ViewParentCompat

notifySubtreeAccessibilityStateChanged

static fun notifySubtreeAccessibilityStateChanged(
    parent: ViewParent!, 
    child: View!, 
    source: View!, 
    changeType: Int
): Unit

Notifies a view parent that the accessibility state of one of its descendants has changed and that the structure of the subtree is different.

onNestedFling

static fun onNestedFling(
    parent: ViewParent!, 
    target: View!, 
    velocityX: Float, 
    velocityY: Float, 
    consumed: Boolean
): Boolean

Request a fling from a nested scroll.

This method signifies that a nested scrolling child has detected suitable conditions for a fling. Generally this means that a touch scroll has ended with a velocity in the direction of scrolling that meets or exceeds the minimum fling velocity along a scrollable axis.

If a nested scrolling child view would normally fling but it is at the edge of its own content, it can use this method to delegate the fling to its nested scrolling parent instead. The parent may optionally consume the fling or observe a child fling.

onNestedPreFling

static fun onNestedPreFling(
    parent: ViewParent!, 
    target: View!, 
    velocityX: Float, 
    velocityY: Float
): Boolean

React to a nested fling before the target view consumes it.

This method siginfies that a nested scrolling child has detected a fling with the given velocity along each axis. Generally this means that a touch scroll has ended with a velocity in the direction of scrolling that meets or exceeds the minimum fling velocity along a scrollable axis.

If a nested scrolling parent is consuming motion as part of a pre-scroll, it may be appropriate for it to also consume the pre-fling to complete that same motion. By returning true from this method, the parent indicates that the child should not fling its own internal content as well.

onNestedPreScroll

static fun onNestedPreScroll(
    parent: ViewParent!, 
    target: View!, 
    dx: Int, 
    dy: Int, 
    consumed: IntArray!
): Unit

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

This version of the method just calls onNestedPreScroll(ViewParent, View, int, int, int[], int) using the touch input type.

onNestedPreScroll

static fun onNestedPreScroll(
    parent: ViewParent!, 
    target: View!, 
    dx: Int, 
    dy: Int, 
    consumed: IntArray!, 
    type: Int
): Unit

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 ViewCompat#dispatchNestedPreScroll(View, 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.

onNestedScroll

static fun onNestedScroll(
    parent: ViewParent!, 
    target: View!, 
    dxConsumed: Int, 
    dyConsumed: Int, 
    dxUnconsumed: Int, 
    dyUnconsumed: Int
): Unit

React to a nested scroll in progress.

This version of the method just calls onNestedScroll(ViewParent, View, int, int, int, int, int) using the touch input type.

onNestedScroll

static fun onNestedScroll(
    parent: ViewParent!, 
    target: View!, 
    dxConsumed: Int, 
    dyConsumed: Int, 
    dxUnconsumed: Int, 
    dyUnconsumed: Int, 
    type: Int
): Unit

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(ViewParent, 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.

onNestedScroll

static fun onNestedScroll(
    parent: ViewParent!, 
    target: View!, 
    dxConsumed: Int, 
    dyConsumed: Int, 
    dxUnconsumed: Int, 
    dyUnconsumed: Int, 
    type: Int, 
    @NonNull consumed: IntArray
): Unit

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(ViewParent, 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.

onNestedScrollAccepted

static fun onNestedScrollAccepted(
    parent: ViewParent!, 
    child: View!, 
    target: View!, 
    nestedScrollAxes: Int
): Unit

React to the successful claiming of a nested scroll operation.

This version of the method just calls onNestedScrollAccepted(ViewParent, View, View, int, int) using the touch input type.

onNestedScrollAccepted

static fun onNestedScrollAccepted(
    parent: ViewParent!, 
    child: View!, 
    target: View!, 
    nestedScrollAxes: Int, 
    type: Int
): Unit

React to the successful claiming of a nested scroll operation.

This method will be called after onStartNestedScroll 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.