Package jasima.core.util.observer

Class ObservableValues

java.lang.Object

jasima.core.util.observer.ObservableValues

public final class ObservableValues
extends Object

Static factory methods to ease the creation of ObservableValues and DerivedObservables.

Author:

Torsten Hildebrandt

See Also:

ObservableValue, DerivedObservable

Field Summary

Fields

Modifier and Type	Field	Description
static ObservableValue<Boolean>	FALSE
static ObservableValue<Boolean>	TRUE

Method Summary

Modifier and Type	Method	Description
static DerivedObservable<Boolean>	and(ObservableValue<Boolean> v1, ObservableValue<Boolean> v2)	Creates a derived observable of type Boolean containing a logical 'and' between two other observable values.
static <T> DerivedObservable<T>	derived(String name, Supplier<T> expression, ObservableValue<?>... dependencies)
static <T> DerivedObservable<T>	derived(Supplier<T> expression, ObservableValue<?>... dependencies)	Creates a new observable value with a value as calculated by some functional expression.
static <T1,T2,R> DerivedObservable<R>	fromBinaryOperation(BiFunction<T1,T2,R> operation, ObservableValue<? extends T1> v1, ObservableValue<? extends T2> v2)	Creates a new DerivedObservable by applying a certain binary function to two other observable values.
static <T,R> DerivedObservable<R>	fromUnaryOperation(Function<T,R> operation, ObservableValue<? extends T> v)	Creates a new DerivedObservable by applying a certain unary function to another observable value.
static <T> DerivedObservable<Boolean>	isEqual(ObservableValue<? extends T> v1, ObservableValue<? extends T> v2)	Returns a derived observable for comparing the values of two other observable values.
static <T,T2 extends T> DerivedObservable<Boolean>	isEqual(ObservableValue<? extends T> v1, T2 v2)	Same as isEqual(ObservableValue, ObservableValue), but comparing an observable value directly to a constant value.
static <T,T2 extends T> DerivedObservable<Boolean>	isEqual(T2 v1, ObservableValue<? extends T> v2)	Same as isEqual(ObservableValue, ObservableValue), but comparing an observable value directly to a constant value.
static DerivedObservable<Boolean>	not(ObservableValue<Boolean> v)	Creates a derived observable of type Boolean containing a logical 'not' of another observable value.
static <T> ObservableValue<T>	observable(String name, T initialValue)
static <T> ObservableValue<T>	observable(T initialValue)	Creates a new observable value with a certain initial value.
static DerivedObservable<Boolean>	or(ObservableValue<Boolean> v1, ObservableValue<Boolean> v2)	Creates a derived observable of type Boolean containing a logical 'or' between two other observable values.
static ObservableValue.ObservableListener<Boolean>	whenTrueExecuteOnce(ObservableValue<Boolean> ov, Runnable action)	Runs the given action when the value of the given observable becomes true.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

TRUE

public static final ObservableValue<Boolean> TRUE

FALSE

public static final ObservableValue<Boolean> FALSE

Method Detail

observable

public static <T> ObservableValue<T> observable(T initialValue)

Creates a new observable value with a certain initial value. Shorthand for calling the constructor ObservableValue(Object).

Type Parameters:

T - Type of the value stored in the observable.

Parameters:

initialValue - The initial value of the observable.

Returns:

The new observable value.

observable

public static <T> ObservableValue<T> observable(String name,
                                                T initialValue)

derived

public static <T> DerivedObservable<T> derived(Supplier<T> expression,
                                               ObservableValue<?>... dependencies)

Creates a new observable value with a value as calculated by some functional expression. Shorthand for calling the constructor DerivedObservable(java.util.function.Supplier, ObservableValue...).

Type Parameters:

T - Type of the value stored in the observable.

Parameters:

expression - Expression to calculated the observable's value.

dependencies - All observable values used in the expression.

Returns:

The new derived observable value.

derived

public static <T> DerivedObservable<T> derived(String name,
                                               Supplier<T> expression,
                                               ObservableValue<?>... dependencies)

isEqual

public static <T> DerivedObservable<Boolean> isEqual(ObservableValue<? extends T> v1,
                                                     ObservableValue<? extends T> v2)

Returns a derived observable for comparing the values of two other observable values.

Type Parameters:

T - Type or common sub-type of the values to compare.

Parameters:

v1 - The first value.

v2 - The second value.

Returns:

A derived observable of type Boolean containing the result of comparing both values.

isEqual

public static <T,T2 extends T> DerivedObservable<Boolean> isEqual(ObservableValue<? extends T> v1,
                                                                        T2 v2)

Same as isEqual(ObservableValue, ObservableValue), but comparing an observable value directly to a constant value.

isEqual

public static <T,T2 extends T> DerivedObservable<Boolean> isEqual(T2 v1,
                                                                        ObservableValue<? extends T> v2)

Same as isEqual(ObservableValue, ObservableValue), but comparing an observable value directly to a constant value.

whenTrueExecuteOnce

public static ObservableValue.ObservableListener<Boolean> whenTrueExecuteOnce(ObservableValue<Boolean> ov,
                                                                              Runnable action)

Runs the given action when the value of the given observable becomes true. This can happen either immediately if the condition is already true when calling this method, or at a later point when the condition changes later.

Parameters:

ov - The observable that should be true.

action - The action to run when "ov" is true.

Returns:

The listener registered with "ov" triggering the execution of "action", or null if ov was already true.

and

public static DerivedObservable<Boolean> and(ObservableValue<Boolean> v1,
                                             ObservableValue<Boolean> v2)

Creates a derived observable of type Boolean containing a logical 'and' between two other observable values.

or

public static DerivedObservable<Boolean> or(ObservableValue<Boolean> v1,
                                            ObservableValue<Boolean> v2)

Creates a derived observable of type Boolean containing a logical 'or' between two other observable values.

not

public static DerivedObservable<Boolean> not(ObservableValue<Boolean> v)

Creates a derived observable of type Boolean containing a logical 'not' of another observable value.

fromBinaryOperation

public static <T1,T2,R> DerivedObservable<R> fromBinaryOperation(BiFunction<T1,T2,R> operation,
                                                                             ObservableValue<? extends T1> v1,
                                                                             ObservableValue<? extends T2> v2)

Creates a new DerivedObservable by applying a certain binary function to two other observable values.

fromUnaryOperation

public static <T,R> DerivedObservable<R> fromUnaryOperation(Function<T,R> operation,
                                                                  ObservableValue<? extends T> v)

Creates a new DerivedObservable by applying a certain unary function to another observable value.