---
title: Types
description: HingeStatus, Hinge, FoldOrientation, Fold, Posture, FoldState and TwoPaneFallback.
---

All types live in the package `com.jantursky.crease`. The generated API docs are on [javadoc.io](https://javadoc.io/doc/io.github.jantursky/crease).

`Hinge`, `Fold` and `FoldState` are plain classes, not data classes, so the library can add to them without breaking binary compatibility. They implement `equals`, `hashCode` and `toString`.

## HingeStatus

```kotlin
public enum class HingeStatus { Closed, PartiallyOpen, FullyOpen }
```

How far the hinge is open, as the platform reports it.

## Hinge

```kotlin
public class Hinge(public val status: HingeStatus, public val angle: Float?)
```

| Property | Type | Description |
| --- | --- | --- |
| `status` | `HingeStatus` | Whether the hinge is shut, half open or fully open. |
| `angle` | `Float?` | Degrees: 0 when shut, 180 when flat. `null` when the device has no angle sensor. |

## FoldOrientation

```kotlin
public enum class FoldOrientation { Vertical, Horizontal }
```

A vertical fold splits the window into a left and a right half. A horizontal fold splits it into a top and a bottom half.

## Fold

```kotlin
public class Fold(
    public val bounds: Rect,
    public val orientation: FoldOrientation,
    public val isSeparating: Boolean,
    public val isOccluding: Boolean,
)
```

| Property | Type | Description |
| --- | --- | --- |
| `bounds` | `Rect` | The fold in window coordinates, in pixels. A seamless panel reports zero width. |
| `orientation` | `FoldOrientation` | Direction of the fold line. |
| `isSeparating` | `Boolean` | Content should stay on one side: the device is half open, or there is a physical gap. |
| `isOccluding` | `Boolean` | The fold hides what is drawn beneath it. |

## Posture

```kotlin
public enum class Posture { Closed, Flat, Book, Tabletop }
```

| Value | Meaning |
| --- | --- |
| `Closed` | The hinge is shut. |
| `Flat` | A phone, a desktop window, or a foldable lying open. |
| `Book` | Half open with a vertical fold, held like a book. |
| `Tabletop` | Half open with a horizontal fold, standing like a laptop. |

See [postures and the hinge](/guides/postures-and-hinge) for the exact rules.

## FoldState

```kotlin
public class FoldState(
    public val hinge: Hinge?,
    public val folds: List<Fold>,
    public val cutouts: List<Rect>,
)
```

| Property | Type | Description |
| --- | --- | --- |
| `hinge` | `Hinge?` | `null` when the device has no hinge or has not reported it yet. |
| `folds` | `List<Fold>` | Folds across the window, usually zero or one. |
| `cutouts` | `List<Rect>` | Camera and sensor housings, in window coordinates and pixels. |
| `fold` | `Fold?` | The first fold, or `null`. |
| `posture` | `Posture` | The current posture. |

### Factories

| Factory | Parameters | Description |
| --- | --- | --- |
| `FoldState.None` | none | No hinge, no folds, no cutouts. |
| `FoldState.closed()` | none | A foldable that is shut. |
| `FoldState.flat(windowSize, orientation, foldWidth)` | `Size`, `FoldOrientation = Vertical`, `Float = 0f` | A foldable lying open. |
| `FoldState.book(windowSize, angle, foldWidth)` | `Size`, `Float = 90f`, `Float = 0f` | Half open, vertical fold in the middle. |
| `FoldState.tabletop(windowSize, angle, foldWidth)` | `Size`, `Float = 90f`, `Float = 0f` | Half open, horizontal fold in the middle. |

`windowSize` and `foldWidth` are in pixels, `angle` in degrees.

## TwoPaneFallback

```kotlin
public enum class TwoPaneFallback { FirstOnly, SideBySide, Stacked }
```

| Value | Description |
| --- | --- |
| `FirstOnly` | Only the first pane. |
| `SideBySide` | Both panes in a row, half each. |
| `Stacked` | Both panes in a column, half each. |