Struct SelectionHelper 

pub struct SelectionHelper { /* private fields */ }

Text-selection logic

This struct holds a CursorRange. There is no requirement on the order of these two positions. Each may be adjusted independently.

Additionally, this struct holds the selection anchor index. This usually equals the selection index, but when using double-click or triple-click selection, the anchor represents the initially-clicked position while the selection index represents the expanded position.

Implementations

impl SelectionHelper

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

Set the cursor position, clearing the selection

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

Set the cursor index without adjusting the selection index

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

Set the selection index without adjusting the edit index

The anchor index is also set to the selection index.

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

Set the selection index only

Prefer Self::set_sel_index unless you know you don’t want to set the anchor.

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 set_anchor(&mut self, clear: bool)

Set the anchor to the edit position

This is used to start a drag-selection. If clear, then the selection position is also set to the edit position.

Self::expand may be used to expand the selection from this anchor.

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

Expand the selection from the range between edit and anchor positions

This moves the cursor range. To obtain repeatable behaviour on drag-selection, set the anchor (Self::set_anchor) initially, then set the edit position and call this method each time the cursor moves.

The selection is expanded by words or lines (if lines). Line expansion requires that text has been prepared (Text::prepare).

pub fn delete_range(&mut self, range: Range<usize>)

Adjust all indices for a deletion from the source text

Methods from Deref<Target = CursorRange>

pub fn is_empty(&self) -> bool

True if the selection index equals the cursor index

pub fn set_empty(&mut self)

Clear selection without changing the edit index

pub fn sel_index(&self) -> usize

Get the selection index

pub fn edit_index(&self) -> usize

Get the edit cursor index

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

Get the selection range

This range is from the edit index to the selection index or reversed, whichever is increasing.

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.

impl Deref for SelectionHelper

type Target = CursorRange

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl DerefMut for SelectionHelper

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.

impl<T: Into<CursorRange>> From<T> for SelectionHelper

fn from(x: T) -> Self

Converts to this type from the input type.