androidx.core.util

Classes

AtomicFile	Static library support version of the framework's `android.util.AtomicFile`, a helper class for performing atomic operations on a file by creating a backup file until a 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.

Top-level functions summary

ArrayMap<K, V>	`arrayMapOf()` Returns an empty new ArrayMap.
ArrayMap<K, V>	`arrayMapOf(vararg pairs: Pair<K, V>)` Returns a new ArrayMap with the specified contents, given as a list of pairs where the first component is the key and the second component is the value.
ArraySet<T>	`arraySetOf()` Returns an empty new ArraySet.
ArraySet<T>	`arraySetOf(vararg values: T)` Returns a new ArraySet with the specified contents.
LruCache<K, V>	`lruCache(maxSize: Int, crossinline sizeOf: (key: K, value: V) -> Int = { _, _ -> 1 }, crossinline create: (key: K) -> V? = { null as V? }, crossinline onEntryRemoved: (evicted: Boolean, key: K, oldValue: V, newValue: V?) -> Unit = { _, _, _, _ -> })` Creates an LruCache with the given parameters.
infix Range<T>	`T.rangeTo(that: T)` Creates a range from this Comparable value to that.

Extension functions summary

For android.util.AtomicFile
Unit	`AtomicFile.tryWrite(block: (out: FileOutputStream) -> Unit)` Perform the write operations inside block on this file.
Unit	`AtomicFile.writeBytes(array: ByteArray)` Sets the content of this file as an array of bytes.
Unit	`AtomicFile.writeText(text: String, charset: Charset = Charsets.UTF_8)` Sets the content of this file as text encoded using UTF-8 or specified charset.
ByteArray	`AtomicFile.readBytes()` Gets the entire content of this file as a byte array.
String	`AtomicFile.readText(charset: Charset = Charsets.UTF_8)` Gets the entire content of this file as a String using UTF-8 or specified charset.

For kotlin.Short
Half	`Short.toHalf()` Returns a Half instance representing given Short.

For kotlin.Float
Half	`Float.toHalf()` Returns a Half instance representing given Float.

For kotlin.Double
Half	`Double.toHalf()` Returns a Half instance representing given Double.

For kotlin.String
Half	`String.toHalf()` Returns a Half instance representing given String.

For android.util.LongSparseArray
operator Boolean	`LongSparseArray<T>.contains(key: Long)` Returns true if the collection contains key.
operator Unit	`LongSparseArray<T>.set(key: Long, value: T)` Allows the use of the index operator for storing values in the collection.
operator LongSparseArray<T>	`LongSparseArray<T>.plus(other: LongSparseArray<T>)` Creates a new collection by adding or replacing entries from other.
Boolean	`LongSparseArray<T>.containsKey(key: Long)` Returns true if the collection contains key.
Boolean	`LongSparseArray<T>.containsValue(value: T)` Returns true if the collection contains value.
T	`LongSparseArray<T>.getOrDefault(key: Long, defaultValue: T)` Return the value corresponding to key, or defaultValue when not present.
T	`LongSparseArray<T>.getOrElse(key: Long, defaultValue: () -> T)` Return the value corresponding to key, or from defaultValue when not present.
Boolean	`LongSparseArray<T>.isEmpty()` Return true when the collection contains no elements.
Boolean	`LongSparseArray<T>.isNotEmpty()` Return true when the collection contains elements.
Boolean	`LongSparseArray<T>.remove(key: Long, value: T)` Removes the entry for key only if it is mapped to value.
Unit	`LongSparseArray<T>.putAll(other: LongSparseArray<T>)` Update this collection by adding or replacing entries from other.
Unit	`LongSparseArray<T>.forEach(action: (key: Long, value: T) -> Unit)` Performs the given action for each key/value entry.
LongIterator	`LongSparseArray<T>.keyIterator()` Return an iterator over the collection's keys.
Iterator<T>	`LongSparseArray<T>.valueIterator()` Return an iterator over the collection's values.

For android.util.SparseArray
operator Boolean	`SparseArray<T>.contains(key: Int)` Returns true if the collection contains key.
operator Unit	`SparseArray<T>.set(key: Int, value: T)` Allows the use of the index operator for storing values in the collection.
operator SparseArray<T>	`SparseArray<T>.plus(other: SparseArray<T>)` Creates a new collection by adding or replacing entries from other.
Boolean	`SparseArray<T>.containsKey(key: Int)` Returns true if the collection contains key.
Boolean	`SparseArray<T>.containsValue(value: T)` Returns true if the collection contains value.
T	`SparseArray<T>.getOrDefault(key: Int, defaultValue: T)` Return the value corresponding to key, or defaultValue when not present.
T	`SparseArray<T>.getOrElse(key: Int, defaultValue: () -> T)` Return the value corresponding to key, or from defaultValue when not present.
Boolean	`SparseArray<T>.isEmpty()` Return true when the collection contains no elements.
Boolean	`SparseArray<T>.isNotEmpty()` Return true when the collection contains elements.
Boolean	`SparseArray<T>.remove(key: Int, value: T)` Removes the entry for key only if it is mapped to value.
Unit	`SparseArray<T>.putAll(other: SparseArray<T>)` Update this collection by adding or replacing entries from other.
Unit	`SparseArray<T>.forEach(action: (key: Int, value: T) -> Unit)` Performs the given action for each key/value entry.
IntIterator	`SparseArray<T>.keyIterator()` Return an iterator over the collection's keys.
Iterator<T>	`SparseArray<T>.valueIterator()` Return an iterator over the collection's values.

For android.util.SparseBooleanArray
operator Boolean	`SparseBooleanArray.contains(key: Int)` Returns true if the collection contains key.
operator Unit	`SparseBooleanArray.set(key: Int, value: Boolean)` Allows the use of the index operator for storing values in the collection.
operator SparseBooleanArray	`SparseBooleanArray.plus(other: SparseBooleanArray)` Creates a new collection by adding or replacing entries from other.
Boolean	`SparseBooleanArray.containsKey(key: Int)` Returns true if the collection contains key.
Boolean	`SparseBooleanArray.containsValue(value: Boolean)` Returns true if the collection contains value.
Boolean	`SparseBooleanArray.getOrDefault(key: Int, defaultValue: Boolean)` Return the value corresponding to key, or defaultValue when not present.
Boolean	`SparseBooleanArray.getOrElse(key: Int, defaultValue: () -> Boolean)` Return the value corresponding to key, or from defaultValue when not present.
Boolean	`SparseBooleanArray.isEmpty()` Return true when the collection contains no elements.
Boolean	`SparseBooleanArray.isNotEmpty()` Return true when the collection contains elements.
Boolean	`SparseBooleanArray.remove(key: Int, value: Boolean)` Removes the entry for key only if it is mapped to value.
Unit	`SparseBooleanArray.putAll(other: SparseBooleanArray)` Update this collection by adding or replacing entries from other.
Unit	`SparseBooleanArray.forEach(action: (key: Int, value: Boolean) -> Unit)` Performs the given action for each key/value entry.
IntIterator	`SparseBooleanArray.keyIterator()` Return an iterator over the collection's keys.
BooleanIterator	`SparseBooleanArray.valueIterator()` Return an iterator over the collection's values.

For android.util.SparseIntArray
operator Boolean	`SparseIntArray.contains(key: Int)` Returns true if the collection contains key.
operator Unit	`SparseIntArray.set(key: Int, value: Int)` Allows the use of the index operator for storing values in the collection.
operator SparseIntArray	`SparseIntArray.plus(other: SparseIntArray)` Creates a new collection by adding or replacing entries from other.
Boolean	`SparseIntArray.containsKey(key: Int)` Returns true if the collection contains key.
Boolean	`SparseIntArray.containsValue(value: Int)` Returns true if the collection contains value.
Int	`SparseIntArray.getOrDefault(key: Int, defaultValue: Int)` Return the value corresponding to key, or defaultValue when not present.
Int	`SparseIntArray.getOrElse(key: Int, defaultValue: () -> Int)` Return the value corresponding to key, or from defaultValue when not present.
Boolean	`SparseIntArray.isEmpty()` Return true when the collection contains no elements.
Boolean	`SparseIntArray.isNotEmpty()` Return true when the collection contains elements.
Boolean	`SparseIntArray.remove(key: Int, value: Int)` Removes the entry for key only if it is mapped to value.
Unit	`SparseIntArray.putAll(other: SparseIntArray)` Update this collection by adding or replacing entries from other.
Unit	`SparseIntArray.forEach(action: (key: Int, value: Int) -> Unit)` Performs the given action for each key/value entry.
IntIterator	`SparseIntArray.keyIterator()` Return an iterator over the collection's keys.
IntIterator	`SparseIntArray.valueIterator()` Return an iterator over the collection's values.

For android.util.SparseLongArray
operator Boolean	`SparseLongArray.contains(key: Int)` Returns true if the collection contains key.
operator Unit	`SparseLongArray.set(key: Int, value: Long)` Allows the use of the index operator for storing values in the collection.
operator SparseLongArray	`SparseLongArray.plus(other: SparseLongArray)` Creates a new collection by adding or replacing entries from other.
Boolean	`SparseLongArray.containsKey(key: Int)` Returns true if the collection contains key.
Boolean	`SparseLongArray.containsValue(value: Long)` Returns true if the collection contains value.
Long	`SparseLongArray.getOrDefault(key: Int, defaultValue: Long)` Return the value corresponding to key, or defaultValue when not present.
Long	`SparseLongArray.getOrElse(key: Int, defaultValue: () -> Long)` Return the value corresponding to key, or from defaultValue when not present.
Boolean	`SparseLongArray.isEmpty()` Return true when the collection contains no elements.
Boolean	`SparseLongArray.isNotEmpty()` Return true when the collection contains elements.
Boolean	`SparseLongArray.remove(key: Int, value: Long)` Removes the entry for key only if it is set to value.
Unit	`SparseLongArray.putAll(other: SparseLongArray)` Update this collection by adding or replacing entries from other.
Unit	`SparseLongArray.forEach(action: (key: Int, value: Long) -> Unit)` Performs the given action for each key/value entry.
IntIterator	`SparseLongArray.keyIterator()` Return an iterator over the collection's keys.
LongIterator	`SparseLongArray.valueIterator()` Return an iterator over the collection's values.

For android.util.Range
operator Range<T>	`Range<T>.plus(value: T)` Return the smallest range that includes this and value.
operator Range<T>	`Range<T>.plus(other: Range<T>)` Return the smallest range that includes this and other.
infix Range<T>	`Range<T>.and(other: Range<T>)` Return the intersection of this range and other.
ClosedRange<T>	`Range<T>.toClosedRange()` Returns this Range as a ClosedRange.

For android.util.Pair
operator F	`Pair<F, S>.component1()` Returns the first component of the pair.
operator S	`Pair<F, S>.component2()` Returns the second component of the pair.
Pair<F, S>	`Pair<F, S>.toKotlinPair()` Returns this Pair as a kotlin.Pair.

For android.util.Size
operator Int	`Size.component1()` Returns "width", the first component of this Size.
operator Int	`Size.component2()` Returns "height", the second component of this Size.

For android.util.SizeF
operator Float	`SizeF.component1()` Returns "width", the first component of this SizeF.
operator Float	`SizeF.component2()` Returns "height", the second component of this SizeF.

For kotlin.Pair
Pair<F, S>	`Pair<F, S>.toAndroidPair()` Returns this kotlin.Pair as an Android Pair.

For kotlin.ranges.ClosedRange
Range<T>	`ClosedRange<T>.toRange()` Returns this ClosedRange as a Range.

Extension properties summary

For java.util.Locale
Int	`Locale.layoutDirection()` Returns layout direction for a given locale.

For android.util.LongSparseArray
Int	`LongSparseArray<T>.size()` Returns the number of key/value pairs in the collection.

For android.util.SparseArray
Int	`SparseArray<T>.size()` Returns the number of key/value pairs in the collection.

For android.util.SparseBooleanArray
Int	`SparseBooleanArray.size()` Returns the number of key/value pairs in the collection.

For android.util.SparseIntArray
Int	`SparseIntArray.size()` Returns the number of key/value pairs in the collection.

For android.util.SparseLongArray
Int	`SparseLongArray.size()` Returns the number of key/value entries in the collection.

Top-level functions

arrayMapOf

inline fun <K, V> arrayMapOf(): ArrayMap<K, V>

Returns an empty new ArrayMap.

arrayMapOf

fun <K, V> arrayMapOf(vararg pairs: Pair<K, V>): ArrayMap<K, V>

Returns a new ArrayMap with the specified contents, given as a list of pairs where the first component is the key and the second component is the value.

If multiple pairs have the same key, the resulting map will contain the value from the last of those pairs.

arraySetOf

inline fun <T> arraySetOf(): ArraySet<T>

Returns an empty new ArraySet.

arraySetOf

fun <T> arraySetOf(vararg values: T): ArraySet<T>

Returns a new ArraySet with the specified contents.

lruCache

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

Creates an LruCache with the given parameters.

Parameters
`maxSize`	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.
`sizeOf`	function that returns the size of the entry for key and value in user-defined units. The default implementation returns 1.
`create`	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.
`onEntryRemoved`	a function called for entries that have been evicted or removed.

See Also

LruCache.sizeOf LruCache.create LruCache.entryRemoved

rangeTo

inline infix fun <T : Comparable<T>> T.rangeTo(that: T): Range<T>

Creates a range from this Comparable value to that.

Exceptions
`IllegalArgumentException`	if this value is comparatively smaller than that.

Extension functions

and

inline infix fun <T : Comparable<T>> Range<T>.and(other: Range<T>): Range<T>

Return the intersection of this range and other.

Exceptions
`IllegalArgumentException`	if this is disjoint from other.

component1

inline operator fun <F, S> 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

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

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

component2

inline operator fun <F, S> 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

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

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