use crate::graphemes; use crate::selection::Range; use crate::state::{Direction, Granularity, Mode, State}; use crate::transaction::{ChangeSet, Transaction}; use crate::Tendril; /// A command is a function that takes the current state and a count, and does a side-effect on the /// state (usually by creating and applying a transaction). pub type Command = fn(state: &mut State, count: usize); pub fn move_char_left(state: &mut State, count: usize) { // TODO: use a transaction let selection = state.move_selection(Direction::Backward, Granularity::Character, count); state.selection = selection; } pub fn move_char_right(state: &mut State, count: usize) { // TODO: use a transaction state.selection = state.move_selection(Direction::Forward, Granularity::Character, count); } pub fn move_line_up(state: &mut State, count: usize) { // TODO: use a transaction state.selection = state.move_selection(Direction::Backward, Granularity::Line, count); } pub fn move_line_down(state: &mut State, count: usize) { // TODO: use a transaction state.selection = state.move_selection(Direction::Forward, Granularity::Line, count); } // avoid select by default by having a visual mode switch that makes movements into selects // insert mode: // first we calculate the correct cursors/selections // then we just append at each cursor // lastly, if it was append mode we shift cursor by 1? // inserts at the start of each selection pub fn insert_mode(state: &mut State, _count: usize) { state.mode = Mode::Insert; state.selection = state .selection .transform(|range| Range::new(range.to(), range.from())) } // inserts at the end of each selection pub fn append_mode(state: &mut State, _count: usize) { state.mode = Mode::Insert; // TODO: as transaction let text = &state.doc.slice(..); state.selection = state.selection.transform(|range| { // TODO: to() + next char Range::new( range.from(), graphemes::next_grapheme_boundary(text, range.to()), ) }) } // I inserts at the start of each line with a selection // A inserts at the end of each line with a selection // o inserts a new line before each line with a selection // O inserts a new line after each line with a selection pub fn normal_mode(state: &mut State, _count: usize) { // TODO: if leaving append mode, move cursor back by 1 state.mode = Mode::Normal; } // TODO: insert means add text just before cursor, on exit we should be on the last letter. pub fn insert_char(state: &mut State, c: char) { let c = Tendril::from_char(c); let transaction = Transaction::insert(&state, c); transaction.apply(state); // TODO: need to store into history if successful } // TODO: handle indent-aware delete pub fn delete_char_backward(state: &mut State, count: usize) { let text = &state.doc.slice(..); let transaction = Transaction::change_by_selection(state, |range| { ( graphemes::nth_prev_grapheme_boundary(text, range.head, count), range.head, None, ) }); transaction.apply(state); // TODO: need to store into history if successful } pub fn delete_char_forward(state: &mut State, count: usize) { let text = &state.doc.slice(..); let transaction = Transaction::change_by_selection(state, |range| { ( graphemes::nth_next_grapheme_boundary(text, range.head, count), range.head, None, ) }); transaction.apply(state); // TODO: need to store into history if successful }