Struct zng_ext_font::SegmentedText

pub struct SegmentedText { /* private fields */ }

A string segmented in sequences of words, spaces, tabs and separated line breaks.

Each segment is tagged with a TextSegmentKind and is defines as an offset from the last segment.

Implementations

impl SegmentedText

pub fn new(text: impl Into<Txt>, base_direction: LayoutDirection) -> Self

New segmented text from any text type.

pub fn text(&self) -> &Txt

The text string.

pub fn segs(&self) -> &[TextSegment]

The text segments.

pub fn seg_from_char(&self, from: usize) -> usize

Get segment index from a char index.

pub fn base_direction(&self) -> LayoutDirection

Contextual direction.

Note that each segment can override the direction, and even the entire text can be a sequence in the opposite direction.

pub fn is_bidi(&self) -> bool

Gets if the text contains segments not in the base direction.

pub fn get(&self, index: usize) -> Option<(&str, TextSegment)>

Returns the text segment if index is in bounds.

pub fn get_clone(&self, index: usize) -> Option<SegmentedText>

Returns a clone of the text segment if index is in bounds.

pub fn is_empty(&self) -> bool

Returns true if text and segments are empty.

pub fn into_parts(self) -> (Txt, Vec<TextSegment>, LayoutDirection)

Destructs self into the text and segments.

pub fn from_parts( text: Txt, segments: Vec<TextSegment>, base_direction: LayoutDirection, ) -> Self

New segmented text from parts.

Panics

Some basic validation is done on the input:

• If one of the inputs is empty but the other is not.
• If text is not empty and the last segment does not end with the text.

pub fn iter(&self) -> SegmentedTextIter<'_>

Segments iterator.

Examples

for (sub_str, seg) in SegmentedText::new("Foo bar!\nBaz.", LayoutDirection::LTR).iter() {
    println!("s: {sub_str:?} is a `{:?}`", seg.kind);
}

pub fn text_range(&self, segs_range: Range<usize>) -> Range<usize>

Convert a segments range to a text bytes range.

pub fn reorder_line_to_ltr(&self, segs_range: Range<usize>) -> Vec<usize>

Compute a map of segments in segs_range to their final LTR display order.

The segs_range must be the segments of a line after line wrap.

pub fn snap_char_boundary(&self, i: usize) -> usize

Find the nearest next char boundary from the byte index i.

If i is larger than the text length, returns the text length, if i is already a char boundary, returns i.

pub fn snap_grapheme_boundary(&self, i: usize) -> usize

Find the nearest grapheme cluster boundary from the byte index i.

If i is larger than the text length, returns the text length, if i is already a grapheme boundary, returns i.

pub fn next_insert_index(&self, from: usize) -> usize

Find the next grapheme cluster, after from.

The from must be in a grapheme boundary or 0 or len. This operation is saturating.

Panics

Panics if from is larger than the text length, or is not at a grapheme boundary.

pub fn prev_insert_index(&self, from: usize) -> usize

Find the previous grapheme cluster, before from.

The from must be in a grapheme boundary or 0 or len. This operation is saturating.

Panics

Panics if from is larger than the text length, or is not at a grapheme boundary.

pub fn next_word_index(&self, from: usize) -> usize

Find the start of the next word or the next line-break segment, after from.

This operation is saturating.

pub fn next_word_end_index(&self, from: usize) -> usize

Find the next word segment end or the next line-break segment end, after from.

This operation is saturating.

pub fn prev_word_index(&self, from: usize) -> usize

Find the start of the previous word segment or the previous line-break segment, before from.

This operation is saturating.

pub fn line_start_index(&self, from: usize) -> usize

Find the start of the line that contains from.

Panics

Panics if from is larger than the text length, or is not a char boundary.

pub fn line_end_index(&self, from: usize) -> usize

Find the end of the line that contains from.

Panics

Panics if from is larger than the text length, or is not a char boundary.

pub fn delete_range(&self, from: usize, count: u32) -> Range<usize>

Find the range that must be removed to delete starting by from a count number of times.

Delete Del action removes the next grapheme cluster, this is different from backspace_range that usually only removes one character.

Panics

Panics if from is larger than the text length, or is not a grapheme boundary.

pub fn backspace_range(&self, from: usize, count: u32) -> Range<usize>

Find the range that must be removed to backspace before from a count number of times.

The character at from is not included, only the previous char is selected, with some exceptions, the selection includes any char before zero-width-joiner (ZWJ), it also includes \r before \n and Emoji char before Emoji modifier or variation selector (VS16).

Panics

Panics if from is larger than the text length, or is not a char boundary.

pub fn backspace_word_range(&self, from: usize, count: u32) -> Range<usize>

Find the range that must be removed to backspace words before from a count number of times.

The character at from is not included, only the previous word is selected.

pub fn delete_word_range(&self, from: usize, count: u32) -> Range<usize>

Find the range that must be removed to delete words starting by from a count number of times.

Trait Implementations

impl Clone for SegmentedText

fn clone(&self) -> SegmentedText

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for SegmentedText

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

Formats the value using the given formatter.

impl Default for SegmentedText

fn default() -> SegmentedText

Returns the “default value” for a type.

impl PartialEq for SegmentedText

fn eq(&self, other: &SegmentedText) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for SegmentedText

impl StructuralPartialEq for SegmentedText