Struct scribe::buffer::Cursor

pub struct Cursor {
    pub data: Rc<RefCell<GapBuffer>>,
    pub position: Position,
    // some fields omitted
}

Read-only wrapper for a Position, to allow field level access to a buffer's cursor while simultaneously enforcing bounds-checking when updating its value.

Fields

data: Rc<RefCell<GapBuffer>>

position: Position

Methods

impl Cursor

fn new(data: Rc<RefCell<GapBuffer>>, position: Position) -> Cursor

Initializes a cursor bound to the specified gap buffer, at the specified position.

fn move_to(&mut self, position: Position) -> bool

Moves the cursor to the specified location. The location is bounds-checked against the data and the cursor will not be updated if it is out-of-bounds.

Examples

use scribe::Buffer;
use scribe::buffer::Position;

let mut buffer = Buffer::new();
let in_bounds = Position{ line: 0, offset: 2 };
let out_of_bounds = Position{ line: 2, offset: 2 };
buffer.insert("scribe");

buffer.cursor.move_to(in_bounds);
assert_eq!(buffer.cursor.line, 0);
assert_eq!(buffer.cursor.offset, 2);

buffer.cursor.move_to(out_of_bounds);
assert_eq!(buffer.cursor.line, 0);
assert_eq!(buffer.cursor.offset, 2);

fn move_up(&mut self)

Decrements the cursor line. The location is bounds-checked against the data and the cursor will not be updated if it is out-of-bounds.

fn move_down(&mut self)

Increments the cursor line. The location is bounds-checked against the data and the cursor will not be updated if it is out-of-bounds.

fn move_left(&mut self)

Decrements the cursor offset. The location is bounds-checked against the data and the cursor will not be updated if it is out-of-bounds.

fn move_right(&mut self)

Increments the cursor offset. The location is bounds-checked against the data and the cursor will not be updated if it is out-of-bounds.

fn move_to_start_of_line(&mut self)

Sets the cursor offset to 0: the start of the current line.

fn move_to_end_of_line(&mut self)

Moves the cursor offset to after the last character on the current line.

fn move_to_last_line(&mut self)

Moves the cursor to the last line in the buffer.

fn move_to_first_line(&mut self)

Moves the cursor to the first line in the buffer.

Methods from Deref<Target = Position>

fn add(&mut self, distance: &Distance)

Adds the specified Distance to the position.

Examples

use scribe::buffer::{Distance, Position};

let mut position = Position{ line: 1, offset: 3 };
let distance = Distance{ lines: 1, offset: 4 };
position.add(&distance);

assert_eq!(position, Position{
    line: 2,
    offset: 4
});

Trait Implementations

impl Clone for Cursor

fn clone(&self) -> Cursor

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Deref for Cursor

type Target = Position

The resulting type after dereferencing

fn deref(&self) -> &Position

The method called to dereference a value

impl DerefMut for Cursor

fn deref_mut(&mut self) -> &mut Position

The method called to mutably dereference a value