added in version 22.2.0
belongs to Maven artifact com.android.support:design:27.1.0

AppBarLayout.Behavior

public static class AppBarLayout.Behavior
extends Behavior<V extends View>

java.lang.Object
↳	android.support.design.widget.CoordinatorLayout.Behavior<V extends android.view.View>
	↳	android.support.design.widget.AppBarLayout.Behavior

The default AppBarLayout.Behavior for AppBarLayout. Implements the necessary nested scroll handling with offsetting.

Summary

Nested classes
`class`	`AppBarLayout.Behavior.DragCallback` Callback to allow control over any `AppBarLayout` dragging.
`class`	`AppBarLayout.Behavior.SavedState`

Public constructors
`AppBarLayout.Behavior()`
`AppBarLayout.Behavior(Context context, AttributeSet attrs)`

Public methods
`int`	`getLeftAndRightOffset()`
`int`	`getTopAndBottomOffset()`
`boolean`	`onInterceptTouchEvent(CoordinatorLayout parent, V child, MotionEvent ev)` Respond to CoordinatorLayout touch events before they are dispatched to child views.
`boolean`	`onLayoutChild(CoordinatorLayout parent, V child, int layoutDirection)` Called when the parent CoordinatorLayout is about the lay out the given child view.
`boolean`	`onLayoutChild(CoordinatorLayout parent, AppBarLayout abl, int layoutDirection)` Called when the parent CoordinatorLayout is about the lay out the given child view.
`boolean`	`onMeasureChild(CoordinatorLayout parent, AppBarLayout child, int parentWidthMeasureSpec, int widthUsed, int parentHeightMeasureSpec, int heightUsed)` Called when the parent CoordinatorLayout is about to measure the given child view.
`void`	`onNestedPreScroll(CoordinatorLayout coordinatorLayout, AppBarLayout child, View target, int dx, int dy, int[] consumed, int type)` Called when a nested scroll in progress is about to update, before the target has consumed any of the scrolled distance.
`void`	`onNestedScroll(CoordinatorLayout coordinatorLayout, AppBarLayout child, View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed, int type)` Called when a nested scroll in progress has updated and the target has scrolled or attempted to scroll.
`void`	`onRestoreInstanceState(CoordinatorLayout parent, AppBarLayout appBarLayout, Parcelable state)` Hook allowing a behavior to re-apply a representation of its internal state that had previously been generated by `onSaveInstanceState(CoordinatorLayout, V)`.
`Parcelable`	`onSaveInstanceState(CoordinatorLayout parent, AppBarLayout abl)` Hook allowing a behavior to generate a representation of its internal state that can later be used to create a new instance with that same state.
`boolean`	`onStartNestedScroll(CoordinatorLayout parent, AppBarLayout child, View directTargetChild, View target, int nestedScrollAxes, int type)` Called when a descendant of the CoordinatorLayout attempts to initiate a nested scroll.
`void`	`onStopNestedScroll(CoordinatorLayout coordinatorLayout, AppBarLayout abl, View target, int type)` Called when a nested scroll has ended.
`boolean`	`onTouchEvent(CoordinatorLayout parent, V child, MotionEvent ev)` Respond to CoordinatorLayout touch events after this Behavior has started `intercepting` them.
`void`	`setDragCallback(AppBarLayout.Behavior.DragCallback callback)` Set a callback to control any `AppBarLayout` dragging.
`boolean`	`setLeftAndRightOffset(int offset)`
`boolean`	`setTopAndBottomOffset(int offset)`

Protected methods
`void`	`layoutChild(CoordinatorLayout parent, V child, int layoutDirection)`

Inherited methods

From class


  
    android.support.design.widget.CoordinatorLayout.Behavior

`boolean`	`blocksInteractionBelow(CoordinatorLayout parent, V child)` Determine whether interaction with views behind the given child in the child order should be blocked.
`boolean`	`getInsetDodgeRect(CoordinatorLayout parent, V child, Rect rect)` Called when a view is set to dodge view insets.
`int`	`getScrimColor(CoordinatorLayout parent, V child)` Supply a scrim color that will be painted behind the associated child view.
`float`	`getScrimOpacity(CoordinatorLayout parent, V child)` Determine the current opacity of the scrim behind a given child view A scrim may be used to indicate that the other elements beneath it are not currently interactive or actionable, drawing user focus and attention to the views above the scrim.
`static Object`	`getTag(View child)` Get the behavior-specific tag object with the given child view.
`boolean`	`layoutDependsOn(CoordinatorLayout parent, V child, View dependency)` Determine whether the supplied child view has another specific sibling view as a layout dependency.
`WindowInsetsCompat`	`onApplyWindowInsets(CoordinatorLayout coordinatorLayout, V child, WindowInsetsCompat insets)` Called when the window insets have changed.
`void`	`onAttachedToLayoutParams(CoordinatorLayout.LayoutParams params)` Called when the Behavior has been attached to a LayoutParams instance.
`boolean`	`onDependentViewChanged(CoordinatorLayout parent, V child, View dependency)` Respond to a change in a child's dependent view This method is called whenever a dependent view changes in size or position outside of the standard layout flow.
`void`	`onDependentViewRemoved(CoordinatorLayout parent, V child, View dependency)` Respond to a child's dependent view being removed.
`void`	`onDetachedFromLayoutParams()` Called when the Behavior has been detached from its holding LayoutParams instance.
`boolean`	`onInterceptTouchEvent(CoordinatorLayout parent, V child, MotionEvent ev)` Respond to CoordinatorLayout touch events before they are dispatched to child views.
`boolean`	`onLayoutChild(CoordinatorLayout parent, V child, int layoutDirection)` Called when the parent CoordinatorLayout is about the lay out the given child view.
`boolean`	`onMeasureChild(CoordinatorLayout parent, V child, int parentWidthMeasureSpec, int widthUsed, int parentHeightMeasureSpec, int heightUsed)` Called when the parent CoordinatorLayout is about to measure the given child view.
`boolean`	`onNestedFling(CoordinatorLayout coordinatorLayout, V child, View target, float velocityX, float velocityY, boolean consumed)` Called when a nested scrolling child is starting a fling or an action that would be a fling.
`boolean`	`onNestedPreFling(CoordinatorLayout coordinatorLayout, V child, View target, float velocityX, float velocityY)` Called when a nested scrolling child is about to start a fling.
`void`	`onNestedPreScroll(CoordinatorLayout coordinatorLayout, V child, View target, int dx, int dy, int[] consumed)` This method was deprecated in API level 26.1.0. You should now override `onNestedPreScroll(CoordinatorLayout, View, View, int, int, int[], int)`. This method will still continue to be called if the type is `TYPE_TOUCH`.
`void`	`onNestedPreScroll(CoordinatorLayout coordinatorLayout, V child, View target, int dx, int dy, int[] consumed, int type)` Called when a nested scroll in progress is about to update, before the target has consumed any of the scrolled distance.
`void`	`onNestedScroll(CoordinatorLayout coordinatorLayout, V child, View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed)` This method was deprecated in API level 26.1.0. You should now override `onNestedScroll(CoordinatorLayout, View, View, int, int, int, int, int)`. This method will still continue to be called if the type is `TYPE_TOUCH`.
`void`	`onNestedScroll(CoordinatorLayout coordinatorLayout, V child, View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed, int type)` Called when a nested scroll in progress has updated and the target has scrolled or attempted to scroll.
`void`	`onNestedScrollAccepted(CoordinatorLayout coordinatorLayout, V child, View directTargetChild, View target, int axes, int type)` Called when a nested scroll has been accepted by the CoordinatorLayout.
`void`	`onNestedScrollAccepted(CoordinatorLayout coordinatorLayout, V child, View directTargetChild, View target, int axes)` This method was deprecated in API level 26.1.0. You should now override `onNestedScrollAccepted(CoordinatorLayout, View, View, View, int, int)`. This method will still continue to be called if the type is `TYPE_TOUCH`.
`boolean`	`onRequestChildRectangleOnScreen(CoordinatorLayout coordinatorLayout, V child, Rect rectangle, boolean immediate)` Called when a child of the view associated with this behavior wants a particular rectangle to be positioned onto the screen.
`void`	`onRestoreInstanceState(CoordinatorLayout parent, V child, Parcelable state)` Hook allowing a behavior to re-apply a representation of its internal state that had previously been generated by `onSaveInstanceState(CoordinatorLayout, V)`.
`Parcelable`	`onSaveInstanceState(CoordinatorLayout parent, V child)` Hook allowing a behavior to generate a representation of its internal state that can later be used to create a new instance with that same state.
`boolean`	`onStartNestedScroll(CoordinatorLayout coordinatorLayout, V child, View directTargetChild, View target, int axes)` This method was deprecated in API level 26.1.0. You should now override `onStartNestedScroll(CoordinatorLayout, View, View, View, int, int)`. This method will still continue to be called if the type is `TYPE_TOUCH`.
`boolean`	`onStartNestedScroll(CoordinatorLayout coordinatorLayout, V child, View directTargetChild, View target, int axes, int type)` Called when a descendant of the CoordinatorLayout attempts to initiate a nested scroll.
`void`	`onStopNestedScroll(CoordinatorLayout coordinatorLayout, V child, View target)` This method was deprecated in API level 26.1.0. You should now override `onStopNestedScroll(CoordinatorLayout, View, View, int)`. This method will still continue to be called if the type is `TYPE_TOUCH`.
`void`	`onStopNestedScroll(CoordinatorLayout coordinatorLayout, V child, View target, int type)` Called when a nested scroll has ended.
`boolean`	`onTouchEvent(CoordinatorLayout parent, V child, MotionEvent ev)` Respond to CoordinatorLayout touch events after this Behavior has started `intercepting` them.
`static void`	`setTag(View child, Object tag)` Associate a Behavior-specific tag object with the given child view.

From class


  
    java.lang.Object

Public constructors

AppBarLayout.Behavior

added in version 22.2.0

AppBarLayout.Behavior ()

AppBarLayout.Behavior

added in version 22.2.0

AppBarLayout.Behavior (Context context, 
                AttributeSet attrs)

Parameters
`context`	`Context`
`attrs`	`AttributeSet`

Public methods

getLeftAndRightOffset

added in version 22.2.0

int getLeftAndRightOffset ()

Returns
`int`

getTopAndBottomOffset

added in version 22.2.0

int getTopAndBottomOffset ()

Returns
`int`

onInterceptTouchEvent

boolean onInterceptTouchEvent (CoordinatorLayout parent, 
                V child, 
                MotionEvent ev)

Respond to CoordinatorLayout touch events before they are dispatched to child views.

Behaviors can use this to monitor inbound touch events until one decides to intercept the rest of the event stream to take an action on its associated child view. This method will return false until it detects the proper intercept conditions, then return true once those conditions have occurred.

Once a Behavior intercepts touch events, the rest of the event stream will be sent to the onTouchEvent(CoordinatorLayout, V, MotionEvent) method.

This method will be called regardless of the visibility of the associated child of the behavior. If you only wish to handle touch events when the child is visible, you should add a check to isShown() on the given child.

The default implementation of this method always returns false.

Parameters
`parent`	`CoordinatorLayout`: the parent view currently receiving this touch event
`child`	`V`: the child view associated with this Behavior
`ev`	`MotionEvent`: the MotionEvent describing the touch event being processed

Returns
`boolean`	true if this Behavior would like to intercept and take over the event stream. The default always returns false.

onLayoutChild

boolean onLayoutChild (CoordinatorLayout parent, 
                V child, 
                int layoutDirection)

Called when the parent CoordinatorLayout is about the lay out the given child view.

This method can be used to perform custom or modified layout of a child view in place of the default child layout behavior. The Behavior's implementation can delegate to the standard CoordinatorLayout measurement behavior by calling parent.onLayoutChild.

If a Behavior implements onDependentViewChanged(CoordinatorLayout, View, View) to change the position of a view in response to a dependent view changing, it should also implement onLayoutChild in such a way that respects those dependent views. onLayoutChild will always be called for a dependent view after its dependency has been laid out.

Parameters
`parent`	`CoordinatorLayout`: the parent CoordinatorLayout
`child`	`V`: child view to lay out
`layoutDirection`	`int`: the resolved layout direction for the CoordinatorLayout, such as `LAYOUT_DIRECTION_LTR` or `LAYOUT_DIRECTION_RTL`.

Returns
`boolean`	true if the Behavior performed layout of the child view, false to request default layout behavior

onLayoutChild

added in version 22.2.0

boolean onLayoutChild (CoordinatorLayout parent, 
                AppBarLayout abl, 
                int layoutDirection)

Called when the parent CoordinatorLayout is about the lay out the given child view.

Parameters
`parent`	`CoordinatorLayout`: the parent CoordinatorLayout
`abl`	`AppBarLayout`: child view to lay out
`layoutDirection`	`int`: the resolved layout direction for the CoordinatorLayout, such as `LAYOUT_DIRECTION_LTR` or `LAYOUT_DIRECTION_RTL`.

Returns
`boolean`	true if the Behavior performed layout of the child view, false to request default layout behavior

onMeasureChild

added in version 23.4.0

boolean onMeasureChild (CoordinatorLayout parent, 
                AppBarLayout child, 
                int parentWidthMeasureSpec, 
                int widthUsed, 
                int parentHeightMeasureSpec, 
                int heightUsed)

Called when the parent CoordinatorLayout is about to measure the given child view.

This method can be used to perform custom or modified measurement of a child view in place of the default child measurement behavior. The Behavior's implementation can delegate to the standard CoordinatorLayout measurement behavior by calling parent.onMeasureChild.

Parameters
`parent`	`CoordinatorLayout`: the parent CoordinatorLayout
`child`	`AppBarLayout`: the child to measure
`parentWidthMeasureSpec`	`int`: the width requirements for this view
`widthUsed`	`int`: extra space that has been used up by the parent horizontally (possibly by other children of the parent)
`parentHeightMeasureSpec`	`int`: the height requirements for this view
`heightUsed`	`int`: extra space that has been used up by the parent vertically (possibly by other children of the parent)

Returns
`boolean`	true if the Behavior measured the child view, false if the CoordinatorLayout should perform its default measurement

onNestedPreScroll

added in version 26.1.0

void onNestedPreScroll (CoordinatorLayout coordinatorLayout, 
                AppBarLayout child, 
                View target, 
                int dx, 
                int dy, 
                int[] consumed, 
                int type)

Called when a nested scroll in progress is about to update, before the target has consumed any of the scrolled distance.

Any Behavior associated with the direct child of the CoordinatorLayout may elect to accept the nested scroll as part of onStartNestedScroll(CoordinatorLayout, V, View, View, int). Each Behavior that returned true will receive subsequent nested scroll events for that nested scroll.

onNestedPreScroll is called each time the nested scroll is updated by the nested scrolling child, before the nested scrolling child has consumed the scroll distance itself. Each Behavior responding to the nested scroll will receive the same values. The CoordinatorLayout will report as consumed the maximum number of pixels in either direction that any Behavior responding to the nested scroll reported as consumed.

Parameters
`coordinatorLayout`	`CoordinatorLayout`: the CoordinatorLayout parent of the view this Behavior is associated with
`child`	`AppBarLayout`: the child view of the CoordinatorLayout this Behavior is associated with
`target`	`View`: the descendant view of the CoordinatorLayout performing the nested scroll
`dx`	`int`: the raw horizontal number of pixels that the user attempted to scroll
`dy`	`int`: the raw vertical number of pixels that the user attempted to scroll
`consumed`	`int`: out parameter. consumed[0] should be set to the distance of dx that was consumed, consumed[1] should be set to the distance of dy that was consumed
`type`	`int`: the type of input which cause this scroll event

onNestedScroll

added in version 26.1.0

void onNestedScroll (CoordinatorLayout coordinatorLayout, 
                AppBarLayout child, 
                View target, 
                int dxConsumed, 
                int dyConsumed, 
                int dxUnconsumed, 
                int dyUnconsumed, 
                int type)

Called when a nested scroll in progress has updated and the target has scrolled or attempted to scroll.

onNestedScroll is called each time the nested scroll is updated by the nested scrolling child, with both consumed and unconsumed components of the scroll supplied in pixels. Each Behavior responding to the nested scroll will receive the same values.

Parameters
`coordinatorLayout`	`CoordinatorLayout`: the CoordinatorLayout parent of the view this Behavior is associated with
`child`	`AppBarLayout`: the child view of the CoordinatorLayout this Behavior is associated with
`target`	`View`: the descendant view of the CoordinatorLayout performing the nested scroll
`dxConsumed`	`int`: horizontal pixels consumed by the target's own scrolling operation
`dyConsumed`	`int`: vertical pixels consumed by the target's own scrolling operation
`dxUnconsumed`	`int`: horizontal pixels not consumed by the target's own scrolling operation, but requested by the user
`dyUnconsumed`	`int`: vertical pixels not consumed by the target's own scrolling operation, but requested by the user
`type`	`int`: the type of input which cause this scroll event

onRestoreInstanceState

added in version 22.2.0

void onRestoreInstanceState (CoordinatorLayout parent, 
                AppBarLayout appBarLayout, 
                Parcelable state)

Hook allowing a behavior to re-apply a representation of its internal state that had previously been generated by onSaveInstanceState(CoordinatorLayout, V). This function will never be called with a null state.

Parameters
`parent`	`CoordinatorLayout`: the parent CoordinatorLayout
`appBarLayout`	`AppBarLayout`: child view to restore from
`state`	`Parcelable`: The frozen state that had previously been returned by `onSaveInstanceState(CoordinatorLayout, V)`.

onSaveInstanceState

added in version 22.2.0

Parcelable onSaveInstanceState (CoordinatorLayout parent, 
                AppBarLayout abl)

Hook allowing a behavior to generate a representation of its internal state that can later be used to create a new instance with that same state. This state should only contain information that is not persistent or can not be reconstructed later.

Behavior state is only saved when both the parent CoordinatorLayout and a view using this behavior have valid IDs set.

Parameters
`parent`	`CoordinatorLayout`: the parent CoordinatorLayout
`abl`	`AppBarLayout`: child view to restore from

Returns
`Parcelable`	Returns a Parcelable object containing the behavior's current dynamic state.

onStartNestedScroll

added in version 26.1.0

boolean onStartNestedScroll (CoordinatorLayout parent, 
                AppBarLayout child, 
                View directTargetChild, 
                View target, 
                int nestedScrollAxes, 
                int type)

Called when a descendant of the CoordinatorLayout attempts to initiate a nested scroll.

Any Behavior associated with any direct child of the CoordinatorLayout may respond to this event and return true to indicate that the CoordinatorLayout should act as a nested scrolling parent for this scroll. Only Behaviors that return true from this method will receive subsequent nested scroll events.

Parameters
`parent`	`CoordinatorLayout`: the CoordinatorLayout parent of the view this Behavior is associated with
`child`	`AppBarLayout`: the child view of the CoordinatorLayout this Behavior is associated with
`directTargetChild`	`View`: the child view of the CoordinatorLayout that either is or contains the target of the nested scroll operation
`target`	`View`: the descendant view of the CoordinatorLayout initiating the nested scroll
`nestedScrollAxes`	`int`: the axes that this nested scroll applies to. See `SCROLL_AXIS_HORIZONTAL`, `SCROLL_AXIS_VERTICAL`
`type`	`int`: the type of input which cause this scroll event

Returns
`boolean`	true if the Behavior wishes to accept this nested scroll

onStopNestedScroll

added in version 26.1.0

void onStopNestedScroll (CoordinatorLayout coordinatorLayout, 
                AppBarLayout abl, 
                View target, 
                int type)

Called when a nested scroll has ended.

Any Behavior associated with any direct child of the CoordinatorLayout may elect to accept the nested scroll as part of onStartNestedScroll(CoordinatorLayout, V, View, View, int). Each Behavior that returned true will receive subsequent nested scroll events for that nested scroll.

onStopNestedScroll marks the end of a single nested scroll event sequence. This is a good place to clean up any state related to the nested scroll.

Parameters
`coordinatorLayout`	`CoordinatorLayout`: the CoordinatorLayout parent of the view this Behavior is associated with
`abl`	`AppBarLayout`: the child view of the CoordinatorLayout this Behavior is associated with
`target`	`View`: the descendant view of the CoordinatorLayout that initiated the nested scroll
`type`	`int`: the type of input which cause this scroll event

onTouchEvent

boolean onTouchEvent (CoordinatorLayout parent, 
                V child, 
                MotionEvent ev)

Respond to CoordinatorLayout touch events after this Behavior has started intercepting them.

Behaviors may intercept touch events in order to help the CoordinatorLayout manipulate its child views. For example, a Behavior may allow a user to drag a UI pane open or closed. This method should perform actual mutations of view layout state.

Parameters
`parent`	`CoordinatorLayout`: the parent view currently receiving this touch event
`child`	`V`: the child view associated with this Behavior
`ev`	`MotionEvent`: the MotionEvent describing the touch event being processed

Returns
`boolean`	true if this Behavior handled this touch event and would like to continue receiving events in this stream. The default always returns false.

setDragCallback

added in version 23.4.0

void setDragCallback (AppBarLayout.Behavior.DragCallback callback)

Set a callback to control any AppBarLayout dragging.

Parameters
`callback`	`AppBarLayout.Behavior.DragCallback`: the callback to use, or `null` to use the default behavior.

setLeftAndRightOffset

added in version 22.2.0

boolean setLeftAndRightOffset (int offset)

Parameters
`offset`	`int`

Returns
`boolean`

setTopAndBottomOffset

added in version 22.2.0

boolean setTopAndBottomOffset (int offset)

Parameters
`offset`	`int`

Returns
`boolean`

Protected methods

layoutChild

void layoutChild (CoordinatorLayout parent, 
                V child, 
                int layoutDirection)

Parameters
`parent`	`CoordinatorLayout`
`child`	`V`
`layoutDirection`	`int`

AppBarLayout.Behavior

Summary

Nested classes

Public constructors

Public methods

Protected methods

Inherited methods

Public constructors

AppBarLayout.Behavior

AppBarLayout.Behavior

Public methods

getLeftAndRightOffset

getTopAndBottomOffset

onInterceptTouchEvent

onLayoutChild

onLayoutChild

onMeasureChild

onNestedPreScroll

onNestedScroll

onRestoreInstanceState

onSaveInstanceState

onStartNestedScroll

onStopNestedScroll

onTouchEvent

setDragCallback

setLeftAndRightOffset

setTopAndBottomOffset

Protected methods

layoutChild

Annotations

Interfaces

Classes