1use super::{ExcerptId, MultiBufferSnapshot, ToOffset, ToPoint};
  2use 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) buffer_id: Option<usize>,
 13    pub(crate) excerpt_id: ExcerptId,
 14    pub(crate) text_anchor: text::Anchor,
 15}
 16
 17impl Anchor {
 18    pub fn min() -> Self {
 19        Self {
 20            buffer_id: None,
 21            excerpt_id: ExcerptId::min(),
 22            text_anchor: text::Anchor::min(),
 23        }
 24    }
 25
 26    pub fn max() -> Self {
 27        Self {
 28            buffer_id: None,
 29            excerpt_id: ExcerptId::max(),
 30            text_anchor: text::Anchor::max(),
 31        }
 32    }
 33
 34    pub fn excerpt_id(&self) -> &ExcerptId {
 35        &self.excerpt_id
 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 if let Some(excerpt) = snapshot.excerpt(&self.excerpt_id) {
 44                self.text_anchor.cmp(&other.text_anchor, &excerpt.buffer)
 45            } else {
 46                Ok(Ordering::Equal)
 47            }
 48        } else {
 49            Ok(excerpt_id_cmp)
 50        }
 51    }
 52
 53    pub fn bias_left(&self, snapshot: &MultiBufferSnapshot) -> Anchor {
 54        if self.text_anchor.bias != Bias::Left {
 55            if let Some(excerpt) = snapshot.excerpt(&self.excerpt_id) {
 56                return Self {
 57                    buffer_id: self.buffer_id,
 58                    excerpt_id: self.excerpt_id.clone(),
 59                    text_anchor: self.text_anchor.bias_left(&excerpt.buffer),
 60                };
 61            }
 62        }
 63        self.clone()
 64    }
 65
 66    pub fn bias_right(&self, snapshot: &MultiBufferSnapshot) -> Anchor {
 67        if self.text_anchor.bias != Bias::Right {
 68            if let Some(excerpt) = snapshot.excerpt(&self.excerpt_id) {
 69                return Self {
 70                    buffer_id: self.buffer_id,
 71                    excerpt_id: self.excerpt_id.clone(),
 72                    text_anchor: self.text_anchor.bias_right(&excerpt.buffer),
 73                };
 74            }
 75        }
 76        self.clone()
 77    }
 78
 79    pub fn summary<D>(&self, snapshot: &MultiBufferSnapshot) -> D
 80    where
 81        D: TextDimension + Ord + Sub<D, Output = D>,
 82    {
 83        snapshot.summary_for_anchor(self)
 84    }
 85}
 86
 87impl ToOffset for Anchor {
 88    fn to_offset(&self, snapshot: &MultiBufferSnapshot) -> usize {
 89        self.summary(snapshot)
 90    }
 91}
 92
 93impl ToPoint for Anchor {
 94    fn to_point<'a>(&self, snapshot: &MultiBufferSnapshot) -> Point {
 95        self.summary(snapshot)
 96    }
 97}
 98
 99pub trait AnchorRangeExt {
100    fn cmp(&self, b: &Range<Anchor>, buffer: &MultiBufferSnapshot) -> Result<Ordering>;
101    fn to_offset(&self, content: &MultiBufferSnapshot) -> Range<usize>;
102    fn to_point(&self, content: &MultiBufferSnapshot) -> Range<Point>;
103}
104
105impl AnchorRangeExt for Range<Anchor> {
106    fn cmp(&self, other: &Range<Anchor>, buffer: &MultiBufferSnapshot) -> Result<Ordering> {
107        Ok(match self.start.cmp(&other.start, buffer)? {
108            Ordering::Equal => other.end.cmp(&self.end, buffer)?,
109            ord @ _ => ord,
110        })
111    }
112
113    fn to_offset(&self, content: &MultiBufferSnapshot) -> Range<usize> {
114        self.start.to_offset(&content)..self.end.to_offset(&content)
115    }
116
117    fn to_point(&self, content: &MultiBufferSnapshot) -> Range<Point> {
118        self.start.to_point(&content)..self.end.to_point(&content)
119    }
120}