# Transition.EpicenterCallback

added in[version 26.1.0](https://developer.android.com/topic/libraries/support-library/revisions)  
belongs to Maven artifact com.android.support:transition:28.0.0-alpha1  
Summary:[Ctors](https://developer.android.com/reference/android/support/transition/Transition.EpicenterCallback#pubctors)\|[Methods](https://developer.android.com/reference/android/support/transition/Transition.EpicenterCallback#pubmethods)\|[Inherited Methods](https://developer.android.com/reference/android/support/transition/Transition.EpicenterCallback#inhmethods)\|[\[Expand All\]](https://developer.android.com/reference/android/support/transition/Transition.EpicenterCallback#)  

# Transition.EpicenterCallback

| This package is part of the Android[support library](https://developer.android.com/topic/libraries/support-library)which is no longer maintained. The support library has been superseded by[AndroidX](https://developer.android.com/jetpack/androidx)which is part of[Jetpack](https://developer.android.com/jetpack). We recommend using the AndroidX libraries in all new projects. You should also consider[migrating](https://developer.android.com/jetpack/androidx/migrate)existing projects to AndroidX. To find the AndroidX class that maps to this deprecated class, see the AndroidX support library[class mappings](https://developer.android.com/jetpack/androidx/migrate/class-mappings).

`
public
static

abstract
class
Transition.EpicenterCallback
`  
`

extends Object


``


`

|---|---------------------------------------------------------|
| java.lang.Object                                           ||
| ↳ | android.support.transition.Transition.EpicenterCallback |

<br />

*** ** * ** ***

Class to get the epicenter of Transition. Use[setEpicenterCallback(EpicenterCallback)](https://developer.android.com/reference/android/support/transition/Transition#setEpicenterCallback(android.support.transition.Transition.EpicenterCallback))to set the callback used to calculate the epicenter of the Transition. Override[getEpicenter()](https://developer.android.com/reference/android/support/transition/Transition#getEpicenter())to return the rectangular region in screen coordinates of the epicenter of the transition.  
**See also:**

- [setEpicenterCallback(EpicenterCallback)](https://developer.android.com/reference/android/support/transition/Transition#setEpicenterCallback(android.support.transition.Transition.EpicenterCallback))

## Summary

|                                                                          ### Public constructors                                                                          ||
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---|
| ` `[Transition.EpicenterCallback](https://developer.android.com/reference/android/support/transition/Transition.EpicenterCallback#Transition.EpicenterCallback())`() ` |

|                                                                                                                                                                                                                             ### Public methods                                                                                                                                                                                                                              ||
|----------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| ` abstract `[Rect](https://developer.android.com/reference/android/graphics/Rect.html) | ` `[onGetEpicenter](https://developer.android.com/reference/android/support/transition/Transition.EpicenterCallback#onGetEpicenter(android.support.transition.Transition))`(`[Transition](https://developer.android.com/reference/android/support/transition/Transition)` transition) ` Implementers must override to return the epicenter of the Transition in screen coordinates. |

| ### Inherited methods |
|-----------------------|---|
| [![](https://developer.android.com/static/assets/images/styles/disclosure_down.png)](https://developer.android.com/reference/android/support/transition/Transition.EpicenterCallback#)From class` java.lang.Object ` |-------------------|-------------------------------| | ` Object`         | ` clone() `                   | | ` boolean`        | ` equals(Object arg0) `       | | ` void`           | ` finalize() `                | | ` final Class<?>` | ` getClass() `                | | ` int`            | ` hashCode() `                | | ` final void`     | ` notify() `                  | | ` final void`     | ` notifyAll() `               | | ` String`         | ` toString() `                | | ` final void`     | ` wait(long arg0, int arg1) ` | | ` final void`     | ` wait(long arg0) `           | | ` final void`     | ` wait() `                    | ||

## Public constructors

### Transition.EpicenterCallback

added in[version 26.1.0](https://developer.android.com/topic/libraries/support-library/revisions)  

```
Transition.EpicenterCallback ()
```

<br />

<br />

## Public methods

### onGetEpicenter

added in[version 26.1.0](https://developer.android.com/topic/libraries/support-library/revisions)  

```
Rect onGetEpicenter (Transition transition)
```

Implementers must override to return the epicenter of the Transition in screen coordinates. Transitions like[Explode](https://developer.android.com/reference/android/transition/Explode.html)depend upon an epicenter for the Transition. In Explode, Views move toward or away from the center of the epicenter Rect along the vector between the epicenter and the center of the View appearing and disappearing. Some Transitions, such as[Fade](https://developer.android.com/reference/android/transition/Fade.html)pay no attention to the epicenter.

<br />

|                                     Parameters                                     ||
|--------------|----------------------------------------------------------------------|
| `transition` | `Transition`: The transition for which the epicenter applies. <br /> |

|                                                                               Returns                                                                               ||
|----------------------------------------------------------------------------|-----------------------------------------------------------------------------------------|
| [Rect](https://developer.android.com/reference/android/graphics/Rect.html) | The Rect region of the epicenter of`transition`or null if there is no epicenter. <br /> |

-

  ## Interfaces

  - [Transition.TransitionListener](https://developer.android.com/reference/android/support/transition/Transition.TransitionListener)
-

  ## Classes

  - [ArcMotion](https://developer.android.com/reference/android/support/transition/ArcMotion)
  - [AutoTransition](https://developer.android.com/reference/android/support/transition/AutoTransition)
  - [ChangeBounds](https://developer.android.com/reference/android/support/transition/ChangeBounds)
  - [ChangeClipBounds](https://developer.android.com/reference/android/support/transition/ChangeClipBounds)
  - [ChangeImageTransform](https://developer.android.com/reference/android/support/transition/ChangeImageTransform)
  - [ChangeScroll](https://developer.android.com/reference/android/support/transition/ChangeScroll)
  - [ChangeTransform](https://developer.android.com/reference/android/support/transition/ChangeTransform)
  - [CircularPropagation](https://developer.android.com/reference/android/support/transition/CircularPropagation)
  - [Explode](https://developer.android.com/reference/android/support/transition/Explode)
  - [Fade](https://developer.android.com/reference/android/support/transition/Fade)
  - [PathMotion](https://developer.android.com/reference/android/support/transition/PathMotion)
  - [PatternPathMotion](https://developer.android.com/reference/android/support/transition/PatternPathMotion)
  - [R](https://developer.android.com/reference/android/support/transition/R)
  - [R.attr](https://developer.android.com/reference/android/support/transition/R.attr)
  - [R.bool](https://developer.android.com/reference/android/support/transition/R.bool)
  - [R.color](https://developer.android.com/reference/android/support/transition/R.color)
  - [R.dimen](https://developer.android.com/reference/android/support/transition/R.dimen)
  - [R.drawable](https://developer.android.com/reference/android/support/transition/R.drawable)
  - [R.id](https://developer.android.com/reference/android/support/transition/R.id)
  - [R.integer](https://developer.android.com/reference/android/support/transition/R.integer)
  - [R.layout](https://developer.android.com/reference/android/support/transition/R.layout)
  - [R.string](https://developer.android.com/reference/android/support/transition/R.string)
  - [R.style](https://developer.android.com/reference/android/support/transition/R.style)
  - [R.styleable](https://developer.android.com/reference/android/support/transition/R.styleable)
  - [Scene](https://developer.android.com/reference/android/support/transition/Scene)
  - [SidePropagation](https://developer.android.com/reference/android/support/transition/SidePropagation)
  - [Slide](https://developer.android.com/reference/android/support/transition/Slide)
  - [Transition](https://developer.android.com/reference/android/support/transition/Transition)
  - [Transition.EpicenterCallback](https://developer.android.com/reference/android/support/transition/Transition.EpicenterCallback)
  - [TransitionInflater](https://developer.android.com/reference/android/support/transition/TransitionInflater)
  - [TransitionListenerAdapter](https://developer.android.com/reference/android/support/transition/TransitionListenerAdapter)
  - [TransitionManager](https://developer.android.com/reference/android/support/transition/TransitionManager)
  - [TransitionPropagation](https://developer.android.com/reference/android/support/transition/TransitionPropagation)
  - [TransitionSet](https://developer.android.com/reference/android/support/transition/TransitionSet)
  - [TransitionValues](https://developer.android.com/reference/android/support/transition/TransitionValues)
  - [Visibility](https://developer.android.com/reference/android/support/transition/Visibility)
  - [VisibilityPropagation](https://developer.android.com/reference/android/support/transition/VisibilityPropagation)