androidx.core.util

Kotlin |Java

Interfaces

`Consumer`	Compat version of `java.util.function.Consumer`
`Function`	Compat version of `java.util.function.Function`
`Pools.Pool`	Interface for managing a pool of objects.
`Predicate`	Compat version of `java.util.function.Predicate`
`Supplier`	Compat version of `java.util.function.Supplier`

Classes

`AtomicFile`	Static library support version of the framework's `android.util.AtomicFile`, a helper class for performing atomic operations on a file by writing to a new file and renaming it into the place of the original file after the write has successfully completed.
`ObjectsCompat`	This class consists of static utility methods for operating on objects.
`Pair`	Container to ease passing around a tuple of two objects.
`PatternsCompat`	Commonly used regular expression patterns.
`Pools`	Helper class for creating pools of objects.
`Pools.SimplePool`	Simple (non-synchronized) pool of objects.
`Pools.SynchronizedPool`	Synchronized pool of objects.
`SizeFCompat`	Immutable class for describing width and height dimensions in some arbitrary unit.
`TypedValueCompat`	Container for a dynamically typed data value.

Top-level functions summary

inline LruCache<K, V>

<K : Any, V : Any> lruCache(
    maxSize: Int,
    crossinline sizeOf: (key, value) -> Int,
    crossinline create: (key) -> V?,
    crossinline onEntryRemoved: (evicted: Boolean, key, oldValue, newValue?) -> Unit
)

Creates an LruCache with the given parameters.

Extension functions summary

`inline infix Range<T>`	`@RequiresApi(value = 21) <T : Comparable<T>> Range<T>.and(other: Range<T>)` Return the intersection of this range and `other`.
`Consumer<T>`	`<T : Any?> Continuation<T>.asAndroidXConsumer()` Returns a `Consumer` that will resume this `Continuation` when the result of an operation is `accepted`.
`Consumer<T>`	`@RequiresApi(value = 24) <T : Any?> Continuation<T>.asConsumer()` Returns a `java.util.function.Consumer` that will resume this `Continuation` when the result of an operation is `accepted`.
`Runnable`	`Continuation<Unit>.asRunnable()` Returns a `Runnable` that will resume this `Continuation` when an operation completes and the returned `Runnable`'s `Runnable.run` method is called.
`inline operator F`	`<F : Any?, S : Any?> Pair<F, S>.component1()` Returns the first component of the pair.
`inline operator F`	`<F : Any?, S : Any?> Pair<F, S>.component1()` Returns the first component of the pair.
`inline operator Int`	`@RequiresApi(value = 21) Size.component1()` Returns "width", the first component of this `Size`.
`inline operator Float`	`@RequiresApi(value = 21) SizeF.component1()` Returns "width", the first component of this `SizeF`.
`inline operator Float`	`SizeFCompat.component1()` Returns "width", the first component of this `SizeFCompat`.
`inline operator S`	`<F : Any?, S : Any?> Pair<F, S>.component2()` Returns the second component of the pair.
`inline operator S`	`<F : Any?, S : Any?> Pair<F, S>.component2()` Returns the second component of the pair.
`inline operator Int`	`@RequiresApi(value = 21) Size.component2()` Returns "height", the second component of this `Size`.
`inline operator Float`	`@RequiresApi(value = 21) SizeF.component2()` Returns "height", the second component of this `SizeF`.
`inline operator Float`	`SizeFCompat.component2()` Returns "height", the second component of this `SizeFCompat`.
`inline operator Boolean`	`<T : Any?> SparseArray<T>.contains(key: Int)` Returns true if the collection contains `key`.
`inline operator Boolean`	`SparseBooleanArray.contains(key: Int)` Returns true if the collection contains `key`.
`inline operator Boolean`	`SparseIntArray.contains(key: Int)` Returns true if the collection contains `key`.
`inline operator Boolean`	`SparseLongArray.contains(key: Int)` Returns true if the collection contains `key`.
`inline operator Boolean`	`<T : Any?> LongSparseArray<T>.contains(key: Long)` Returns true if the collection contains `key`.
`inline Boolean`	`<T : Any?> SparseArray<T>.containsKey(key: Int)` Returns true if the collection contains `key`.
`inline Boolean`	`SparseBooleanArray.containsKey(key: Int)` Returns true if the collection contains `key`.
`inline Boolean`	`SparseIntArray.containsKey(key: Int)` Returns true if the collection contains `key`.
`inline Boolean`	`SparseLongArray.containsKey(key: Int)` Returns true if the collection contains `key`.
`inline Boolean`	`<T : Any?> LongSparseArray<T>.containsKey(key: Long)` Returns true if the collection contains `key`.
`inline Boolean`	`SparseBooleanArray.containsValue(value: Boolean)` Returns true if the collection contains `value`.
`inline Boolean`	`SparseIntArray.containsValue(value: Int)` Returns true if the collection contains `value`.
`inline Boolean`	`SparseLongArray.containsValue(value: Long)` Returns true if the collection contains `value`.
`inline Boolean`	`<T : Any?> LongSparseArray<T>.containsValue(value: T)` Returns true if the collection contains `value`.
`inline Boolean`	`<T : Any?> SparseArray<T>.containsValue(value: T)` Returns true if the collection contains `value`.
`inline Unit`	`<T : Any?> LongSparseArray<T>.forEach(action: (key: Long, value) -> Unit)` Performs the given `action` for each key/value entry.
`inline Unit`	`<T : Any?> SparseArray<T>.forEach(action: (key: Int, value) -> Unit)` Performs the given `action` for each key/value entry.
`inline Unit`	`SparseBooleanArray.forEach(action: (key: Int, value: Boolean) -> Unit)` Performs the given `action` for each key/value entry.
`inline Unit`	`SparseIntArray.forEach(action: (key: Int, value: Int) -> Unit)` Performs the given `action` for each key/value entry.
`inline Unit`	`SparseLongArray.forEach(action: (key: Int, value: Long) -> Unit)` Performs the given `action` for each key/value entry.
`inline Boolean`	`SparseBooleanArray.getOrDefault(key: Int, defaultValue: Boolean)` Return the value corresponding to `key`, or `defaultValue` when not present.
`inline Int`	`SparseIntArray.getOrDefault(key: Int, defaultValue: Int)` Return the value corresponding to `key`, or `defaultValue` when not present.
`inline Long`	`SparseLongArray.getOrDefault(key: Int, defaultValue: Long)` Return the value corresponding to `key`, or `defaultValue` when not present.
`inline T`	`<T : Any?> SparseArray<T>.getOrDefault(key: Int, defaultValue: T)` Return the value corresponding to `key`, or `defaultValue` when not present.
`inline T`	`<T : Any?> LongSparseArray<T>.getOrDefault(key: Long, defaultValue: T)` Return the value corresponding to `key`, or `defaultValue` when not present.
`inline T`	`<T : Any?> SparseArray<T>.getOrElse(key: Int, defaultValue: () -> T)` Return the value corresponding to `key`, or from `defaultValue` when not present.
`inline Boolean`	`SparseBooleanArray.getOrElse(key: Int, defaultValue: () -> Boolean)` Return the value corresponding to `key`, or from `defaultValue` when not present.
`inline Int`	`SparseIntArray.getOrElse(key: Int, defaultValue: () -> Int)` Return the value corresponding to `key`, or from `defaultValue` when not present.
`inline Long`	`SparseLongArray.getOrElse(key: Int, defaultValue: () -> Long)` Return the value corresponding to `key`, or from `defaultValue` when not present.
`inline T`	`<T : Any?> LongSparseArray<T>.getOrElse(key: Long, defaultValue: () -> T)` Return the value corresponding to `key`, or from `defaultValue` when not present.
`inline Boolean`	`<T : Any?> LongSparseArray<T>.isEmpty()` Return true when the collection contains no elements.
`inline Boolean`	`<T : Any?> SparseArray<T>.isEmpty()` Return true when the collection contains no elements.
`inline Boolean`	`SparseBooleanArray.isEmpty()` Return true when the collection contains no elements.
`inline Boolean`	`SparseIntArray.isEmpty()` Return true when the collection contains no elements.
`inline Boolean`	`SparseLongArray.isEmpty()` Return true when the collection contains no elements.
`inline Boolean`	`<T : Any?> LongSparseArray<T>.isNotEmpty()` Return true when the collection contains elements.
`inline Boolean`	`<T : Any?> SparseArray<T>.isNotEmpty()` Return true when the collection contains elements.
`inline Boolean`	`SparseBooleanArray.isNotEmpty()` Return true when the collection contains elements.
`inline Boolean`	`SparseIntArray.isNotEmpty()` Return true when the collection contains elements.
`inline Boolean`	`SparseLongArray.isNotEmpty()` Return true when the collection contains elements.
`LongIterator`	`<T : Any?> LongSparseArray<T>.keyIterator()` Return an iterator over the collection's keys.
`IntIterator`	`<T : Any?> SparseArray<T>.keyIterator()` Return an iterator over the collection's keys.
`IntIterator`	`SparseBooleanArray.keyIterator()` Return an iterator over the collection's keys.
`IntIterator`	`SparseIntArray.keyIterator()` Return an iterator over the collection's keys.
`IntIterator`	`SparseLongArray.keyIterator()` Return an iterator over the collection's keys.
`operator LongSparseArray<T>`	`<T : Any?> LongSparseArray<T>.plus(other: LongSparseArray<T>)` Creates a new collection by adding or replacing entries from `other`.
`inline operator Range<T>`	`@RequiresApi(value = 21) <T : Comparable<T>> Range<T>.plus(other: Range<T>)` Return the smallest range that includes this and `other`.
`operator SparseArray<T>`	`<T : Any?> SparseArray<T>.plus(other: SparseArray<T>)` Creates a new collection by adding or replacing entries from `other`.
`operator SparseBooleanArray`	`SparseBooleanArray.plus(other: SparseBooleanArray)` Creates a new collection by adding or replacing entries from `other`.
`operator SparseIntArray`	`SparseIntArray.plus(other: SparseIntArray)` Creates a new collection by adding or replacing entries from `other`.
`operator SparseLongArray`	`SparseLongArray.plus(other: SparseLongArray)` Creates a new collection by adding or replacing entries from `other`.
`inline operator Range<T>`	`@RequiresApi(value = 21) <T : Comparable<T>> Range<T>.plus(value: T)` Return the smallest range that includes this and `value`.
`Unit`	`<T : Any?> LongSparseArray<T>.putAll(other: LongSparseArray<T>)` Update this collection by adding or replacing entries from `other`.
`Unit`	`<T : Any?> SparseArray<T>.putAll(other: SparseArray<T>)` Update this collection by adding or replacing entries from `other`.
`Unit`	`SparseBooleanArray.putAll(other: SparseBooleanArray)` Update this collection by adding or replacing entries from `other`.
`Unit`	`SparseIntArray.putAll(other: SparseIntArray)` Update this collection by adding or replacing entries from `other`.
`Unit`	`SparseLongArray.putAll(other: SparseLongArray)` Update this collection by adding or replacing entries from `other`.
`inline infix Range<T>`	`@RequiresApi(value = 21) <T : Comparable<T>> T.rangeTo(that: T)` Creates a range from this `Comparable` value to `that`.
`inline ByteArray`	`AtomicFile.readBytes()` Gets the entire content of this file as a byte array.
`String`	`AtomicFile.readText(charset: Charset)` Gets the entire content of this file as a String using UTF-8 or specified `charset`.
`Boolean`	`SparseBooleanArray.remove(key: Int, value: Boolean)` Removes the entry for `key` only if it is mapped to `value`.
`Boolean`	`SparseIntArray.remove(key: Int, value: Int)` Removes the entry for `key` only if it is mapped to `value`.
`Boolean`	`SparseLongArray.remove(key: Int, value: Long)` Removes the entry for `key` only if it is set to `value`.
`Boolean`	`<T : Any?> SparseArray<T>.remove(key: Int, value: T)` Removes the entry for `key` only if it is mapped to `value`.
`Boolean`	`<T : Any?> LongSparseArray<T>.remove(key: Long, value: T)` Removes the entry for `key` only if it is mapped to `value`.
`inline operator Unit`	`SparseBooleanArray.set(key: Int, value: Boolean)` Allows the use of the index operator for storing values in the collection.
`inline operator Unit`	`SparseIntArray.set(key: Int, value: Int)` Allows the use of the index operator for storing values in the collection.
`inline operator Unit`	`SparseLongArray.set(key: Int, value: Long)` Allows the use of the index operator for storing values in the collection.
`inline operator Unit`	`<T : Any?> SparseArray<T>.set(key: Int, value: T)` Allows the use of the index operator for storing values in the collection.
`inline operator Unit`	`<T : Any?> LongSparseArray<T>.set(key: Long, value: T)` Allows the use of the index operator for storing values in the collection.
`inline Pair<F, S>`	`<F : Any?, S : Any?> Pair<F, S>.toAndroidPair()` Returns this `Kotlin Pair` as an `Android Pair`.
`inline Pair<F, S>`	`<F : Any?, S : Any?> Pair<F, S>.toAndroidXPair()` Returns this `Kotlin Pair` as an `AndroidX Pair`.
`ClosedRange<T>`	`@RequiresApi(value = 21) <T : Comparable<T>> Range<T>.toClosedRange()` Returns this `Range` as a `ClosedRange`.
`inline Half`	`@RequiresApi(value = 26) @HalfFloat Short.toHalf()` Returns a `Half` instance representing given `Short`.
`inline Half`	`@RequiresApi(value = 26) Float.toHalf()` Returns a `Half` instance representing given `Float`.
`inline Half`	`@RequiresApi(value = 26) Double.toHalf()` Returns a `Half` instance representing given `Double`.
`inline Half`	`@RequiresApi(value = 26) String.toHalf()` Returns a `Half` instance representing given `String`.
`inline Pair<F, S>`	`<F : Any?, S : Any?> Pair<F, S>.toKotlinPair()` Returns this `AndroidX Pair` as a `Kotlin Pair`.
`inline Pair<F, S>`	`<F : Any?, S : Any?> Pair<F, S>.toKotlinPair()` Returns this `Android Pair` as a `Kotlin Pair`.
`Range<T>`	`@RequiresApi(value = 21) <T : Comparable<T>> ClosedRange<T>.toRange()` Returns this `ClosedRange` as a `Range`.
`inline Unit`	`AtomicFile.tryWrite(block: (out: FileOutputStream) -> Unit)` Perform the write operations inside `block` on this file.
`Iterator<T>`	`<T : Any?> LongSparseArray<T>.valueIterator()` Return an iterator over the collection's values.
`Iterator<T>`	`<T : Any?> SparseArray<T>.valueIterator()` Return an iterator over the collection's values.
`BooleanIterator`	`SparseBooleanArray.valueIterator()` Return an iterator over the collection's values.
`IntIterator`	`SparseIntArray.valueIterator()` Return an iterator over the collection's values.
`LongIterator`	`SparseLongArray.valueIterator()` Return an iterator over the collection's values.
`Unit`	`AtomicFile.writeBytes(array: ByteArray)` Sets the content of this file as an `array` of bytes.
`Unit`	`AtomicFile.writeText(text: String, charset: Charset)` Sets the content of this file as `text` encoded using UTF-8 or specified `charset`.

Extension properties summary

`Int`	`LongSparseArray<T>.size` Returns the number of key/value pairs in the collection.
`Int`	`SparseArray<T>.size` Returns the number of key/value pairs in the collection.
`Int`	`SparseBooleanArray.size` Returns the number of key/value pairs in the collection.
`Int`	`SparseIntArray.size` Returns the number of key/value pairs in the collection.
`Int`	`SparseLongArray.size` Returns the number of key/value entries in the collection.

Top-level functions

lruCache

Artifact: androidx.core:core-ktx

View Source

Added in 1.1.0

inline fun <K : Any, V : Any> lruCache(
    maxSize: Int,
    crossinline sizeOf: (key, value) -> Int = { _, _ -> 1 },
    crossinline create: (key) -> V? = { null as V? },
    crossinline onEntryRemoved: (evicted: Boolean, key, oldValue, newValue?) -> Unit = { _, _, _, _ ->
        }
): LruCache<K, V>

Creates an LruCache with the given parameters.

Parameters
`maxSize: Int`	for caches that do not specify `sizeOf`, this is the maximum number of entries in the cache. For all other caches, this is the maximum sum of the sizes of the entries in this cache.
`crossinline sizeOf: (key, value) -> Int = { _, _ -> 1 }`	function that returns the size of the entry for key and value in user-defined units. The default implementation returns 1.
`crossinline create: (key) -> V? = { null as V? }`	a create called after a cache miss to compute a value for the corresponding key. Returns the computed value or null if no value can be computed. The default implementation returns null.
`crossinline onEntryRemoved: (evicted: Boolean, key, oldValue, newValue?) -> Unit = { _, _, _, _ -> }`	a function called for entries that have been evicted or removed.

See also
`sizeOf`
`create`
`entryRemoved`

Extension functions

and

Artifact: androidx.core:core-ktx

View Source

@RequiresApi(value = 21)
inline infix fun <T : Comparable<T>> Range<T>.and(other: Range<T>): Range<T>

Return the intersection of this range and other.

Throws
`kotlin.IllegalArgumentException`	if this is disjoint from `other`.

asAndroidXConsumer

Artifact: androidx.core:core-ktx

View Source

fun <T : Any?> Continuation<T>.asAndroidXConsumer(): Consumer<T>

Returns a Consumer that will resume this Continuation when the result of an operation is accepted.

Useful for writing suspend bindings to async Jetpack library methods that accept Consumer as a result callback for a one-time operation:

public suspend fun FancinessManager.query(
    query: FancinessManager.Query
): FancinessManager.QueryResult = suspendCancellableCoroutine<QueryResult> { continuation ->

    // Any Android API that supports cancellation should be configured to propagate
    // coroutine cancellation as follows:
    val canceller = CancellationSignal()
    continuation.invokeOnCancellation { canceller.cancel() }

    // Invoke the FancinessManager#queryAsync method as follows:
    queryAsync(
        query,
        canceller,
        // Use a direct executor to avoid extra dispatch. Resuming the continuation will
        // handle getting to the right thread or pool via the ContinuationInterceptor.
        Runnable::run,
        continuation.asAndroidXConsumer()
    )
}

asConsumer

Artifact: androidx.core:core-ktx

View Source

@RequiresApi(value = 24)
fun <T : Any?> Continuation<T>.asConsumer(): Consumer<T>

Returns a java.util.function.Consumer that will resume this Continuation when the result of an operation is accepted.

Useful for writing suspend bindings to async methods that accept java.util.function.Consumer as a result callback for a one-time operation:

public suspend fun FancinessManager.query(
    query: FancinessManager.Query
): FancinessManager.QueryResult = suspendCancellableCoroutine<QueryResult> { continuation ->

    // Any Android API that supports cancellation should be configured to propagate
    // coroutine cancellation as follows:
    val canceller = CancellationSignal()
    continuation.invokeOnCancellation { canceller.cancel() }

    // Invoke the FancinessManager#queryAsync method as follows:
    queryAsync(
        query,
        canceller,
        // Use a direct executor to avoid extra dispatch. Resuming the continuation will
        // handle getting to the right thread or pool via the ContinuationInterceptor.
        Runnable::run,
        continuation.asConsumer()
    )
}

asRunnable

Artifact: androidx.core:core-ktx

View Source

fun Continuation<Unit>.asRunnable(): Runnable

Returns a Runnable that will resume this Continuation when an operation completes and the returned Runnable's Runnable.run method is called.

Useful for writing suspend bindings to async Jetpack library methods that accept Runnable as a completion callback for a one-time operation:

public suspend fun FancinessManager.setFanciness(
    fanciness: Float
): Unit = suspendCancellableCoroutine<Unit> { continuation ->

    // Any Android API that supports cancellation should be configured to propagate
    // coroutine cancellation as follows:
    val canceller = CancellationSignal()
    continuation.invokeOnCancellation { canceller.cancel() }

    // Invoke the FancinessManager#setFanciness method as follows:
    queryAsync(
        fanciness,
        canceller,
        // Use a direct executor to avoid extra dispatch. Resuming the continuation will
        // handle getting to the right thread or pool via the ContinuationInterceptor.
        Runnable::run,
        continuation.asRunnable()
    )
}

component1

Artifact: androidx.core:core-ktx

View Source

Added in 1.5.0

inline operator fun <F : Any?, S : Any?> Pair<F, S>.component1(): F

Returns the first component of the pair.

This method allows to use destructuring declarations when working with pairs, for example:

val (first, second) = myPair

component1

Artifact: androidx.core:core-ktx

View Source

Added in 1.1.0

inline operator fun <F : Any?, S : Any?> Pair<F, S>.component1(): F

Returns the first component of the pair.

This method allows to use destructuring declarations when working with pairs, for example:

val (first, second) = myPair

component1

Artifact: androidx.core:core-ktx

View Source

Added in 1.1.0

@RequiresApi(value = 21)
inline operator fun Size.component1(): Int

Returns "width", the first component of this Size.

This method allows to use destructuring declarations when working with sizes, for example:

val (w, h) = mySize

component1

Artifact: androidx.core:core-ktx

View Source

Added in 1.1.0

@RequiresApi(value = 21)
inline operator fun SizeF.component1(): Float

Returns "width", the first component of this SizeF.

This method allows to use destructuring declarations when working with sizes, for example:

val (w, h) = mySize

component1

Artifact: androidx.core:core-ktx

View Source

Added in 1.8.0

inline operator fun SizeFCompat.component1(): Float

Returns "width", the first component of this SizeFCompat.

This method allows to use destructuring declarations when working with sizes, for example:

val (w, h) = mySize

component2

Artifact: androidx.core:core-ktx

View Source

Added in 1.5.0

inline operator fun <F : Any?, S : Any?> Pair<F, S>.component2(): S

Returns the second component of the pair.

This method allows to use destructuring declarations when working with pairs, for example:

val (first, second) = myPair

component2

Artifact: androidx.core:core-ktx

View Source

Added in 1.1.0

inline operator fun <F : Any?, S : Any?> Pair<F, S>.component2(): S

Returns the second component of the pair.

This method allows to use destructuring declarations when working with pairs, for example:

val (first, second) = myPair

component2

Artifact: androidx.core:core-ktx

View Source

Added in 1.1.0

@RequiresApi(value = 21)
inline operator fun Size.component2(): Int

Returns "height", the second component of this Size.

This method allows to use destructuring declarations when working with sizes, for example:

val (w, h) = mySize

component2

Artifact: androidx.core:core-ktx

View Source

Added in 1.1.0

@RequiresApi(value = 21)
inline operator fun SizeF.component2(): Float

Returns "height", the second component of this SizeF.

This method allows to use destructuring declarations when working with sizes, for example:

val (w, h) = mySize

component2

Artifact: androidx.core:core-ktx

View Source

Added in 1.8.0

inline operator fun SizeFCompat.component2(): Float

Returns "height", the second component of this SizeFCompat.

This method allows to use destructuring declarations when working with sizes, for example:

val (w, h) = mySize

contains

Artifact: androidx.core:core-ktx

View Source

Added in 1.1.0

inline operator fun <T : Any?> SparseArray<T>.contains(key: Int): Boolean