Foreground

Cells occupy the main slide body. The foreground plane sits above them, covering the slide without changing the grid. Put recurring foreground content in m.setup(foreground:), and set it for one slide with the same argument on m.slide. A plane is not a cell, so it never appears in cells:. Use foreground: none on a slide to hide inherited content. Footer text belongs in a grid cell because it takes part in the layout; see Footer and progress. The Background page covers the plane behind the body.

Placed content

Foreground content is painted over the slide body. Use native place calls to position images, logos, text, shapes, labels, or counters independently of the grid.

#import "@preview/mosaic:0.0.1" as m

#show: m.setup

#let badge(body, color) = rect(
  fill: color,
  radius: 0.25em,
  inset: (x: 0.55em, y: 0.3em),
  text(fill: white, weight: "bold", body),
)

#m.slide(
  foreground: [
    #place(
      top + right,
      dx: -1.35em,
      dy: 1.35em,
      badge([Label], rgb("#0072b2")),
    )
    #place(
      right + horizon,
      dx: -2.4em,
      circle(width: 3em, fill: rgb("#e69f00")),
    )
    #place(
      bottom + right,
      dx: -1.35em,
      dy: -2em,
      text(size: 1.25em, weight: "bold")[Any content],
    )
  ],
)[
  #block(width: 52%)[
    == Place arbitrary objects

    A foreground can contain any number of independently placed Typst objects.
  ]
]

Arbitrary foreground objects, first frame of 1

Open slideshow · 1 frame

A logo on every slide

A logo is the usual reason to reach for the plane, and it is the case setup handles best: state the place() call once and every slide in the deck carries it at the same spot. Because place resolves its alignment against the slide rather than against the content, the logo does not drift when one slide holds more than another, and dx and dy in em units keep its inset proportional to the deck’s type size.

Any slide can still replace the deck’s foreground with one of its own, or hide it with foreground: none. The fourth slide below does exactly that.

#import "@preview/mosaic:0.0.1" as m

#show: m.setup.with(
  foreground: [
    #place(
      bottom + right,
      dx: -1.35em,
      dy: -1.35em,
      m.components.image(
        path("/docs-src/assets/images/mosaic-logo.svg"),
        width: 2.5em,
        height: auto,
        alt: "The Mosaic logo",
      ),
    )
  ],
)

#m.slide[
  == One logo, every slide

  A `foreground` passed to `setup` is painted over every slide in the deck.
]

#m.slide[
  == It does not move

  The `place()` alignment resolves against the slide rather than the content,
  so the logo lands in the same spot however full the slide is.
]

#m.slide[
  == Refining the position

  `dx` and `dy` nudge it away from the edge. Em units keep that inset
  proportional to the deck's type size.
]

#m.slide(foreground: none)[
  == Hiding it

  One slide opts out with `foreground: none`.
]

Open slideshow · 4 frames