Struct Selection 

pub struct Selection {
    pub anchor: usize,
    pub head: usize,
}

Represents a text selection using an anchor and a head.

The anchor is the position where the selection started, while the head is the current cursor position. When they differ, the selection extends between these two positions.

Both positions are byte offsets into the document.

Examples

A collapsed selection, where the cursor is at byte offset 10:

let selection = Selection::point(10);
assert!(selection.is_empty());

A selection from byte offset 10 to 20:

let selection = Selection::range(10, 20);
assert_eq!(selection.byte_range(), 10..20);

Fields

anchor: usize

The byte offset where the selection started.

This remains fixed while the selection is extended or contracted by moving the head.

head: usize

The current cursor position, represented as a byte offset.

Moving the head changes the extent and direction of the selection while the anchor remains fixed.

Implementations

impl Selection

pub const fn point(offset: usize) -> Self

Creates a collapsed selection with the cursor at offset.

Both the anchor and head are initialized to the same position.

pub const fn range(anchor: usize, head: usize) -> Self

Creates a selection from an anchor position to a head position.

The positions are not reordered, so anchor may be greater than head. Use Self::byte_range to obtain the normalized range.

pub fn is_empty(&self) -> bool

Returns true if the selection is collapsed.

A collapsed selection has the anchor and head at the same position.

pub fn byte_range(&self) -> Range<usize>

Returns the normalized byte range covered by the selection.

The returned range always starts at the smaller of the anchor and head and ends at the larger, regardless of the direction in which the selection was made.

Trait Implementations

impl Clone for Selection

fn clone(&self) -> Selection

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for Selection

impl Debug for Selection

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for Selection

impl PartialEq for Selection

fn eq(&self, other: &Selection) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for Selection