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/// document.rs - has Document, for opening, editing and saving documents
use crate::event::{Error, Event, Result, Status, EventMgmt};
use crate::map::{CharMap, form_map};
use crate::searching::{Searcher, Match};
use crate::utils::{Loc, Size, get_range, trim, width};
use ropey::Rope;
use std::fs::File;
use std::io::{BufReader, BufWriter};
use std::ops::RangeBounds;
/// A document struct manages a file.
/// It has tools to read, write and traverse a document.
/// By default, it uses file buffering so it can open almost immediately.
/// To start executing events, remember to use the `Document::exe` function and check out
/// the documentation for `Event` to learn how to form editing events.
#[derive(Clone, PartialEq, Eq, Debug)]
pub struct Document {
/// The file name of the document opened
pub file_name: String,
/// The rope of the document to facilitate reading and writing to disk
pub file: Rope,
/// Contains the number of lines buffered into the document
pub loaded_to: usize,
/// Cache of all the loaded lines in this document
pub lines: Vec<String>,
/// Stores the locations of double width characters
pub dbl_map: CharMap,
/// Stores the locations of tab characters
pub tab_map: CharMap,
/// Contains the size of this document for purposes of offset
pub size: Size,
/// Contains where the cursor is within the terminal
pub cursor: Loc,
/// Contains the offset (scrolling for longer documents)
pub offset: Loc,
/// Keeps track of where the character pointer is
pub char_ptr: usize,
/// Manages events, for the purpose of undo and redo
pub event_mgmt: EventMgmt,
/// true if the file has been modified since saving, false otherwise
pub modified: bool,
/// The number of spaces a tab should be rendered as
pub tab_width: usize,
}
impl Document {
/// Open a document from a file name.
/// # Errors
/// Returns an error when file doesn't exist, or has incorrect permissions.
/// Also returns an error if the rope fails to initialise due to character set issues or
/// disk errors.
#[cfg(not(tarpaulin_include))]
pub fn open<S: Into<String>>(size: Size, file_name: S) -> Result<Self> {
let file_name = file_name.into();
Ok(Self {
file: Rope::from_reader(BufReader::new(File::open(&file_name)?))?,
lines: vec![],
dbl_map: CharMap::default(),
tab_map: CharMap::default(),
loaded_to: 0,
file_name,
cursor: Loc::default(),
offset: Loc::default(),
size,
char_ptr: 0,
event_mgmt: EventMgmt::default(),
modified: false,
tab_width: 4,
})
}
/// Sets the tab display width measured in spaces, default being 4
pub fn set_tab_width(&mut self, tab_width: usize) {
self.tab_width = tab_width;
}
/// Save back to the file the document was opened from.
/// # Errors
/// Returns an error if the file fails to write, due to permissions
/// or character set issues.
pub fn save(&mut self) -> Result<()> {
self.modified = false;
self.file.write_to(BufWriter::new(File::create(&self.file_name)?))?;
Ok(())
}
/// Save to a specified file.
/// # Errors
/// Returns an error if the file fails to write, due to permissions
/// or character set issues.
pub fn save_as(&self, file_name: &str) -> Result<()> {
self.file.write_to(BufWriter::new(File::create(file_name)?))?;
Ok(())
}
/// Execute an event, registering it in the undo / redo.
/// You should always edit a document through this method to ensure undo and redo work.
/// # Errors
/// Will return an error if the event was unable to be completed.
pub fn exe(&mut self, ev: Event) -> Result<()> {
self.event_mgmt.register(ev.clone());
self.forth(ev)
}
/// Undo the last patch in the document.
/// # Errors
/// Will return an error if any of the events failed to be reversed.
pub fn undo(&mut self) -> Result<()> {
for ev in self.event_mgmt.undo().unwrap_or_default() {
self.forth(ev.reverse())?;
}
self.modified = !self.event_mgmt.is_undo_empty();
Ok(())
}
/// Redo the last patch in the document.
/// # Errors
/// Will return an error if any of the events failed to be re-executed.
pub fn redo(&mut self) -> Result<()> {
for ev in self.event_mgmt.redo().unwrap_or_default() {
self.forth(ev)?;
}
self.modified = true;
Ok(())
}
/// Handle an editing event, use the method `exe` for executing events.
/// # Errors
/// Returns an error if there is a problem with the specified operation.
pub fn forth(&mut self, ev: Event) -> Result<()> {
match ev {
Event::Insert(loc, ch) => self.insert(&loc, &ch),
Event::Delete(loc, st) => self.delete(loc.x..=loc.x + st.chars().count(), loc.y),
Event::InsertLine(loc, st) => self.insert_line(loc, st),
Event::DeleteLine(loc, _) => self.delete_line(loc),
Event::SplitDown(loc) => self.split_down(&loc),
Event::SpliceUp(loc) => self.splice_up(loc.y),
}
}
/// Inserts a string into this document.
/// # Errors
/// Returns an error if location is out of range.
pub fn insert(&mut self, loc: &Loc, st: &str) -> Result<()> {
self.out_of_range(loc.x, loc.y)?;
self.modified = true;
// Move cursor to location
self.goto(loc);
// Update rope
let idx = self.file.line_to_char(loc.y) + loc.x;
self.file.insert(idx, st);
// Update cache
let line: String = self.file.line(loc.y).chars().collect();
self.lines[loc.y] = line.trim_end_matches(&['\n', '\r']).to_string();
// Update unicode map
let dbl_start = self.dbl_map.shift_insertion(loc, st, self.tab_width);
let tab_start = self.tab_map.shift_insertion(loc, st, self.tab_width);
// Register new double widths and tabs
let (mut dbls, mut tabs) = form_map(st, self.tab_width);
// Shift up to match insertion position in the document
let tab_shift = self.tab_width.saturating_sub(1) * tab_start;
for e in &mut dbls {
*e = (e.0 + loc.x + dbl_start + tab_shift, e.1 + loc.x);
}
for e in &mut tabs {
*e = (e.0 + loc.x + tab_shift + dbl_start, e.1 + loc.x);
}
self.dbl_map.splice(loc, dbl_start, dbls);
self.tab_map.splice(loc, tab_start, tabs);
// Go to end x position
self.goto_x(loc.x + st.chars().count());
Ok(())
}
/// Deletes a range from this document.
/// # Errors
/// Returns an error if location is out of range.
pub fn delete<R>(&mut self, x: R, y: usize) -> Result<()>
where
R: RangeBounds<usize>,
{
let line_start = self.file.try_line_to_char(y)?;
let line_end = line_start + self.line(y).ok_or(Error::OutOfRange)?.chars().count();
// Extract range information
let (mut start, mut end) = get_range(&x, line_start, line_end);
self.valid_range(start, end, y)?;
self.modified = true;
self.goto(&Loc::at(start, y));
start += line_start;
end += line_start;
let removed = self.file.slice(start..end).to_string();
// Update unicode and tab map
self.dbl_map.shift_deletion(&Loc::at(line_start, y), (start, end), &removed, self.tab_width);
self.tab_map.shift_deletion(&Loc::at(line_start, y), (start, end), &removed, self.tab_width);
// Update rope
self.file.remove(start..end);
// Update cache
let line: String = self.file.line(y).chars().collect();
self.lines[y] = line.trim_end_matches(&['\n', '\r']).to_string();
Ok(())
}
/// Inserts a line into the document.
/// # Errors
/// Returns an error if location is out of range.
pub fn insert_line(&mut self, loc: usize, contents: String) -> Result<()> {
if !self.lines.is_empty() {
if !(self.len_lines() == 0 && loc == 0) {
self.out_of_range(0, loc.saturating_sub(1))?;
}
}
self.modified = true;
// Update unicode and tab map
self.dbl_map.shift_down(loc);
self.tab_map.shift_down(loc);
// Calculate the unicode map and tab map of this line
let (dbl_map, tab_map) = form_map(&contents, self.tab_width);
self.dbl_map.insert(loc, dbl_map);
self.tab_map.insert(loc, tab_map);
// Update cache
self.lines.insert(loc, contents.to_string());
// Update rope
let char_idx = self.file.line_to_char(loc);
self.file.insert(char_idx, &(contents + "\n"));
self.loaded_to += 1;
// Goto line
self.goto_y(loc);
Ok(())
}
/// Deletes a line from the document.
/// # Errors
/// Returns an error if location is out of range.
pub fn delete_line(&mut self, loc: usize) -> Result<()> {
self.out_of_range(0, loc)?;
// Update tab & unicode map
self.dbl_map.delete(loc);
self.tab_map.delete(loc);
self.modified = true;
// Shift down other line numbers in the hashmap
self.dbl_map.shift_up(loc);
self.tab_map.shift_up(loc);
// Update cache
self.lines.remove(loc);
// Update rope
let idx_start = self.file.line_to_char(loc);
let idx_end = self.file.line_to_char(loc + 1);
self.file.remove(idx_start..idx_end);
self.loaded_to = self.loaded_to.saturating_sub(1);
// Goto line
self.goto_y(loc);
Ok(())
}
/// Split a line in half, putting the right hand side below on a new line.
/// For when the return key is pressed.
/// # Errors
/// Returns an error if location is out of range.
pub fn split_down(&mut self, loc: &Loc) -> Result<()> {
self.out_of_range(loc.x, loc.y)?;
self.modified = true;
// Gather context
let line = self.line(loc.y).ok_or(Error::OutOfRange)?;
let rhs: String = line.chars().skip(loc.x).collect();
self.delete(loc.x.., loc.y)?;
self.insert_line(loc.y + 1, rhs)?;
self.goto(&Loc::at(0, loc.y + 1));
Ok(())
}
/// Remove the line below the specified location and append that to it.
/// For when backspace is pressed on the start of a line.
/// # Errors
/// Returns an error if location is out of range.
pub fn splice_up(&mut self, y: usize) -> Result<()> {
self.out_of_range(0, y + 1)?;
self.modified = true;
// Gather context
let length = self.line(y).ok_or(Error::OutOfRange)?.chars().count();
let below = self.line(y + 1).ok_or(Error::OutOfRange)?;
self.delete_line(y + 1)?;
self.insert(&Loc::at(length, y), &below)?;
self.goto(&Loc::at(length, y));
Ok(())
}
/// Move the cursor up
pub fn move_up(&mut self) -> Status {
// Return if already at start of document
if self.loc().y == 0 {
return Status::StartOfFile;
}
// Move up one line
if self.cursor.y == 0 {
self.offset.y -= 1;
} else {
self.cursor.y -= 1;
}
// Snap to end of line
self.fix_dangling_cursor();
// Move back if in the middle of a longer character
self.fix_split();
// Update the character pointer
self.update_char_ptr();
Status::None
}
/// Move the cursor down
pub fn move_down(&mut self) -> Status {
// Return if already on end of document
if self.len_lines() < self.loc().y + 1 {
return Status::EndOfFile;
}
// Ensure that line is loaded from buffer
self.load_to(self.loc().y + 2);
// Move down one line
if self.cursor.y == self.size.h.saturating_sub(1) {
self.offset.y += 1;
} else {
self.cursor.y += 1;
}
// Snap to end of line
self.fix_dangling_cursor();
// Move back if in the middle of a longer character
self.fix_split();
// Update the character pointer
self.update_char_ptr();
Status::None
}
/// Move the cursor left
pub fn move_left(&mut self) -> Status {
// Return if already at start of line
if self.loc().x == 0 {
return Status::StartOfLine;
}
// Determine the width of the character to traverse
let width = self.width_of(self.loc().y, self.char_ptr.saturating_sub(1));
// Move back the correct amount
for _ in 0..width {
if self.cursor.x == 0 {
self.offset.x -= 1;
} else {
self.cursor.x -= 1;
}
}
// Update the character pointer
self.char_ptr -= 1;
Status::None
}
/// Move the cursor right
pub fn move_right(&mut self) -> Status {
// Return if already on end of line
let line = self.line(self.loc().y).unwrap_or_else(|| "".to_string());
let width = width(&line, self.tab_width);
if width == self.loc().x {
return Status::EndOfLine;
}
// Determine the width of the character to traverse
let width = self.width_of(self.loc().y, self.char_ptr);
// Move forward the correct amount
for _ in 0..width {
if self.cursor.x == self.size.w.saturating_sub(1) {
self.offset.x += 1;
} else {
self.cursor.x += 1;
}
}
// Update the character pointer
self.char_ptr += 1;
Status::None
}
/// Move to the start of the line
pub fn move_home(&mut self) {
self.cursor.x = 0;
self.offset.x = 0;
self.char_ptr = 0;
}
/// Move to the end of the line
pub fn move_end(&mut self) {
let line = self.line(self.loc().y).unwrap_or_else(|| "".to_string());
let length = line.chars().count();
self.goto_x(length);
}
/// Move to the top of the document
pub fn move_top(&mut self) {
self.goto(&Loc::at(0, 0));
}
/// Move to the bottom of the document
pub fn move_bottom(&mut self) {
let last = self.len_lines();
self.goto(&Loc::at(0, last));
}
/// Move up by 1 page
pub fn move_page_up(&mut self) {
// Shift viewport to have current line at top of the document
self.offset.y += self.cursor.y;
let y = self.cursor.y;
self.cursor.y = 0;
self.char_ptr = 0;
self.cursor.x = 0;
self.offset.x = 0;
// Shift the offset up by 1 page
self.offset.y = self.offset.y.saturating_sub(self.size.h + y);
}
/// Move down by 1 page
pub fn move_page_down(&mut self) {
// Shift viewport to have current line at top of document
self.offset.y += self.cursor.y;
let y = self.cursor.y;
self.cursor.y = 0;
self.char_ptr = 0;
self.cursor.x = 0;
self.offset.x = 0;
// Shift the offset down by 1 page
let by = self.size.h.saturating_sub(y);
let len = self.len_lines();
if self.offset.y + by > len {
self.offset.y = len;
} else {
self.offset.y += by;
// Buffer new lines in viewport
self.load_to(self.offset.y + self.size.h);
}
}
/// Moves to the previous word in the document
pub fn move_prev_word(&mut self) -> Status {
let Loc { x, y } = self.char_loc();
if x == 0 && y != 0 {
return Status::StartOfLine;
}
let re = format!("(\t| {{{}}}|^| )", self.tab_width);
if let Some(mut mtch) = self.prev_match(&re) {
let len = mtch.text.chars().count();
let same = mtch.loc.x + len == x;
if !same {
mtch.loc.x += len;
}
self.goto(&mtch.loc);
if same && self.loc().x != 0 {
return self.move_prev_word();
}
}
Status::None
}
/// Moves to the next word in the document
pub fn move_next_word(&mut self) -> Status {
let Loc { x, y } = self.char_loc();
let line = self.line(y).unwrap_or_else(|| "".to_string());
if x == line.chars().count() && y != self.len_lines() {
return Status::EndOfLine;
}
let re = format!("(\t| {{{}}}|$|^ +| )", self.tab_width);
if let Some(mut mtch) = self.next_match(&re, 0) {
mtch.loc.x += mtch.text.chars().count();
self.goto(&mtch.loc);
}
Status::None
}
/// Function to search the document to find the next occurance of a regex
pub fn next_match(&mut self, regex: &str, inc: usize) -> Option<Match> {
// Prepare
let mut srch = Searcher::new(regex);
// Check current line for matches
let current: String = self.line(self.loc().y)?
.chars()
.skip(self.char_ptr + inc)
.collect();
if let Some(mut mtch) = srch.lfind(¤t) {
mtch.loc.y = self.loc().y;
mtch.loc.x += self.char_ptr + inc;
return Some(mtch)
}
// Check subsequent lines for matches
let mut line_no = self.loc().y + 1;
while let Some(line) = self.line(line_no) {
if let Some(mut mtch) = srch.lfind(&line) {
mtch.loc.y = line_no;
return Some(mtch);
}
line_no += 1;
self.load_to(line_no + 1);
}
None
}
/// Function to search the document to find the previous occurance of a regex
pub fn prev_match(&mut self, regex: &str) -> Option<Match> {
// Prepare
let mut srch = Searcher::new(regex);
// Check current line for matches
let current: String = self.line(self.loc().y)?
.chars()
.take(self.char_ptr)
.collect();
if let Some(mut mtch) = srch.rfind(¤t) {
mtch.loc.y = self.loc().y;
return Some(mtch);
}
// Check antecedent lines for matches
self.load_to(self.loc().y + 1);
let mut line_no = self.loc().y.saturating_sub(1);
while let Some(line) = self.line(line_no) {
if let Some(mut mtch) = srch.rfind(&line) {
mtch.loc.y = line_no;
return Some(mtch);
}
if line_no == 0 { break; }
line_no = line_no.saturating_sub(1);
}
None
}
/// Replace a specific part of the document with another string.
/// # Errors
/// Will error if the replacement failed to be executed.
pub fn replace(&mut self, loc: Loc, target: &str, into: &str) -> Result<()> {
self.exe(Event::Delete(loc, target.to_string()))?;
self.exe(Event::Insert(loc, into.to_string()))?;
Ok(())
}
/// Replace all instances of a regex with another string
pub fn replace_all(&mut self, target: &str, into: &str) {
self.goto(&Loc::at(0, 0));
while let Some(mtch) = self.next_match(target, 1) {
drop(self.replace(mtch.loc, &mtch.text, into));
}
}
/// Function to go to a specific position
pub fn goto(&mut self, loc: &Loc) {
self.goto_y(loc.y);
self.goto_x(loc.x);
}
/// Function to go to a specific x position
pub fn goto_x(&mut self, x: usize) {
let line = self.line(self.loc().y).unwrap_or_else(|| "".to_string());
// Bounds checking
if self.char_ptr == x {
return;
}
if line.chars().count() < x {
return;
}
// Update char position
self.char_ptr = x;
// Calculate display index
let x = self.display_idx(&Loc::at(x, self.loc().y));
let viewport = self.offset.x..self.offset.x + self.size.w;
// Move cursor
if x < self.size.w {
// Cursor will be in the viewport if the offset is 0
self.offset.x = 0;
self.cursor.x = x;
} else if viewport.contains(&x) {
// If the idx is already in viewport, don't adjust offset
self.cursor.x = x - self.offset.x;
} else {
// Index is outside of viewport
self.cursor.x = 0;
self.offset.x = x;
}
}
/// Function to go to a specific y position
pub fn goto_y(&mut self, y: usize) {
// Bounds checking
if self.loc().y != y && y <= self.len_lines() {
// Move cursor
let viewport = self.offset.y..self.offset.y + self.size.h;
if y < self.size.h {
// Cursor will be in viewport if the offset is 0
self.offset.y = 0;
self.cursor.y = y;
} else if viewport.contains(&y) {
// If the line is in viewport already, only move the cursor
self.cursor.y = y - self.offset.y;
} else {
// Index is outside of viewport
self.cursor.y = self.size.h.saturating_sub(1);
self.offset.y = y - (self.size.h.saturating_sub(1));
}
}
// Snap to end of line
self.fix_dangling_cursor();
// Ensure cursor isn't in the middle of a longer character
self.fix_split();
// Correct the character pointer
self.update_char_ptr();
// Load any lines necessary
self.load_to(self.offset.y + self.size.h);
}
/// Determines if specified coordinates are out of range of the document.
/// # Errors
/// Returns an error when the given coordinates are out of range.
pub fn out_of_range(&self, x: usize, y: usize) -> Result<()> {
let msg = "Did you forget to use load_to?";
if y >= self.len_lines() || x > self.line(y).expect(msg).chars().count() {
return Err(Error::OutOfRange);
}
Ok(())
}
/// Determines if a range is in range of the document.
/// # Errors
/// Returns an error when the given range is out of range.
pub fn valid_range(&self, start: usize, end: usize, y: usize) -> Result<()> {
self.out_of_range(start, y)?;
self.out_of_range(end, y)?;
if start > end {
return Err(Error::OutOfRange);
}
Ok(())
}
/// Calculate the display index from the character index on a certain line
fn display_idx(&self, loc: &Loc) -> usize {
let mut idx = loc.x;
// Account for double width characters
idx += self.dbl_map.count(loc, false).unwrap_or(0);
// Account for tab characters
idx += self.tab_map.count(loc, false).unwrap_or(0) * self.tab_width.saturating_sub(1);
idx
}
/// A utility function to update the character pointer when moving up or down
fn update_char_ptr(&mut self) {
let mut idx = self.loc().x;
let dbl_count = self.dbl_map.count(&self.loc(), true).unwrap_or(0);
idx -= dbl_count;
let tab_count = self.tab_map.count(&self.loc(), true).unwrap_or(0);
idx -= tab_count * self.tab_width.saturating_sub(1);
self.char_ptr = idx;
}
/// A utility function to make sure the cursor doesn't go out of range when moving
fn fix_dangling_cursor(&mut self) {
if let Some(line) = self.line(self.loc().y) {
if self.loc().x > width(&line, self.tab_width) {
self.goto_x(line.chars().count());
}
} else {
self.move_home();
}
}
/// Fixes double width and tab boundary issues
fn fix_split(&mut self) {
let mut magnitude = 0;
let Loc { x, y } = self.loc();
if let Some(map) = self.dbl_map.get(y) {
let last_dbl = self.dbl_map.count(&self.loc(), true).unwrap().saturating_sub(1);
let start = map[last_dbl].0;
if x == start + 1 {
magnitude += 1;
}
}
if let Some(map) = self.tab_map.get(y) {
let last_tab = self.tab_map.count(&self.loc(), true).unwrap().saturating_sub(1);
let start = map[last_tab].0;
let range = start..start + self.tab_width;
if range.contains(&x) {
magnitude += x - start;
}
}
for _ in 0..magnitude {
if self.cursor.x == 0 {
self.offset.x -= 1;
} else {
self.cursor.x -= 1;
}
}
}
/// Load lines in this document up to a specified index.
/// This must be called before starting to edit the document as
/// this is the function that actually load and processes the text.
pub fn load_to(&mut self, mut to: usize) {
// Make sure to doesn't go over the number of lines in the buffer
let len_lines = self.file.len_lines();
if to >= len_lines {
to = len_lines;
}
// Only act if there are lines we haven't loaded yet
if to > self.loaded_to {
// For each line, run through each character and make note of any double width characters
for i in self.loaded_to..to {
let line: String = self.file.line(i).chars().collect();
// Add to char maps
let (dbl_map, tab_map) = form_map(&line, self.tab_width);
self.dbl_map.insert(i, dbl_map);
self.tab_map.insert(i, tab_map);
// Cache this line
self.lines.push(line.trim_end_matches(&['\n', '\r']).to_string());
}
// Store new loaded point
self.loaded_to = to;
}
}
/// Get the line at a specified index
#[must_use]
pub fn line(&self, line: usize) -> Option<String> {
Some(self.lines.get(line)?.to_string())
}
/// Get the line at a specified index and trim it
#[must_use]
pub fn line_trim(&self, line: usize, start: usize, length: usize) -> Option<String> {
let line = self.line(line);
Some(trim(&line?, start, length, self.tab_width))
}
/// Returns the number of lines in the document
#[must_use]
pub fn len_lines(&self) -> usize {
self.file.len_lines().saturating_sub(1)
}
/// Evaluate the line number text for a specific line
#[must_use]
pub fn line_number(&self, request: usize) -> String {
let total = self.len_lines().to_string().len();
let num = if request + 1 > self.len_lines() {
"~".to_string()
} else {
(request + 1).to_string()
};
format!("{}{}", " ".repeat(total - num.len()), num)
}
/// Determine if a character at a certain location is a double width character.
/// x is the display index.
#[must_use]
pub fn is_dbl_width(&self, y: usize, x: usize) -> bool {
if let Some(line) = self.dbl_map.get(y) {
line.iter().any(|i| x == i.1)
} else {
false
}
}
/// Determine if a character at a certain location is a tab character.
/// x is the display index.
#[must_use]
pub fn is_tab(&self, y: usize, x: usize) -> bool {
if let Some(line) = self.tab_map.get(y) {
line.iter().any(|i| x == i.1)
} else {
false
}
}
/// Determine the width of a character at a certain location
#[must_use]
pub fn width_of(&self, y: usize, x: usize) -> usize {
if self.is_dbl_width(y, x) {
2
} else if self.is_tab(y, x) {
self.tab_width
} else {
1
}
}
/// Get the current position within the document, including offset
#[must_use]
pub const fn loc(&self) -> Loc {
Loc {
x: self.cursor.x + self.offset.x,
y: self.cursor.y + self.offset.y,
}
}
/// Get the current position within the document, with x being the character index
#[must_use]
pub const fn char_loc(&self) -> Loc {
Loc {
x: self.char_ptr,
y: self.cursor.y + self.offset.y,
}
}
}