1 files changed, 56 insertions, 0 deletions
diff --git a/crates/typst-library/src/layout/measure.rs b/crates/typst-library/src/layout/measure.rs
new file mode 100644
index 00000000..eb8e509e
--- /dev/null
+++ b/crates/typst-library/src/layout/measure.rs
@@ -0,0 +1,56 @@
+use crate::prelude::*;
+
+/// Measures the layouted size of content.
+///
+/// The `measure` function lets you determine the layouted size of content.
+/// Note that an infinite space is assumed, therefore the measured height/width
+/// may not necessarily match the final height/width of the measured content.
+/// If you want to measure in the current layout dimensions, you can combined
+/// `measure` and [`layout`]($func/layout).
+///
+/// # Example { #example }
+/// The same content can have a different size depending on the styles that
+/// are active when it is layouted. For example, in the example below
+/// `[#content]` is of course bigger when we increase the font size.
+///
+/// ```example
+/// #let content = [Hello!]
+/// #content
+/// #set text(14pt)
+/// #content
+/// ```
+///
+/// To do a meaningful measurement, you therefore first need to retrieve the
+/// active styles with the [`style`]($func/style) function. You can then pass
+/// them to the `measure` function.
+///
+/// ```example
+/// #let thing(body) = style(styles => {
+///   let size = measure(body, styles)
+///   [Width of "#body" is #size.width]
+/// })
+///
+/// #thing[Hey] \
+/// #thing[Welcome]
+/// ```
+///
+/// The measure function returns a dictionary with the entries `width` and
+/// `height`, both of type [`length`]($type/length).
+///
+/// Display: Measure
+/// Category: layout
+#[func]
+pub fn measure(
+    /// The content whose size to measure.
+    content: Content,
+    /// The styles with which to layout the content.
+    styles: Styles,
+    /// The virtual machine.
+    vm: &mut Vm,
+) -> SourceResult<Dict> {
+    let pod = Regions::one(Axes::splat(Abs::inf()), Axes::splat(false));
+    let styles = StyleChain::new(&styles);
+    let frame = content.measure(&mut vm.vt, styles, pod)?.into_frame();
+    let Size { x, y } = frame.size();
+    Ok(dict! { "width" => x, "height" => y })
+}