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Modifiers
Jetpack Compose layout modifiers for @expo/ui components.
Jetpack Compose modifiers allow you to customize the layout, appearance, and behavior of UI components. Modifiers are the Compose equivalent of style properties — they control sizing, padding, backgrounds, interactions, and more.
Installation
If you are installing this in an existing React Native app, make sure to install expo in your project.
Usage
Modifiers are applied to components using the modifiers prop with an array syntax. You can combine multiple modifiers to create complex styling and behavior. Modifiers are applied in the order they appear in the array, which can affect the final result (for example, applying padding before background produces different results than the reverse).
import { Button, Host } from '@expo/ui/jetpack-compose'; import { paddingAll, fillMaxWidth, background, border, shadow, clickable, } from '@expo/ui/jetpack-compose/modifiers'; function ModifiersExample() { return ( <Host style={{ flex: 1 }}> {/* Basic styling modifiers */} <Button modifiers={[paddingAll(16), fillMaxWidth(), background('#FF6B6B')]}> Full-width padded button </Button> {/* Complex combination with border and shadow */} <Button modifiers={[paddingAll(12), background('#4ECDC4'), border(2, '#2C3E50'), shadow(4)]}> Styled with border and shadow </Button> </Host> ); }
Padding
Control the spacing around a component's content.
paddingAll(all)
Applies equal padding on all four sides.
import { paddingAll } from '@expo/ui/jetpack-compose/modifiers'; <Button modifiers={[paddingAll(16)]}>Padded button</Button>;
padding(start, top, end, bottom)
Applies individual padding to each side.
import { padding } from '@expo/ui/jetpack-compose/modifiers'; <Button modifiers={[padding(16, 8, 16, 8)]}>Custom padding</Button>;
Size
Control the dimensions of a component.
size(width, height)
Sets exact dimensions for the component.
import { size } from '@expo/ui/jetpack-compose/modifiers'; <Button modifiers={[size(200, 48)]}>Fixed size</Button>;
fillMaxSize(fraction?)
Fills all available space in both dimensions.
import { fillMaxSize } from '@expo/ui/jetpack-compose/modifiers'; <Button modifiers={[fillMaxSize()]}>Fill all space</Button> <Button modifiers={[fillMaxSize(0.5)]}>Fill half</Button>
fillMaxWidth(fraction?)
Fills available width.
import { fillMaxWidth } from '@expo/ui/jetpack-compose/modifiers'; <Button modifiers={[fillMaxWidth()]}>Full width</Button>;
fillMaxHeight(fraction?)
Fills available height.
width(value)
Sets an exact width.
height(value)
Sets an exact height.
wrapContentWidth(alignment?)
Sizes the component to wrap its content width.
wrapContentHeight(alignment?)
Sizes the component to wrap its content height.
Position
Control the position of a component relative to its natural placement.
offset(x, y)
Offsets the component from its natural position without affecting the layout of surrounding components.
import { offset } from '@expo/ui/jetpack-compose/modifiers'; <Button modifiers={[offset(10, 5)]}>Offset button</Button>;
Appearance
Control the visual appearance of a component.
background(color)
Sets the background color.
import { background } from '@expo/ui/jetpack-compose/modifiers'; <Button modifiers={[background('#3498DB')]}>Blue background</Button>;
border(borderWidth, borderColor)
Adds a border around the component.
import { border } from '@expo/ui/jetpack-compose/modifiers'; <Button modifiers={[border(2, '#E74C3C')]}>Bordered button</Button>;
shadow(elevation)
Adds an elevation shadow beneath the component.
import { shadow } from '@expo/ui/jetpack-compose/modifiers'; <Button modifiers={[shadow(8)]}>Elevated button</Button>;
alpha(alpha)
Controls the opacity of the component.
import { alpha } from '@expo/ui/jetpack-compose/modifiers'; <Button modifiers={[alpha(0.5)]}>Semi-transparent</Button>;
blur(radius)
Applies a blur effect to the component.
import { blur } from '@expo/ui/jetpack-compose/modifiers'; <Button modifiers={[blur(4)]}>Blurred button</Button>;
Transform
Apply visual transformations to a component.
rotate(degrees)
Rotates the component.
import { rotate } from '@expo/ui/jetpack-compose/modifiers'; <Button modifiers={[rotate(45)]}>Rotated</Button>;
zIndex(index)
Controls the drawing order of overlapping components.
import { zIndex } from '@expo/ui/jetpack-compose/modifiers'; <Button modifiers={[zIndex(10)]}>On top</Button>;
Animation
Animate layout changes within a component.
animateContentSize(dampingRatio?, stiffness?)
Animates size changes of the component's content using a spring animation.
import { animateContentSize } from '@expo/ui/jetpack-compose/modifiers'; <Button modifiers={[animateContentSize()]}>Animated size</Button> <Button modifiers={[animateContentSize(0.5, 200)]}>Custom spring</Button>
Layout
Control how a component is sized and positioned within its parent container.
weight(weight)
Assigns a flexible weight to a component inside a Row or Column, distributing available space proportionally among weighted children.
import { weight } from '@expo/ui/jetpack-compose/modifiers'; // In a Row, the first button takes 2/3 and the second takes 1/3 <Button modifiers={[weight(2)]}>Wider</Button> <Button modifiers={[weight(1)]}>Narrower</Button>
align(alignment)
Sets the alignment of the component within its parent container.
matchParentSize()
Sizes the component to match the size of its parent Box. Unlike fillMaxSize, this does not affect the parent's measurement.
import { matchParentSize } from '@expo/ui/jetpack-compose/modifiers'; <Button modifiers={[matchParentSize()]}>Match parent</Button>;
Interaction
Add user interaction handlers to a component.
clickable(handler)
Makes the component respond to click events.
import { clickable } from '@expo/ui/jetpack-compose/modifiers'; <Button modifiers={[clickable(() => console.log('Clicked!'))]}>Clickable</Button>;
selectable(selected, handler)
Makes the component selectable, similar to a radio button.
import { selectable } from '@expo/ui/jetpack-compose/modifiers'; <Button modifiers={[selectable(isSelected, () => setIsSelected(!isSelected))]}> Selectable option </Button>;
Clipping
Clip a component's content to a specific shape.
clip(shape)
Clips the component to the given shape. Content outside the shape boundary is not drawn.
Available shapes
import { clip } from '@expo/ui/jetpack-compose/modifiers'; import { Shapes } from '@expo/ui/jetpack-compose/modifiers'; // Circular clipping <Button modifiers={[clip(Shapes.Circle)]}>Circle</Button> // Rounded corners with uniform radius <Button modifiers={[clip(Shapes.RoundedCorner(12))]}>Rounded</Button> // Rounded corners with individual radii <Button modifiers={[ clip(Shapes.RoundedCorner({ topStart: 16, topEnd: 16, bottomStart: 0, bottomEnd: 0 })), ]}> Top rounded only </Button> // Cut corners <Button modifiers={[clip(Shapes.CutCorner(8))]}>Cut corners</Button>
Utility
testID(tag)
Assigns a test identifier to the component for use in UI testing.
import { testID } from '@expo/ui/jetpack-compose/modifiers'; <Button modifiers={[testID('submit-button')]}>Submit</Button>;
API
import { paddingAll, padding, size, fillMaxWidth, background, clickable, clip, Shapes } from '@expo/ui/jetpack-compose/modifiers';
Constants
Type: {
Circle: BuiltinShape,
CutCorner: (params: number | CornerRadii) => BuiltinShape,
Material: {
Arch: BuiltinShape,
Boom: BuiltinShape,
Bun: BuiltinShape,
Clover4Leaf: BuiltinShape,
Clover8Leaf: BuiltinShape,
Cookie12Sided: BuiltinShape,
Cookie4Sided: BuiltinShape,
Cookie6Sided: BuiltinShape,
Cookie7Sided: BuiltinShape,
Cookie9Sided: BuiltinShape,
Diamond: BuiltinShape,
Fan: BuiltinShape,
Ghostish: BuiltinShape,
Heart: BuiltinShape,
Oval: BuiltinShape,
Pentagon: BuiltinShape,
Pill: BuiltinShape,
PixelCircle: BuiltinShape,
PixelTriangle: BuiltinShape,
Puffy: BuiltinShape,
PuffyDiamond: BuiltinShape,
Slanted: BuiltinShape,
SoftBurst: BuiltinShape,
Sunny: BuiltinShape,
Triangle: BuiltinShape,
VerySunny: BuiltinShape
},
Rectangle: BuiltinShape,
RoundedCorner: (params: number | CornerRadii) => BuiltinShape
}
Predefined shapes for use with the clip modifier.
Example
clip(Shapes.Circle) clip(Shapes.RoundedCorner(16)) clip(Shapes.RoundedCorner({ topStart: 8, bottomEnd: 16 })) clip(Shapes.Material.Heart)
Methods
Animates size changes with spring animation.
ModifierConfigApplies a graphics layer transformation with animation support.
ModifierConfigAdds padding to avoid the software keyboard (IME). When the keyboard is visible, padding is added to keep content above it.
ModifierConfig{
$type: 'keyframes',
delayMillis: number,
durationMillis: number,
keyframes: Record<number, number>
}Makes the view match the parent Box size. Only works when used inside Box.
ModifierConfigApplies padding with individual values for each side.
ModifierConfigMakes the view selectable, like a radio button row.
ModifierConfig{
$type: 'spring',
dampingRatio: number,
stiffness: number,
visibilityThreshold: number
}{
$type: 'tween',
delayMillis: number,
durationMillis: number,
easing: 'linear' | 'fastOutSlowIn' | 'fastOutLinearIn' | 'linearOutSlowIn' | 'ease'
}Sets the weight for flexible sizing in Row or Column. Only works when used inside Row or Column.
ModifierConfigTypes
Literal type: string
Acceptable values are: 'topStart' | 'topCenter' | 'topEnd' | 'centerStart' | 'center' | 'centerEnd' | 'bottomStart' | 'bottomCenter' | 'bottomEnd' | 'top' | 'centerVertically' | 'bottom' | 'start' | 'centerHorizontally' | 'end'
Built-in Jetpack Compose shape for the clip modifier.
Type: object shaped as below:
Or object shaped as below:
Or object shaped as below:
Or object shaped as below:
Or object shaped as below: