Luminance final

final class Luminance extends Quantity<Luminance>

A quantity representing luminance — the luminous intensity per unit area of a surface emitting or reflecting light in a given direction.

Inheritance

Object → Quantity<A extends Quantity<A>> → Luminance

Constructors

Luminance()

Luminance(double value, UnitOfMeasure<Luminance> unit)

Implementation

Luminance(super.value, super.unit);

Properties

hashCode no setter inherited

int get hashCode

The hash code for this object.

A hash code is a single integer which represents the state of the object that affects operator == comparisons.

All objects have hash codes. The default hash code implemented by Object represents only the identity of the object, the same way as the default operator == implementation only considers objects equal if they are identical (see identityHashCode).

If operator == is overridden to use the object state instead, the hash code must also be changed to represent that state, otherwise the object cannot be used in hash based data structures like the default Set and Map implementations.

Hash codes must be the same for objects that are equal to each other according to operator ==. The hash code of an object should only change if the object changes in a way that affects equality. There are no further requirements for the hash codes. They need not be consistent between executions of the same program and there are no distribution guarantees.

Objects that are not equal are allowed to have the same hash code. It is even technically allowed that all instances have the same hash code, but if clashes happen too often, it may reduce the efficiency of hash-based data structures like HashSet or HashMap.

If a subclass overrides hashCode, it should override the operator == operator as well to maintain consistency.

Inherited from Quantity.

Implementation

@override
int get hashCode => Object.hash(value, unit);

runtimeType no setter inherited

Type get runtimeType

A representation of the runtime type of the object.

Inherited from Object.

Implementation

external Type get runtimeType;

toFootlamberts no setter

Luminance get toFootlamberts

Converts this to footlamberts (fL).

Implementation

Luminance get toFootlamberts => to(footlamberts).footlamberts;

toLamberts no setter

Luminance get toLamberts

Converts this to lamberts (L).

Implementation

Luminance get toLamberts => to(lamberts).lamberts;

toNits no setter

Luminance get toNits

Converts this to nits (cd/m²).

Implementation

Luminance get toNits => to(nits).nits;

toStilbs no setter

Luminance get toStilbs

Converts this to stilbs (sb).

Implementation

Luminance get toStilbs => to(stilbs).stilbs;

unit final inherited

final UnitOfMeasure<Luminance> unit

The unit of measure that value is expressed in.

Inherited from Quantity.

Implementation

final UnitOfMeasure<A> unit;

value final inherited

final double value

The raw numeric value of this quantity expressed in unit.

Inherited from Quantity.

Implementation

final double value;

Methods

equivalentTo() inherited

bool equivalentTo(Quantity<Luminance> other)

Returns true if this quantity represents the same physical magnitude as other, regardless of which unit each is expressed in.

Inherited from Quantity.

Implementation

bool equivalentTo(Quantity<A> other) => other.to(unit) == value;

noSuchMethod() inherited

dynamic noSuchMethod(Invocation invocation)

Invoked when a nonexistent method or property is accessed.

A dynamic member invocation can attempt to call a member which doesn't exist on the receiving object. Example:

dynamic object = 1;
object.add(42); // Statically allowed, run-time error

This invalid code will invoke the noSuchMethod method of the integer 1 with an Invocation representing the .add(42) call and arguments (which then throws).

Classes can override noSuchMethod to provide custom behavior for such invalid dynamic invocations.

A class with a non-default noSuchMethod invocation can also omit implementations for members of its interface. Example:

class MockList<T> implements List<T> {
  noSuchMethod(Invocation invocation) {
    log(invocation);
    super.noSuchMethod(invocation); // Will throw.
  }
}
void main() {
  MockList().add(42);
}

This code has no compile-time warnings or errors even though the MockList class has no concrete implementation of any of the List interface methods. Calls to List methods are forwarded to noSuchMethod, so this code will log an invocation similar to Invocation.method(#add, [42]) and then throw.

If a value is returned from noSuchMethod, it becomes the result of the original invocation. If the value is not of a type that can be returned by the original invocation, a type error occurs at the invocation.

The default behavior is to throw a NoSuchMethodError.

Inherited from Object.

Implementation

@pragma("vm:entry-point")
@pragma("wasm:entry-point")
external dynamic noSuchMethod(Invocation invocation);

to() inherited

double to(UnitOfMeasure<Luminance> uom)

Converts this quantity to uom and returns the raw double value.

If uom equals unit, the current value is returned unchanged.

Inherited from Quantity.

Implementation

double to(UnitOfMeasure<A> uom) => uom == unit ? value : uom.convertTo(unit.convertFrom(value));

toString() inherited

String toString()

A string representation of this object.

Some classes have a default textual representation, often paired with a static parse function (like int.parse). These classes will provide the textual representation as their string representation.

Other classes have no meaningful textual representation that a program will care about. Such classes will typically override toString to provide useful information when inspecting the object, mainly for debugging or logging.

Inherited from Quantity.

Implementation

@override
String toString() => '$value ${unit.symbol}';

Operators

operator +()

Luminance operator +(Luminance that)

Returns the sum of this and that in the units of this Luminance.

Implementation

Luminance operator +(Luminance that) => Luminance(value + that.to(unit), unit);

operator -()

Luminance operator -(Luminance that)

Returns the difference between this and that in the units of this Luminance.

Implementation

Luminance operator -(Luminance that) => Luminance(value - that.to(unit), unit);

operator <() inherited

bool operator <(Luminance that)

Returns true if this quantity is less than that.

that is converted to unit before comparing.

Inherited from Quantity.

Implementation

bool operator <(A that) => value < that.to(unit);

operator <=() inherited

bool operator <=(Luminance that)

Returns true if this quantity is less than or equal to that.

that is converted to unit before comparing.

Inherited from Quantity.

Implementation

bool operator <=(A that) => value <= that.to(unit);

operator ==() inherited

bool operator ==(Object other)

The equality operator.

The default behavior for all Objects is to return true if and only if this object and other are the same object.

Override this method to specify a different equality relation on a class. The overriding method must still be an equivalence relation. That is, it must be:

• Total: It must return a boolean for all arguments. It should never throw.

• Reflexive: For all objects o, o == o must be true.

• Symmetric: For all objects o1 and o2, o1 == o2 and o2 == o1 must either both be true, or both be false.

• Transitive: For all objects o1, o2, and o3, if o1 == o2 and o2 == o3 are true, then o1 == o3 must be true.

The method should also be consistent over time, so whether two objects are equal should only change if at least one of the objects was modified.

If a subclass overrides the equality operator, it should override the hashCode method as well to maintain consistency.

Inherited from Quantity.

Implementation

@override
bool operator ==(Object other) =>
    identical(this, other) ||
    (other is Quantity<A> && other.value == value && other.unit == unit);

operator >() inherited

bool operator >(Luminance that)

Returns true if this quantity is greater than that.

that is converted to unit before comparing.

Inherited from Quantity.

Implementation

bool operator >(A that) => value > that.to(unit);

operator >=() inherited

bool operator >=(Luminance that)

Returns true if this quantity is greater than or equal to that.

that is converted to unit before comparing.

Inherited from Quantity.

Implementation

bool operator >=(A that) => value >= that.to(unit);

Static Methods

parse() override

Option<Luminance> parse(String s)

Parses s into a Luminance, returning None if parsing fails.

Implementation

static Option<Luminance> parse(String s) => Quantity.parse(s, units);

Constants

footlamberts

const LuminanceUnit footlamberts

Unit for footlamberts (fL).

Implementation

static const LuminanceUnit footlamberts = Footlamberts._();

lamberts

const LuminanceUnit lamberts

Unit for lamberts (L).

Implementation

static const LuminanceUnit lamberts = Lamberts._();

nits

const LuminanceUnit nits

Unit for nits (cd/m²) — the SI unit of luminance.

Implementation

static const LuminanceUnit nits = Nits._();

stilbs

const LuminanceUnit stilbs

Unit for stilbs (sb) — CGS unit of luminance (1 sb = 10 000 cd/m²).

Implementation

static const LuminanceUnit stilbs = Stilbs._();

units

const Set<LuminanceUnit> units

All supported Luminance units.

Implementation

static const units = {
  nits,
  stilbs,
  footlamberts,
  lamberts,
};