term/src/ui/helix.log
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/helix-term/src/ui/helix.log
diff --git a/helix-term/src/ui/mod.rs b/helix-term/src/ui/mod.rs
index bc79e09c..b778f531 100644
--- a/helix-term/src/ui/mod.rs
+++ b/helix-term/src/ui/mod.rs
@@ -1,8 +1,10 @@
 mod editor;
+mod picker;
 mod prompt;
 
 pub use editor::EditorView;
-pub use prompt::Prompt;
+pub use picker::Picker;
+pub use prompt::{Prompt, PromptEvent};
 
 pub use tui::layout::Rect;
 pub use tui::style::{Color, Modifier, Style};
@@ -12,3 +14,35 @@ pub use tui::style::{Color, Modifier, Style};
 pub fn text_color() -> Style {
     Style::default().fg(Color::Rgb(219, 191, 239)) // lilac
 }
+
+use std::path::PathBuf;
+pub fn file_picker(root: &str) -> Picker<PathBuf> {
+    use ignore::Walk;
+    // TODO: determine root based on git root
+    let files = Walk::new(root).filter_map(|entry| match entry {
+        Ok(entry) => {
+            // filter dirs, but we might need special handling for symlinks!
+            if !entry.file_type().unwrap().is_dir() {
+                Some(entry.into_path())
+            } else {
+                None
+            }
+        }
+        Err(_err) => None,
+    });
+
+    const MAX: usize = 1024;
+
+    use helix_view::Editor;
+    Picker::new(
+        files.take(MAX).collect(),
+        |path: &PathBuf| {
+            // format_fn
+            path.strip_prefix("./").unwrap().to_str().unwrap() // TODO: render paths without ./
+        },
+        |editor: &mut Editor, path: &PathBuf| {
+            let size = editor.view().unwrap().size;
+            editor.open(path.into(), size);
+        },
+    )
+}
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)
+    }
+}
diff --git a/helix-term/src/ui/prompt.rs b/helix-term/src/ui/prompt.rs
index ce00a129..58efd560 100644
--- a/helix-term/src/ui/prompt.rs
+++ b/helix-term/src/ui/prompt.rs
@@ -10,24 +10,32 @@ pub struct Prompt {
     pub line: String,
     pub cursor: usize,
     pub completion: Vec<String>,
-    pub should_close: bool,
     pub completion_selection_index: Option<usize>,
     completion_fn: Box<dyn FnMut(&str) -> Vec<String>>,
-    callback_fn: Box<dyn FnMut(&mut Editor, &str)>,
+    callback_fn: Box<dyn FnMut(&mut Editor, &str, PromptEvent)>,
+}
+
+#[derive(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,
 }
 
 impl Prompt {
     pub fn new(
         prompt: String,
         mut completion_fn: impl FnMut(&str) -> Vec<String> + 'static,
-        callback_fn: impl FnMut(&mut Editor, &str) + 'static,
+        callback_fn: impl FnMut(&mut Editor, &str, PromptEvent) + 'static,
     ) -> Prompt {
         Prompt {
             prompt,
             line: String::new(),
             cursor: 0,
             completion: completion_fn(""),
-            should_close: false,
             completion_selection_index: None,
             completion_fn: Box::new(completion_fn),
             callback_fn: Box::new(callback_fn),
@@ -42,9 +50,7 @@ impl Prompt {
     }
 
     pub fn move_char_left(&mut self) {
-        if self.cursor > 0 {
-            self.cursor -= 1;
-        }
+        self.cursor = self.cursor.saturating_sub(1)
     }
 
     pub fn move_char_right(&mut self) {
@@ -141,9 +147,15 @@ impl Prompt {
                 }
             }
         }
+        let line = area.height - 1;
         // render buffer text
-        surface.set_string(1, area.height - 1, &self.prompt, text_color);
-        surface.set_string(2, area.height - 1, &self.line, text_color);
+        surface.set_string(area.x, area.y + line, &self.prompt, text_color);
+        surface.set_string(
+            area.x + self.prompt.len() as u16,
+            area.y + line,
+            &self.line,
+            text_color,
+        );
     }
 }
 
@@ -151,21 +163,28 @@ 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::NONE,
-            } => self.insert_char(c),
+            } => {
+                self.insert_char(c);
+                (self.callback_fn)(cx.editor, &self.line, PromptEvent::Update);
+            }
             KeyEvent {
                 code: KeyCode::Esc, ..
             } => {
-                return EventResult::Consumed(Some(Box::new(|compositor: &mut Compositor| {
-                    // remove the layer
-                    compositor.pop();
-                })));
+                (self.callback_fn)(cx.editor, &self.line, PromptEvent::Abort);
+                return close_fn;
             }
             KeyEvent {
                 code: KeyCode::Right,
@@ -186,11 +205,17 @@ impl Component for Prompt {
             KeyEvent {
                 code: KeyCode::Backspace,
                 modifiers: KeyModifiers::NONE,
-            } => self.delete_char_backwards(),
+            } => {
+                self.delete_char_backwards();
+                (self.callback_fn)(cx.editor, &self.line, PromptEvent::Update);
+            }
             KeyEvent {
                 code: KeyCode::Enter,
                 ..
-            } => (self.callback_fn)(cx.editor, &self.line),
+            } => {
+                (self.callback_fn)(cx.editor, &self.line, PromptEvent::Validate);
+                return close_fn;
+            }
             KeyEvent {
                 code: KeyCode::Tab, ..
             } => self.change_completion_selection(),
@@ -210,8 +235,8 @@ impl Component for Prompt {
 
     fn cursor_position(&self, area: Rect, ctx: &mut Context) -> Option<Position> {
         Some(Position::new(
-            area.height as usize - 1,
-            area.x as usize + 2 + self.cursor,
+            area.height as usize,
+            area.x as usize + self.prompt.len() + self.cursor,
         ))
     }
 }