Offset

value class Offset(val packedValue: Long)

An immutable 2D floating-point offset.

Generally speaking, Offsets can be interpreted in two ways:

1. As representing a point in Cartesian space a specified distance from a separately-maintained origin. For example, the top-left position of children in the RenderBox protocol is typically represented as an Offset from the top left of the parent box.
2. As a vector that can be applied to coordinates. For example, when painting a widget, the parent is passed an Offset from the screen's origin which it can add to the offsets of its children to find the Offset from the screen's origin to each of the children.

Because a particular Offset can be interpreted as one sense at one time then as the other sense at a later time, the same class is used for both senses.

See also:

• Size, which represents a vector describing the size of a rectangle.

To create an Offset, call the top-level function that accepts an x/y pair of coordinates:

val offset = Offset(x, y)

The primary constructor of Offset is intended to be used with the packedValue property to allow storing offsets in arrays or collections of primitives without boxing.

Parameters

Properties

inline val x: Float

inline val y: Float

Functions

inline operator fun component1(): Float

inline operator fun component2(): Float

fun copy(x: Float = unpackFloat1(packedValue), y: Float = unpackFloat2(packedValue)) =
        Offset(packFloats(x, y))

Returns a copy of this Offset instance optionally overriding the x or y parameter

inline fun isValid(): Boolean

Returns:

• False if x or y is a NaN
• True if x or y is infinite
• True otherwise

fun getDistance(): Float

The magnitude of the offset.

If you need this value to compare it to another Offset's distance, consider using getDistanceSquared instead, since it is cheaper to compute.

fun getDistanceSquared(): Float

The square of the magnitude of the offset.

This is cheaper than computing the getDistance itself.

inline operator fun unaryMinus(): Offset

Unary negation operator.

Returns an offset with the coordinates negated.

If the Offset represents an arrow on a plane, this operator returns the same arrow but pointing in the reverse direction.

operator fun minus(other: Offset): Offset

Binary subtraction operator.

Returns an offset whose x value is the left-hand-side operand's x minus the right-hand-side operand's x and whose y value is the left-hand-side operand's y minus the right-hand-side operand's y.

operator fun plus(other: Offset): Offset

Binary addition operator.

Returns an offset whose x value is the sum of the x values of the two operands, and whose y value is the sum of the y values of the two operands.

operator fun times(operand: Float): Offset

Multiplication operator.

Returns an offset whose coordinates are the coordinates of the left-hand-side operand (an Offset) multiplied by the scalar right-hand-side operand (a Float).

operator fun div(operand: Float): Offset

Division operator.

Returns an offset whose coordinates are the coordinates of the left-hand-side operand (an Offset) divided by the scalar right-hand-side operand (a Float).

operator fun rem(operand: Float): Offset

Modulo (remainder) operator.

Returns an offset whose coordinates are the remainder of dividing the coordinates of the left-hand-side operand (an Offset) by the scalar right-hand-side operand (a Float).

Companion Object

Properties

val Zero = Offset(0x0L)

An offset with zero magnitude.

This can be used to represent the origin of a coordinate space.

val Infinite = Offset(DualFloatInfinityBase)

An offset with infinite x and y components.

See also isFinite to check whether both components are finite.

val Unspecified = Offset(UnspecifiedPackedFloats)

Represents an unspecified Offset value, usually a replacement for null when a primitive value is desired.