Merge pull request #6 from helix-editor/compositor

Compositor v2 rewrite

1 files changed, 217 insertions, 0 deletions

diff --git a/helix-term/src/ui/prompt.rs b/helix-term/src/ui/prompt.rs
new file mode 100644
index 00000000..ce00a129
--- /dev/null
+++ b/helix-term/src/ui/prompt.rs
@@ -0,0 +1,217 @@
+use crate::compositor::{Component, Compositor, Context, EventResult};
+use crossterm::event::{Event, KeyCode, KeyEvent, KeyModifiers};
+use helix_core::Position;
+use helix_view::Editor;
+use helix_view::Theme;
+use std::string::String;
+
+pub struct Prompt {
+    pub prompt: String,
+    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)>,
+}
+
+impl Prompt {
+    pub fn new(
+        prompt: String,
+        mut completion_fn: impl FnMut(&str) -> Vec<String> + 'static,
+        callback_fn: impl FnMut(&mut Editor, &str) + '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),
+        }
+    }
+
+    pub fn insert_char(&mut self, c: char) {
+        self.line.insert(self.cursor, c);
+        self.cursor += 1;
+        self.completion = (self.completion_fn)(&self.line);
+        self.exit_selection();
+    }
+
+    pub fn move_char_left(&mut self) {
+        if self.cursor > 0 {
+            self.cursor -= 1;
+        }
+    }
+
+    pub fn move_char_right(&mut self) {
+        if self.cursor < self.line.len() {
+            self.cursor += 1;
+        }
+    }
+
+    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) {
+        if self.cursor > 0 {
+            self.line.remove(self.cursor - 1);
+            self.cursor -= 1;
+            self.completion = (self.completion_fn)(&self.line);
+        }
+        self.exit_selection();
+    }
+
+    pub fn change_completion_selection(&mut self) {
+        if self.completion.is_empty() {
+            return;
+        }
+        let index =
+            self.completion_selection_index.map(|i| i + 1).unwrap_or(0) % self.completion.len();
+        self.completion_selection_index = Some(index);
+        self.line = self.completion[index].clone();
+    }
+    pub fn exit_selection(&mut self) {
+        self.completion_selection_index = None;
+    }
+}
+
+use tui::{
+    buffer::Buffer as Surface,
+    layout::Rect,
+    style::{Color, Modifier, Style},
+};
+
+const BASE_WIDTH: u16 = 30;
+use crate::ui::text_color;
+
+impl Prompt {
+    pub fn render_prompt(&self, area: Rect, surface: &mut Surface, theme: &Theme) {
+        let text_color = text_color();
+        // completion
+        if !self.completion.is_empty() {
+            // TODO: find out better way of clearing individual lines of the screen
+            let mut row = 0;
+            let mut col = 0;
+            let max_col = area.width / BASE_WIDTH;
+            let col_height = ((self.completion.len() as u16 + max_col - 1) / max_col);
+
+            for i in (3..col_height + 3) {
+                surface.set_string(
+                    0,
+                    area.height - i as u16,
+                    " ".repeat(area.width as usize),
+                    text_color,
+                );
+            }
+            surface.set_style(
+                Rect::new(0, area.height - col_height - 2, area.width, col_height),
+                theme.get("ui.statusline"),
+            );
+            for (i, command) in self.completion.iter().enumerate() {
+                let color = if self.completion_selection_index.is_some()
+                    && i == self.completion_selection_index.unwrap()
+                {
+                    Style::default().bg(Color::Rgb(104, 060, 232))
+                } else {
+                    text_color
+                };
+                surface.set_stringn(
+                    1 + col * BASE_WIDTH,
+                    area.height - col_height - 2 + row,
+                    &command,
+                    BASE_WIDTH as usize - 1,
+                    color,
+                );
+                row += 1;
+                if row > col_height - 1 {
+                    row = 0;
+                    col += 1;
+                }
+                if col > max_col {
+                    break;
+                }
+            }
+        }
+        // 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);
+    }
+}
+
+impl Component for Prompt {
+    fn handle_event(&mut self, event: Event, cx: &mut Context) -> EventResult {
+        let event = match event {
+            Event::Key(event) => event,
+            _ => return EventResult::Ignored,
+        };
+
+        match event {
+            KeyEvent {
+                code: KeyCode::Char(c),
+                modifiers: KeyModifiers::NONE,
+            } => self.insert_char(c),
+            KeyEvent {
+                code: KeyCode::Esc, ..
+            } => {
+                return EventResult::Consumed(Some(Box::new(|compositor: &mut Compositor| {
+                    // remove the layer
+                    compositor.pop();
+                })));
+            }
+            KeyEvent {
+                code: KeyCode::Right,
+                ..
+            } => self.move_char_right(),
+            KeyEvent {
+                code: KeyCode::Left,
+                ..
+            } => self.move_char_left(),
+            KeyEvent {
+                code: KeyCode::Char('e'),
+                modifiers: KeyModifiers::CONTROL,
+            } => self.move_end(),
+            KeyEvent {
+                code: KeyCode::Char('a'),
+                modifiers: KeyModifiers::CONTROL,
+            } => self.move_start(),
+            KeyEvent {
+                code: KeyCode::Backspace,
+                modifiers: KeyModifiers::NONE,
+            } => self.delete_char_backwards(),
+            KeyEvent {
+                code: KeyCode::Enter,
+                ..
+            } => (self.callback_fn)(cx.editor, &self.line),
+            KeyEvent {
+                code: KeyCode::Tab, ..
+            } => self.change_completion_selection(),
+            KeyEvent {
+                code: KeyCode::Char('q'),
+                modifiers: KeyModifiers::CONTROL,
+            } => self.exit_selection(),
+            _ => (),
+        };
+
+        EventResult::Consumed(None)
+    }
+
+    fn render(&self, area: Rect, surface: &mut Surface, cx: &mut Context) {
+        self.render_prompt(area, surface, &cx.editor.theme)
+    }
+
+    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,
+        ))
+    }
+}