# NestedScrollingParent2

added in[version 26.1.0](https://developer.android.com/topic/libraries/support-library/revisions)  
belongs to Maven artifact com.android.support:support-compat:28.0.0-alpha1  
Summary:[Methods](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent2#pubmethods)\|[Inherited Methods](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent2#inhmethods)\|[\[Expand All\]](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent2#)  

# NestedScrollingParent2

| 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package is part of the Android[support library](https://developer.android.com/topic/libraries/support-library)which is no longer maintained. The support library has been superseded by[AndroidX](https://developer.android.com/jetpack/androidx)which is part of[Jetpack](https://developer.android.com/jetpack).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


interface
NestedScrollingParent2
`  
`


implements

`[NestedScrollingParent](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent)`


`

|------------------------------------------------|
| android.support.v4.view.NestedScrollingParent2 |

|---|---|
| [![](https://developer.android.com/static/assets/images/styles/disclosure_down.png)](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent2#)Known Indirect Subclasses [CoordinatorLayout](https://developer.android.com/reference/android/support/design/widget/CoordinatorLayout) |--------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------| | [CoordinatorLayout](https://developer.android.com/reference/android/support/design/widget/CoordinatorLayout) | CoordinatorLayout is a super-powered[FrameLayout](https://developer.android.com/reference/android/widget/FrameLayout.html). | ||

<br />

*** ** * ** ***

This interface should be implemented by[ViewGroup](https://developer.android.com/reference/android/view/ViewGroup.html)subclasses that wish to support scrolling operations delegated by a nested child view.

Classes implementing this interface should create a final instance of a[NestedScrollingParentHelper](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParentHelper)as a field and delegate any View or ViewGroup methods to the`NestedScrollingParentHelper`methods of the same signature.

Views invoking nested scrolling functionality should always do so from the relevant[ViewCompat](https://developer.android.com/reference/android/support/v4/view/ViewCompat),[ViewGroupCompat](https://developer.android.com/reference/android/support/v4/view/ViewGroupCompat)or[ViewParentCompat](https://developer.android.com/reference/android/support/v4/view/ViewParentCompat)compatibility shim static methods. This ensures interoperability with nested scrolling views on all versions of Android.

<br />

## Summary

|                                                                                                                                                                                                                                                    ### Public methods                                                                                                                                                                                                                                                     ||
|---------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| ` abstract void`    | ` `[onNestedPreScroll](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent2#onNestedPreScroll(android.view.View, int, int, int[], int))`(`[View](https://developer.android.com/reference/android/view/View.html)` target, int dx, int dy, int[] consumed, int type) ` React to a nested scroll in progress before the target view consumes a portion of the scroll.                                                                                                |
| ` abstract void`    | ` `[onNestedScroll](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent2#onNestedScroll(android.view.View, int, int, int, int, int))`(`[View](https://developer.android.com/reference/android/view/View.html)` target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed, int type) ` React to a nested scroll in progress.                                                                                                                       |
| ` abstract void`    | ` `[onNestedScrollAccepted](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent2#onNestedScrollAccepted(android.view.View, android.view.View, int, int))`(`[View](https://developer.android.com/reference/android/view/View.html)` child, `[View](https://developer.android.com/reference/android/view/View.html)` target, int axes, int type) ` React to the successful claiming of a nested scroll operation.                                                    |
| ` abstract boolean` | ` `[onStartNestedScroll](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent2#onStartNestedScroll(android.view.View, android.view.View, int, int))`(`[View](https://developer.android.com/reference/android/view/View.html)` child, `[View](https://developer.android.com/reference/android/view/View.html)` target, int axes, int type) ` React to a descendant view initiating a nestable scroll operation, claiming the nested scroll operation if appropriate. |
| ` abstract void`    | ` `[onStopNestedScroll](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent2#onStopNestedScroll(android.view.View, int))`(`[View](https://developer.android.com/reference/android/view/View.html)` target, int type) ` React to a nested scroll operation ending.                                                                                                                                                                                                  |

| ### Inherited methods |
|-----------------------|---|
| [![](https://developer.android.com/static/assets/images/styles/disclosure_down.png)](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent2#)From interface` `[android.support.v4.view.NestedScrollingParent](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent)` ` |---------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | ` abstract int`     | ` `[getNestedScrollAxes](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent#getNestedScrollAxes())`() ` Return the current axes of nested scrolling for this NestedScrollingParent.                                                                                                                                                                                                                                                               | | ` abstract boolean` | ` `[onNestedFling](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent#onNestedFling(android.view.View, float, float, boolean))`(`[View](https://developer.android.com/reference/android/view/View.html)` target, float velocityX, float velocityY, boolean consumed) ` Request a fling from a nested scroll.                                                                                                                                      | | ` abstract boolean` | ` `[onNestedPreFling](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent#onNestedPreFling(android.view.View, float, float))`(`[View](https://developer.android.com/reference/android/view/View.html)` target, float velocityX, float velocityY) ` React to a nested fling before the target view consumes it.                                                                                                                                     | | ` abstract void`    | ` `[onNestedPreScroll](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent#onNestedPreScroll(android.view.View, int, int, int[]))`(`[View](https://developer.android.com/reference/android/view/View.html)` target, int dx, int dy, int[] consumed) ` React to a nested scroll in progress before the target view consumes a portion of the scroll.                                                                                                | | ` abstract void`    | ` `[onNestedScroll](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent#onNestedScroll(android.view.View, int, int, int, int))`(`[View](https://developer.android.com/reference/android/view/View.html)` target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed) ` React to a nested scroll in progress.                                                                                                                       | | ` abstract void`    | ` `[onNestedScrollAccepted](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent#onNestedScrollAccepted(android.view.View, android.view.View, int))`(`[View](https://developer.android.com/reference/android/view/View.html)` child, `[View](https://developer.android.com/reference/android/view/View.html)` target, int axes) ` React to the successful claiming of a nested scroll operation.                                                    | | ` abstract boolean` | ` `[onStartNestedScroll](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent#onStartNestedScroll(android.view.View, android.view.View, int))`(`[View](https://developer.android.com/reference/android/view/View.html)` child, `[View](https://developer.android.com/reference/android/view/View.html)` target, int axes) ` React to a descendant view initiating a nestable scroll operation, claiming the nested scroll operation if appropriate. | | ` abstract void`    | ` `[onStopNestedScroll](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent#onStopNestedScroll(android.view.View))`(`[View](https://developer.android.com/reference/android/view/View.html)` target) ` React to a nested scroll operation ending.                                                                                                                                                                                                  | ||

## Public methods

### onNestedPreScroll

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

```
void onNestedPreScroll (View target, 
                int dx, 
                int dy, 
                int[] consumed, 
                int type)
```

React to a nested scroll in progress before the target view consumes a portion of the scroll.

When working with nested scrolling often the parent view may want an opportunity to consume the scroll before the nested scrolling child does. An example of this is a drawer that contains a scrollable list. The user will want to be able to scroll the list fully into view before the list itself begins scrolling.

`onNestedPreScroll`is called when a nested scrolling child invokes[dispatchNestedPreScroll(int, int, int[], int[])](https://developer.android.com/reference/android/view/View.html#dispatchNestedPreScroll(int, int, int[], int[])). The implementation should report how any pixels of the scroll reported by dx, dy were consumed in the`consumed`array. Index 0 corresponds to dx and index 1 corresponds to dy. This parameter will never be null. Initial values for consumed\[0\] and consumed\[1\] will always be 0.

<br />

<br />

|                                              Parameters                                               ||
|------------|-------------------------------------------------------------------------------------------|
| `target`   | `View`: View that initiated the nested scroll <br />                                      |
| `dx`       | `int`: Horizontal scroll distance in pixels <br />                                        |
| `dy`       | `int`: Vertical scroll distance in pixels <br />                                          |
| `consumed` | `int`: Output. The horizontal and vertical scroll distance consumed by this parent <br /> |
| `type`     | `int`: the type of input which cause this scroll event <br />                             |

### onNestedScroll

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

```
void onNestedScroll (View target, 
                int dxConsumed, 
                int dyConsumed, 
                int dxUnconsumed, 
                int dyUnconsumed, 
                int type)
```

React to a nested scroll in progress.

This method will be called when the ViewParent's current nested scrolling child view dispatches a nested scroll event. To receive calls to this method the ViewParent must have previously returned`true`for a call to[onStartNestedScroll(View, View, int, int)](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent2#onStartNestedScroll(android.view.View, android.view.View, int, int)).

Both the consumed and unconsumed portions of the scroll distance are reported to the ViewParent. An implementation may choose to use the consumed portion to match or chase scroll position of multiple child elements, for example. The unconsumed portion may be used to allow continuous dragging of multiple scrolling or draggable elements, such as scrolling a list within a vertical drawer where the drawer begins dragging once the edge of inner scrolling content is reached.

<br />

<br />

|                                          Parameters                                           ||
|----------------|-------------------------------------------------------------------------------|
| `target`       | `View`: The descendent view controlling the nested scroll <br />              |
| `dxConsumed`   | `int`: Horizontal scroll distance in pixels already consumed by target <br /> |
| `dyConsumed`   | `int`: Vertical scroll distance in pixels already consumed by target <br />   |
| `dxUnconsumed` | `int`: Horizontal scroll distance in pixels not consumed by target <br />     |
| `dyUnconsumed` | `int`: Vertical scroll distance in pixels not consumed by target <br />       |
| `type`         | `int`: the type of input which cause this scroll event <br />                 |

### onNestedScrollAccepted

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

```
void onNestedScrollAccepted (View child, 
                View target, 
                int axes, 
                int type)
```

React to the successful claiming of a nested scroll operation.

This method will be called after[onStartNestedScroll](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent2#onStartNestedScroll(android.view.View, android.view.View, int, int))returns true. It offers an opportunity for the view and its superclasses to perform initial configuration for the nested scroll. Implementations of this method should always call their superclass's implementation of this method if one is present.

<br />

<br />

|                                                                                                                                              Parameters                                                                                                                                               ||
|----------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `child`  | `View`: Direct child of this ViewParent containing target <br />                                                                                                                                                                                                                            |
| `target` | `View`: View that initiated the nested scroll <br />                                                                                                                                                                                                                                        |
| `axes`   | `int`: Flags consisting of[SCROLL_AXIS_HORIZONTAL](https://developer.android.com/reference/android/support/v4/view/ViewCompat#SCROLL_AXIS_HORIZONTAL),[SCROLL_AXIS_VERTICAL](https://developer.android.com/reference/android/support/v4/view/ViewCompat#SCROLL_AXIS_VERTICAL)or both <br /> |
| `type`   | `int`: the type of input which cause this scroll event <br />                                                                                                                                                                                                                               |

**See also:**

- [onStartNestedScroll(View, View, int, int)](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent2#onStartNestedScroll(android.view.View, android.view.View, int, int))
- [onStopNestedScroll(View, int)](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent2#onStopNestedScroll(android.view.View, int))  

### onStartNestedScroll

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

```
boolean onStartNestedScroll (View child, 
                View target, 
                int axes, 
                int type)
```

React to a descendant view initiating a nestable scroll operation, claiming the nested scroll operation if appropriate.

This method will be called in response to a descendant view invoking[startNestedScroll(View, int)](https://developer.android.com/reference/android/support/v4/view/ViewCompat#startNestedScroll(android.view.View, int)). Each parent up the view hierarchy will be given an opportunity to respond and claim the nested scrolling operation by returning`true`.

This method may be overridden by ViewParent implementations to indicate when the view is willing to support a nested scrolling operation that is about to begin. If it returns true, this ViewParent will become the target view's nested scrolling parent for the duration of the scroll operation in progress. When the nested scroll is finished this ViewParent will receive a call to[onStopNestedScroll(View, int)](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent2#onStopNestedScroll(android.view.View, int)).

<br />

<br />

|                                                                                                                                              Parameters                                                                                                                                               ||
|----------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `child`  | `View`: Direct child of this ViewParent containing target <br />                                                                                                                                                                                                                            |
| `target` | `View`: View that initiated the nested scroll <br />                                                                                                                                                                                                                                        |
| `axes`   | `int`: Flags consisting of[SCROLL_AXIS_HORIZONTAL](https://developer.android.com/reference/android/support/v4/view/ViewCompat#SCROLL_AXIS_HORIZONTAL),[SCROLL_AXIS_VERTICAL](https://developer.android.com/reference/android/support/v4/view/ViewCompat#SCROLL_AXIS_VERTICAL)or both <br /> |
| `type`   | `int`: the type of input which cause this scroll event <br />                                                                                                                                                                                                                               |

|                                    Returns                                    ||
|-----------|--------------------------------------------------------------------|
| `boolean` | true if this ViewParent accepts the nested scroll operation <br /> |

### onStopNestedScroll

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

```
void onStopNestedScroll (View target, 
                int type)
```

React to a nested scroll operation ending.

Perform cleanup after a nested scrolling operation. This method will be called when a nested scroll stops, for example when a nested touch scroll ends with a[ACTION_UP](https://developer.android.com/reference/android/view/MotionEvent.html#ACTION_UP)or[ACTION_CANCEL](https://developer.android.com/reference/android/view/MotionEvent.html#ACTION_CANCEL)event. Implementations of this method should always call their superclass's implementation of this method if one is present.

<br />

<br />

|                               Parameters                                ||
|----------|---------------------------------------------------------------|
| `target` | `View`: View that initiated the nested scroll <br />          |
| `type`   | `int`: the type of input which cause this scroll event <br /> |

-

  ## Annotations

  - [ViewPager.DecorView](https://developer.android.com/reference/android/support/v4/view/ViewPager.DecorView)
-

  ## Interfaces

  - [ActionProvider.VisibilityListener](https://developer.android.com/reference/android/support/v4/view/ActionProvider.VisibilityListener)
  - [AsyncLayoutInflater.OnInflateFinishedListener](https://developer.android.com/reference/android/support/v4/view/AsyncLayoutInflater.OnInflateFinishedListener)
  - [LayoutInflaterFactory](https://developer.android.com/reference/android/support/v4/view/LayoutInflaterFactory)
  - [MenuItemCompat.OnActionExpandListener](https://developer.android.com/reference/android/support/v4/view/MenuItemCompat.OnActionExpandListener)
  - [NestedScrollingChild](https://developer.android.com/reference/android/support/v4/view/NestedScrollingChild)
  - [NestedScrollingChild2](https://developer.android.com/reference/android/support/v4/view/NestedScrollingChild2)
  - [NestedScrollingParent](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent)
  - [NestedScrollingParent2](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParent2)
  - [OnApplyWindowInsetsListener](https://developer.android.com/reference/android/support/v4/view/OnApplyWindowInsetsListener)
  - [ScrollingView](https://developer.android.com/reference/android/support/v4/view/ScrollingView)
  - [TintableBackgroundView](https://developer.android.com/reference/android/support/v4/view/TintableBackgroundView)
  - [ViewPager.OnAdapterChangeListener](https://developer.android.com/reference/android/support/v4/view/ViewPager.OnAdapterChangeListener)
  - [ViewPager.OnPageChangeListener](https://developer.android.com/reference/android/support/v4/view/ViewPager.OnPageChangeListener)
  - [ViewPager.PageTransformer](https://developer.android.com/reference/android/support/v4/view/ViewPager.PageTransformer)
  - [ViewPropertyAnimatorListener](https://developer.android.com/reference/android/support/v4/view/ViewPropertyAnimatorListener)
  - [ViewPropertyAnimatorUpdateListener](https://developer.android.com/reference/android/support/v4/view/ViewPropertyAnimatorUpdateListener)
-

  ## Classes

  - [AbsSavedState](https://developer.android.com/reference/android/support/v4/view/AbsSavedState)
  - [AccessibilityDelegateCompat](https://developer.android.com/reference/android/support/v4/view/AccessibilityDelegateCompat)
  - [ActionProvider](https://developer.android.com/reference/android/support/v4/view/ActionProvider)
  - [AsyncLayoutInflater](https://developer.android.com/reference/android/support/v4/view/AsyncLayoutInflater)
  - [GestureDetectorCompat](https://developer.android.com/reference/android/support/v4/view/GestureDetectorCompat)
  - [GravityCompat](https://developer.android.com/reference/android/support/v4/view/GravityCompat)
  - [InputDeviceCompat](https://developer.android.com/reference/android/support/v4/view/InputDeviceCompat)
  - [LayoutInflaterCompat](https://developer.android.com/reference/android/support/v4/view/LayoutInflaterCompat)
  - [MarginLayoutParamsCompat](https://developer.android.com/reference/android/support/v4/view/MarginLayoutParamsCompat)
  - [MenuCompat](https://developer.android.com/reference/android/support/v4/view/MenuCompat)
  - [MenuItemCompat](https://developer.android.com/reference/android/support/v4/view/MenuItemCompat)
  - [MotionEventCompat](https://developer.android.com/reference/android/support/v4/view/MotionEventCompat)
  - [NestedScrollingChildHelper](https://developer.android.com/reference/android/support/v4/view/NestedScrollingChildHelper)
  - [NestedScrollingParentHelper](https://developer.android.com/reference/android/support/v4/view/NestedScrollingParentHelper)
  - [PagerAdapter](https://developer.android.com/reference/android/support/v4/view/PagerAdapter)
  - [PagerTabStrip](https://developer.android.com/reference/android/support/v4/view/PagerTabStrip)
  - [PagerTitleStrip](https://developer.android.com/reference/android/support/v4/view/PagerTitleStrip)
  - [PointerIconCompat](https://developer.android.com/reference/android/support/v4/view/PointerIconCompat)
  - [ScaleGestureDetectorCompat](https://developer.android.com/reference/android/support/v4/view/ScaleGestureDetectorCompat)
  - [VelocityTrackerCompat](https://developer.android.com/reference/android/support/v4/view/VelocityTrackerCompat)
  - [ViewCompat](https://developer.android.com/reference/android/support/v4/view/ViewCompat)
  - [ViewConfigurationCompat](https://developer.android.com/reference/android/support/v4/view/ViewConfigurationCompat)
  - [ViewGroupCompat](https://developer.android.com/reference/android/support/v4/view/ViewGroupCompat)
  - [ViewPager](https://developer.android.com/reference/android/support/v4/view/ViewPager)
  - [ViewPager.LayoutParams](https://developer.android.com/reference/android/support/v4/view/ViewPager.LayoutParams)
  - [ViewPager.SavedState](https://developer.android.com/reference/android/support/v4/view/ViewPager.SavedState)
  - [ViewPager.SimpleOnPageChangeListener](https://developer.android.com/reference/android/support/v4/view/ViewPager.SimpleOnPageChangeListener)
  - [ViewParentCompat](https://developer.android.com/reference/android/support/v4/view/ViewParentCompat)
  - [ViewPropertyAnimatorCompat](https://developer.android.com/reference/android/support/v4/view/ViewPropertyAnimatorCompat)
  - [ViewPropertyAnimatorListenerAdapter](https://developer.android.com/reference/android/support/v4/view/ViewPropertyAnimatorListenerAdapter)
  - [WindowCompat](https://developer.android.com/reference/android/support/v4/view/WindowCompat)
  - [WindowInsetsCompat](https://developer.android.com/reference/android/support/v4/view/WindowInsetsCompat)