| // Copyright 2016 Joe Wilm, The Alacritty Project Contributors |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| //! A specialized 2d grid implementation optimized for use in a terminal. |
| |
| use std::cmp::{min, max, Ordering}; |
| use std::ops::{Deref, Range, Index, IndexMut, RangeTo, RangeFrom, RangeFull}; |
| |
| use index::{self, Point, Line, Column, IndexRange}; |
| use selection::Selection; |
| |
| mod row; |
| pub use self::row::Row; |
| |
| #[cfg(test)] |
| mod tests; |
| |
| mod storage; |
| use self::storage::Storage; |
| |
| /// Bidirection iterator |
| pub trait BidirectionalIterator: Iterator { |
| fn prev(&mut self) -> Option<Self::Item>; |
| } |
| |
| /// An item in the grid along with its Line and Column. |
| pub struct Indexed<T> { |
| pub inner: T, |
| pub line: Line, |
| pub column: Column, |
| } |
| |
| impl<T> Deref for Indexed<T> { |
| type Target = T; |
| |
| #[inline] |
| fn deref(&self) -> &T { |
| &self.inner |
| } |
| } |
| |
| impl<T: PartialEq> ::std::cmp::PartialEq for Grid<T> { |
| fn eq(&self, other: &Self) -> bool { |
| self.cols.eq(&other.cols) && |
| self.lines.eq(&other.lines) && |
| self.raw.eq(&other.raw) |
| } |
| } |
| |
| /// Represents the terminal display contents |
| #[derive(Clone, Debug, Deserialize, Serialize)] |
| pub struct Grid<T> { |
| /// Lines in the grid. Each row holds a list of cells corresponding to the |
| /// columns in that row. |
| raw: Storage<Row<T>>, |
| |
| /// Number of columns |
| cols: index::Column, |
| |
| /// Number of lines. |
| /// |
| /// Invariant: lines is equivalent to raw.len() |
| lines: index::Line, |
| |
| /// Offset of displayed area |
| /// |
| /// If the displayed region isn't at the bottom of the screen, it stays |
| /// stationary while more text is emitted. The scrolling implementation |
| /// updates this offset accordingly. |
| #[serde(default)] |
| display_offset: usize, |
| |
| /// An limit on how far back it's possible to scroll |
| #[serde(default)] |
| scroll_limit: usize, |
| |
| /// Selected region |
| #[serde(skip)] |
| pub selection: Option<Selection>, |
| } |
| |
| pub struct GridIterator<'a, T: 'a> { |
| /// Immutable grid reference |
| grid: &'a Grid<T>, |
| |
| /// Current position of the iterator within the grid. |
| pub cur: Point<usize>, |
| |
| /// Bottom of screen (buffer) |
| bot: usize, |
| |
| /// Top of screen (buffer) |
| top: usize, |
| } |
| |
| pub enum Scroll { |
| Lines(isize), |
| PageUp, |
| PageDown, |
| Top, |
| Bottom, |
| } |
| |
| impl<T: Copy + Clone> Grid<T> { |
| pub fn new(lines: index::Line, cols: index::Column, scrollback: usize, template: T) -> Grid<T> { |
| let mut raw = Storage::with_capacity(*lines + scrollback, lines); |
| |
| // Allocate all lines in the buffer, including scrollback history |
| // |
| // TODO (jwilm) Allocating each line at this point is expensive and |
| // delays startup. A nice solution might be having `Row` delay |
| // allocation until it's actually used. |
| for _ in 0..raw.capacity() { |
| raw.push(Row::new(cols, &template)); |
| } |
| |
| Grid { |
| raw, |
| cols, |
| lines, |
| display_offset: 0, |
| scroll_limit: 0, |
| selection: None, |
| } |
| } |
| |
| pub fn visible_to_buffer(&self, point: Point) -> Point<usize> { |
| Point { |
| line: self.visible_line_to_buffer(point.line), |
| col: point.col |
| } |
| } |
| |
| pub fn buffer_to_visible(&self, point: Point<usize>) -> Point { |
| Point { |
| line: self.buffer_line_to_visible(point.line).expect("Line not visible"), |
| col: point.col |
| } |
| } |
| |
| pub fn buffer_line_to_visible(&self, line: usize) -> Option<Line> { |
| if line >= self.display_offset { |
| self.offset_to_line(line - self.display_offset) |
| } else { |
| None |
| } |
| } |
| |
| pub fn visible_line_to_buffer(&self, line: Line) -> usize { |
| self.line_to_offset(line) + self.display_offset |
| } |
| |
| pub fn scroll_display(&mut self, scroll: Scroll) { |
| match scroll { |
| Scroll::Lines(count) => { |
| self.display_offset = min( |
| max((self.display_offset as isize) + count, 0isize) as usize, |
| self.scroll_limit |
| ); |
| }, |
| Scroll::PageUp => { |
| self.display_offset = min( |
| self.display_offset + self.lines.0, |
| self.scroll_limit |
| ); |
| }, |
| Scroll::PageDown => { |
| self.display_offset -= min( |
| self.display_offset, |
| self.lines.0 |
| ); |
| }, |
| Scroll::Top => self.display_offset = self.scroll_limit, |
| Scroll::Bottom => self.display_offset = 0, |
| } |
| } |
| |
| pub fn resize( |
| &mut self, |
| lines: index::Line, |
| cols: index::Column, |
| template: &T, |
| ) { |
| // Check that there's actually work to do and return early if not |
| if lines == self.lines && cols == self.cols { |
| return; |
| } |
| |
| match self.lines.cmp(&lines) { |
| Ordering::Less => self.grow_lines(lines, template), |
| Ordering::Greater => self.shrink_lines(lines), |
| Ordering::Equal => (), |
| } |
| |
| match self.cols.cmp(&cols) { |
| Ordering::Less => self.grow_cols(cols, template), |
| Ordering::Greater => self.shrink_cols(cols), |
| Ordering::Equal => (), |
| } |
| } |
| |
| fn increase_scroll_limit(&mut self, count: usize) { |
| self.scroll_limit = min(self.scroll_limit + count, self.raw.len() - *self.lines); |
| } |
| |
| fn decrease_scroll_limit(&mut self, count: usize) { |
| self.scroll_limit = self.scroll_limit.saturating_sub(count); |
| } |
| |
| /// Add lines to the visible area |
| /// |
| /// The behavior in Terminal.app and iTerm.app is to keep the cursor at the |
| /// bottom of the screen as long as there is scrollback available. Once |
| /// scrollback is exhausted, new lines are simply added to the bottom of the |
| /// screen. |
| /// |
| /// Alacritty takes a different approach. Rather than trying to move with |
| /// the scrollback, we simply pull additional lines from the back of the |
| /// buffer in order to populate the new area. |
| fn grow_lines( |
| &mut self, |
| new_line_count: index::Line, |
| template: &T, |
| ) { |
| let previous_scroll_limit = self.scroll_limit; |
| let lines_added = new_line_count - self.lines; |
| |
| // Need to "resize" before updating buffer |
| self.raw.set_visible_lines(new_line_count); |
| self.lines = new_line_count; |
| |
| // Add new lines to bottom |
| self.scroll_up(&(Line(0)..new_line_count), lines_added, template); |
| |
| self.scroll_limit = self.scroll_limit.saturating_sub(*lines_added); |
| } |
| |
| fn grow_cols(&mut self, cols: index::Column, template: &T) { |
| for row in self.raw.iter_mut() { |
| row.grow(cols, template); |
| } |
| |
| // Update self cols |
| self.cols = cols; |
| } |
| |
| /// Remove lines from the visible area |
| /// |
| /// The behavior in Terminal.app and iTerm.app is to keep the cursor at the |
| /// bottom of the screen. This is achieved by pushing history "out the top" |
| /// of the terminal window. |
| /// |
| /// Alacritty takes the same approach. |
| fn shrink_lines(&mut self, target: index::Line) { |
| // TODO handle disabled scrollback |
| // while index::Line(self.raw.len()) != lines { |
| // self.raw.pop(); |
| // } |
| |
| let prev = self.lines; |
| |
| self.selection = None; |
| self.raw.rotate(*prev as isize - *target as isize); |
| self.raw.set_visible_lines(target); |
| self.lines = target; |
| } |
| |
| /// Convert a Line index (active region) to a buffer offset |
| /// |
| /// # Panics |
| /// |
| /// This method will panic if `Line` is larger than the grid dimensions |
| pub fn line_to_offset(&self, line: index::Line) -> usize { |
| assert!(line < self.num_lines()); |
| |
| *(self.num_lines() - line - 1) |
| } |
| |
| pub fn offset_to_line(&self, offset: usize) -> Option<Line> { |
| if offset < *self.num_lines() { |
| Some(self.lines - offset - 1) |
| } else { |
| None |
| } |
| } |
| |
| #[inline] |
| pub fn scroll_down( |
| &mut self, |
| region: &Range<index::Line>, |
| positions: index::Line, |
| template: &T, |
| ) { |
| // Whether or not there is a scrolling region active, as long as it |
| // starts at the top, we can do a full rotation which just involves |
| // changing the start index. |
| // |
| // To accomodate scroll regions, rows are reordered at the end. |
| if region.start == Line(0) { |
| // Rotate the entire line buffer. If there's a scrolling region |
| // active, the bottom lines are restored in the next step. |
| self.raw.rotate_up(*positions); |
| if let Some(ref mut selection) = self.selection { |
| selection.rotate(-(*positions as isize)); |
| } |
| |
| self.decrease_scroll_limit(*positions); |
| |
| // Now, restore any scroll region lines |
| let lines = self.lines; |
| for i in IndexRange(region.end .. lines) { |
| self.raw.swap_lines(i, i + positions); |
| } |
| |
| // Finally, reset recycled lines |
| for i in IndexRange(Line(0)..positions) { |
| self.raw[i].reset(&template); |
| } |
| } else { |
| // Subregion rotation |
| for line in IndexRange((region.start + positions)..region.end).rev() { |
| self.raw.swap_lines(line, line - positions); |
| } |
| |
| for line in IndexRange(region.start .. (region.start + positions)) { |
| self.raw[line].reset(&template); |
| } |
| } |
| } |
| |
| /// scroll_up moves lines at the bottom towards the top |
| /// |
| /// This is the performance-sensitive part of scrolling. |
| #[inline] |
| pub fn scroll_up( |
| &mut self, |
| region: &Range<index::Line>, |
| positions: index::Line, |
| template: &T |
| ) { |
| if region.start == Line(0) { |
| // Update display offset when not pinned to active area |
| if self.display_offset != 0 { |
| self.display_offset += *positions; |
| } |
| |
| self.increase_scroll_limit(*positions); |
| |
| // Rotate the entire line buffer. If there's a scrolling region |
| // active, the bottom lines are restored in the next step. |
| self.raw.rotate(-(*positions as isize)); |
| if let Some(ref mut selection) = self.selection { |
| selection.rotate(*positions as isize); |
| } |
| |
| // Now, restore any lines outside the scroll region |
| for idx in (*region.end .. *self.num_lines()).rev() { |
| // First do the swap |
| self.raw.swap_lines(Line(idx), Line(idx) - positions); |
| } |
| |
| // Finally, reset recycled lines |
| // |
| // Recycled lines are just above the end of the scrolling region. |
| for i in 0..*positions { |
| self.raw[region.end - i - 1].reset(&template); |
| } |
| } else { |
| // Subregion rotation |
| for line in IndexRange(region.start..(region.end - positions)) { |
| self.raw.swap_lines(line, line + positions); |
| } |
| |
| // Clear reused lines |
| for line in IndexRange((region.end - positions) .. region.end) { |
| self.raw[line].reset(&template); |
| } |
| } |
| } |
| } |
| |
| impl<T> Grid<T> { |
| #[inline] |
| pub fn num_lines(&self) -> index::Line { |
| self.lines |
| } |
| |
| pub fn display_iter(&self) -> DisplayIter<T> { |
| DisplayIter::new(self) |
| } |
| |
| #[inline] |
| pub fn num_cols(&self) -> index::Column { |
| self.cols |
| } |
| |
| pub fn iter_from(&self, point: Point<usize>) -> GridIterator<T> { |
| GridIterator { |
| grid: self, |
| cur: point, |
| bot: self.display_offset, |
| top: self.display_offset + *self.num_lines() - 1, |
| } |
| } |
| |
| #[inline] |
| pub fn contains(&self, point: &Point) -> bool { |
| self.lines > point.line && self.cols > point.col |
| } |
| |
| // /// Swap two lines in the grid |
| // /// |
| // /// This could have used slice::swap internally, but we are able to have |
| // /// better error messages by doing the bounds checking ourselves. |
| // #[inline] |
| // pub fn swap_lines(&mut self, src: index::Line, dst: index::Line) { |
| // self.raw.swap(*src, *dst); |
| // } |
| |
| fn shrink_cols(&mut self, cols: index::Column) { |
| for row in self.raw.iter_mut() { |
| row.shrink(cols); |
| } |
| |
| self.cols = cols; |
| } |
| } |
| |
| impl<'a, T> Iterator for GridIterator<'a, T> { |
| type Item = &'a T; |
| |
| fn next(&mut self) -> Option<Self::Item> { |
| let last_col = self.grid.num_cols() - Column(1); |
| match self.cur { |
| Point { line, col } if (line == self.bot) && (col == last_col) => None, |
| Point { col, .. } if |
| (col == last_col) => { |
| self.cur.line -= 1; |
| self.cur.col = Column(0); |
| Some(&self.grid[self.cur.line][self.cur.col]) |
| }, |
| _ => { |
| self.cur.col += Column(1); |
| Some(&self.grid[self.cur.line][self.cur.col]) |
| } |
| } |
| } |
| } |
| |
| impl<'a, T> BidirectionalIterator for GridIterator<'a, T> { |
| fn prev(&mut self) -> Option<Self::Item> { |
| let num_cols = self.grid.num_cols(); |
| |
| match self.cur { |
| Point { line, col: Column(0) } if line == self.top => None, |
| Point { col: Column(0), .. } => { |
| self.cur.line += 1; |
| self.cur.col = num_cols - Column(1); |
| Some(&self.grid[self.cur.line][self.cur.col]) |
| }, |
| _ => { |
| self.cur.col -= Column(1); |
| Some(&self.grid[self.cur.line][self.cur.col]) |
| } |
| } |
| } |
| } |
| |
| /// Index active region by line |
| impl<T> Index<index::Line> for Grid<T> { |
| type Output = Row<T>; |
| |
| #[inline] |
| fn index(&self, index: index::Line) -> &Row<T> { |
| &self.raw[index] |
| } |
| } |
| |
| /// Index with buffer offset |
| impl<T> Index<usize> for Grid<T> { |
| type Output = Row<T>; |
| |
| #[inline] |
| fn index(&self, index: usize) -> &Row<T> { |
| &self.raw[index] |
| } |
| } |
| |
| impl<T> IndexMut<index::Line> for Grid<T> { |
| #[inline] |
| fn index_mut(&mut self, index: index::Line) -> &mut Row<T> { |
| &mut self.raw[index] |
| } |
| } |
| |
| impl<'point, T> Index<&'point Point> for Grid<T> { |
| type Output = T; |
| |
| #[inline] |
| fn index<'a>(&'a self, point: &Point) -> &'a T { |
| &self[point.line][point.col] |
| } |
| } |
| |
| impl<'point, T> IndexMut<&'point Point> for Grid<T> { |
| #[inline] |
| fn index_mut<'a, 'b>(&'a mut self, point: &'b Point) -> &'a mut T { |
| &mut self[point.line][point.col] |
| } |
| } |
| |
| // ------------------------------------------------------------------------------------------------- |
| // REGIONS |
| // ------------------------------------------------------------------------------------------------- |
| |
| /// A subset of lines in the grid |
| /// |
| /// May be constructed using Grid::region(..) |
| pub struct Region<'a, T: 'a> { |
| start: Line, |
| end: Line, |
| raw: &'a Storage<Row<T>>, |
| } |
| |
| /// A mutable subset of lines in the grid |
| /// |
| /// May be constructed using Grid::region_mut(..) |
| pub struct RegionMut<'a, T: 'a> { |
| start: Line, |
| end: Line, |
| raw: &'a mut Storage<Row<T>>, |
| } |
| |
| impl<'a, T> RegionMut<'a, T> { |
| /// Call the provided function for every item in this region |
| pub fn each<F: Fn(&mut T)>(self, func: F) { |
| for row in self { |
| for item in row { |
| func(item) |
| } |
| } |
| } |
| } |
| |
| pub trait IndexRegion<I, T> { |
| /// Get an immutable region of Self |
| fn region<'a>(&'a self, _: I) -> Region<'a, T>; |
| |
| /// Get a mutable region of Self |
| fn region_mut<'a>(&'a mut self, _: I) -> RegionMut<'a, T>; |
| } |
| |
| impl<T> IndexRegion<Range<Line>, T> for Grid<T> { |
| fn region(&self, index: Range<Line>) -> Region<T> { |
| assert!(index.start < self.num_lines()); |
| assert!(index.end <= self.num_lines()); |
| assert!(index.start <= index.end); |
| Region { |
| start: index.start, |
| end: index.end, |
| raw: &self.raw |
| } |
| } |
| fn region_mut(&mut self, index: Range<Line>) -> RegionMut<T> { |
| assert!(index.start < self.num_lines()); |
| assert!(index.end <= self.num_lines()); |
| assert!(index.start <= index.end); |
| RegionMut { |
| start: index.start, |
| end: index.end, |
| raw: &mut self.raw |
| } |
| } |
| } |
| |
| impl<T> IndexRegion<RangeTo<Line>, T> for Grid<T> { |
| fn region(&self, index: RangeTo<Line>) -> Region<T> { |
| assert!(index.end <= self.num_lines()); |
| Region { |
| start: Line(0), |
| end: index.end, |
| raw: &self.raw |
| } |
| } |
| fn region_mut(&mut self, index: RangeTo<Line>) -> RegionMut<T> { |
| assert!(index.end <= self.num_lines()); |
| RegionMut { |
| start: Line(0), |
| end: index.end, |
| raw: &mut self.raw |
| } |
| } |
| } |
| |
| impl<T> IndexRegion<RangeFrom<Line>, T> for Grid<T> { |
| fn region(&self, index: RangeFrom<Line>) -> Region<T> { |
| assert!(index.start < self.num_lines()); |
| Region { |
| start: index.start, |
| end: self.num_lines(), |
| raw: &self.raw |
| } |
| } |
| fn region_mut(&mut self, index: RangeFrom<Line>) -> RegionMut<T> { |
| assert!(index.start < self.num_lines()); |
| RegionMut { |
| start: index.start, |
| end: self.num_lines(), |
| raw: &mut self.raw |
| } |
| } |
| } |
| |
| impl<T> IndexRegion<RangeFull, T> for Grid<T> { |
| fn region(&self, _: RangeFull) -> Region<T> { |
| Region { |
| start: Line(0), |
| end: self.num_lines(), |
| raw: &self.raw |
| } |
| } |
| |
| fn region_mut(&mut self, _: RangeFull) -> RegionMut<T> { |
| RegionMut { |
| start: Line(0), |
| end: self.num_lines(), |
| raw: &mut self.raw |
| } |
| } |
| } |
| |
| pub struct RegionIter<'a, T: 'a> { |
| end: Line, |
| cur: Line, |
| raw: &'a Storage<Row<T>>, |
| } |
| |
| pub struct RegionIterMut<'a, T: 'a> { |
| end: Line, |
| cur: Line, |
| raw: &'a mut Storage<Row<T>>, |
| } |
| |
| impl<'a, T> IntoIterator for Region<'a, T> { |
| type Item = &'a Row<T>; |
| type IntoIter = RegionIter<'a, T>; |
| |
| fn into_iter(self) -> Self::IntoIter { |
| RegionIter { |
| end: self.end, |
| cur: self.start, |
| raw: self.raw |
| } |
| } |
| } |
| |
| impl<'a, T> IntoIterator for RegionMut<'a, T> { |
| type Item = &'a mut Row<T>; |
| type IntoIter = RegionIterMut<'a, T>; |
| |
| fn into_iter(self) -> Self::IntoIter { |
| RegionIterMut { |
| end: self.end, |
| cur: self.start, |
| raw: self.raw |
| } |
| } |
| } |
| |
| impl<'a, T> Iterator for RegionIter<'a, T> { |
| type Item = &'a Row<T>; |
| fn next(&mut self) -> Option<Self::Item> { |
| if self.cur < self.end { |
| let index = self.cur; |
| self.cur += 1; |
| Some(&self.raw[index]) |
| } else { |
| None |
| } |
| } |
| } |
| |
| impl<'a, T> Iterator for RegionIterMut<'a, T> { |
| type Item = &'a mut Row<T>; |
| fn next(&mut self) -> Option<Self::Item> { |
| if self.cur < self.end { |
| let index = self.cur; |
| self.cur += 1; |
| unsafe { |
| Some(&mut *(&mut self.raw[index] as *mut _)) |
| } |
| } else { |
| None |
| } |
| } |
| } |
| |
| // ------------------------------------------------------------------------------------------------- |
| // DISPLAY ITERATOR |
| // ------------------------------------------------------------------------------------------------- |
| |
| /// Iterates over the visible area accounting for buffer transform |
| pub struct DisplayIter<'a, T: 'a> { |
| grid: &'a Grid<T>, |
| offset: usize, |
| limit: usize, |
| col: Column, |
| line: Line, |
| } |
| |
| impl<'a, T: 'a> DisplayIter<'a, T> { |
| pub fn new(grid: &'a Grid<T>) -> DisplayIter<'a, T> { |
| let offset = grid.display_offset + *grid.num_lines() - 1; |
| let limit = grid.display_offset; |
| let col = Column(0); |
| let line = Line(0); |
| |
| DisplayIter { grid, offset, col, limit, line } |
| } |
| |
| pub fn offset(&self) -> usize { |
| self.offset |
| } |
| |
| pub fn column(&self) -> Column { |
| self.col |
| } |
| |
| pub fn line(&self) -> Line { |
| self.line |
| } |
| } |
| |
| impl<'a, T: Copy + 'a> Iterator for DisplayIter<'a, T> { |
| type Item = Indexed<T>; |
| |
| #[inline] |
| fn next(&mut self) -> Option<Self::Item> { |
| // Make sure indices are valid. Return None if we've reached the end. |
| let next_line = self.col == self.grid.num_cols(); |
| if next_line { |
| if self.offset == self.limit { |
| return None; |
| } |
| |
| self.col = Column(0); |
| self.offset -= 1; |
| self.line = Line(*self.grid.lines - 1 - (self.offset - self.limit)); |
| } |
| |
| // Return the next item. |
| let item = Some(Indexed { |
| inner: self.grid.raw[self.offset][self.col], |
| line: self.line, |
| column: self.col |
| }); |
| |
| if !next_line { |
| self.col += 1; |
| } |
| item |
| } |
| } |