diff options
Diffstat (limited to 'src/grid/storage.rs')
| -rw-r--r-- | src/grid/storage.rs | 214 |
1 files changed, 205 insertions, 9 deletions
diff --git a/src/grid/storage.rs b/src/grid/storage.rs index cc32d6d1..f6fcc8f3 100644 --- a/src/grid/storage.rs +++ b/src/grid/storage.rs @@ -47,15 +47,49 @@ impl<T> Storage<T> { self.inner.capacity() } - pub fn set_visible_lines(&mut self, next: Line) { - // Change capacity to fit scrollback + screen size - if next > self.visible_lines + 1 { - self.inner.reserve_exact((next - (self.visible_lines + 1)).0); - } else if next < self.visible_lines + 1 { - let shrinkage = (self.visible_lines + 1 - next).0; - let new_size = self.inner.capacity() - shrinkage; - self.inner.truncate(new_size); - self.inner.shrink_to_fit(); + /// Increase the number of lines in the buffer + pub fn grow_visible_lines(&mut self, next: Line, template_row: T) + where + T: Clone, + { + // Calculate insert position (before the first line) + let offset = self.zero % self.inner.len(); + + // Insert new template row for every line grown + let lines_to_grow = (next - (self.visible_lines + 1)).0; + for _ in 0..lines_to_grow { + self.inner.insert(offset, template_row.clone()); + } + + // Set zero to old zero + lines grown + self.zero = offset + lines_to_grow; + + // Update visible lines + self.visible_lines = next - 1; + } + + /// Decrease the number of lines in the buffer + pub fn shrink_visible_lines(&mut self, next: Line) { + // Calculate shrinkage and last line of buffer + let shrinkage = (self.visible_lines + 1 - next).0; + let offset = (self.zero + self.inner.len() - 1) % self.inner.len(); + + // Generate range of lines that have to be deleted before the zero line + let start = offset.saturating_sub(shrinkage - 1); + let shrink_before = start..=offset; + + // Generate range of lines that have to be deleted after the zero line + let shrink_after = (self.inner.len() + offset + 1 - shrinkage)..self.inner.len(); + + // Delete all lines in reverse order + for i in shrink_before.chain(shrink_after).rev() { + self.inner.remove(i); + } + + // Check if zero has moved (not the first line in the buffer) + if self.zero % (self.inner.len() + shrinkage) != 0 { + // Set zero to the first deleted line in the buffer + self.zero = start; } // Update visible lines @@ -159,3 +193,165 @@ impl<'a, T: 'a> Iterator for IterMut<'a, T> { } } } + +/// Grow the buffer one line at the end of the buffer +/// +/// Before: +/// 0: 0 <- Zero +/// 1: 1 +/// 2: - +/// After: +/// 0: - +/// 1: 0 <- Zero +/// 2: 1 +/// 3: - +#[test] +fn grow_after_zero() { + // Setup storage area + let mut storage = Storage { + inner: vec!["0", "1", "-"], + zero: 0, + visible_lines: Line(2), + }; + + // Grow buffer + storage.grow_visible_lines(Line(4), "-"); + + // Make sure the result is correct + let expected = Storage { + inner: vec!["-", "0", "1", "-"], + zero: 1, + visible_lines: Line(0), + }; + assert_eq!(storage.inner, expected.inner); + assert_eq!(storage.zero, expected.zero); +} + +/// Grow the buffer one line at the start of the buffer +/// +/// Before: +/// 0: - +/// 1: 0 <- Zero +/// 2: 1 +/// After: +/// 0: - +/// 1: - +/// 2: 0 <- Zero +/// 3: 1 +#[test] +fn grow_before_zero() { + // Setup storage area + let mut storage = Storage { + inner: vec!["-", "0", "1"], + zero: 1, + visible_lines: Line(2), + }; + + // Grow buffer + storage.grow_visible_lines(Line(4), "-"); + + // Make sure the result is correct + let expected = Storage { + inner: vec!["-", "-", "0", "1"], + zero: 2, + visible_lines: Line(0), + }; + assert_eq!(storage.inner, expected.inner); + assert_eq!(storage.zero, expected.zero); +} + +/// Shrink the buffer one line at the start of the buffer +/// +/// Before: +/// 0: 2 +/// 1: 0 <- Zero +/// 2: 1 +/// After: +/// 0: 0 <- Zero +/// 1: 1 +#[test] +fn shrink_before_zero() { + // Setup storage area + let mut storage = Storage { + inner: vec!["2", "0", "1"], + zero: 1, + visible_lines: Line(2), + }; + + // Shrink buffer + storage.shrink_visible_lines(Line(2)); + + // Make sure the result is correct + let expected = Storage { + inner: vec!["0", "1"], + zero: 0, + visible_lines: Line(0), + }; + assert_eq!(storage.inner, expected.inner); + assert_eq!(storage.zero, expected.zero); +} + +/// Shrink the buffer one line at the end of the buffer +/// +/// Before: +/// 0: 0 <- Zero +/// 1: 1 +/// 2: 2 +/// After: +/// 0: 0 <- Zero +/// 1: 1 +#[test] +fn shrink_after_zero() { + // Setup storage area + let mut storage = Storage { + inner: vec!["0", "1", "2"], + zero: 0, + visible_lines: Line(2), + }; + + // Shrink buffer + storage.shrink_visible_lines(Line(2)); + + // Make sure the result is correct + let expected = Storage { + inner: vec!["0", "1"], + zero: 0, + visible_lines: Line(0), + }; + assert_eq!(storage.inner, expected.inner); + assert_eq!(storage.zero, expected.zero); +} + +/// Shrink the buffer at the start and end of the buffer +/// +/// Before: +/// 0: 4 +/// 1: 5 +/// 2: 0 <- Zero +/// 3: 1 +/// 4: 2 +/// 5: 3 +/// After: +/// 0: 0 <- Zero +/// 1: 1 +#[test] +fn shrink_before_and_after_zero() { + // Setup storage area + let mut storage = Storage { + inner: vec!["4", "5", "0", "1", "2", "3"], + zero: 2, + visible_lines: Line(5), + }; + + // Shrink buffer + storage.shrink_visible_lines(Line(2)); + + // Make sure the result is correct + let expected = Storage { + inner: vec!["0", "1"], + zero: 0, + visible_lines: Line(0), + }; + assert_eq!(storage.inner, expected.inner); + assert_eq!(storage.zero, expected.zero); +} |