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            self.text_anchor.cmp(
 35                &other.text_anchor,
 36                snapshot
 37                    .buffer_snapshot_for_excerpt(&self.excerpt_id)
 38                    .ok_or_else(|| anyhow!("excerpt {:?} not found", self.excerpt_id))?,
 39            )
 40        } else {
 41            return Ok(excerpt_id_cmp);
 42        }
 43    }
 44
 45    pub fn bias_left(&self, snapshot: &MultiBufferSnapshot) -> Anchor {
 46        if self.text_anchor.bias != Bias::Left {
 47            if let Some(buffer_snapshot) = snapshot.buffer_snapshot_for_excerpt(&self.excerpt_id) {
 48                return Self {
 49                    excerpt_id: self.excerpt_id.clone(),
 50                    text_anchor: self.text_anchor.bias_left(buffer_snapshot),
 51                };
 52            }
 53        }
 54        self.clone()
 55    }
 56
 57    pub fn bias_right(&self, snapshot: &MultiBufferSnapshot) -> Anchor {
 58        if self.text_anchor.bias != Bias::Right {
 59            if let Some(buffer_snapshot) = snapshot.buffer_snapshot_for_excerpt(&self.excerpt_id) {
 60                return Self {
 61                    excerpt_id: self.excerpt_id.clone(),
 62                    text_anchor: self.text_anchor.bias_right(buffer_snapshot),
 63                };
 64            }
 65        }
 66        self.clone()
 67    }
 68
 69    pub fn summary<D>(&self, snapshot: &MultiBufferSnapshot) -> D
 70    where
 71        D: TextDimension + Ord + Sub<D, Output = D>,
 72    {
 73        snapshot.summary_for_anchor(self)
 74    }
 75}
 76
 77impl ToOffset for Anchor {
 78    fn to_offset<'a>(&self, snapshot: &MultiBufferSnapshot) -> usize {
 79        self.summary(snapshot)
 80    }
 81}
 82
 83impl ToPoint for Anchor {
 84    fn to_point<'a>(&self, snapshot: &MultiBufferSnapshot) -> Point {
 85        self.summary(snapshot)
 86    }
 87}
 88
 89pub trait AnchorRangeExt {
 90    fn cmp(&self, b: &Range<Anchor>, buffer: &MultiBufferSnapshot) -> Result<Ordering>;
 91    fn to_offset(&self, content: &MultiBufferSnapshot) -> Range<usize>;
 92    fn to_point(&self, content: &MultiBufferSnapshot) -> Range<Point>;
 93}
 94
 95impl AnchorRangeExt for Range<Anchor> {
 96    fn cmp(&self, other: &Range<Anchor>, buffer: &MultiBufferSnapshot) -> Result<Ordering> {
 97        Ok(match self.start.cmp(&other.start, buffer)? {
 98            Ordering::Equal => other.end.cmp(&self.end, buffer)?,
 99            ord @ _ => ord,
100        })
101    }
102
103    fn to_offset(&self, content: &MultiBufferSnapshot) -> Range<usize> {
104        self.start.to_offset(&content)..self.end.to_offset(&content)
105    }
106
107    fn to_point(&self, content: &MultiBufferSnapshot) -> Range<Point> {
108        self.start.to_point(&content)..self.end.to_point(&content)
109    }
110}