Offset class

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 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

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

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 left and positive values of the y-axis go down. [...]
read-only
distance → double
The magnitude of the offset. [...]
read-only
distanceSquared → double
The square of the magnitude of the offset. [...]
read-only
dx → double
The x component of the offset. [...]
read-only
dy → double
The y component of the offset. [...]
read-only
hashCode → int
The hash code for this object. [...]
read-only, override
isFinite → bool
Whether both components are finite (neither infinite nor NaN). [...]
read-only, inherited
isInfinite → bool
Returns true if either component is double.infinity, and false if both are finite (or negative infinity, or NaN). [...]
read-only, inherited
runtimeType → Type
A representation of the runtime type of the object.
read-only, inherited

Methods

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
Returns 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. [...]
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed. [...]
inherited

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 ==(dynamic other) → bool
Compares two Offsets for equality.
override
operator unary-() → Offset
Unary negation operator. [...]
operator ~/(double operand) → Offset
Integer (truncating) division operator. [...]
operator <(OffsetBase other) → bool
Less-than 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 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 another Offset 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 >(OffsetBase other) → bool
Greater-than 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 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

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. [...]
const Offset(double.infinity, double.infinity)
zero → const Offset
An offset with zero magnitude. [...]
const Offset(0.0, 0.0)