Struct Buffer 

pub struct Buffer {
    pub file: Option<String>,
    pub dirty: bool,
    pub position: (usize, usize),
    pub vtop: usize,
    /* private fields */
}

The internal representation of an opened file

This entity contains the contents of a file, whether that file exists or is to be written, and maintains state information about the file, such as whether it is “dirty” (changes have been made that have not been saved yet), etc.

Fields

file: Option<String>

The path to the file; optional because we can open empty buffers that can be written to files using Action::SaveAs

dirty: bool

State flag for keeping track of unsaved (dirty) changes

position: (usize, usize)

Cursor position within the buffer

vtop: usize

The y coordinate of the top of the view

Implementations

impl Buffer

pub fn new(file: Option<String>, contents: String) -> Self

Create a new buffer using a file path and some file contents

Arguments

• file: Optional file path
• contents: String representation of the contents of the associated file

Examples

use tsu_editor::buffer::Buffer;

let file = Some("some_file.rs".to_string());
let contents = "";

let buffer = Buffer::new(file.clone(), contents.to_string());

assert_eq!(buffer.file, file);

pub async fn from_file(file: Option<String>) -> Result<Self>

Create a new buffer by opening a file and retrieving its contents

Arguments

• file: An optional file path

Examples

use tsu_editor::buffer::Buffer;


let file_path_str = Some(file_path.clone().into_os_string().into_string().unwrap());
let buffer = Buffer::from_file(file_path_str.clone()).await.unwrap();
assert_eq!(buffer.file, file_path_str);

Errors

Can return an IoError if the file cannot be read from

pub fn contents(&self) -> String

Returns the entirety of the content as a String

Returns

• The contents of self as a String

pub fn save(&mut self) -> Result<String>

Writes the contents of self to file

Returns

• A message to print to the command line of the editor

Errors

Can return an IoError if it fails to write the contents to the provided file

pub fn save_as(&mut self, new_file_name: &str) -> Result<String>

Writes the contents of self to a new file

Arguments

• new_file_name: The path to the file to be written

Returns

• A message to print to the command line of the editor

Errors

Can return an IoError if it fails to write the contents to the provided file

pub fn name(&self) -> &str

Retrieves the name of the buffer which corresponds to the file path it was created from

Returns

• The name of the buffer; if the buffer was not created from a file, returns “[No name]”

pub fn is_dirty(&self) -> bool

Check if the buffer is dirty, i.e., has unsaved changes’

Returns

• true if the buffer is dirty, false otherwise

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

Retrieves the contents at a specific line in the buffer

Arguments

• line: The line number

Returns

• The contents of the line if the line exists, i.e., is within the bounds of the buffer

pub fn len(&self) -> usize

Get the length of the buffer, i.e., the number of lines

Returns

• The size of the buffer expressed as the number of lines

pub fn is_empty(&self) -> bool

Check if the buffer is empty, i.e., the number of lines is 0

Returns

• True if the buffer is empty, false otherwise

pub fn insert(&mut self, x: usize, y: usize, c: char)

Put a character at a coordinate position within the buffer

Arguments

• x: The coordinate along the x axis (column)
• y: The coordinate along the y axis (row)
• c: Character to insert at the specified coordinates

pub fn insert_line(&mut self, line: usize, content: &str)

Insert a line at the specified line index (row)

Arguments

• line: The line index where the contents will be inserted
• content: The string to insert at the specified row

pub fn remove(&mut self, x: usize, y: usize)

Remove a character at the specified coordinates

Arguments

• x: The coordinate along the x axis (column)
• y: The coordinate along the y axis (row)

pub fn replace_line(&mut self, line: usize, new_line: &str)

Replaces the line at a given line index with a new String

Arguments

• line: The index of the line being replaced
• new_line: The String to be written to the line index

pub fn remove_line(&mut self, line: usize)

Removes a line at the given line index

Arguments

• line: The index of the line being removed

pub fn view(&self, vtop: usize, vheight: usize) -> String

Calculates the view inside the buffer using a specified view top and view height

Arguments

• vtop: The top of the view corresponding to a line index
• vheight: The height of the view corresponding to the number of lines to display

Returns

• The contents within the calculated view as a String

pub fn column_to_char_index(&self, column: usize, y: usize) -> usize

Converts a column index to a character index

Arguments

• column: The column index which is to be converted to a character index
• y: The y coordinate which corresponds to the line number

Returns

• The character index as calculated from the column index and the specified line number

Trait Implementations

impl Debug for Buffer

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

Formats the value using the given formatter.