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helix-plus/helix-view/src/view.rs

417 lines
13 KiB
Rust

use std::borrow::Cow;
use crate::{
graphics::Rect,
gutter::{self, Gutter},
Document, DocumentId, ViewId,
};
use helix_core::{
graphemes::{grapheme_width, RopeGraphemes},
line_ending::line_end_char_index,
visual_coords_at_pos, Position, RopeSlice, Selection,
};
type Jump = (DocumentId, Selection);
#[derive(Debug, Clone)]
pub struct JumpList {
jumps: Vec<Jump>,
current: usize,
}
impl JumpList {
pub fn new(initial: Jump) -> Self {
Self {
jumps: vec![initial],
current: 0,
}
}
pub fn push(&mut self, jump: Jump) {
self.jumps.truncate(self.current);
// don't push duplicates
if self.jumps.last() != Some(&jump) {
self.jumps.push(jump);
self.current = self.jumps.len();
}
}
pub fn forward(&mut self, count: usize) -> Option<&Jump> {
if self.current + count < self.jumps.len() {
self.current += count;
self.jumps.get(self.current)
} else {
None
}
}
// Taking view and doc to prevent unnecessary cloning when jump is not required.
pub fn backward(&mut self, view_id: ViewId, doc: &mut Document, count: usize) -> Option<&Jump> {
if let Some(current) = self.current.checked_sub(count) {
if self.current == self.jumps.len() {
let jump = (doc.id(), doc.selection(view_id).clone());
self.push(jump);
}
self.current = current;
self.jumps.get(self.current)
} else {
None
}
}
pub fn remove(&mut self, doc_id: &DocumentId) {
self.jumps.retain(|(other_id, _)| other_id != doc_id);
}
}
const GUTTERS: &[(Gutter, usize)] = &[(gutter::diagnostic, 1), (gutter::line_number, 5)];
#[derive(Debug)]
pub struct View {
pub id: ViewId,
pub doc: DocumentId,
pub offset: Position,
pub area: Rect,
pub jumps: JumpList,
/// the last accessed file before the current one
pub last_accessed_doc: Option<DocumentId>,
/// the last modified files before the current one
/// ordered from most frequent to least frequent
// uses two docs because we want to be able to swap between the
// two last modified docs which we need to manually keep track of
pub last_modified_docs: [Option<DocumentId>; 2],
/// used to store previous selections of tree-sitter objecs
pub object_selections: Vec<Selection>,
}
impl View {
pub fn new(doc: DocumentId) -> Self {
Self {
id: ViewId::default(),
doc,
offset: Position::new(0, 0),
area: Rect::default(), // will get calculated upon inserting into tree
jumps: JumpList::new((doc, Selection::point(0))), // TODO: use actual sel
last_accessed_doc: None,
last_modified_docs: [None, None],
object_selections: Vec::new(),
}
}
pub fn gutters(&self) -> &[(Gutter, usize)] {
GUTTERS
}
pub fn inner_area(&self) -> Rect {
// TODO: cache this
let offset = self
.gutters()
.iter()
.map(|(_, width)| *width as u16)
.sum::<u16>()
+ 1; // +1 for some space between gutters and line
self.area.clip_left(offset).clip_bottom(1) // -1 for statusline
}
//
pub fn offset_coords_to_in_view(
&self,
doc: &Document,
scrolloff: usize,
) -> Option<(usize, usize)> {
let cursor = doc
.selection(self.id)
.primary()
.cursor(doc.text().slice(..));
let Position { col, row: line } =
visual_coords_at_pos(doc.text().slice(..), cursor, doc.tab_width());
let inner_area = self.inner_area();
let last_line = (self.offset.row + inner_area.height as usize).saturating_sub(1);
// - 1 so we have at least one gap in the middle.
// a height of 6 with padding of 3 on each side will keep shifting the view back and forth
// as we type
let scrolloff = scrolloff.min(inner_area.height.saturating_sub(1) as usize / 2);
let last_col = self.offset.col + inner_area.width.saturating_sub(1) as usize;
let row = if line > last_line.saturating_sub(scrolloff) {
// scroll down
self.offset.row + line - (last_line.saturating_sub(scrolloff))
} else if line < self.offset.row + scrolloff {
// scroll up
line.saturating_sub(scrolloff)
} else {
self.offset.row
};
let col = if col > last_col.saturating_sub(scrolloff) {
// scroll right
self.offset.col + col - (last_col.saturating_sub(scrolloff))
} else if col < self.offset.col + scrolloff {
// scroll left
col.saturating_sub(scrolloff)
} else {
self.offset.col
};
if row == self.offset.row && col == self.offset.col {
None
} else {
Some((row, col))
}
}
pub fn ensure_cursor_in_view(&mut self, doc: &Document, scrolloff: usize) {
if let Some((row, col)) = self.offset_coords_to_in_view(doc, scrolloff) {
self.offset.row = row;
self.offset.col = col;
}
}
pub fn is_cursor_in_view(&mut self, doc: &Document, scrolloff: usize) -> bool {
self.offset_coords_to_in_view(doc, scrolloff).is_none()
}
/// Calculates the last visible line on screen
#[inline]
pub fn last_line(&self, doc: &Document) -> usize {
let height = self.inner_area().height;
std::cmp::min(
// Saturating subs to make it inclusive zero indexing.
(self.offset.row + height as usize).saturating_sub(1),
doc.text().len_lines().saturating_sub(1),
)
}
/// Translates a document position to an absolute position in the terminal.
/// Returns a (line, col) position if the position is visible on screen.
// TODO: Could return width as well for the character width at cursor.
pub fn screen_coords_at_pos(
&self,
doc: &Document,
text: RopeSlice,
pos: usize,
) -> Option<Position> {
let line = text.char_to_line(pos);
if line < self.offset.row || line > self.last_line(doc) {
// Line is not visible on screen
return None;
}
let line_start = text.line_to_char(line);
let line_slice = text.slice(line_start..pos);
let mut col = 0;
let tab_width = doc.tab_width();
for grapheme in RopeGraphemes::new(line_slice) {
if grapheme == "\t" {
col += tab_width;
} else {
let grapheme = Cow::from(grapheme);
col += grapheme_width(&grapheme);
}
}
// It is possible for underflow to occur if the buffer length is larger than the terminal width.
let row = line.saturating_sub(self.offset.row);
let col = col.saturating_sub(self.offset.col);
Some(Position::new(row, col))
}
pub fn text_pos_at_screen_coords(
&self,
text: &RopeSlice,
row: u16,
column: u16,
tab_width: usize,
) -> Option<usize> {
let inner = self.inner_area();
// 1 for status
if row < inner.top() || row >= inner.bottom() {
return None;
}
if column < inner.left() || column > inner.right() {
return None;
}
let line_number = (row - inner.y) as usize + self.offset.row;
if line_number > text.len_lines() - 1 {
return Some(text.len_chars());
}
let mut pos = text.line_to_char(line_number);
let current_line = text.line(line_number);
let target = (column - inner.x) as usize + self.offset.col;
let mut selected = 0;
for grapheme in RopeGraphemes::new(current_line) {
if selected >= target {
break;
}
if grapheme == "\t" {
selected += tab_width;
} else {
let width = grapheme_width(&Cow::from(grapheme));
selected += width;
}
pos += grapheme.chars().count();
}
Some(pos.min(line_end_char_index(&text.slice(..), line_number)))
}
/// Translates a screen position to position in the text document.
/// Returns a usize typed position in bounds of the text if found in this view, None if out of view.
pub fn pos_at_screen_coords(&self, doc: &Document, row: u16, column: u16) -> Option<usize> {
self.text_pos_at_screen_coords(&doc.text().slice(..), row, column, doc.tab_width())
}
// pub fn traverse<F>(&self, text: RopeSlice, start: usize, end: usize, fun: F)
// where
// F: Fn(usize, usize),
// {
// let start = self.screen_coords_at_pos(text, start);
// let end = self.screen_coords_at_pos(text, end);
// match (start, end) {
// // fully on screen
// (Some(start), Some(end)) => {
// // we want to calculate ends of lines for each char..
// }
// // from start to end of screen
// (Some(start), None) => {}
// // from start of screen to end
// (None, Some(end)) => {}
// // not on screen
// (None, None) => return,
// }
// }
}
#[cfg(test)]
mod tests {
use super::*;
use helix_core::Rope;
const OFFSET: u16 = 7; // 1 diagnostic + 5 linenr + 1 gutter
// const OFFSET: u16 = GUTTERS.iter().map(|(_, width)| *width as u16).sum();
#[test]
fn test_text_pos_at_screen_coords() {
let mut view = View::new(DocumentId::default());
view.area = Rect::new(40, 40, 40, 40);
let rope = Rope::from_str("abc\n\tdef");
let text = rope.slice(..);
assert_eq!(view.text_pos_at_screen_coords(&text, 40, 2, 4), None);
assert_eq!(view.text_pos_at_screen_coords(&text, 40, 41, 4), None);
assert_eq!(view.text_pos_at_screen_coords(&text, 0, 2, 4), None);
assert_eq!(view.text_pos_at_screen_coords(&text, 0, 49, 4), None);
assert_eq!(view.text_pos_at_screen_coords(&text, 0, 41, 4), None);
assert_eq!(view.text_pos_at_screen_coords(&text, 40, 81, 4), None);
assert_eq!(view.text_pos_at_screen_coords(&text, 78, 41, 4), None);
assert_eq!(
view.text_pos_at_screen_coords(&text, 40, 40 + OFFSET + 3, 4),
Some(3)
);
assert_eq!(view.text_pos_at_screen_coords(&text, 40, 80, 4), Some(3));
assert_eq!(
view.text_pos_at_screen_coords(&text, 41, 40 + OFFSET + 1, 4),
Some(5)
);
assert_eq!(
view.text_pos_at_screen_coords(&text, 41, 40 + OFFSET + 4, 4),
Some(5)
);
assert_eq!(
view.text_pos_at_screen_coords(&text, 41, 40 + OFFSET + 7, 4),
Some(8)
);
assert_eq!(view.text_pos_at_screen_coords(&text, 41, 80, 4), Some(8));
}
#[test]
fn test_text_pos_at_screen_coords_cjk() {
let mut view = View::new(DocumentId::default());
view.area = Rect::new(40, 40, 40, 40);
let rope = Rope::from_str("Hi! こんにちは皆さん");
let text = rope.slice(..);
assert_eq!(
view.text_pos_at_screen_coords(&text, 40, 40 + OFFSET + 0, 4),
Some(0)
);
assert_eq!(
view.text_pos_at_screen_coords(&text, 40, 40 + OFFSET + 5, 4),
Some(5)
);
assert_eq!(
view.text_pos_at_screen_coords(&text, 40, 40 + OFFSET + 6, 4),
Some(5)
);
assert_eq!(
view.text_pos_at_screen_coords(&text, 40, 40 + OFFSET + 7, 4),
Some(6)
);
assert_eq!(
view.text_pos_at_screen_coords(&text, 40, 40 + OFFSET + 8, 4),
Some(6)
);
}
#[test]
fn test_text_pos_at_screen_coords_graphemes() {
let mut view = View::new(DocumentId::default());
view.area = Rect::new(40, 40, 40, 40);
let rope = Rope::from_str("Hèl̀l̀ò world!");
let text = rope.slice(..);
assert_eq!(
view.text_pos_at_screen_coords(&text, 40, 40 + OFFSET + 0, 4),
Some(0)
);
assert_eq!(
view.text_pos_at_screen_coords(&text, 40, 40 + OFFSET + 1, 4),
Some(1)
);
assert_eq!(
view.text_pos_at_screen_coords(&text, 40, 40 + OFFSET + 2, 4),
Some(3)
);
assert_eq!(
view.text_pos_at_screen_coords(&text, 40, 40 + OFFSET + 3, 4),
Some(5)
);
assert_eq!(
view.text_pos_at_screen_coords(&text, 40, 40 + OFFSET + 4, 4),
Some(7)
);
}
}