Struct TextLayout 

pub struct TextLayout(/* private fields */);

The laid-out state of a text element, for mapping between byte indices and pixels.

Get one from StyledText::layout, or from the text state that other text elements keep. Clones share the same state. The query methods read the most recent layout, so a query made after a relayout returns the new result.

The text elements fill this in during layout and prepaint. The query methods panic if the element hasn’t been laid out yet, and the ones that need pixel positions panic if it hasn’t been prepainted.

Implementations

impl TextLayout

pub fn evaluate_wrap_width( white_space: &WhiteSpace, known_dimensions: Size<Option<Pixels>>, available_space: Size<AvailableSpace>, ) -> Option<Pixels>

Returns the width that text wraps at, or None when it doesn’t wrap.

Text does not wrap when white_space is WhiteSpace::Nowrap. Otherwise the width comes from TextLayout::evaluate_alignment_width.

pub fn evaluate_alignment_width( known_dimensions: Size<Option<Pixels>>, available_space: Size<AvailableSpace>, ) -> Option<Pixels>

Returns the width that text aligns within, from the known or available width.

The known width wins. Otherwise a definite available width is used. Under min-content or max-content sizing, this returns None.

pub fn evaluate_overflow( text_style: &TextStyle, known_dimensions: Size<Option<Pixels>>, available_space: Size<AvailableSpace>, ) -> TextLayoutTruncation

Returns how the text should be truncated, from the style’s text_overflow.

When the style has no text_overflow, the result has no width and an empty affix, so the text is never truncated.

pub fn apply_truncation<'runs>( text: SharedString, text_style: &TextStyle, font_size: Pixels, line_height: Pixels, wrap_width: Option<Pixels>, truncation: &TextLayoutTruncation, runs: &'runs [TextRun], paragraph_direction: ParagraphDirection, unicode_bidi: UnicodeBidi, window: &mut Window, cx: &mut App, ) -> (SharedString, Cow<'runs, [TextRun]>)

Shortens text so that it fits truncation.width, and returns the text to display.

When truncation.width is None, the text and runs come back unchanged. Otherwise the removed part is replaced by truncation.affix, on the side given by truncation.source. Wrapping and line_clamp from text_style still apply. The returned runs match the returned text. They borrow runs when nothing changes.

pub fn paint_background(&self, window: &mut Window, cx: &mut App) -> Result<()>

Paints the backgrounds of the text runs without the glyphs, so callers can paint content such as highlights between the backgrounds and text.

pub fn paint_foreground(&self, window: &mut Window, cx: &mut App) -> Result<()>

Paints the glyphs and decorations without the run backgrounds.

pub fn index_for_position( &self, pixel_point: Point<Pixels>, ) -> Result<usize, usize>

Returns the UTF-8 byte index of the character at pixel_point, in window coordinates.

Returns Ok with the index of the character under the point. Returns Err with 0 when the point is above the text. Points to the side of or below the text return Err with the closest index. Use this for hit testing, such as placing a caret on click.

Panics

Panics if the element hasn’t been laid out or prepainted.

pub fn position_for_index(&self, byte_index: usize) -> Option<Point<Pixels>>

Returns the top-left corner of the caret for byte_index, in window coordinates.

Returns None if the text has no shaped layout, or if byte_index is past the end of the text. Use this to place a caret or an overlay at a position in the text.

Panics

Panics if the element hasn’t been laid out or prepainted.

pub fn line_layout_for_index( &self, index: usize, ) -> Option<Arc<ShapedTextLayout>>

Returns the shaped layout of the text, or None if index is past the end or the text has not been shaped.

The layout covers the whole text, not one visual line or paragraph. Use TextLayout::line_layouts to get every layout in source order.

Panics

Panics if the element hasn’t been laid out.

pub fn line_layouts(&self) -> SmallVec<[Arc<ShapedTextLayout>; 1]>

Returns the shaped layout of the text as a collection with one entry.

This returns an empty collection if the text has not been shaped.

Panics

Panics if the element hasn’t been laid out.

pub fn bounds(&self) -> Bounds<Pixels>

Returns the window bounds of the element, as set during prepaint.

Panics

Panics if the element hasn’t been prepainted.

pub fn line_height(&self) -> Pixels

Returns the line height that the text is laid out with, in logical pixels.

Panics

Panics if the element hasn’t been laid out.

pub fn len(&self) -> usize

Returns the length of the shaped text in UTF-8 bytes.

This is the length after any text transform or truncation. It is 0 when the text has not been shaped.

Panics

Panics if the element hasn’t been laid out.

pub fn text(&self) -> String

Returns the text that was shaped, as a String.

This is the text after any TextTransform and truncation. A truncated text includes the affix, such as an ellipsis. It returns an empty string if the text has not been shaped.

Panics

Panics if the element hasn’t been laid out.

pub fn wrapped_text(&self) -> String

Returns the shaped text with each visual line followed by a \n, except the last.

Soft wraps therefore become \n. A hard line break keeps its own \n as part of its line, so it is followed by one more \n. Use this to copy wrapped text as it appears on screen.

Panics

Panics if the element hasn’t been laid out.

Trait Implementations

impl Clone for TextLayout

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Default for TextLayout

fn default() -> Self

Returns the “default value” for a type.