wip: directional focus!

crates/tek_core/src/focus.rs

@@ -1,5 +1,70 @@
 use crate::*;
 
+pub trait FocusGrid<T> {
+    fn layout (&self) -> &[&[T]];
+    fn cursor (&self) -> (usize, usize);
+    fn cursor_mut (&mut self) -> &mut (usize, usize);
+    fn focused (&self) -> &T {
+        let (x, y) = self.cursor();
+        &self.layout()[y][x]
+    }
+    fn focus_up (&mut self) {
+        let layout = self.layout();
+        let (x, y) = self.cursor();
+        let next_y = if y == 0 { layout.len() - 1 } else { y - 1 };
+        let next_x = if layout[y].len() == layout[next_y].len() { x } else {
+            ((x as f32 / layout[y].len() as f32) * layout[next_y].len() as f32) as usize
+        };
+        *self.cursor_mut() = (next_x, next_y);
+    }
+    fn focus_down (&mut self) {
+        let layout = self.layout();
+        let (x, y) = self.cursor();
+        let next_y = if y >= layout.len() - 1 { 0 } else { y + 1 };
+        let next_x = if layout[y].len() == layout[next_y].len() { x } else {
+            ((x as f32 / layout[y].len() as f32) * layout[next_y].len() as f32) as usize
+        };
+        *self.cursor_mut() = (next_x, next_y);
+    }
+    fn focus_left (&mut self) {
+        let layout = self.layout();
+        let (x, y) = self.cursor();
+        let next_x = if x == 0 { layout[y].len() - 1 } else { x - 1 };
+        *self.cursor_mut() = (next_x, y);
+    }
+    fn focus_right (&mut self) {
+        let layout = self.layout();
+        let (x, y) = self.cursor();
+        let next_x = if x >= layout[y].len() - 1 { 0 } else { x - 1 };
+        *self.cursor_mut() = (next_x, y);
+    }
+    fn focus_next (&mut self) {
+        todo!();
+    }
+    fn focus_prev (&mut self) {
+        todo!();
+    }
+}
+
+//pub struct FocusFrame<'a, E: Engine>(usize, Vec<FocusCell<'a, E>>);
+
+//pub struct FocusCell<'a, E: Engine> {
+    //item:  &'a dyn Handle<E>,
+    //next:  Option<&'a FocusCell<'a, E>>,
+    //prev:  Option<&'a FocusCell<'a, E>>,
+    //up:    Option<&'a FocusCell<'a, E>>,
+    //down:  Option<&'a FocusCell<'a, E>>,
+    //left:  Option<&'a FocusCell<'a, E>>,
+    //right: Option<&'a FocusCell<'a, E>>,
+//}
+
+pub trait FocusContainer<E: Engine> {
+    fn focused (&mut self) -> &mut dyn Handle<E>;
+    fn handle_focus (&mut self, _: &E::Input) -> Perhaps<bool> {
+        Ok(None)
+    }
+}
+
 /// A component that may contain [Focusable] components.
 pub trait Focus <const N: usize, E: Engine>: Widget<Engine = E> + Handle<E> {
     fn focus (&self) -> usize;

crates/tek_core/src/tui.rs

@@ -219,6 +219,14 @@ pub type KeyMap<T> = [KeyBinding<T>];
             kind:      crossterm::event::KeyEventKind::Press,
             state:     crossterm::event::KeyEventState::NONE
         }))
+    };
+    (Shift-$code:pat) => {
+        TuiEvent::Input(crossterm::event::Event::Key(crossterm::event::KeyEvent {
+            code:      $code,
+            modifiers: crossterm::event::KeyModifiers::SHIFT,
+            kind:      crossterm::event::KeyEventKind::Press,
+            state:     crossterm::event::KeyEventState::NONE
+        }))
     }
 }
 pub struct TuiOutput {