Struct TextBuffer 

pub struct TextBuffer { /* private fields */ }

A text buffer backed by a rope data structure for efficient editing.

Provides line-oriented access and editing operations suitable for building a text editor widget. All positions are expressed as (line, col) pairs using zero-based indexing.

Implementations

impl TextBuffer

pub fn new() -> Self

Create a new empty text buffer.

pub fn from_text(text: &str) -> Self

Create a text buffer from a string.

pub fn line_count(&self) -> usize

Return the number of lines in the buffer.

An empty buffer has 1 line. A buffer ending with a newline has an extra empty line at the end.

pub fn line(&self, idx: usize) -> Option<String>

Get the content of a line by index (without trailing newline).

Returns None if the index is out of bounds.

pub fn line_len(&self, idx: usize) -> Option<usize>

Get the character count of a line (excluding trailing newline).

Returns None if the index is out of bounds.

pub fn total_chars(&self) -> usize

Return the total number of characters in the buffer.

pub fn insert_char(&mut self, line: usize, col: usize, ch: char)

Insert a character at the given (line, col) position.

If the position is beyond the end of a line, the character is appended at the end of that line.

pub fn insert_str(&mut self, line: usize, col: usize, text: &str)

Insert a string at the given (line, col) position.

The string may contain newlines, which will split the line.

pub fn delete_char(&mut self, line: usize, col: usize)

Delete a single character at the given (line, col) position.

If the position is at the end of a line, the trailing newline is removed, joining this line with the next.

pub fn delete_range( &mut self, start_line: usize, start_col: usize, end_line: usize, end_col: usize, )

Delete a range of text between two (line, col) positions.

The range is from (start_line, start_col) inclusive to (end_line, end_col) exclusive. If start equals end, nothing is deleted.

pub fn lines_range(&self, start: usize, end: usize) -> Vec<String>

Get a range of lines as strings (without trailing newlines).

The range is [start, end) (end-exclusive). Returns an empty Vec if the range is invalid.

Trait Implementations

impl Clone for TextBuffer

fn clone(&self) -> TextBuffer

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TextBuffer

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

Formats the value using the given formatter.

impl Default for TextBuffer

fn default() -> Self

Returns the “default value” for a type.

impl Display for TextBuffer

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

Formats the value using the given formatter.