Struct TextFieldBuffer 

pub struct TextFieldBuffer { /* private fields */ }

A mutable text buffer that can be edited.

This provides methods for changing text content:

• replace - Replace a range with new text
• append - Add text at the end
• insert - Insert text at cursor position
• delete - Delete a range of text

And for manipulating cursor/selection:

• place_cursor_at_end
• place_cursor_before_char
• select_all

Example

use cranpose_foundation::text::{TextFieldBuffer, TextRange};

let mut buffer = TextFieldBuffer::new("Hello");
buffer.place_cursor_at_end();
buffer.insert(", World!");
assert_eq!(buffer.text(), "Hello, World!");

Implementations

impl TextFieldBuffer

pub fn new(initial_text: impl Into<String>) -> TextFieldBuffer

Creates a new buffer with the given initial text. Cursor is placed at the end of the text.

pub fn with_selection( text: impl Into<String>, selection: TextRange, ) -> TextFieldBuffer

Creates a buffer with text and specified selection.

pub fn text(&self) -> &str

Returns the current text content.

pub fn len(&self) -> usize

Returns the length of the text in bytes.

pub fn is_empty(&self) -> bool

Returns true if the buffer is empty.

pub fn selection(&self) -> TextRange

Returns the current selection range.

pub fn composition(&self) -> Option<TextRange>

Returns the current composition (IME) range, if any.

pub fn has_selection(&self) -> bool

Returns true if there’s a non-collapsed selection.

pub fn has_changes(&self) -> bool

Returns true if any changes have been made.

pub fn replace(&mut self, range: TextRange, replacement: &str)

Replaces text in the given range with new text.

The selection is adjusted based on the replacement:

• If replacing before selection, selection shifts
• If replacing within selection, cursor moves to end of replacement

pub fn insert(&mut self, text: &str)

Inserts text at the current cursor position (or replaces selection).

pub fn append(&mut self, text: &str)

Appends text at the end of the buffer.

pub fn delete(&mut self, range: TextRange)

Deletes text in the given range.

pub fn delete_before_cursor(&mut self)

Deletes the character before the cursor (backspace).

pub fn delete_after_cursor(&mut self)

Deletes the character after the cursor (delete key).

pub fn delete_surrounding(&mut self, before_bytes: usize, after_bytes: usize)

Deletes text surrounding the cursor or selection.

before_bytes and after_bytes are byte counts in UTF-8. The deletion respects character boundaries and preserves any IME composition range.

pub fn clear(&mut self)

Clears all text.

pub fn place_cursor_at_end(&mut self)

Places the cursor at the end of the text.

pub fn place_cursor_at_start(&mut self)

Places the cursor at the start of the text.

pub fn place_cursor_before_char(&mut self, index: usize)

Places the cursor before the character at the given index.

pub fn select_all(&mut self)

Selects all text.

pub fn extend_selection_left(&mut self)

Extends the selection one character to the left.

start is the anchor and end is the moving cursor, which is what makes this and Self::extend_selection_right inverses of each other: shift-left followed by shift-right returns to where it began. Moving whichever end happens to be smaller instead would leave the two growing from opposite ends, and shift-right after shift-left would grow the selection rather than shrink it.

A reverse range (start > end) is how an anchor to the right of the cursor is represented; see TextRange.

pub fn extend_selection_right(&mut self)

Extends the selection one character to the right.

The anchor stays where it is and the cursor moves; see Self::extend_selection_left.

pub fn select(&mut self, range: TextRange)

Selects the given range.

pub fn set_composition(&mut self, range: Option<TextRange>)

Sets the composition (IME) range.

pub fn copy_selection(&self) -> Option<String>

Returns the selected text for copy operations. Returns None if no selection.

pub fn cut_selection(&mut self) -> Option<String>

Cuts the selected text (returns it and deletes from buffer). Returns the cut text, or None if no selection.

Trait Implementations

impl Clone for TextFieldBuffer

fn clone(&self) -> TextFieldBuffer

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TextFieldBuffer

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

Formats the value using the given formatter.

impl Default for TextFieldBuffer

fn default() -> TextFieldBuffer

Returns the “default value” for a type.