NestedScrollingParentHelper

public class NestedScrollingParentHelper
extends Object

java.lang.Object
   ↳ androidx.core.view.NestedScrollingParentHelper


Helper class for implementing nested scrolling parent views compatible with Android platform versions earlier than Android 5.0 Lollipop (API 21).

ViewGroup subclasses should instantiate a final instance of this class as a field at construction. For each ViewGroup method that has a matching method signature in this class, delegate the operation to the helper instance in an overridden method implementation. This implements the standard framework policy for nested scrolling.

Views invoking nested scrolling functionality should always do so from the relevant ViewCompat, ViewGroupCompat or ViewParentCompat compatibility shim static methods. This ensures interoperability with nested scrolling views on Android 5.0 Lollipop and newer.

Summary

Public constructors

NestedScrollingParentHelper(ViewGroup viewGroup)

Construct a new helper for a given ViewGroup

Public methods

int getNestedScrollAxes()

Return the current axes of nested scrolling for this ViewGroup.

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

Called when a nested scrolling operation initiated by a descendant view is accepted by this ViewGroup.

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

Called when a nested scrolling operation initiated by a descendant view is accepted by this ViewGroup.

void onStopNestedScroll(View target, int type)

React to a nested scroll operation ending.

void onStopNestedScroll(View target)

React to a nested scroll operation ending.

Inherited methods

Public constructors

NestedScrollingParentHelper

public NestedScrollingParentHelper (ViewGroup viewGroup)

Construct a new helper for a given ViewGroup

Parameters
viewGroup ViewGroup

Public methods

getNestedScrollAxes

public int getNestedScrollAxes ()

Return the current axes of nested scrolling for this ViewGroup.

This is a delegate method. Call it from your ViewGroup subclass method/NestedScrollingParent interface method with the same signature to implement the standard policy.

Returns
int

onNestedScrollAccepted

public void onNestedScrollAccepted (View child, 
                View target, 
                int axes)

Called when a nested scrolling operation initiated by a descendant view is accepted by this ViewGroup.

This is a delegate method. Call it from your ViewGroup subclass method/NestedScrollingParent interface method with the same signature to implement the standard policy.

Parameters
child View

target View

axes int

onNestedScrollAccepted

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

Called when a nested scrolling operation initiated by a descendant view is accepted by this ViewGroup.

This is a delegate method. Call it from your ViewGroup subclass method/NestedScrollingParent2 interface method with the same signature to implement the standard policy.

Parameters
child View

target View

axes int

type int

onStopNestedScroll

public void onStopNestedScroll (View target, 
                int type)

React to a nested scroll operation ending.

This is a delegate method. Call it from your ViewGroup subclass method/NestedScrollingParent2 interface method with the same signature to implement the standard policy.

Parameters
target View

type int

onStopNestedScroll

public void onStopNestedScroll (View target)

React to a nested scroll operation ending.

This is a delegate method. Call it from your ViewGroup subclass method/NestedScrollingParent interface method with the same signature to implement the standard policy.

Parameters
target View