LocusId

public final class LocusId
extends Object implements Parcelable

An identifier for an unique state (locus) in the application. Should be stable across reboots and backup / restore.

Locus is a new concept introduced on Android Q and it lets the intelligence service provided by the Android System to correlate state between different subsystems such as content capture, shortcuts, and notifications.

For example, if your app provides an activity representing a chat between 2 users (say A and B, this chat state could be represented by:


 LocusId chatId = new LocusId("Chat_A_B");

And then you should use that chatId by:

Setting it in the chat notification (through Notification.Builder.setLocusId(chatId)).
Setting it into the ShortcutInfo (through ShortcutInfo.Builder.setLocusId(chatId)), if you provide a launcher shortcut for that chat conversation.
Associating it with the ContentCaptureContext of the root view of the chat conversation activity (through View.getContentCaptureSession(), then new ContentCaptureContext.Builder(chatId).build() and ContentCaptureSession.setContentCaptureContext(android.view.contentcapture.ContentCaptureContext) - see ContentCaptureManager for more info about content capture).
Configuring your app to launch the chat conversation through the Intent#ACTION_VIEW_LOCUS intent.

NOTE: The LocusId is only used by an on-device intelligence service provided by the Android System, see ContentCaptureManager for more details.

Summary

Inherited constants

From interface android.os.Parcelable

`int`	`CONTENTS_FILE_DESCRIPTOR` Descriptor bit used with `describeContents()`: indicates that the Parcelable object's flattened representation includes a file descriptor.
`int`	`PARCELABLE_WRITE_RETURN_VALUE` Flag for use with `writeToParcel(Parcel, int)`: the object being written is a return value, that is the result of a function such as "`Parcelable someFunction()`", "`void someFunction(out Parcelable)`", or "`void someFunction(inout Parcelable)`".

Fields
`public static final Creator<LocusId>`	`CREATOR`

Public constructors
`LocusId(String id)` Default constructor.

Public methods
`int`	`describeContents()` Describe the kinds of special objects contained in this Parcelable instance's marshaled representation.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`String`	`getId()` Gets the canonical `id` associated with the locus.
`int`	`hashCode()` Returns a hash code value for the object.
`String`	`toString()` Returns a string representation of the object.
`void`	`writeToParcel(Parcel parcel, int flags)` Flatten this object in to a Parcel.

Inherited methods

From class java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeoutMillis, int nanos)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

From interface android.os.Parcelable

`abstract int`	`describeContents()` Describe the kinds of special objects contained in this Parcelable instance's marshaled representation.
`abstract void`	`writeToParcel(Parcel dest, int flags)` Flatten this object in to a Parcel.

Fields

Public constructors

public LocusId (String id)

Default constructor.

Parameters
`id`	`String`: This value cannot be `null`.

Throws
`IllegalArgumentException`	if `id` is empty or `null`.

Public methods

describeContents

public int describeContents ()

Describe the kinds of special objects contained in this Parcelable instance's marshaled representation. For example, if the object will include a file descriptor in the output of writeToParcel(android.os.Parcel, int), the return value of this method must include the CONTENTS_FILE_DESCRIPTOR bit.

Returns
`int`	a bitmask indicating the set of special object types marshaled by this Parcelable object instance. Value is either `0` or `CONTENTS_FILE_DESCRIPTOR`

equals

public boolean equals (Object obj)

Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

It is reflexive: for any non-null reference value x, x.equals(x) should return true.
It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
For any non-null reference value x, x.equals(null) should return false.

The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any non-null reference values x and y, this method returns true if and only if x and y refer to the same object (x == y has the value true).

Note that it is generally necessary to override the hashCode method whenever this method is overridden, so as to maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.

Parameters
`obj`	`Object`: This value may be `null`.

Returns
`boolean`	`true` if this object is the same as the obj argument; `false` otherwise.

getId

public String getId ()

Gets the canonical id associated with the locus.

Returns
`String`	This value cannot be `null`.

hashCode

public int hashCode ()

Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by HashMap.

The general contract of hashCode is:

Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.
It is not required that if two objects are unequal according to the equals(java.lang.Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (The hashCode may or may not be implemented as some function of an object's memory address at some point in time.)

Returns
`int`	a hash code value for this object.

toString

public String toString ()

Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.

The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:

 getClass().getName() + '@' + Integer.toHexString(hashCode())

Returns
`String`	a string representation of the object.

writeToParcel

public void writeToParcel (Parcel parcel, 
                int flags)

Flatten this object in to a Parcel.

Parameters
`parcel`	`Parcel`: The Parcel in which the object should be written. This value cannot be `null`.
`flags`	`int`: Additional flags about how the object should be written. May be 0 or `Parcelable.PARCELABLE_WRITE_RETURN_VALUE`. Value is either `0` or a combination of `Parcelable.PARCELABLE_WRITE_RETURN_VALUE`, and android.os.Parcelable.PARCELABLE_ELIDE_DUPLICATES