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helix/helix-view/src/view.rs

523 lines
17 KiB
Rust

use crate::{
graphics::Rect,
gutter::{self, Gutter},
Document, DocumentId, ViewId,
};
use helix_core::{
pos_at_visual_coords, visual_coords_at_pos, Position, RopeSlice, Selection, Transaction,
};
use std::fmt;
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);
}
pub fn get(&self) -> &[Jump] {
&self.jumps
}
/// Applies a [`Transaction`] of changes to the jumplist.
/// This is necessary to ensure that changes to documents do not leave jump-list
/// selections pointing to parts of the text which no longer exist.
fn apply(&mut self, transaction: &Transaction, doc: &Document) {
let text = doc.text().slice(..);
for (doc_id, selection) in &mut self.jumps {
if doc.id() == *doc_id {
*selection = selection
.clone()
.map(transaction.changes())
.ensure_invariants(text);
}
}
}
}
#[derive(Clone)]
pub struct View {
pub id: ViewId,
pub offset: Position,
pub area: Rect,
pub doc: DocumentId,
pub jumps: JumpList,
// documents accessed from this view from the oldest one to last viewed one
pub docs_access_history: Vec<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 objects
pub object_selections: Vec<Selection>,
/// Gutter (constructor) and width of gutter, used to calculate
/// `gutter_offset`
gutters: Vec<(Gutter, usize)>,
/// cached total width of gutter
gutter_offset: u16,
}
impl fmt::Debug for View {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("View")
.field("id", &self.id)
.field("area", &self.area)
.field("doc", &self.doc)
.finish()
}
}
impl View {
pub fn new(doc: DocumentId, gutter_types: Vec<crate::editor::GutterType>) -> Self {
let mut gutters: Vec<(Gutter, usize)> = vec![];
let mut gutter_offset = 0;
use crate::editor::GutterType;
for gutter_type in &gutter_types {
let width = match gutter_type {
GutterType::Diagnostics => 1,
GutterType::LineNumbers => 5,
GutterType::Spacer => 1,
};
gutter_offset += width;
gutters.push((
match gutter_type {
GutterType::Diagnostics => gutter::diagnostics_or_breakpoints,
GutterType::LineNumbers => gutter::line_numbers,
GutterType::Spacer => gutter::padding,
},
width as usize,
));
}
if !gutter_types.is_empty() {
gutter_offset += 1;
}
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
docs_access_history: Vec::new(),
last_modified_docs: [None, None],
object_selections: Vec::new(),
gutters,
gutter_offset,
}
}
pub fn add_to_history(&mut self, id: DocumentId) {
if let Some(pos) = self.docs_access_history.iter().position(|&doc| doc == id) {
self.docs_access_history.remove(pos);
}
self.docs_access_history.push(id);
}
pub fn inner_area(&self) -> Rect {
// TODO add abilty to not use cached offset for runtime configurable gutter
self.area.clip_left(self.gutter_offset).clip_bottom(1) // -1 for statusline
}
pub fn gutters(&self) -> &[(Gutter, usize)] {
&self.gutters
}
//
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 tab_width = doc.tab_width();
// TODO: visual_coords_at_pos also does char_to_line which we ignore, can we reuse the call?
let Position { col, .. } = visual_coords_at_pos(text, pos, tab_width);
// 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 text_row = (row - inner.y) as usize + self.offset.row;
if text_row > text.len_lines() - 1 {
return Some(text.len_chars());
}
let text_col = (column - inner.x) as usize + self.offset.col;
Some(pos_at_visual_coords(
*text,
Position {
row: text_row,
col: text_col,
},
tab_width,
))
}
/// 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())
}
/// Translates screen coordinates into coordinates on the gutter of the view.
/// Returns a tuple of usize typed line and column numbers starting with 0.
/// Returns None if coordinates are not on the gutter.
pub fn gutter_coords_at_screen_coords(&self, row: u16, column: u16) -> Option<Position> {
// 1 for status
if row < self.area.top() || row >= self.area.bottom() {
return None;
}
if column < self.area.left() || column > self.area.right() {
return None;
}
Some(Position::new(
(row - self.area.top()) as usize,
(column - self.area.left()) as usize,
))
}
pub fn remove_document(&mut self, doc_id: &DocumentId) {
self.jumps.remove(doc_id);
self.docs_access_history.retain(|doc| doc != doc_id);
}
// 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,
// }
// }
/// Applies a [`Transaction`] to the view.
/// Instead of calling this function directly, use [crate::apply_transaction]
/// which applies a transaction to the [`Document`] and view together.
pub fn apply(&mut self, transaction: &Transaction, doc: &Document) -> bool {
self.jumps.apply(transaction, doc);
true
}
}
#[cfg(test)]
mod tests {
use super::*;
use helix_core::Rope;
const OFFSET: u16 = 7; // 1 diagnostic + 5 linenr + 1 gutter
const OFFSET_WITHOUT_LINE_NUMBERS: u16 = 2; // 1 diagnostic + 1 gutter
// const OFFSET: u16 = GUTTERS.iter().map(|(_, width)| *width as u16).sum();
use crate::editor::GutterType;
#[test]
fn test_text_pos_at_screen_coords() {
let mut view = View::new(
DocumentId::default(),
vec![GutterType::Diagnostics, GutterType::LineNumbers],
);
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(4)
);
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_without_line_numbers_gutter() {
let mut view = View::new(DocumentId::default(), vec![GutterType::Diagnostics]);
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, 41, 40 + OFFSET_WITHOUT_LINE_NUMBERS + 1, 4),
Some(4)
);
}
#[test]
fn test_text_pos_at_screen_coords_without_any_gutters() {
let mut view = View::new(DocumentId::default(), vec![]);
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, 41, 40 + 1, 4),
Some(4)
);
}
#[test]
fn test_text_pos_at_screen_coords_cjk() {
let mut view = View::new(
DocumentId::default(),
vec![GutterType::Diagnostics, GutterType::LineNumbers],
);
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, 4),
Some(0)
);
assert_eq!(
view.text_pos_at_screen_coords(&text, 40, 40 + OFFSET + 4, 4),
Some(4)
);
assert_eq!(
view.text_pos_at_screen_coords(&text, 40, 40 + OFFSET + 5, 4),
Some(4)
);
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(5)
);
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(),
vec![GutterType::Diagnostics, GutterType::LineNumbers],
);
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, 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)
);
}
}