add basic user-definable keybinds

6 files changed, 237 insertions, 27 deletions

diff --git a/src/app.rs b/src/app.rs
index 70d68b8..e69794f 100644
--- a/src/app.rs
+++ b/src/app.rs
@@ -8,7 +8,8 @@ use crate::{
     error::AppError,
     grid::Grid,
     guide::Guide,
-    lisp::{eval, lex::Lexer, parse::Parser, prelude, EnvList},
+    keybind::Keybind,
+    lisp::{eval, expr::LispExpr, lex::Lexer, parse::Parser, prelude, EnvList},
     message::Message,
     rect,
     symmetry::Symmetry,
@@ -59,6 +60,7 @@ pub struct AppState<'ctx> {
     pub grid: Grid,
     pub minimap: bool,
     pub lisp_env: EnvList,
+    pub keybinds: HashMap<Keybind, LispExpr>,
     pub message: Message,
     pub mode: Mode,
     pub mouse: (i32, i32),
@@ -303,21 +305,23 @@ impl<'ctx> AppState<'ctx> {
         }
     }
 
+    pub fn eval_expr(&mut self, expr: &LispExpr) {
+        let mut evaluator = eval::Evaluator {
+            app: self,
+            context: Vec::new(),
+        };
+        match evaluator.eval(expr) {
+            Ok(val) => self.message.set_info(format!("{}", val)),
+            Err(eval_err) => self.message.set_error(format!("{}", eval_err)),
+        }
+    }
+
     pub fn eval_command(&mut self) {
         let lisp_expr = &self.command_box.text;
         let mut parser = Parser::new(Lexer::new(lisp_expr));
         let res = parser.parse_single_expr();
         match res {
-            Ok(expr) => {
-                let mut evaluator = eval::Evaluator {
-                    app: self,
-                    context: Vec::new(),
-                };
-                match evaluator.eval(&expr) {
-                    Ok(val) => self.message.set_info(format!("{}", val)),
-                    Err(eval_err) => self.message.set_error(format!("{}", eval_err)),
-                }
-            }
+            Ok(expr) => self.eval_expr(&expr),
             Err(err) => self.message = handle_error(err, &lisp_expr, "repl"),
         }
         self.command_box.hist_append();
@@ -612,11 +616,11 @@ impl<'ctx> AppState<'ctx> {
             self.grid
                 .draw(&mut self.canvas, self.zoom, &self.start, width, height);
         }
+        self.draw_guides();
+        self.draw_symmetry();
         if self.minimap {
             self.draw_minimap();
         }
-        self.draw_guides();
-        self.draw_symmetry();
         self.draw_statusline();
         self.draw_command_box();
         self.draw_brush();
@@ -663,23 +667,24 @@ impl<'ctx> AppState<'ctx> {
         let mut app = Self {
             active_color: true,
             brush: Brush::new(0),
+            cache: RefCell::new(None),
             canvas,
             command_box: CommandBox::new(),
             context,
-            cache: RefCell::new(None),
-            guides: HashMap::new(),
             current_operation: Vec::new(),
             dither_level: 16,
             file_name,
             grid: Grid::new(),
+            guides: HashMap::new(),
+            keybinds: HashMap::new(),
             lisp_env: vec![prelude::new_env().map_err(AppError::Lisp)?],
             message: Message::new().text(" "),
-            mode: Mode::Draw,
             minimap: false,
+            mode: Mode::Draw,
             mouse: (0, 0),
+            pan_start: Point::new(0, 0),
             pixmap,
             start: Point::new(60, 60),
-            pan_start: Point::new(0, 0),
             symmetry: Default::default(),
             ttf_context,
             undo_stack: UndoStack::new(),
@@ -732,7 +737,7 @@ impl<'ctx> AppState<'ctx> {
                         match event {
                             Event::KeyDown {
                                 keycode: Some(k),
-                                keymod,
+                                keymod: Mod::NOMOD,
                                 ..
                             } => {
                                 match k {
@@ -742,9 +747,9 @@ impl<'ctx> AppState<'ctx> {
                                     Keycode::S => self.pan((0, -10)),
                                     Keycode::D => self.pan((-10, 0)),
                                     // zoom
-                                    Keycode::C if keymod == Mod::LSHIFTMOD => {
-                                        self.center_grid();
-                                    }
+                                    // Keycode::C if keymod == Mod::LSHIFTMOD => {
+                                    //     self.center_grid();
+                                    // }
                                     Keycode::C => {
                                         let cursor = (mouse.x(), mouse.y());
                                         self.zoom_in(cursor);
@@ -799,7 +804,7 @@ impl<'ctx> AppState<'ctx> {
                                         }
                                         continue;
                                     }
-                                    _ if keymod == Mod::LCTRLMOD || keymod == Mod::RCTRLMOD => {
+                                    Keycode::LCtrl | Keycode::RCtrl => {
                                         self.brush = Brush::line(
                                             self.cache
                                                 .borrow()
@@ -812,6 +817,26 @@ impl<'ctx> AppState<'ctx> {
                                     _ => (),
                                 }
                             }
+                            Event::KeyDown {
+                                keycode: Some(k),
+                                keymod,
+                                ..
+                            } if self.keybinds.contains_key(&Keybind::new(k, keymod)) => {
+                                let body = self.keybinds.get(&Keybind::new(k, keymod)).unwrap();
+                                self.eval_expr(&body.clone());
+                            }
+                            Event::KeyDown {
+                                keycode: Some(k), ..
+                            } if k == Keycode::LCtrl || k == Keycode::RCtrl => {
+                                self.brush = Brush::line(
+                                    self.cache
+                                        .borrow()
+                                        .as_ref()
+                                        .map(|c| c.last_brush.size().unwrap_or(0))
+                                        .unwrap_or(0),
+                                    true,
+                                );
+                            }
                             Event::KeyUp {
                                 keycode: Some(k), ..
                             } if k == Keycode::LCtrl || k == Keycode::RCtrl => {
diff --git a/src/keybind.rs b/src/keybind.rs
new file mode 100644
index 0000000..8ab479a
--- /dev/null
+++ b/src/keybind.rs
@@ -0,0 +1,146 @@
+use std::{fmt, str::FromStr};
+
+use sdl2::keyboard::{Keycode, Mod};
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
+pub struct Keybind {
+    keycode: Keycode,
+    keymod: Mod,
+}
+
+impl Keybind {
+    pub fn new(keycode: Keycode, keymod: Mod) -> Self {
+        Self { keycode, keymod }
+    }
+}
+
+// ctrl keys: C-<letter>   len 3
+// shift keys: S-<letter>  len 3
+// normal keys: <letter>   len 1
+
+#[derive(Debug, Copy, Clone, PartialEq)]
+pub enum KeybindError {
+    Parse,
+    InvalidMod,
+    InvalidKey,
+}
+
+impl fmt::Display for KeybindError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Parse => write!(f, "error parsing keybind"),
+            Self::InvalidKey => write!(f, "unsupported keybind, try `A-Z0-9`"),
+            Self::InvalidMod => {
+                write!(f, "unsupported keybind modifier, try `C-<key> or S-<key>`")
+            }
+        }
+    }
+}
+
+impl std::error::Error for KeybindError {}
+
+impl FromStr for Keybind {
+    type Err = KeybindError;
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        parse_from_str(s)
+    }
+}
+
+fn parse_from_str(s: &str) -> Result<Keybind, KeybindError> {
+    let s = s.to_lowercase();
+    match s.len() {
+        // either ctrl or shift key
+        3 => {
+            let keymod = parse_modifier(&s[..2])?;
+            let keybind = parse_keybind(&s[2..])?;
+            Ok(Keybind::new(keybind, keymod))
+        }
+        1 => {
+            let keybind = parse_keybind(&s)?;
+            Ok(Keybind::new(keybind, Mod::NOMOD))
+        }
+        _ => Err(KeybindError::Parse),
+    }
+}
+
+fn parse_modifier(s: &str) -> Result<Mod, KeybindError> {
+    match s {
+        "c-" => Ok(Mod::LCTRLMOD),
+        "s-" => Ok(Mod::LSHIFTMOD),
+        _ => Err(KeybindError::InvalidMod),
+    }
+}
+
+fn parse_keybind(s: &str) -> Result<Keycode, KeybindError> {
+    match s.to_uppercase().as_str() {
+        "0" => Ok(Keycode::Num0),
+        "1" => Ok(Keycode::Num1),
+        "2" => Ok(Keycode::Num2),
+        "3" => Ok(Keycode::Num3),
+        "4" => Ok(Keycode::Num4),
+        "5" => Ok(Keycode::Num5),
+        "6" => Ok(Keycode::Num6),
+        "7" => Ok(Keycode::Num7),
+        "8" => Ok(Keycode::Num8),
+        "9" => Ok(Keycode::Num9),
+        "A" | "B" | "C" | "D" | "E" | "F" | "G" | "H" | "I" | "J" | "K" | "L" | "M" | "N" | "O"
+        | "P" | "Q" | "R" | "S" | "T" | "U" | "V" | "W" | "X" | "Y" | "Z" => {
+            Ok(Keycode::from_name(s).unwrap())
+        }
+        _ => Err(KeybindError::InvalidKey),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn without_mod() {
+        assert_eq!(
+            Keybind::from_str("x").unwrap(),
+            Keybind::new(Keycode::X, Mod::NOMOD)
+        );
+        assert_eq!(
+            Keybind::from_str("X").unwrap(),
+            Keybind::new(Keycode::X, Mod::NOMOD)
+        );
+    }
+    #[test]
+    fn with_ctrl_mod() {
+        assert_eq!(
+            Keybind::from_str("c-x").unwrap(),
+            Keybind::new(Keycode::X, Mod::LCTRLMOD)
+        );
+        assert_eq!(
+            Keybind::from_str("C-x").unwrap(),
+            Keybind::new(Keycode::X, Mod::LCTRLMOD)
+        );
+        assert_eq!(
+            Keybind::from_str("c-X").unwrap(),
+            Keybind::new(Keycode::X, Mod::LCTRLMOD)
+        );
+        assert_eq!(
+            Keybind::from_str("C-X").unwrap(),
+            Keybind::new(Keycode::X, Mod::LCTRLMOD)
+        );
+    }
+    #[test]
+    fn with_shift_mod() {
+        assert_eq!(
+            Keybind::from_str("s-x").unwrap(),
+            Keybind::new(Keycode::X, Mod::LSHIFTMOD)
+        );
+        assert_eq!(
+            Keybind::from_str("S-x").unwrap(),
+            Keybind::new(Keycode::X, Mod::LSHIFTMOD)
+        );
+        assert_eq!(
+            Keybind::from_str("s-X").unwrap(),
+            Keybind::new(Keycode::X, Mod::LSHIFTMOD)
+        );
+        assert_eq!(
+            Keybind::from_str("S-X").unwrap(),
+            Keybind::new(Keycode::X, Mod::LSHIFTMOD)
+        );
+    }
+}
diff --git a/src/lisp/error.rs b/src/lisp/error.rs
index 9e9dc90..7bde872 100644
--- a/src/lisp/error.rs
+++ b/src/lisp/error.rs
@@ -1,7 +1,10 @@
-use crate::lisp::{
-    expr::{Arity, LispExpr},
-    lex::{Span, SpanDisplay},
-    number::LispNumber,
+use crate::{
+    keybind::KeybindError,
+    lisp::{
+        expr::{Arity, LispExpr},
+        lex::{Span, SpanDisplay},
+        number::LispNumber,
+    },
 };
 
 use std::{fmt, io};
@@ -104,6 +107,7 @@ pub enum EvalError {
     AssertionError { expected: LispExpr, got: LispExpr },
     ScriptLoadError(io::Error),
     CustomInternal(&'static str),
+    KeybindError(KeybindError),
     Custom(String),
 }
 
@@ -134,6 +138,7 @@ impl fmt::Display for EvalError {
                 write!(f, "assertion error: expected `{}` got `{}`", expected, got)
             }
             Self::ScriptLoadError(s) => write!(f, "error while loading script: {}", s),
+            Self::KeybindError(k) => write!(f, "keybind error: {}", k),
             Self::CustomInternal(s) => write!(f, "{}", s),
             Self::Custom(s) => write!(f, "error: {}", s),
         }
diff --git a/src/lisp/eval.rs b/src/lisp/eval.rs
index 75cb5c9..677fa23 100644
--- a/src/lisp/eval.rs
+++ b/src/lisp/eval.rs
@@ -1,5 +1,6 @@
 use crate::{
     app::AppState,
+    keybind::Keybind,
     lisp::{
         error::{EvalError, LispError},
         expr::{Arity, Ident, LispExpr, LispFunction},
@@ -8,7 +9,7 @@ use crate::{
     type_match,
 };
 
-use std::convert::TryInto;
+use std::{convert::TryInto, str::FromStr};
 
 use log::{error, info};
 
@@ -44,6 +45,7 @@ where
                         "for" => self.eval_for(&li[1..]),
                         "quote" => Ok(apply_quote(&li[1])),
                         "let" => self.eval_let(&li[1..]),
+                        "bind-key" => self.eval_bind_key(&li[1..]),
                         _ => {
                             let mut new_ls = vec![self.eval(&func_expr)?];
                             new_ls.extend(li[1..].to_vec());
@@ -302,6 +304,22 @@ where
             }
         }
     }
+
+    pub fn eval_bind_key(&mut self, args: &[LispExpr]) -> Result<LispExpr, LispError> {
+        let arity = Arity::Exact(2);
+        if !arity.check(args) {
+            Err(arity.to_error())
+        } else {
+            match args {
+                [LispExpr::StringLit(s), body] => {
+                    let bind = Keybind::from_str(&s).map_err(EvalError::KeybindError)?;
+                    self.app.keybinds.insert(bind, body.clone());
+                    Ok(LispExpr::Unit)
+                }
+                _ => Err(EvalError::BadForm.into()),
+            }
+        }
+    }
 }
 
 pub fn apply_quote(arg: &LispExpr) -> LispExpr {
diff --git a/src/lisp/std.lisp b/src/lisp/std.lisp
index a256125..fe09a8a 100644
--- a/src/lisp/std.lisp
+++ b/src/lisp/std.lisp
@@ -72,3 +72,18 @@
           acc
           (rev-helper (cdr p) (cons (car p) acc))))
     (rev-helper ls '())))
+
+(define (append l1 l2)
+  (if (null? l1)
+      l2
+      (cons (car l1)
+            (append (cdr l1) l2))))
+
+(define (cross xs ys)
+  (if (or (null? xs)
+          (null? ys))
+      '()
+      (fold '()
+            append
+            (map (lambda (x)
+                   (map (lambda (y) (list x y)) ys)) xs))))
diff --git a/src/main.rs b/src/main.rs
index 225c37c..c933e2a 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -16,6 +16,7 @@ mod dither;
 mod error;
 mod grid;
 mod guide;
+mod keybind;
 mod lisp;
 mod message;
 mod symmetry;