Struct SelectionHelper

pub struct SelectionHelper { /* private fields */ }

Text-selection logic

This struct holds an “edit pos” and a “selection pos”, which together form a range. There is no requirement on the order of these two positions. Each may be adjusted independently.

Implementations

impl SelectionHelper

pub fn new(edit_pos: usize, sel_pos: usize) -> Self

Construct from (edit, selection) positions

The anchor position is set to the selection position.

pub fn clear(&mut self)

Reset to the default state

All positions are set to 0.

pub fn is_empty(&self) -> bool

True if the edit pos equals the selection pos

pub fn set_empty(&mut self)

Clear selection without changing edit pos

pub fn set_pos(&mut self, pos: usize)

Set both edit and selection positions to this value

pub fn edit_pos(&self) -> usize

Get the edit pos

pub fn set_edit_pos(&mut self, pos: usize)

Set the edit pos without adjusting the selection pos

pub fn sel_pos(&self) -> usize

Get the selection pos

pub fn set_sel_pos(&mut self, pos: usize)

Set the selection pos without adjusting the edit pos

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

Apply new limit to the maximum length

Call this method if the string changes under the selection to ensure that the selection does not exceed the length of the new string.

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

Construct a range from the edit pos and selection pos

The range is from the minimum of (edit pos, selection pos) to the maximum of the two.

pub fn set_anchor(&mut self)

Set the anchor position from the edit position

pub fn expand<T: FormattableText>(&mut self, text: &Text<T>, repeats: u32)

Expand the selection from the range between edit pos and anchor pos

This moves both edit pos and sel pos. To obtain repeatable behaviour, first use SelectionHelper::set_anchor to set the anchor position, then before each time this method is called set the edit position.

If repeats <= 2, the selection is expanded by words, otherwise it is expanded by lines. Line expansion only works if text is line-wrapped (layout has been solved).

pub fn action<T: FormattableText>( &mut self, text: &Text<T>, action: SelectionAction, )

Handle an action

Trait Implementations

impl Clone for SelectionHelper

fn clone(&self) -> SelectionHelper

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SelectionHelper

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

Formats the value using the given formatter.

impl Default for SelectionHelper

fn default() -> SelectionHelper

Returns the “default value” for a type.