Dimension value representing device-independent pixels (dp). Component APIs specify their dimensions such as line thickness in DP with Dp objects. Hairline (1 pixel) thickness may be specified with Hairline, a dimension that take up no space. Dp are normally defined using dp, which can be applied to Int, Double, and Float.

import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.padding
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp

Box(
    Modifier.padding(
        10.dp, // Int
        10f.dp, // Float
        20.0.dp, // Double
        10.dp,
    )
)

Drawing and Layout are done in pixels. To retrieve the pixel size of a Dp, use Density.toPx:

import androidx.compose.foundation.Canvas
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.drawscope.Stroke
import androidx.compose.ui.graphics.drawscope.inset
import androidx.compose.ui.unit.dp

val lineThickness = 6.dp
Canvas(Modifier.fillMaxSize()) {
    val lineThicknessPx = lineThickness.toPx()
    inset(lineThicknessPx / 2) { drawRect(Color.Red, style = Stroke(lineThicknessPx)) }
}

Summary

Nested types

Public companion properties
Dp

A dimension used to represent a hairline drawing element.
Cmn
Dp

Infinite dp dimension.
Cmn
Dp

Constant that means unspecified Dp.
Cmn

Public constructors
Dp(value: Float)
Cmn

Public functions
open operator Int
compareTo(other: Dp)

Support comparing Dimensions with comparison operators.
Cmn
inline operator Float
div(other: Dp)

Divide by another Dp to get a scalar.
Cmn
inline operator Dp
div(other: Float)

Divide a Dp by a scalar.
Cmn
inline operator Dp
div(other: Int)
Cmn
inline operator Dp
minus(other: Dp)

Subtract a Dp from another one.
Cmn
inline operator Dp
plus(other: Dp)

Add two Dps together.
Cmn
inline operator Dp
times(other: Float)

Multiply a Dp by a scalar.
Cmn
inline operator Dp
times(other: Int)
Cmn
open String
Cmn
inline operator Dp

This is the same as multiplying the Dp by -1.0.
Cmn

Public properties
Float
Cmn

Extension functions
Unit
Dp.assertIsEqualTo(expected: Dp, subject: String, tolerance: Dp)

Asserts that this value is equal to the given expected value.
Cmn
inline Dp
Dp.coerceAtLeast(minimumValue: Dp)

Ensures that this value is not less than the specified minimumValue.
Cmn
inline Dp
Dp.coerceAtMost(maximumValue: Dp)

Ensures that this value is not greater than the specified maximumValue.
Cmn
inline Dp
Dp.coerceIn(minimumValue: Dp, maximumValue: Dp)

Ensures that this value lies in the specified range minimumValue..
Cmn
inline Dp
Dp.takeOrElse(block: () -> Dp)

If this Dp then this is returned, otherwise block is executed and its result is returned.
Cmn
inline Meter

Converts a Dp value to Meter.
android
Unit
Dp.assertIsEqualTo(expected: Dp, subject: String, tolerance: Dp)

Asserts that this value is equal to the given expected value.
android

Extension properties
Boolean

Return true when it is finite or false when it is Dp.Infinity
Cmn
Boolean

false when this is Dp.Unspecified.
Cmn
Boolean

true when this is Dp.Unspecified.
Cmn

Public companion properties

Hairline

Cmn
Added in 1.0.0
val Hairline: Dp

A dimension used to represent a hairline drawing element. Hairline elements take up no space, but will draw a single pixel, independent of the device's resolution and density.

Infinity

Cmn
Added in 1.0.0
val Infinity: Dp

Infinite dp dimension.

Unspecified

Cmn
Added in 1.0.0
val Unspecified: Dp

Constant that means unspecified Dp. Instead of comparing a Dp value to this constant, consider using isSpecified and isUnspecified instead.

Public constructors

Dp

Cmn
Added in 1.2.0
Dp(value: Float)

Public functions

compareTo

Cmn 
open operator fun compareTo(other: Dp): Int

Support comparing Dimensions with comparison operators.

div

Cmn 
inline operator fun div(other: Dp): Float

Divide by another Dp to get a scalar.

div

Cmn
Added in 1.1.0
inline operator fun div(other: Float): Dp

Divide a Dp by a scalar.

div

Cmn
Added in 1.1.0
inline operator fun div(other: Int): Dp

minus

Cmn 
inline operator fun minus(other: Dp): Dp

Subtract a Dp from another one.

plus

Cmn 
inline operator fun plus(other: Dp): Dp

Add two Dps together.

times

Cmn
Added in 1.1.0
inline operator fun times(other: Float): Dp

Multiply a Dp by a scalar.

times

Cmn
Added in 1.1.0
inline operator fun times(other: Int): Dp

toString

Cmn 
open fun toString(): String

unaryMinus

Cmn
Added in 1.1.0
inline operator fun unaryMinus(): Dp

This is the same as multiplying the Dp by -1.0.

Public properties

value

Cmn
Added in 1.0.0
val value: Float

Extension functions

assertIsEqualTo

Cmn 
fun Dp.assertIsEqualTo(expected: Dp, subject: String, tolerance: Dp = Dp(.5f)): Unit

Asserts that this value is equal to the given expected value.

Performs the comparison with the given tolerance or the default one if none is provided. It is recommended to use tolerance when comparing positions and size coming from the framework as there can be rounding operation performed by individual layouts so the values can be slightly off from the expected ones.

Parameters
expected: Dp

The expected value to which this one should be equal to.
subject: String

Used in the error message to identify which item this assertion failed on.
tolerance: Dp = Dp(.5f)

The tolerance within which the values should be treated as equal.
Throws
kotlin.AssertionError

if comparison fails.

coerceAtLeast

Cmn 
inline fun Dp.coerceAtLeast(minimumValue: Dp): Dp

Ensures that this value is not less than the specified minimumValue.

Returns
Dp

this value if it's greater than or equal to the minimumValue or the minimumValue otherwise.

coerceAtMost

Cmn 
inline fun Dp.coerceAtMost(maximumValue: Dp): Dp

Ensures that this value is not greater than the specified maximumValue.

Returns
Dp

this value if it's less than or equal to the maximumValue or the maximumValue otherwise.

coerceIn

Cmn 
inline fun Dp.coerceIn(minimumValue: Dp, maximumValue: Dp): Dp

Ensures that this value lies in the specified range minimumValue..maximumValue.

Returns
Dp

this value if it's in the range, or minimumValue if this value is less than minimumValue, or maximumValue if this value is greater than maximumValue.

takeOrElse

Cmn 
inline fun Dp.takeOrElse(block: () -> Dp): Dp

If this Dp then this is returned, otherwise block is executed and its result is returned.

toMeter

android 
inline fun Dp.toMeter(): Meter

Converts a Dp value to Meter.

Handles unspecified and infinite Dp values gracefully.

Returns
Meter

the equivalent value in meters, or Meter.NaN if the Dp is unspecified, or Meter.Infinity if the Dp is infinite.

assertIsEqualTo

android 
fun Dp.assertIsEqualTo(expected: Dp, subject: String, tolerance: Dp = Dp(.5f)): Unit

Asserts that this value is equal to the given expected value.

Performs the comparison with the given tolerance or the default one if none is provided. It is recommended to use tolerance when comparing positions and size coming from the framework as there can be rounding operation performed by individual layouts so the values can be slightly off from the expected ones.

Parameters
expected: Dp

The expected value to which this one should be equal to.
subject: String

Used in the error message to identify which item this assertion failed on.
tolerance: Dp = Dp(.5f)

The tolerance within which the values should be treated as equal.
Throws
kotlin.AssertionError

if comparison fails.

Extension properties

isFinite

Cmn 
val Dp.isFinite: Boolean

Return true when it is finite or false when it is Dp.Infinity

isSpecified

Cmn 
val Dp.isSpecified: Boolean

false when this is Dp.Unspecified.

isUnspecified

Cmn 
val Dp.isUnspecified: Boolean

true when this is Dp.Unspecified.