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authorMatouš Dzivjak2022-01-06 02:12:02 +0000
committerGitHub2022-01-06 02:12:02 +0000
commit2e02a1d6bc004212033b9c4e5ed0de0fd880796c (patch)
treee73a695e58ddf7242d3cab282b93dd1ad9488ee5 /helix-core/src/selection.rs
parent66afbc9fff1ec5947ea5718f7817887aa0c853c8 (diff)
feat(commands): shrink_selection (#1340)
* feat(commands): shrink_selection Add `shrink_selection` command that can be used to shrink previously expanded selection. To make `shrink_selection` work it was necessary to add selection history to the Document since we want to shrink the selection towards the syntax tree node that was initially selected. Selection history is cleared any time the user changes selection other way than by `expand_selection`. This ensures that we don't get some funky edge cases when user calls `shrink_selection`. Related: https://github.com/helix-editor/helix/discussions/1328 * Refactor shrink_selection, move history to view * Remove useless comment * Add default key mapping for extend&shrink selection * Rework contains_selection method * Shrink selection without expand selects first child
Diffstat (limited to 'helix-core/src/selection.rs')
-rw-r--r--helix-core/src/selection.rs64
1 files changed, 64 insertions, 0 deletions
diff --git a/helix-core/src/selection.rs b/helix-core/src/selection.rs
index 06ea9d67..1515c4fc 100644
--- a/helix-core/src/selection.rs
+++ b/helix-core/src/selection.rs
@@ -140,6 +140,11 @@ impl Range {
self.from() == other.from() || (self.to() > other.from() && other.to() > self.from())
}
+ #[inline]
+ pub fn contains_range(&self, other: &Self) -> bool {
+ self.from() <= other.from() && self.to() >= other.to()
+ }
+
pub fn contains(&self, pos: usize) -> bool {
self.from() <= pos && pos < self.to()
}
@@ -544,6 +549,39 @@ impl Selection {
pub fn len(&self) -> usize {
self.ranges.len()
}
+
+ // returns true if self ⊇ other
+ pub fn contains(&self, other: &Selection) -> bool {
+ // can't contain other if it is larger
+ if other.len() > self.len() {
+ return false;
+ }
+
+ let (mut iter_self, mut iter_other) = (self.iter(), other.iter());
+ let (mut ele_self, mut ele_other) = (iter_self.next(), iter_other.next());
+
+ loop {
+ match (ele_self, ele_other) {
+ (Some(ra), Some(rb)) => {
+ if !ra.contains_range(rb) {
+ // `self` doesn't contain next element from `other`, advance `self`, we need to match all from `other`
+ ele_self = iter_self.next();
+ } else {
+ // matched element from `other`, advance `other`
+ ele_other = iter_other.next();
+ };
+ }
+ (None, Some(_)) => {
+ // exhausted `self`, we can't match the reminder of `other`
+ return false;
+ }
+ (_, None) => {
+ // no elements from `other` left to match, `self` contains `other`
+ return true;
+ }
+ }
+ }
+ }
}
impl<'a> IntoIterator for &'a Selection {
@@ -982,4 +1020,30 @@ mod test {
&["", "abcd", "efg", "rs", "xyz"]
);
}
+ #[test]
+ fn test_selection_contains() {
+ fn contains(a: Vec<(usize, usize)>, b: Vec<(usize, usize)>) -> bool {
+ let sela = Selection::new(a.iter().map(|a| Range::new(a.0, a.1)).collect(), 0);
+ let selb = Selection::new(b.iter().map(|b| Range::new(b.0, b.1)).collect(), 0);
+ sela.contains(&selb)
+ }
+
+ // exact match
+ assert!(contains(vec!((1, 1)), vec!((1, 1))));
+
+ // larger set contains smaller
+ assert!(contains(vec!((1, 1), (2, 2), (3, 3)), vec!((2, 2))));
+
+ // multiple matches
+ assert!(contains(vec!((1, 1), (2, 2)), vec!((1, 1), (2, 2))));
+
+ // smaller set can't contain bigger
+ assert!(!contains(vec!((1, 1)), vec!((1, 1), (2, 2))));
+
+ assert!(contains(
+ vec!((1, 1), (2, 4), (5, 6), (7, 9), (10, 13)),
+ vec!((3, 4), (7, 9))
+ ));
+ assert!(!contains(vec!((1, 1), (5, 6)), vec!((1, 6))));
+ }
}