led/src/editor.rs

468 lines
14 KiB
Rust

#![allow(dead_code)]
use buffer::Buffer;
use std::path::Path;
use std::cmp::min;
use files::{load_file_to_buffer, save_buffer_to_file};
use string_utils::grapheme_count;
/// A text cursor. Also represents selections when range.0 != range.1.
///
/// `range` is a pair of 1d grapheme indexes into the text.
///
/// `vis_start` is the visual 2d horizontal position of the cursor. This
/// doesn't affect editing operations at all, but is used for cursor movement.
pub struct Cursor {
pub range: (usize, usize), // start, end
pub vis_start: usize, // start
}
impl Cursor {
pub fn new() -> Cursor {
Cursor {
range: (0, 0),
vis_start: 0,
}
}
pub fn update_vis_start(&mut self, buf: &Buffer, tab_width: usize) {
let (v, h) = buf.index_to_line_col(self.range.0);
self.vis_start = buf.get_line(v).grapheme_index_to_closest_vis_pos(h, tab_width);
}
}
pub struct Editor {
pub buffer: Buffer,
pub file_path: Path,
pub soft_tabs: bool,
pub tab_width: usize,
pub dirty: bool,
// The dimensions and position of the editor's view within the buffer
pub view_dim: (usize, usize), // (height, width)
pub view_pos: (usize, usize), // (line, col)
// The editing cursor position
pub cursor: Cursor,
}
impl Editor {
/// Create a new blank editor
pub fn new() -> Editor {
Editor {
buffer: Buffer::new(),
file_path: Path::new(""),
soft_tabs: false,
tab_width: 4,
dirty: false,
view_dim: (0, 0),
view_pos: (0, 0),
cursor: Cursor::new(),
}
}
pub fn new_from_file(path: &Path) -> Editor {
let buf = load_file_to_buffer(path).unwrap();
let mut ed = Editor {
buffer: buf,
file_path: path.clone(),
soft_tabs: false,
tab_width: 4,
dirty: false,
view_dim: (0, 0),
view_pos: (0, 0),
cursor: Cursor::new(),
};
ed.auto_detect_indentation_style();
return ed;
}
pub fn save_if_dirty(&mut self) {
if self.dirty && self.file_path != Path::new("") {
let _ = save_buffer_to_file(&self.buffer, &self.file_path);
self.dirty = false;
}
}
pub fn auto_detect_indentation_style(&mut self) {
let mut tab_blocks: usize = 0;
let mut space_blocks: usize = 0;
let mut space_histogram: [usize; 9] = [0, 0, 0, 0, 0, 0, 0, 0, 0];
let mut last_indent = (false, 0us); // (was_tabs, indent_count)
// Collect statistics
let mut line_i: usize = 0;
for line in self.buffer.line_iter() {
let mut g_iter = line.grapheme_iter();
match g_iter.next() {
Some("\t") => {
// Count leading tabs
let mut count = 1;
for g in g_iter {
if g == "\t" {
count += 1;
}
else {
break;
}
}
// Update stats
if last_indent.0 && last_indent.1 < count {
tab_blocks += 1;
}
// Store last line info
last_indent = (true, count);
},
Some(" ") => {
// Count leading spaces
let mut count = 1;
for g in g_iter {
if g == " " {
count += 1;
}
else {
break;
}
}
// Update stats
if !last_indent.0 && last_indent.1 < count {
space_blocks += 1;
let amount = count - last_indent.1;
if amount < 9 {
space_histogram[amount] += 1;
}
else {
space_histogram[8] += 1;
}
}
// Store last line info
last_indent = (false, count);
},
_ => {},
}
// Stop after 1000 lines
line_i += 1;
if line_i > 1000 {
break;
}
}
// Analyze stats and make a determination
if space_blocks == 0 && tab_blocks == 0 {
return;
}
if space_blocks > (tab_blocks * 2) {
let mut width = 0;
let mut width_count = 0;
for i in range(0, 9) {
if space_histogram[i] > width_count {
width = i;
width_count = space_histogram[i];
}
}
self.soft_tabs = true;
self.tab_width = width;
}
else {
self.soft_tabs = false;
}
}
pub fn update_dim(&mut self, h: usize, w: usize) {
self.view_dim = (h, w);
}
pub fn undo(&mut self) {
if let Some(pos) = self.buffer.undo() {
self.cursor.range.0 = pos;
self.cursor.range.1 = pos;
self.cursor.update_vis_start(&(self.buffer), self.tab_width);
self.move_view_to_cursor();
}
}
pub fn redo(&mut self) {
if let Some(pos) = self.buffer.redo() {
self.cursor.range.0 = pos;
self.cursor.range.1 = pos;
self.cursor.update_vis_start(&(self.buffer), self.tab_width);
self.move_view_to_cursor();
}
}
/// Moves the editor's view the minimum amount to show the cursor
pub fn move_view_to_cursor(&mut self) {
let (v, h) = self.buffer.index_to_v2d(self.cursor.range.0, self.tab_width);
// Horizontal
if h < self.view_pos.1 {
self.view_pos.1 = h;
}
else if h >= (self.view_pos.1 + self.view_dim.1) {
self.view_pos.1 = 1 + h - self.view_dim.1;
}
// Vertical
if v < self.view_pos.0 {
self.view_pos.0 = v;
}
else if v >= (self.view_pos.0 + self.view_dim.0) {
self.view_pos.0 = 1 + v - self.view_dim.0;
}
}
pub fn insert_text_at_cursor(&mut self, text: &str) {
let str_len = grapheme_count(text);
// Insert text
self.buffer.insert_text(text, self.cursor.range.0);
self.dirty = true;
// Move cursor
self.cursor.range.0 += str_len;
self.cursor.range.1 += str_len;
self.cursor.update_vis_start(&(self.buffer), self.tab_width);
// Adjust view
self.move_view_to_cursor();
}
pub fn insert_tab_at_cursor(&mut self) {
if self.soft_tabs {
// Figure out how many spaces to insert
let (v, h) = self.buffer.index_to_line_col(self.cursor.range.0);
let vis_pos = self.buffer.get_line(v).grapheme_index_to_closest_vis_pos(h, self.tab_width);
let next_tab_stop = ((vis_pos / self.tab_width) + 1) * self.tab_width;
let space_count = min(next_tab_stop - vis_pos, 8);
// Insert spaces
let space_strs = ["", " ", " ", " ", " ", " ", " ", " ", " "];
self.buffer.insert_text(space_strs[space_count], self.cursor.range.0);
self.dirty = true;
// Move cursor
self.cursor.range.0 += space_count;
self.cursor.range.1 += space_count;
self.cursor.update_vis_start(&(self.buffer), self.tab_width);
// Adjust view
self.move_view_to_cursor();
}
else {
self.insert_text_at_cursor("\t");
}
}
pub fn backspace_at_cursor(&mut self) {
self.remove_text_behind_cursor(1);
}
pub fn insert_text_at_grapheme(&mut self, text: &str, pos: usize) {
self.dirty = true;
let buf_len = self.buffer.grapheme_count();
self.buffer.insert_text(text, if pos < buf_len {pos} else {buf_len});
}
pub fn remove_text_behind_cursor(&mut self, grapheme_count: usize) {
let pos_b = self.cursor.range.0;
let pos_a = if pos_b >= grapheme_count {pos_b - grapheme_count} else {0};
let tot_g = pos_b - pos_a;
// Remove text
self.buffer.remove_text(pos_a, pos_b);
self.dirty = true;
// Move cursor
self.cursor.range.0 -= tot_g;
self.cursor.range.1 -= tot_g;
self.cursor.update_vis_start(&(self.buffer), self.tab_width);
// Adjust view
self.move_view_to_cursor();
}
pub fn remove_text_in_front_of_cursor(&mut self, grapheme_count: usize) {
let pos_a = self.cursor.range.1;
let pos_b = if (pos_a + grapheme_count) <= self.buffer.grapheme_count() {pos_a + grapheme_count} else {self.buffer.grapheme_count()};
// Remove text
self.buffer.remove_text(pos_a, pos_b);
self.dirty = true;
// Move cursor
self.cursor.update_vis_start(&(self.buffer), self.tab_width);
// Adjust view
self.move_view_to_cursor();
}
pub fn remove_text_inside_cursor(&mut self) {
// If selection, remove text
if self.cursor.range.0 < self.cursor.range.1 {
self.buffer.remove_text(self.cursor.range.0, self.cursor.range.1);
self.dirty = true;
}
// Move cursor
self.cursor.range.1 = self.cursor.range.0;
self.cursor.update_vis_start(&(self.buffer), self.tab_width);
// Adjust view
self.move_view_to_cursor();
}
pub fn cursor_to_beginning_of_buffer(&mut self) {
self.cursor.range = (0, 0);
self.cursor.update_vis_start(&(self.buffer), self.tab_width);
// Adjust view
self.move_view_to_cursor();
}
pub fn cursor_to_end_of_buffer(&mut self) {
let end = self.buffer.grapheme_count();
self.cursor.range = (end, end);
self.cursor.update_vis_start(&(self.buffer), self.tab_width);
// Adjust view
self.move_view_to_cursor();
}
pub fn cursor_left(&mut self, n: usize) {
if self.cursor.range.0 >= n {
self.cursor.range.0 -= n;
}
else {
self.cursor.range.0 = 0;
}
self.cursor.range.1 = self.cursor.range.0;
self.cursor.update_vis_start(&(self.buffer), self.tab_width);
// Adjust view
self.move_view_to_cursor();
}
pub fn cursor_right(&mut self, n: usize) {
if self.cursor.range.1 <= (self.buffer.grapheme_count() - n) {
self.cursor.range.1 += n;
}
else {
self.cursor.range.1 = self.buffer.grapheme_count();
}
self.cursor.range.0 = self.cursor.range.1;
self.cursor.update_vis_start(&(self.buffer), self.tab_width);
// Adjust view
self.move_view_to_cursor();
}
pub fn cursor_up(&mut self, n: usize) {
let (v, _) = self.buffer.index_to_v2d(self.cursor.range.0, self.tab_width);
if v >= n {
self.cursor.range.0 = self.buffer.v2d_to_index((v - n, self.cursor.vis_start), self.tab_width);
self.cursor.range.1 = self.cursor.range.0;
}
else {
self.cursor_to_beginning_of_buffer();
}
// Adjust view
self.move_view_to_cursor();
}
pub fn cursor_down(&mut self, n: usize) {
let (v, _) = self.buffer.index_to_v2d(self.cursor.range.0, self.tab_width);
if v < (self.buffer.line_count() - n) {
self.cursor.range.0 = self.buffer.v2d_to_index((v + n, self.cursor.vis_start), self.tab_width);
self.cursor.range.1 = self.cursor.range.0;
}
else {
self.cursor_to_end_of_buffer();
}
// Adjust view
self.move_view_to_cursor();
}
pub fn page_up(&mut self) {
if self.view_pos.0 > 0 {
let move_amount = self.view_dim.0 - (self.view_dim.0 / 8);
if self.view_pos.0 >= move_amount {
self.view_pos.0 -= move_amount;
}
else {
self.view_pos.0 = 0;
}
self.cursor_up(move_amount);
}
else {
self.cursor_to_beginning_of_buffer();
}
// Adjust view
self.move_view_to_cursor();
}
pub fn page_down(&mut self) {
// TODO
let nlc = self.buffer.line_count() - 1;
if self.view_pos.0 < nlc {
let move_amount = self.view_dim.0 - (self.view_dim.0 / 8);
let max_move = nlc - self.view_pos.0;
if max_move >= move_amount {
self.view_pos.0 += move_amount;
}
else {
self.view_pos.0 += max_move;
}
self.cursor_down(move_amount);
}
else {
self.cursor_to_end_of_buffer();
}
// Adjust view
self.move_view_to_cursor();
}
pub fn jump_to_line(&mut self, n: usize) {
let pos = self.buffer.line_col_to_index((n, 0));
let (v, _) = self.buffer.index_to_v2d(pos, self.tab_width);
self.cursor.range.0 = self.buffer.v2d_to_index((v, self.cursor.vis_start), self.tab_width);
self.cursor.range.1 = self.cursor.range.0;
// Adjust view
self.move_view_to_cursor();
}
}