use crate::{align_view, editor::GutterType, graphics::Rect, Align, Document, DocumentId, ViewId}; use helix_core::{ pos_at_visual_coords, visual_coords_at_pos, Position, RopeSlice, Selection, Transaction, }; use std::{ collections::{HashMap, VecDeque}, fmt, }; const JUMP_LIST_CAPACITY: usize = 30; type Jump = (DocumentId, Selection); #[derive(Debug, Clone)] pub struct JumpList { jumps: VecDeque, current: usize, } impl JumpList { pub fn new(initial: Jump) -> Self { let mut jumps = VecDeque::with_capacity(JUMP_LIST_CAPACITY); jumps.push_back(initial); Self { jumps, current: 0 } } pub fn push(&mut self, jump: Jump) { self.jumps.truncate(self.current); // don't push duplicates if self.jumps.back() != Some(&jump) { // If the jumplist is full, drop the oldest item. while self.jumps.len() >= JUMP_LIST_CAPACITY { self.jumps.pop_front(); } self.jumps.push_back(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 iter(&self) -> impl Iterator { self.jumps.iter() } /// 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, /// 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; 2], /// used to store previous selections of tree-sitter objects pub object_selections: Vec, /// GutterTypes used to fetch Gutter (constructor) and width for rendering gutters: Vec, /// A mapping between documents and the last history revision the view was updated at. /// Changes between documents and views are synced lazily when switching windows. This /// mapping keeps track of the last applied history revision so that only new changes /// are applied. doc_revisions: HashMap, } 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) -> 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 docs_access_history: Vec::new(), last_modified_docs: [None, None], object_selections: Vec::new(), gutters: gutter_types, doc_revisions: HashMap::new(), } } 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, doc: &Document) -> Rect { self.area.clip_left(self.gutter_offset(doc)).clip_bottom(1) // -1 for statusline } pub fn inner_height(&self) -> usize { self.area.clip_bottom(1).height.into() // -1 for statusline } pub fn gutters(&self) -> &[GutterType] { &self.gutters } pub fn gutter_offset(&self, doc: &Document) -> u16 { self.gutters .iter() .map(|gutter| gutter.width(self, doc) as u16) .sum() } // pub fn offset_coords_to_in_view( &self, doc: &Document, scrolloff: usize, ) -> Option<(usize, usize)> { self.offset_coords_to_in_view_center(doc, scrolloff, false) } pub fn offset_coords_to_in_view_center( &self, doc: &Document, scrolloff: usize, centering: bool, ) -> 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(doc); let last_line = (self.offset.row + inner_area.height as usize).saturating_sub(1); let last_col = self.offset.col + inner_area.width.saturating_sub(1) as usize; let new_offset = |scrolloff: usize| { // - 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 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 }; (row, col) }; let current_offset = (self.offset.row, self.offset.col); if centering { // return None if cursor is out of view let offset = new_offset(0); (offset == current_offset).then(|| { if scrolloff == 0 { offset } else { new_offset(scrolloff) } }) } else { // return None if cursor is in (view - scrolloff) let offset = new_offset(scrolloff); (offset != current_offset).then(|| offset) // TODO: use 'then_some' when 1.62 <= MSRV } } pub fn ensure_cursor_in_view(&mut self, doc: &Document, scrolloff: usize) { if let Some((row, col)) = self.offset_coords_to_in_view_center(doc, scrolloff, false) { self.offset.row = row; self.offset.col = col; } } pub fn ensure_cursor_in_view_center(&mut self, doc: &Document, scrolloff: usize) { if let Some((row, col)) = self.offset_coords_to_in_view_center(doc, scrolloff, true) { self.offset.row = row; self.offset.col = col; } else { align_view(doc, self, Align::Center); } } 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 { std::cmp::min( // Saturating subs to make it inclusive zero indexing. (self.offset.row + self.inner_height()).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 { 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, doc: &Document, row: u16, column: u16, tab_width: usize, ) -> Option { let text = doc.text().slice(..); let inner = self.inner_area(doc); // 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 { self.text_pos_at_screen_coords(doc, 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 { // 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(&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. pub fn apply(&mut self, transaction: &Transaction, doc: &mut Document) { self.jumps.apply(transaction, doc); self.doc_revisions .insert(doc.id(), doc.get_current_revision()); } pub fn sync_changes(&mut self, doc: &mut Document) { let latest_revision = doc.get_current_revision(); let current_revision = *self .doc_revisions .entry(doc.id()) .or_insert(latest_revision); if current_revision == latest_revision { return; } log::debug!( "Syncing view {:?} between {} and {}", self.id, current_revision, latest_revision ); if let Some(transaction) = doc.history.get_mut().changes_since(current_revision) { self.apply(&transaction, doc); } } } #[cfg(test)] mod tests { use super::*; use helix_core::Rope; const OFFSET: u16 = 3; // 1 diagnostic + 2 linenr (< 100 lines) const OFFSET_WITHOUT_LINE_NUMBERS: u16 = 1; // 1 diagnostic // const OFFSET: u16 = GUTTERS.iter().map(|(_, width)| *width as u16).sum(); use crate::document::Document; 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 doc = Document::from(rope, None); assert_eq!(view.text_pos_at_screen_coords(&doc, 40, 2, 4), None); assert_eq!(view.text_pos_at_screen_coords(&doc, 40, 41, 4), None); assert_eq!(view.text_pos_at_screen_coords(&doc, 0, 2, 4), None); assert_eq!(view.text_pos_at_screen_coords(&doc, 0, 49, 4), None); assert_eq!(view.text_pos_at_screen_coords(&doc, 0, 41, 4), None); assert_eq!(view.text_pos_at_screen_coords(&doc, 40, 81, 4), None); assert_eq!(view.text_pos_at_screen_coords(&doc, 78, 41, 4), None); assert_eq!( view.text_pos_at_screen_coords(&doc, 40, 40 + OFFSET + 3, 4), Some(3) ); assert_eq!(view.text_pos_at_screen_coords(&doc, 40, 80, 4), Some(3)); assert_eq!( view.text_pos_at_screen_coords(&doc, 41, 40 + OFFSET + 1, 4), Some(4) ); assert_eq!( view.text_pos_at_screen_coords(&doc, 41, 40 + OFFSET + 4, 4), Some(5) ); assert_eq!( view.text_pos_at_screen_coords(&doc, 41, 40 + OFFSET + 7, 4), Some(8) ); assert_eq!(view.text_pos_at_screen_coords(&doc, 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 doc = Document::from(rope, None); assert_eq!( view.text_pos_at_screen_coords(&doc, 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 doc = Document::from(rope, None); assert_eq!(view.text_pos_at_screen_coords(&doc, 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 doc = Document::from(rope, None); assert_eq!( view.text_pos_at_screen_coords(&doc, 40, 40 + OFFSET, 4), Some(0) ); assert_eq!( view.text_pos_at_screen_coords(&doc, 40, 40 + OFFSET + 4, 4), Some(4) ); assert_eq!( view.text_pos_at_screen_coords(&doc, 40, 40 + OFFSET + 5, 4), Some(4) ); assert_eq!( view.text_pos_at_screen_coords(&doc, 40, 40 + OFFSET + 6, 4), Some(5) ); assert_eq!( view.text_pos_at_screen_coords(&doc, 40, 40 + OFFSET + 7, 4), Some(5) ); assert_eq!( view.text_pos_at_screen_coords(&doc, 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 doc = Document::from(rope, None); assert_eq!( view.text_pos_at_screen_coords(&doc, 40, 40 + OFFSET, 4), Some(0) ); assert_eq!( view.text_pos_at_screen_coords(&doc, 40, 40 + OFFSET + 1, 4), Some(1) ); assert_eq!( view.text_pos_at_screen_coords(&doc, 40, 40 + OFFSET + 2, 4), Some(3) ); assert_eq!( view.text_pos_at_screen_coords(&doc, 40, 40 + OFFSET + 3, 4), Some(5) ); assert_eq!( view.text_pos_at_screen_coords(&doc, 40, 40 + OFFSET + 4, 4), Some(7) ); } }