anchor.rs

  1use super::{ExcerptId, MultiBufferSnapshot, ToOffset, ToOffsetUtf16, ToPoint};
  2use language::{OffsetUtf16, Point, TextDimension};
  3use std::{
  4    cmp::Ordering,
  5    ops::{Range, Sub},
  6};
  7use sum_tree::Bias;
  8use text::BufferId;
  9
 10#[derive(Clone, Copy, Eq, PartialEq, Debug, Hash)]
 11pub struct Anchor {
 12    pub buffer_id: Option<BufferId>,
 13    pub excerpt_id: ExcerptId,
 14    pub text_anchor: text::Anchor,
 15    pub diff_base_anchor: Option<text::Anchor>,
 16}
 17
 18impl Anchor {
 19    pub fn in_buffer(
 20        excerpt_id: ExcerptId,
 21        buffer_id: BufferId,
 22        text_anchor: text::Anchor,
 23    ) -> Self {
 24        Self {
 25            buffer_id: Some(buffer_id),
 26            excerpt_id,
 27            text_anchor,
 28            diff_base_anchor: None,
 29        }
 30    }
 31
 32    pub fn range_in_buffer(
 33        excerpt_id: ExcerptId,
 34        buffer_id: BufferId,
 35        range: Range<text::Anchor>,
 36    ) -> Range<Self> {
 37        Self::in_buffer(excerpt_id, buffer_id, range.start)
 38            ..Self::in_buffer(excerpt_id, buffer_id, range.end)
 39    }
 40
 41    pub fn min() -> Self {
 42        Self {
 43            buffer_id: None,
 44            excerpt_id: ExcerptId::min(),
 45            text_anchor: text::Anchor::MIN,
 46            diff_base_anchor: None,
 47        }
 48    }
 49
 50    pub fn max() -> Self {
 51        Self {
 52            buffer_id: None,
 53            excerpt_id: ExcerptId::max(),
 54            text_anchor: text::Anchor::MAX,
 55            diff_base_anchor: None,
 56        }
 57    }
 58
 59    pub fn cmp(&self, other: &Anchor, snapshot: &MultiBufferSnapshot) -> Ordering {
 60        if self == other {
 61            return Ordering::Equal;
 62        }
 63
 64        let self_excerpt_id = snapshot.latest_excerpt_id(self.excerpt_id);
 65        let other_excerpt_id = snapshot.latest_excerpt_id(other.excerpt_id);
 66
 67        let excerpt_id_cmp = self_excerpt_id.cmp(&other_excerpt_id, snapshot);
 68        if excerpt_id_cmp.is_ne() {
 69            return excerpt_id_cmp;
 70        }
 71        if self_excerpt_id == ExcerptId::min() || self_excerpt_id == ExcerptId::max() {
 72            return Ordering::Equal;
 73        }
 74        if let Some(excerpt) = snapshot.excerpt(self_excerpt_id) {
 75            let text_cmp = self.text_anchor.cmp(&other.text_anchor, &excerpt.buffer);
 76            if text_cmp.is_ne() {
 77                return text_cmp;
 78            }
 79            if (self.diff_base_anchor.is_some() || other.diff_base_anchor.is_some())
 80                && let Some(base_text) = snapshot
 81                    .diffs
 82                    .get(&excerpt.buffer_id)
 83                    .map(|diff| diff.base_text())
 84                {
 85                    let self_anchor = self.diff_base_anchor.filter(|a| base_text.can_resolve(a));
 86                    let other_anchor = other.diff_base_anchor.filter(|a| base_text.can_resolve(a));
 87                    return match (self_anchor, other_anchor) {
 88                        (Some(a), Some(b)) => a.cmp(&b, base_text),
 89                        (Some(_), None) => match other.text_anchor.bias {
 90                            Bias::Left => Ordering::Greater,
 91                            Bias::Right => Ordering::Less,
 92                        },
 93                        (None, Some(_)) => match self.text_anchor.bias {
 94                            Bias::Left => Ordering::Less,
 95                            Bias::Right => Ordering::Greater,
 96                        },
 97                        (None, None) => Ordering::Equal,
 98                    };
 99                }
100        }
101        Ordering::Equal
102    }
103
104    pub fn bias(&self) -> Bias {
105        self.text_anchor.bias
106    }
107
108    pub fn bias_left(&self, snapshot: &MultiBufferSnapshot) -> Anchor {
109        if self.text_anchor.bias != Bias::Left
110            && let Some(excerpt) = snapshot.excerpt(self.excerpt_id) {
111                return Self {
112                    buffer_id: self.buffer_id,
113                    excerpt_id: self.excerpt_id,
114                    text_anchor: self.text_anchor.bias_left(&excerpt.buffer),
115                    diff_base_anchor: self.diff_base_anchor.map(|a| {
116                        if let Some(base_text) = snapshot
117                            .diffs
118                            .get(&excerpt.buffer_id)
119                            .map(|diff| diff.base_text())
120                            && a.buffer_id == Some(base_text.remote_id()) {
121                                return a.bias_left(base_text);
122                            }
123                        a
124                    }),
125                };
126            }
127        *self
128    }
129
130    pub fn bias_right(&self, snapshot: &MultiBufferSnapshot) -> Anchor {
131        if self.text_anchor.bias != Bias::Right
132            && let Some(excerpt) = snapshot.excerpt(self.excerpt_id) {
133                return Self {
134                    buffer_id: self.buffer_id,
135                    excerpt_id: self.excerpt_id,
136                    text_anchor: self.text_anchor.bias_right(&excerpt.buffer),
137                    diff_base_anchor: self.diff_base_anchor.map(|a| {
138                        if let Some(base_text) = snapshot
139                            .diffs
140                            .get(&excerpt.buffer_id)
141                            .map(|diff| diff.base_text())
142                            && a.buffer_id == Some(base_text.remote_id()) {
143                                return a.bias_right(base_text);
144                            }
145                        a
146                    }),
147                };
148            }
149        *self
150    }
151
152    pub fn summary<D>(&self, snapshot: &MultiBufferSnapshot) -> D
153    where
154        D: TextDimension + Ord + Sub<D, Output = D>,
155    {
156        snapshot.summary_for_anchor(self)
157    }
158
159    pub fn is_valid(&self, snapshot: &MultiBufferSnapshot) -> bool {
160        if *self == Anchor::min() || *self == Anchor::max() {
161            true
162        } else if let Some(excerpt) = snapshot.excerpt(self.excerpt_id) {
163            (self.text_anchor == excerpt.range.context.start
164                || self.text_anchor == excerpt.range.context.end
165                || self.text_anchor.is_valid(&excerpt.buffer))
166                && excerpt.contains(self)
167        } else {
168            false
169        }
170    }
171}
172
173impl ToOffset for Anchor {
174    fn to_offset(&self, snapshot: &MultiBufferSnapshot) -> usize {
175        self.summary(snapshot)
176    }
177}
178
179impl ToOffsetUtf16 for Anchor {
180    fn to_offset_utf16(&self, snapshot: &MultiBufferSnapshot) -> OffsetUtf16 {
181        self.summary(snapshot)
182    }
183}
184
185impl ToPoint for Anchor {
186    fn to_point<'a>(&self, snapshot: &MultiBufferSnapshot) -> Point {
187        self.summary(snapshot)
188    }
189}
190
191pub trait AnchorRangeExt {
192    fn cmp(&self, other: &Range<Anchor>, buffer: &MultiBufferSnapshot) -> Ordering;
193    fn includes(&self, other: &Range<Anchor>, buffer: &MultiBufferSnapshot) -> bool;
194    fn overlaps(&self, other: &Range<Anchor>, buffer: &MultiBufferSnapshot) -> bool;
195    fn to_offset(&self, content: &MultiBufferSnapshot) -> Range<usize>;
196    fn to_point(&self, content: &MultiBufferSnapshot) -> Range<Point>;
197}
198
199impl AnchorRangeExt for Range<Anchor> {
200    fn cmp(&self, other: &Range<Anchor>, buffer: &MultiBufferSnapshot) -> Ordering {
201        match self.start.cmp(&other.start, buffer) {
202            Ordering::Equal => other.end.cmp(&self.end, buffer),
203            ord => ord,
204        }
205    }
206
207    fn includes(&self, other: &Range<Anchor>, buffer: &MultiBufferSnapshot) -> bool {
208        self.start.cmp(&other.start, buffer).is_le() && other.end.cmp(&self.end, buffer).is_le()
209    }
210
211    fn overlaps(&self, other: &Range<Anchor>, buffer: &MultiBufferSnapshot) -> bool {
212        self.end.cmp(&other.start, buffer).is_ge() && self.start.cmp(&other.end, buffer).is_le()
213    }
214
215    fn to_offset(&self, content: &MultiBufferSnapshot) -> Range<usize> {
216        self.start.to_offset(content)..self.end.to_offset(content)
217    }
218
219    fn to_point(&self, content: &MultiBufferSnapshot) -> Range<Point> {
220        self.start.to_point(content)..self.end.to_point(content)
221    }
222}
223
224#[derive(Clone, Copy, Eq, PartialEq, Debug, Hash, Ord, PartialOrd)]
225pub struct Offset(pub usize);