Struct Selection 

pub struct Selection {
    pub index: usize,
    pub len: usize,
    /* private fields */
}

Wrap-around index navigation with viewport scrolling

Uses Cell for offset/visible to allow updates from immutable context (e.g., render).

Fields

index: usize

Currently selected index

len: usize

Total number of items

Implementations

impl Selection

pub fn new(len: usize) -> Self

Create a new selection with given item count

pub fn next(&mut self)

Move to next item (wraps to 0 at end)

pub fn prev(&mut self)

Move to previous item (wraps to end at 0)

pub fn down(&mut self)

Move down without wrapping

pub fn up(&mut self)

Move up without wrapping

pub fn first(&mut self)

Jump to first item

pub fn last(&mut self)

Jump to last item

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

Set index with bounds check

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

Select specific index (alias for set)

pub fn set_len(&mut self, len: usize)

Update length (adjusts index if needed)

pub fn set_visible(&self, visible: usize)

Set visible count (can be called from &self context due to Cell)

pub fn offset(&self) -> usize

Get current scroll offset

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

Get visible range (start..end indices)

pub fn reset_offset(&mut self)

Reset offset to 0 (scroll to top)

pub fn is_selected(&self, index: usize) -> bool

Check if index is currently selected

pub fn is_empty(&self) -> bool

Check if list is empty

pub fn page_down(&mut self)

Page down (move by visible count)

pub fn page_up(&mut self)

Page up (move by visible count)

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 Debug for Selection

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

Formats the value using the given formatter.

impl Default for Selection

fn default() -> Self

Returns the “default value” for a type.