SavedStateReader

Artifact: androidx.savedstate:savedstate

Kotlin |Java

value public final class SavedStateReader

An inline class that encapsulates an opaque SavedState, and provides an API for reading the platform specific state.

See also
`read`

Summary

Public methods
`final boolean`	`contains(@NonNull String key)` Checks if the `SavedState` contains the specified `key`.
`final boolean`	`contentDeepEquals(@NonNull SavedState other)` Checks if the two specified `SavedState` are deeply equal to one another.
`final int`	`contentDeepHashCode()` Returns a hash code based on the "deep contents" of specified `SavedState`.
`final @NonNull String`	`contentDeepToString()` Returns a string representation of the contents of this `SavedState` as if it is a `List`.
`final @NonNull IBinder`	`getBinder(@NonNull String key)` Retrieves an `IBinder` value associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final IBinder`	`getBinderOrNull(@NonNull String key)` Retrieves a `IBinder` value associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final boolean`	`getBoolean(@NonNull String key)` Retrieves a `Boolean` value associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final @NonNull boolean[]`	`getBooleanArray(@NonNull String key)` Retrieves a `BooleanArray` value associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final boolean[]`	`getBooleanArrayOrNull(@NonNull String key)` Retrieves a `BooleanArray` value associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final Boolean`	`getBooleanOrNull(@NonNull String key)` Retrieves a `Boolean` value associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final char`	`getChar(@NonNull String key)` Retrieves a `Char` value associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final @NonNull char[]`	`getCharArray(@NonNull String key)` Retrieves a `CharSequence` value associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final char[]`	`getCharArrayOrNull(@NonNull String key)` Retrieves a `CharArray` value associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final Character`	`getCharOrNull(@NonNull String key)` Retrieves a `Char` value associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final @NonNull CharSequence`	`getCharSequence(@NonNull String key)` Retrieves a `CharSequence` value associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final @NonNull CharSequence[]`	`getCharSequenceArray(@NonNull String key)` Retrieves an `Array` of `CharSequence` values associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final CharSequence[]`	`getCharSequenceArrayOrNull(@NonNull String key)` Retrieves an `Array` of `CharSequence` values associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final @NonNull List<@NonNull CharSequence>`	`getCharSequenceList(@NonNull String key)` Retrieves a `List` of `CharSequence` values associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final List<@NonNull CharSequence>`	`getCharSequenceListOrNull(@NonNull String key)` Retrieves a `List` of `CharSequence` values associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final CharSequence`	`getCharSequenceOrNull(@NonNull String key)` Retrieves a `CharSequence` value associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final double`	`getDouble(@NonNull String key)` Retrieves a `Double` value associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final @NonNull double[]`	`getDoubleArray(@NonNull String key)` Retrieves a `DoubleArray` value associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final double[]`	`getDoubleArrayOrNull(@NonNull String key)` Retrieves a `DoubleArray` value associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final Double`	`getDoubleOrNull(@NonNull String key)` Retrieves a `Double` value associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final float`	`getFloat(@NonNull String key)` Retrieves a `Float` value associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final @NonNull float[]`	`getFloatArray(@NonNull String key)` Retrieves a `FloatArray` value associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final float[]`	`getFloatArrayOrNull(@NonNull String key)` Retrieves a `FloatArray` value associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final Float`	`getFloatOrNull(@NonNull String key)` Retrieves a `Float` value associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final int`	`getInt(@NonNull String key)` Retrieves an `Int` value associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final @NonNull int[]`	`getIntArray(@NonNull String key)` Retrieves a `IntArray` value associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final int[]`	`getIntArrayOrNull(@NonNull String key)` Retrieves a `IntArray` value associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final @NonNull List<@NonNull Integer>`	`getIntList(@NonNull String key)` Retrieves a `List` of `String` values associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final List<@NonNull Integer>`	`getIntListOrNull(@NonNull String key)` Retrieves a `List` of `Int` values associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final Integer`	`getIntOrNull(@NonNull String key)` Retrieves an `Int` value associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final @NonNull T`	`<T extends Serializable> getJavaSerializable(@NonNull String key)` Retrieves a `Serializable` value associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final @NonNull T`	`<T extends Serializable> getJavaSerializable( @NonNull String key, @NonNull KClass<@NonNull T> serializableClass )` Retrieves a `Serializable` value associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final T`	`<T extends Serializable> getJavaSerializableOrNull(@NonNull String key)` Retrieves a `Serializable` value associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final T`	`<T extends Serializable> getJavaSerializableOrNull( @NonNull String key, @NonNull KClass<@NonNull T> serializableClass )` Retrieves a `Serializable` value associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final long`	`getLong(@NonNull String key)` Retrieves a `Long` value associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final @NonNull long[]`	`getLongArray(@NonNull String key)` Retrieves a `LongArray` value associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final long[]`	`getLongArrayOrNull(@NonNull String key)` Retrieves a `LongArray` value associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final Long`	`getLongOrNull(@NonNull String key)` Retrieves a `Long` value associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final @NonNull T`	`<T extends Parcelable> getParcelable(@NonNull String key)` Retrieves a `Parcelable` value associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final @NonNull T`	`<T extends Parcelable> getParcelable( @NonNull String key, @NonNull KClass<@NonNull T> parcelableClass )` Retrieves a `Parcelable` value associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final @NonNull T[]`	`<T extends Parcelable> getParcelableArray(@NonNull String key)` Retrieves an `Array` of `Parcelable` values associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final @NonNull T[]`	`<T extends Parcelable> getParcelableArray( @NonNull String key, @NonNull KClass<@NonNull T> parcelableClass )` Retrieves an `Array` of `Parcelable` values associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final T[]`	`<T extends Parcelable> getParcelableArrayOrNull(@NonNull String key)` Retrieves an `Array` of `Parcelable` values associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final T[]`	`<T extends Parcelable> getParcelableArrayOrNull( @NonNull String key, @NonNull KClass<@NonNull T> parcelableClass )` Retrieves an `Array` of `Parcelable` values associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final @NonNull List<@NonNull T>`	`<T extends Parcelable> getParcelableList(@NonNull String key)` Retrieves a `List` of `Parcelable` values associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final @NonNull List<@NonNull T>`	`<T extends Parcelable> getParcelableList( @NonNull String key, @NonNull KClass<@NonNull T> parcelableClass )` Retrieves a `List` of `Parcelable` values associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final List<@NonNull T>`	`<T extends Parcelable> getParcelableListOrNull(@NonNull String key)` Retrieves a `List` of `Parcelable` values associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final List<@NonNull T>`	`<T extends Parcelable> getParcelableListOrNull( @NonNull String key, @NonNull KClass<@NonNull T> parcelableClass )` Retrieves a `List` of `Parcelable` values associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final T`	`<T extends Parcelable> getParcelableOrNull(@NonNull String key)` Retrieves a `Parcelable` value associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final T`	`<T extends Parcelable> getParcelableOrNull( @NonNull String key, @NonNull KClass<@NonNull T> parcelableClass )` Retrieves a `Parcelable` value associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final @NonNull SavedState`	`getSavedState(@NonNull String key)` Retrieves a `SavedState` value associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final @NonNull SavedState[]`	`getSavedStateArray(@NonNull String key)` Retrieves an `Array` of `SavedState` values associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final SavedState[]`	`getSavedStateArrayOrNull(@NonNull String key)` Retrieves an `Array` of `SavedState` values associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final @NonNull List<@NonNull SavedState>`	`getSavedStateList(@NonNull String key)` Retrieves a `List` of `SavedState` values associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final List<@NonNull SavedState>`	`getSavedStateListOrNull(@NonNull String key)` Retrieves a `List` of `SavedState` values associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final SavedState`	`getSavedStateOrNull(@NonNull String key)` Retrieves a `SavedState` value associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final @NonNull Size`	`getSize(@NonNull String key)` Retrieves a `Size` value associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final @NonNull SizeF`	`getSizeF(@NonNull String key)` Retrieves a `SizeF` value associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final SizeF`	`getSizeFOrNull(@NonNull String key)` Retrieves a `SizeF` value associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final Size`	`getSizeOrNull(@NonNull String key)` Retrieves a `Size` value associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final @NonNull SparseArray<@NonNull T>`	`<T extends Parcelable> getSparseParcelableArray(@NonNull String key)` Retrieves a `SparseArray` of `Parcelable` values associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final @NonNull SparseArray<@NonNull T>`	`<T extends Parcelable> getSparseParcelableArray( @NonNull String key, @NonNull KClass<@NonNull T> parcelableClass )` Retrieves a `SparseArray` of `Parcelable` values associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final SparseArray<@NonNull T>`	`<T extends Parcelable> getSparseParcelableArrayOrNull(@NonNull String key)` Retrieves a `Array` of `Parcelable` values associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final SparseArray<@NonNull T>`	`<T extends Parcelable> getSparseParcelableArrayOrNull( @NonNull String key, @NonNull KClass<@NonNull T> parcelableClass )` Retrieves a `Array` of `Parcelable` values associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final @NonNull String`	`getString(@NonNull String key)` Retrieves a `String` value associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final @NonNull String[]`	`getStringArray(@NonNull String key)` Retrieves an `Array` of `String` values associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final String[]`	`getStringArrayOrNull(@NonNull String key)` Retrieves an `Array` of `String` values associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final @NonNull List<@NonNull String>`	`getStringList(@NonNull String key)` Retrieves a `List` of `String` values associated with the specified `key`, or throws an `IllegalArgumentException` if this `SavedState` does not contain a valid value for the key.
`final List<@NonNull String>`	`getStringListOrNull(@NonNull String key)` Retrieves a `List` of `String` values associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final String`	`getStringOrNull(@NonNull String key)` Retrieves a `String` value associated with the specified `key`, or `null` if this `SavedState` does not contain a valid value for the key.
`final boolean`	`isEmpty()` Checks if the `SavedState` is empty (contains no key-value pairs).
`final boolean`	`isNull(@NonNull String key)` Checks if the `SavedState` contains a null reference for the specified `key`.
`final int`	`size()` Returns the number of key-value pairs in the `SavedState`.
`final @NonNull Map<@NonNull String, Object>`	`toMap()` Returns a new `Map` containing all key-value pairs from the `SavedState`.

Public methods

contains

Added in 1.3.0-rc01

public final boolean contains(@NonNull String key)

Checks if the SavedState contains the specified key.

Parameters
`@NonNull String key`	The `key` to check for.

Returns
`boolean`	`true` if the `SavedState` contains the `key`, `false` otherwise.

contentDeepEquals

public final boolean contentDeepEquals(@NonNull SavedState other)

Checks if the two specified SavedState are deeply equal to one another.

Two SavedState are considered deeply equal if they have the same size, and elements at corresponding keys are deeply equal. That is, if two corresponding elements are nested SavedState, they are also compared deeply.

If any of SavedState contains itself on any nesting level the behavior is undefined.

Parameters
`@NonNull SavedState other`	the object to compare deeply with this.

Returns
`boolean`	`true` if the two are deeply equal, `false` otherwise.

contentDeepHashCode

Added in 1.3.0-rc01

public final int contentDeepHashCode()

Returns a hash code based on the "deep contents" of specified SavedState. If the SavedState contains other SavedState as elements, the hash code is based on their contents and so on.

The computation of the hash code returned is as if the SavedState is a List. Nested SavedState are treated as lists too.

If any of SavedState contains itself on any nesting level the behavior is undefined.

Returns
`int`	a deep-content-based hash code for `SavedState`.

contentDeepToString

Added in 1.3.0-rc01

public final @NonNull String contentDeepToString()

Returns a string representation of the contents of this SavedState as if it is a List. Nested SavedState are treated as lists too.

If any of SavedState contains itself on any nesting level that reference is rendered as "[...]" to prevent recursion.

getBinder

Added in 1.3.0-rc01

public final @NonNull IBinder getBinder(@NonNull String key)

Retrieves an IBinder value associated with the specified key, or throws an IllegalArgumentException if this SavedState does not contain a valid value for the key.

More specifically, a SavedState is considered to contain a valid value for a key if the key exists, the associated value is not null, and it is of the expected type.

Parameters
`@NonNull String key`	The `key` to retrieve the value for.

Returns
`@NonNull IBinder`	The value associated with the `key`.

Throws
`kotlin.IllegalArgumentException`	If the `key` is not found.
`kotlin.IllegalArgumentException`	If associated value is `null`.
`kotlin.IllegalArgumentException`	if associated value has wrong type.

getBinderOrNull

Added in 1.3.0-rc01

public final IBinder getBinderOrNull(@NonNull String key)

Retrieves a IBinder value associated with the specified key, or null if this SavedState does not contain a valid value for the key.

More specifically, a SavedState is considered to contain a valid value for a key if the key exists, the associated value is not null, and it is of the expected type.

Parameters
`@NonNull String key`	The `key` to retrieve the value for.

Returns
`IBinder`	The value associated with the `key`, or `null` if no valid value is found.

getBoolean

Added in 1.3.0-rc01

public final boolean getBoolean(@NonNull String key)

Retrieves a Boolean value associated with the specified key, or throws an IllegalArgumentException if this SavedState does not contain a valid value for the key.

More specifically, a SavedState is considered to contain a valid value for a key if the key exists, the associated value is not null, and it is of the expected type.

Parameters
`@NonNull String key`	The `key` to retrieve the value for.

Returns
`boolean`	The value associated with the `key`.

Throws
`kotlin.IllegalArgumentException`	If the `key` is not found.
`kotlin.IllegalArgumentException`	If associated value is `null`.
`kotlin.IllegalArgumentException`	if associated value has wrong type.

getBooleanArray

Added in 1.3.0-rc01

public final @NonNull boolean[] getBooleanArray(@NonNull String key)

Retrieves a BooleanArray value associated with the specified key, or throws an IllegalArgumentException if this SavedState does not contain a valid value for the key.

More specifically, a SavedState is considered to contain a valid value for a key if the key exists, the associated value is not null, and it is of the expected type.

Parameters
`@NonNull String key`	The `key` to retrieve the value for.

Returns
`@NonNull boolean[]`	The value associated with the `key`.

Throws
`kotlin.IllegalArgumentException`	If the `key` is not found.
`kotlin.IllegalArgumentException`	If associated value is `null`.
`kotlin.IllegalArgumentException`	if associated value has wrong type.

getBooleanArrayOrNull

Added in 1.3.0-rc01

public final boolean[] getBooleanArrayOrNull(@NonNull String key)

Retrieves a BooleanArray value associated with the specified key, or null if this SavedState does not contain a valid value for the key.

More specifically, a SavedState is considered to contain a valid value for a key if the key exists, the associated value is not null, and it is of the expected type.

Parameters
`@NonNull String key`	The `key` to retrieve the value for.

Returns
`boolean[]`	The value associated with the `key`, or `null` if no valid value is found.

getBooleanOrNull

Added in 1.3.0-rc01

public final Boolean getBooleanOrNull(@NonNull String key)

Retrieves a Boolean value associated with the specified key, or null if this SavedState does not contain a valid value for the key.

More specifically, a SavedState is considered to contain a valid value for a key if the key exists, the associated value is not null, and it is of the expected type.

Note: This method returns a nullable primitive, causing auto-boxing on JVM targets.

Parameters
`@NonNull String key`	The `key` to retrieve the value for.

Returns
`Boolean`	The value associated with the `key`, or `null` if no valid value is found.

getChar

Added in 1.3.0-rc01

public final char getChar(@NonNull String key)

Retrieves a Char value associated with the specified key, or throws an IllegalArgumentException if this