layout
Provides access to the current outer container's (or page's, if none) dimensions (width and height).
Accepts a function that receives a single parameter, which is a dictionary with keys width
and height
, both of type length
. The function is provided context, meaning you don't need to use it in combination with the context
keyword. This is why measure
can be called in the example below.
#let text = lorem(30)
#layout(size => [
#let (height,) = measure(
block(width: size.width, text),
)
This text is #height high with
the current page width: \
#text
])

Note that the layout
function forces its contents into a block-level container, so placement relative to the page or pagebreaks are not possible within it.
If the layout
call is placed inside a box with a width of 800pt
and a height of 400pt
, then the specified function will be given the argument (width: 800pt, height: 400pt)
. If it is placed directly into the page, it receives the page's dimensions minus its margins. This is mostly useful in combination with measurement.
You can also use this function to resolve ratio
to fixed lengths. This might come in handy if you're building your own layout abstractions.
#layout(size => {
let half = 50% * size.width
[Half a page is #half wide.]
})

Note that the width or height provided by layout
will be infinite if the corresponding page dimension is set to auto
.
Parameters
func
A function to call with the outer container's size. Its return value is displayed in the document.
The container's size is given as a dictionary with the keys width
and height
.
This function is called once for each time the content returned by layout
appears in the document. This makes it possible to generate content that depends on the dimensions of its container.