Offset class - dart:ui library (original) (raw)

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 anOffset from the top left of the parent box.
2. As a vector that can be applied to coordinates. For example, when painting a RenderObject, 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.

Inheritance

• Object
• OffsetBase
• Offset

Constructors

Offset(double dx, double dy)

Creates an offset. The first argument sets dx, the horizontal component, and the second sets dy, the vertical component.

const

Offset.fromDirection(double direction, [double distance = 1.0])

Creates an offset from its direction and distance.

factory

Properties

direction → double

The angle of this offset as radians clockwise from the positive x-axis, in the range -pi to pi, assuming positive values of the x-axis go to the right and positive values of the y-axis go down.

no setter

distance → double

The magnitude of the offset.

no setter

distanceSquared → double

The square of the magnitude of the offset.

no setter

dx → double

The x component of the offset.

no setter

dy → double

The y component of the offset.

no setter

hashCode → int

The hash code for this object.

no setteroverride

isFinite → bool

Whether both components are finite (neither infinite nor NaN).

no setterinherited

isInfinite → bool

Returns true if either component is double.infinity, and false if both are finite (or negative infinity, or NaN).

no setterinherited

runtimeType → Type

A representation of the runtime type of the object.

no setterinherited

Methods

noSuchMethod(Invocation invocation)→ dynamic

Invoked when a nonexistent method or property is accessed.

inherited

scale(double scaleX, double scaleY)→ Offset

Returns a new offset with the x component scaled by scaleX and the y component scaled by scaleY.

toString()→ String

A string representation of this object.

override

translate(double translateX, double translateY)→ Offset

Returns a new offset with translateX added to the x component and translateY added to the y component.

Operators

operator %(double operand)→ Offset

Modulo (remainder) operator.

operator &(Size other)→ Rect

Rectangle constructor operator.

operator *(double operand)→ Offset

Multiplication operator.

operator +(Offset other)→ Offset

Binary addition operator.

operator -(Offset other)→ Offset

Binary subtraction operator.

operator /(double operand)→ Offset

Division operator.

operator <(OffsetBase other)→ bool

Less-than operator. Compares an Offset or Size to another Offset orSize, and returns true if both the horizontal and vertical values of the left-hand-side operand are smaller than the horizontal and vertical values of the right-hand-side operand respectively. Returns false otherwise.

inherited

operator <=(OffsetBase other)→ bool

Less-than-or-equal-to operator. Compares an Offset or Size to anotherOffset or Size, and returns true if both the horizontal and vertical values of the left-hand-side operand are smaller than or equal to the horizontal and vertical values of the right-hand-side operand respectively. Returns false otherwise.

inherited

operator ==(Object other)→ bool

Compares two Offsets for equality.

override

operator >(OffsetBase other)→ bool

Greater-than operator. Compares an Offset or Size to another Offsetor Size, and returns true if both the horizontal and vertical values of the left-hand-side operand are bigger than the horizontal and vertical values of the right-hand-side operand respectively. Returns false otherwise.

inherited

operator >=(OffsetBase other)→ bool

Greater-than-or-equal-to operator. Compares an Offset or Size to another Offset or Size, and returns true if both the horizontal and vertical values of the left-hand-side operand are bigger than or equal to the horizontal and vertical values of the right-hand-side operand respectively. Returns false otherwise.

inherited

operator unary-()→ Offset

Unary negation operator.

operator ~/(double operand)→ Offset

Integer (truncating) division operator.

Static Methods

lerp(Offset? a, Offset? b, double t)→ Offset?

Linearly interpolate between two offsets.

Constants

infinite → const Offset

An offset with infinite x and y components.

zero → const Offset

An offset with zero magnitude.