# WindowId.FocusObserver

Added in[API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)  
Summary:[Ctors](https://developer.android.com/reference/android/view/WindowId.FocusObserver#pubctors)\|[Methods](https://developer.android.com/reference/android/view/WindowId.FocusObserver#pubmethods)\|[Inherited Methods](https://developer.android.com/reference/android/view/WindowId.FocusObserver#inhmethods)  

# WindowId.FocusObserver

*** ** * ** ***

[Kotlin](https://developer.android.com/reference/kotlin/android/view/WindowId.FocusObserver "View this page in Kotlin")\|Java

`
public
static

abstract
class
WindowId.FocusObserver
`  
`

extends `[Object](https://developer.android.com/reference/java/lang/Object)`


``


`

|---|-------------------------------------|
| [java.lang.Object](https://developer.android.com/reference/java/lang/Object) ||
| ↳ | android.view.WindowId.FocusObserver |

<br />

*** ** * ** ***

Subclass for observing changes to the focus state of an[WindowId](https://developer.android.com/reference/android/view/WindowId). You should use the same instance of this class for observing multiple[WindowId](https://developer.android.com/reference/android/view/WindowId)objects, since this class is fairly heavy-weight -- the base class includes all of the mechanisms for connecting to and receiving updates from the window.

## Summary

|                                                              ### Public constructors                                                              ||
|------------------------------------------------------------------------------------------------------------------------------------------------|---|
| ` `[FocusObserver](https://developer.android.com/reference/android/view/WindowId.FocusObserver#FocusObserver())`() ` Construct a new observer. |

|                                                                                                                                            ### Public methods                                                                                                                                            ||
|------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| ` abstract void` | ` `[onFocusGained](https://developer.android.com/reference/android/view/WindowId.FocusObserver#onFocusGained(android.view.WindowId))`(`[WindowId](https://developer.android.com/reference/android/view/WindowId)` token) ` Called when one of the monitored windows gains input focus. |
| ` abstract void` | ` `[onFocusLost](https://developer.android.com/reference/android/view/WindowId.FocusObserver#onFocusLost(android.view.WindowId))`(`[WindowId](https://developer.android.com/reference/android/view/WindowId)` token) ` Called when one of the monitored windows loses input focus.     |

| ### Inherited methods |
|-----------------------|---|
| From class` `[java.lang.Object](https://developer.android.com/reference/java/lang/Object)` ` |--------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | ` `[Object](https://developer.android.com/reference/java/lang/Object)          | ` `[clone](https://developer.android.com/reference/java/lang/Object#clone())`() ` Creates and returns a copy of this object.                                                                                                                                                      | | ` boolean`                                                                     | ` `[equals](https://developer.android.com/reference/java/lang/Object#equals(java.lang.Object))`(`[Object](https://developer.android.com/reference/java/lang/Object)` obj) ` Indicates whether some other object is "equal to" this one.                                           | | ` void`                                                                        | ` `[finalize](https://developer.android.com/reference/java/lang/Object#finalize())`() ` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.                                                          | | ` final `[Class](https://developer.android.com/reference/java/lang/Class)`<?>` | ` `[getClass](https://developer.android.com/reference/java/lang/Object#getClass())`() ` Returns the runtime class of this`Object`.                                                                                                                                                | | ` int`                                                                         | ` `[hashCode](https://developer.android.com/reference/java/lang/Object#hashCode())`() ` Returns a hash code value for the object.                                                                                                                                                 | | ` final void`                                                                  | ` `[notify](https://developer.android.com/reference/java/lang/Object#notify())`() ` Wakes up a single thread that is waiting on this object's monitor.                                                                                                                            | | ` final void`                                                                  | ` `[notifyAll](https://developer.android.com/reference/java/lang/Object#notifyAll())`() ` Wakes up all threads that are waiting on this object's monitor.                                                                                                                         | | ` `[String](https://developer.android.com/reference/java/lang/String)          | ` `[toString](https://developer.android.com/reference/java/lang/Object#toString())`() ` Returns a string representation of the object.                                                                                                                                            | | ` final void`                                                                  | ` `[wait](https://developer.android.com/reference/java/lang/Object#wait(long,%20int))`(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](https://developer.android.com/reference/java/lang/Object#wait(long))`(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](https://developer.android.com/reference/java/lang/Object#wait())`() ` Causes the current thread to wait until it is awakened, typically by being*notified* or*interrupted*.                                                                                             | ||

## Public constructors

### FocusObserver

Added in[API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)  

```
public FocusObserver ()
```

Construct a new observer. This observer will be configured so that all of its callbacks are dispatched on the current calling thread.

<br />

## Public methods

### onFocusGained

Added in[API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)  

```
public abstract void onFocusGained (WindowId token)
```

Called when one of the monitored windows gains input focus.

<br />

|         Parameters         ||
|---------|-------------------|
| `token` | `WindowId` <br /> |

### onFocusLost

Added in[API level 18](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)  

```
public abstract void onFocusLost (WindowId token)
```

Called when one of the monitored windows loses input focus.

<br />

|         Parameters         ||
|---------|-------------------|
| `token` | `WindowId` <br /> |