1use super::{ExcerptId, MultiBufferSnapshot, ToOffset, ToPoint};
  2use anyhow::{anyhow, Result};
  3use std::{
  4    cmp::Ordering,
  5    ops::{Range, Sub},
  6};
  7use sum_tree::Bias;
  8use text::{rope::TextDimension, Point};
  9
 10#[derive(Clone, Eq, PartialEq, Debug, Hash)]
 11pub struct Anchor {
 12    pub(crate) excerpt_id: ExcerptId,
 13    pub(crate) text_anchor: text::Anchor,
 14}
 15
 16impl Anchor {
 17    pub fn min() -> Self {
 18        Self {
 19            excerpt_id: ExcerptId::min(),
 20            text_anchor: text::Anchor::min(),
 21        }
 22    }
 23
 24    pub fn max() -> Self {
 25        Self {
 26            excerpt_id: ExcerptId::max(),
 27            text_anchor: text::Anchor::max(),
 28        }
 29    }
 30
 31    pub fn cmp<'a>(&self, other: &Anchor, snapshot: &MultiBufferSnapshot) -> Result<Ordering> {
 32        let excerpt_id_cmp = self.excerpt_id.cmp(&other.excerpt_id);
 33        if excerpt_id_cmp.is_eq() {
 34            if self.excerpt_id == ExcerptId::min() || self.excerpt_id == ExcerptId::max() {
 35                Ok(Ordering::Equal)
 36            } else {
 37                self.text_anchor.cmp(
 38                    &other.text_anchor,
 39                    snapshot
 40                        .buffer_snapshot_for_excerpt(&self.excerpt_id)
 41                        .ok_or_else(|| anyhow!("excerpt {:?} not found", self.excerpt_id))?,
 42                )
 43            }
 44        } else {
 45            return Ok(excerpt_id_cmp);
 46        }
 47    }
 48
 49    pub fn bias_left(&self, snapshot: &MultiBufferSnapshot) -> Anchor {
 50        if self.text_anchor.bias != Bias::Left {
 51            if let Some(buffer_snapshot) = snapshot.buffer_snapshot_for_excerpt(&self.excerpt_id) {
 52                return Self {
 53                    excerpt_id: self.excerpt_id.clone(),
 54                    text_anchor: self.text_anchor.bias_left(buffer_snapshot),
 55                };
 56            }
 57        }
 58        self.clone()
 59    }
 60
 61    pub fn bias_right(&self, snapshot: &MultiBufferSnapshot) -> Anchor {
 62        if self.text_anchor.bias != Bias::Right {
 63            if let Some(buffer_snapshot) = snapshot.buffer_snapshot_for_excerpt(&self.excerpt_id) {
 64                return Self {
 65                    excerpt_id: self.excerpt_id.clone(),
 66                    text_anchor: self.text_anchor.bias_right(buffer_snapshot),
 67                };
 68            }
 69        }
 70        self.clone()
 71    }
 72
 73    pub fn summary<D>(&self, snapshot: &MultiBufferSnapshot) -> D
 74    where
 75        D: TextDimension + Ord + Sub<D, Output = D>,
 76    {
 77        snapshot.summary_for_anchor(self)
 78    }
 79}
 80
 81impl ToOffset for Anchor {
 82    fn to_offset<'a>(&self, snapshot: &MultiBufferSnapshot) -> usize {
 83        self.summary(snapshot)
 84    }
 85}
 86
 87impl ToPoint for Anchor {
 88    fn to_point<'a>(&self, snapshot: &MultiBufferSnapshot) -> Point {
 89        self.summary(snapshot)
 90    }
 91}
 92
 93pub trait AnchorRangeExt {
 94    fn cmp(&self, b: &Range<Anchor>, buffer: &MultiBufferSnapshot) -> Result<Ordering>;
 95    fn to_offset(&self, content: &MultiBufferSnapshot) -> Range<usize>;
 96    fn to_point(&self, content: &MultiBufferSnapshot) -> Range<Point>;
 97}
 98
 99impl AnchorRangeExt for Range<Anchor> {
100    fn cmp(&self, other: &Range<Anchor>, buffer: &MultiBufferSnapshot) -> Result<Ordering> {
101        Ok(match self.start.cmp(&other.start, buffer)? {
102            Ordering::Equal => other.end.cmp(&self.end, buffer)?,
103            ord @ _ => ord,
104        })
105    }
106
107    fn to_offset(&self, content: &MultiBufferSnapshot) -> Range<usize> {
108        self.start.to_offset(&content)..self.end.to_offset(&content)
109    }
110
111    fn to_point(&self, content: &MultiBufferSnapshot) -> Range<Point> {
112        self.start.to_point(&content)..self.end.to_point(&content)
113    }
114}