Struct WindowTextSystem 

pub struct WindowTextSystem { /* private fields */ }

The GPUI text layout subsystem.

Implementations

impl WindowTextSystem

pub fn new(text_system: Arc<TextSystem>) -> Self

Create a new WindowTextSystem with the given TextSystem.

pub fn shape_line( &self, text: SharedString, font_size: Pixels, runs: &[TextRun], force_width: Option<Pixels>, ) -> ShapedLine

Shape the given line, at the given font_size, for painting to the screen. Subsets of the line can be styled independently with the runs parameter.

Note that this method can only shape a single line of text. It will panic if the text contains newlines. If you need to shape multiple lines of text, use Self::shape_text instead.

pub fn shape_line_by_hash( &self, text_hash: u64, text_len: usize, font_size: Pixels, runs: &[TextRun], force_width: Option<Pixels>, materialize_text: impl FnOnce() -> SharedString, ) -> ShapedLine

Shape the given line using a caller-provided content hash as the cache key.

This enables cache hits without materializing a contiguous SharedString for the text. If the cache misses, materialize_text is invoked to produce the SharedString for shaping.

Contract (caller enforced):

• Same text_hash implies identical text content (collision risk accepted by caller).
• text_len should be the UTF-8 byte length of the text (helps reduce accidental collisions).

Like Self::shape_line, this must be used only for single-line text (no \n).

pub fn shape_text<S: AsRef<str> + Into<SharedString>>( &self, text: S, font_size: Pixels, runs: &[TextRun], wrap_width: Option<Pixels>, line_clamp: Option<usize>, ) -> Result<SmallVec<[WrappedLine; 1]>>

Shape a multi line string of text, at the given font_size, for painting to the screen. Subsets of the text can be styled independently with the runs parameter, where each run dictates the length of utf8 characters in text that it styles. The length (utf8 characters) of last item in runs is semantically ignored as it represents the “rest” of the text.

If wrap_width is provided, the line breaks will be adjusted to fit within the given width.

If the text provided is SharedString and does not contain new-lines, it will be used as-is without additional allocations. If the text provided is not a SharedString or contains new-lines, new SharedStrings will be allocated for each substring between new-line characters (minimum of 1).

pub fn layout_line( &self, text: &str, font_size: Pixels, runs: &[TextRun], force_width: Option<Pixels>, ) -> Arc<LineLayout>

Layout the given line of text, at the given font_size. Subsets of the line can be styled independently with the runs parameter. Generally, you should prefer to use Self::shape_line instead, which can be painted directly.

pub fn layout_width( &self, font_id: FontId, font_size: Pixels, ch: char, ) -> Pixels

Returns the shaped layout width of for the given character, in the given font and size.

pub fn em_layout_width(&self, font_id: FontId, font_size: Pixels) -> Pixels

Returns the shaped layout width of an em.

pub fn try_layout_line_by_hash( &self, text_hash: u64, text_len: usize, font_size: Pixels, runs: &[TextRun], force_width: Option<Pixels>, ) -> Option<Arc<LineLayout>>

Probe the line layout cache using a caller-provided content hash, without allocating.

Returns Some(layout) if the layout is already cached in either the current frame or the previous frame. Returns None if it is not cached.

Contract (caller enforced):

• Same text_hash implies identical text content (collision risk accepted by caller).
• text_len should be the UTF-8 byte length of the text (helps reduce accidental collisions).

pub fn layout_line_by_hash( &self, text_hash: u64, text_len: usize, font_size: Pixels, runs: &[TextRun], force_width: Option<Pixels>, materialize_text: impl FnOnce() -> SharedString, ) -> Arc<LineLayout>

Layout the given line of text using a caller-provided content hash as the cache key.

This enables cache hits without materializing a contiguous SharedString for the text. If the cache misses, materialize_text is invoked to produce the SharedString for shaping.

Contract (caller enforced):

• Same text_hash implies identical text content (collision risk accepted by caller).
• text_len should be the UTF-8 byte length of the text (helps reduce accidental collisions).

Trait Implementations

impl Deref for WindowTextSystem

type Target = Arc<TextSystem>

The resulting type after dereferencing.

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

Dereferences the value.