Introduction

Kotlin Multiplatform library for the hinge angle, fold position and fold-aware layouts in Compose Multiplatform, on Android foldables and iPhone Duo.

Crease is a Kotlin Multiplatform library that gives Compose Multiplatform one API for the hinge of a foldable phone, on Android foldables and the iPhone Duo. You can read the hinge angle, find out where the fold is, and lay out two panes around it. The same code runs on Android foldables and on the iPhone Duo. On a phone, a desktop window or a browser it reports “no hinge” and your layout falls back to whatever you chose.

The current version is 1.3.0. See the changelog for what each release changed. Add it to commonMain:

implementation("io.github.jantursky:crease:1.3.0")

The source is on GitHub, MIT licensed.

import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import com.jantursky.crease.FoldAwareTwoPane
import com.jantursky.crease.TwoPaneFallback

@Composable
fun RecipeScreen() {
    FoldAwareTwoPane(
        first = { Text("Ingredients") },
        second = { Text("Steps") },
        fallback = TwoPaneFallback.SideBySide,
    )
}

When the device is half open and the fold separates the screen, Ingredients fills one side of the fold and Steps the other. On any other device both panes share the window 50/50, because that is the fallback.

What you get

• The hinge as a value: its status (Closed, PartiallyOpen, FullyOpen) and its angle in degrees, when the device has an angle sensor.
• Fold geometry: bounds in window pixels, orientation, whether content should avoid it and whether it hides what is drawn beneath it.
• A Posture (Closed, Flat, Book, Tabletop) worked out from those, for layout decisions.
• FoldAwareTwoPane, TabletopLayout and Modifier.avoidFold().
• Camera and sensor cutouts in window coordinates.
• ProvideFoldState and FoldState factories, so previews and tests can pretend to be any foldable.

Platforms

Everything compiles for every target, so shared code needs no expect or actual for the fold.