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 new(excerpt_id: ExcerptId, text_anchor: text::Anchor) -> Self {
 18        Self {
 19            excerpt_id,
 20            text_anchor,
 21        }
 22    }
 23
 24    pub fn min() -> Self {
 25        Self {
 26            excerpt_id: ExcerptId::min(),
 27            text_anchor: text::Anchor::min(),
 28        }
 29    }
 30
 31    pub fn max() -> Self {
 32        Self {
 33            excerpt_id: ExcerptId::max(),
 34            text_anchor: text::Anchor::max(),
 35        }
 36    }
 37
 38    pub fn cmp<'a>(&self, other: &Anchor, snapshot: &MultiBufferSnapshot) -> Result<Ordering> {
 39        let excerpt_id_cmp = self.excerpt_id.cmp(&other.excerpt_id);
 40        if excerpt_id_cmp.is_eq() {
 41            if self.excerpt_id == ExcerptId::min() || self.excerpt_id == ExcerptId::max() {
 42                Ok(Ordering::Equal)
 43            } else {
 44                self.text_anchor.cmp(
 45                    &other.text_anchor,
 46                    snapshot
 47                        .buffer_snapshot_for_excerpt(&self.excerpt_id)
 48                        .ok_or_else(|| anyhow!("excerpt {:?} not found", self.excerpt_id))?,
 49                )
 50            }
 51        } else {
 52            return Ok(excerpt_id_cmp);
 53        }
 54    }
 55
 56    pub fn bias_left(&self, snapshot: &MultiBufferSnapshot) -> Anchor {
 57        if self.text_anchor.bias != Bias::Left {
 58            if let Some(buffer_snapshot) = snapshot.buffer_snapshot_for_excerpt(&self.excerpt_id) {
 59                return Self {
 60                    excerpt_id: self.excerpt_id.clone(),
 61                    text_anchor: self.text_anchor.bias_left(buffer_snapshot),
 62                };
 63            }
 64        }
 65        self.clone()
 66    }
 67
 68    pub fn bias_right(&self, snapshot: &MultiBufferSnapshot) -> Anchor {
 69        if self.text_anchor.bias != Bias::Right {
 70            if let Some(buffer_snapshot) = snapshot.buffer_snapshot_for_excerpt(&self.excerpt_id) {
 71                return Self {
 72                    excerpt_id: self.excerpt_id.clone(),
 73                    text_anchor: self.text_anchor.bias_right(buffer_snapshot),
 74                };
 75            }
 76        }
 77        self.clone()
 78    }
 79
 80    pub fn summary<D>(&self, snapshot: &MultiBufferSnapshot) -> D
 81    where
 82        D: TextDimension + Ord + Sub<D, Output = D>,
 83    {
 84        snapshot.summary_for_anchor(self)
 85    }
 86}
 87
 88impl ToOffset for Anchor {
 89    fn to_offset<'a>(&self, snapshot: &MultiBufferSnapshot) -> usize {
 90        self.summary(snapshot)
 91    }
 92}
 93
 94impl ToPoint for Anchor {
 95    fn to_point<'a>(&self, snapshot: &MultiBufferSnapshot) -> Point {
 96        self.summary(snapshot)
 97    }
 98}
 99
100pub trait AnchorRangeExt {
101    fn cmp(&self, b: &Range<Anchor>, buffer: &MultiBufferSnapshot) -> Result<Ordering>;
102    fn to_offset(&self, content: &MultiBufferSnapshot) -> Range<usize>;
103    fn to_point(&self, content: &MultiBufferSnapshot) -> Range<Point>;
104}
105
106impl AnchorRangeExt for Range<Anchor> {
107    fn cmp(&self, other: &Range<Anchor>, buffer: &MultiBufferSnapshot) -> Result<Ordering> {
108        Ok(match self.start.cmp(&other.start, buffer)? {
109            Ordering::Equal => other.end.cmp(&self.end, buffer)?,
110            ord @ _ => ord,
111        })
112    }
113
114    fn to_offset(&self, content: &MultiBufferSnapshot) -> Range<usize> {
115        self.start.to_offset(&content)..self.end.to_offset(&content)
116    }
117
118    fn to_point(&self, content: &MultiBufferSnapshot) -> Range<Point> {
119        self.start.to_point(&content)..self.end.to_point(&content)
120    }
121}