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RecyclerView.LayoutManager

public static abstract class RecyclerView.LayoutManager
extends Object

java.lang.Object
↳	android.support.v7.widget.RecyclerView.LayoutManager

Known Direct Subclasses

LinearLayoutManager, StaggeredGridLayoutManager

Known Indirect Subclasses

GridLayoutManager

A LayoutManager is responsible for measuring and positioning item views within a RecyclerView as well as determining the policy for when to recycle item views that are no longer visible to the user. By changing the LayoutManager a RecyclerView can be used to implement a standard vertically scrolling list, a uniform grid, staggered grids, horizontally scrolling collections and more. Several stock layout managers are provided for general use.

If the LayoutManager specifies a default constructor or one with the signature (Context, AttributeSet, int, int), RecyclerView will instantiate and set the LayoutManager when being inflated. Most used properties can be then obtained from getProperties(Context, AttributeSet, int, int). In case a LayoutManager specifies both constructors, the non-default constructor will take precedence.

Summary

Nested classes
`class`	`RecyclerView.LayoutManager.Properties` Some general properties that a LayoutManager may want to use.

XML attributes
`android.support.v7.recyclerview:reverseLayout`
`android.support.v7.recyclerview:spanCount`
`android.support.v7.recyclerview:stackFromEnd`
`android:orientation`

Public constructors
`RecyclerView.LayoutManager()`

Public methods
`void`	`addDisappearingView(View child, int index)` To be called only during `onLayoutChildren(Recycler, State)` to add a view to the layout that is known to be going away, either because it has been `removed` or because it is actually not in the visible portion of the container but is being laid out in order to inform RecyclerView in how to animate the item out of view.
`void`	`addDisappearingView(View child)` To be called only during `onLayoutChildren(Recycler, State)` to add a view to the layout that is known to be going away, either because it has been `removed` or because it is actually not in the visible portion of the container but is being laid out in order to inform RecyclerView in how to animate the item out of view.
`void`	`addView(View child, int index)` Add a view to the currently attached RecyclerView if needed.
`void`	`addView(View child)` Add a view to the currently attached RecyclerView if needed.
`void`	`assertInLayoutOrScroll(String message)` Checks if RecyclerView is in the middle of a layout or scroll and throws an `IllegalStateException` if it is not.
`void`	`assertNotInLayoutOrScroll(String message)` Checks if RecyclerView is in the middle of a layout or scroll and throws an `IllegalStateException` if it is.
`void`	`attachView(View child)` Reattach a previously `detached` view.
`void`	`attachView(View child, int index)` Reattach a previously `detached` view.
`void`	`attachView(View child, int index, RecyclerView.LayoutParams lp)` Reattach a previously `detached` view.
`void`	`calculateItemDecorationsForChild(View child, Rect outRect)` Calculates the item decor insets applied to the given child and updates the provided Rect instance with the inset values.
`boolean`	`canScrollHorizontally()` Query if horizontal scrolling is currently supported.
`boolean`	`canScrollVertically()` Query if vertical scrolling is currently supported.
`boolean`	`checkLayoutParams(RecyclerView.LayoutParams lp)` Determines the validity of the supplied LayoutParams object.
`static int`	`chooseSize(int spec, int desired, int min)` Chooses a size from the given specs and parameters that is closest to the desired size and also complies with the spec.
`int`	`computeHorizontalScrollExtent(RecyclerView.State state)` Override this method if you want to support scroll bars.
`int`	`computeHorizontalScrollOffset(RecyclerView.State state)` Override this method if you want to support scroll bars.
`int`	`computeHorizontalScrollRange(RecyclerView.State state)` Override this method if you want to support scroll bars.
`int`	`computeVerticalScrollExtent(RecyclerView.State state)` Override this method if you want to support scroll bars.
`int`	`computeVerticalScrollOffset(RecyclerView.State state)` Override this method if you want to support scroll bars.
`int`	`computeVerticalScrollRange(RecyclerView.State state)` Override this method if you want to support scroll bars.
`void`	`detachAndScrapAttachedViews(RecyclerView.Recycler recycler)` Temporarily detach and scrap all currently attached child views.
`void`	`detachAndScrapView(View child, RecyclerView.Recycler recycler)` Detach a child view and add it to a `Recycler's` scrap heap.
`void`	`detachAndScrapViewAt(int index, RecyclerView.Recycler recycler)` Detach a child view and add it to a `Recycler's` scrap heap.
`void`	`detachView(View child)` Temporarily detach a child view.
`void`	`detachViewAt(int index)` Temporarily detach a child view.
`void`	`endAnimation(View view)` Ends all animations on the view created by the `RecyclerView.ItemAnimator`.
`View`	`findContainingItemView(View view)` Traverses the ancestors of the given view and returns the item view that contains it and also a direct child of the LayoutManager.
`View`	`findViewByPosition(int position)` Finds the view which represents the given adapter position.
`abstract RecyclerView.LayoutParams`	`generateDefaultLayoutParams()` Create a default `LayoutParams` object for a child of the RecyclerView.
`RecyclerView.LayoutParams`	`generateLayoutParams(Context c, AttributeSet attrs)` Create a LayoutParams object suitable for this LayoutManager from an inflated layout resource.
`RecyclerView.LayoutParams`	`generateLayoutParams(ViewGroup.LayoutParams lp)` Create a LayoutParams object suitable for this LayoutManager, copying relevant values from the supplied LayoutParams object if possible.
`int`	`getBaseline()` Returns offset of the RecyclerView's text baseline from the its top boundary.
`int`	`getBottomDecorationHeight(View child)` Returns the total height of item decorations applied to child's bottom.
`View`	`getChildAt(int index)` Return the child view at the given index
`int`	`getChildCount()` Return the current number of child views attached to the parent RecyclerView.
`static int`	`getChildMeasureSpec(int parentSize, int parentMode, int padding, int childDimension, boolean canScroll)` Calculate a MeasureSpec value for measuring a child view in one dimension.
`static int`	`getChildMeasureSpec(int parentSize, int padding, int childDimension, boolean canScroll)` This method is deprecated. use `getChildMeasureSpec(int, int, int, int, boolean)`
`boolean`	`getClipToPadding()` Check if the RecyclerView is configured to clip child views to its padding.
`int`	`getColumnCountForAccessibility(RecyclerView.Recycler recycler, RecyclerView.State state)` Returns the number of columns for accessibility.
`int`	`getDecoratedBottom(View child)` Returns the bottom edge of the given child view within its parent, offset by any applied `ItemDecorations`.
`void`	`getDecoratedBoundsWithMargins(View view, Rect outBounds)` Returns the bounds of the view including its decoration and margins.
`int`	`getDecoratedLeft(View child)` Returns the left edge of the given child view within its parent, offset by any applied `ItemDecorations`.
`int`	`getDecoratedMeasuredHeight(View child)` Returns the measured height of the given child, plus the additional size of any insets applied by `ItemDecorations`.
`int`	`getDecoratedMeasuredWidth(View child)` Returns the measured width of the given child, plus the additional size of any insets applied by `ItemDecorations`.
`int`	`getDecoratedRight(View child)` Returns the right edge of the given child view within its parent, offset by any applied `ItemDecorations`.
`int`	`getDecoratedTop(View child)` Returns the top edge of the given child view within its parent, offset by any applied `ItemDecorations`.
`View`	`getFocusedChild()` Returns the item View which has or contains focus.
`int`	`getHeight()` Return the height of the parent RecyclerView
`int`	`getHeightMode()` Return the height measurement spec mode of the RecyclerView.
`int`	`getItemCount()` Returns the number of items in the adapter bound to the parent RecyclerView.
`int`	`getItemViewType(View view)` Returns the View type defined by the adapter.
`int`	`getLayoutDirection()` Returns the resolved layout direction for this RecyclerView.
`int`	`getLeftDecorationWidth(View child)` Returns the total width of item decorations applied to child's left.
`int`	`getMinimumHeight()`
`int`	`getMinimumWidth()`
`int`	`getPaddingBottom()` Return the bottom padding of the parent RecyclerView
`int`	`getPaddingEnd()` Return the end padding of the parent RecyclerView
`int`	`getPaddingLeft()` Return the left padding of the parent RecyclerView
`int`	`getPaddingRight()` Return the right padding of the parent RecyclerView
`int`	`getPaddingStart()` Return the start padding of the parent RecyclerView
`int`	`getPaddingTop()` Return the top padding of the parent RecyclerView
`int`	`getPosition(View view)` Returns the adapter position of the item represented by the given View.
`static RecyclerView.LayoutManager.Properties`	`getProperties(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes)` Parse the xml attributes to get the most common properties used by layout managers.
`int`	`getRightDecorationWidth(View child)` Returns the total width of item decorations applied to child's right.
`int`	`getRowCountForAccessibility(RecyclerView.Recycler recycler, RecyclerView.State state)` Returns the number of rows for accessibility.
`int`	`getSelectionModeForAccessibility(RecyclerView.Recycler recycler, RecyclerView.State state)` Returns the selection mode for accessibility.
`int`	`getTopDecorationHeight(View child)` Returns the total height of item decorations applied to child's top.
`void`	`getTransformedBoundingBox(View child, boolean includeDecorInsets, Rect out)` Calculates the bounding box of the View while taking into account its matrix changes (translation, scale etc) with respect to the RecyclerView.
`int`	`getWidth()` Return the width of the parent RecyclerView
`int`	`getWidthMode()` Return the width measurement spec mode of the RecyclerView.
`boolean`	`hasFocus()` Returns true if the RecyclerView this LayoutManager is bound to has or contains focus.
`void`	`ignoreView(View view)` Flags a view so that it will not be scrapped or recycled.
`boolean`	`isAttachedToWindow()` Returns whether LayoutManager is currently attached to a RecyclerView which is attached to a window.
`boolean`	`isAutoMeasureEnabled()` Returns whether the LayoutManager uses the automatic measurement API or not.
`boolean`	`isFocused()` Returns true if the RecyclerView this LayoutManager is bound to has focus.
`boolean`	`isLayoutHierarchical(RecyclerView.Recycler recycler, RecyclerView.State state)` Returns whether layout is hierarchical or not to be used for accessibility.
`boolean`	`isMeasurementCacheEnabled()` In addition to the View Framework's measurement cache, RecyclerView uses its own additional measurement cache for its children to avoid re-measuring them when not necessary.
`boolean`	`isSmoothScrolling()`
`void`	`layoutDecorated(View child, int left, int top, int right, int bottom)` Lay out the given child view within the RecyclerView using coordinates that include any current `ItemDecorations`.
`void`	`layoutDecoratedWithMargins(View child, int left, int top, int right, int bottom)` Lay out the given child view within the RecyclerView using coordinates that include any current `ItemDecorations` and margins.
`void`	`measureChild(View child, int widthUsed, int heightUsed)` Measure a child view using standard measurement policy, taking the padding of the parent RecyclerView and any added item decorations into account.
`void`	`measureChildWithMargins(View child, int widthUsed, int heightUsed)` Measure a child view using standard measurement policy, taking the padding of the parent RecyclerView, any added item decorations and the child margins into account.
`void`	`moveView(int fromIndex, int toIndex)` Moves a View from one position to another.
`void`	`offsetChildrenHorizontal(int dx)` Offset all child views attached to the parent RecyclerView by dx pixels along the horizontal axis.
`void`	`offsetChildrenVertical(int dy)` Offset all child views attached to the parent RecyclerView by dy pixels along the vertical axis.
`void`	`onAdapterChanged(Adapter oldAdapter, Adapter newAdapter)` Called if the RecyclerView this LayoutManager is bound to has a different adapter set.
`boolean`	`onAddFocusables(RecyclerView recyclerView, ArrayList<View> views, int direction, int focusableMode)` Called to populate focusable views within the RecyclerView.
`void`	`onAttachedToWindow(RecyclerView view)` Called when this LayoutManager is both attached to a RecyclerView and that RecyclerView is attached to a window.
`void`	`onDetachedFromWindow(RecyclerView view, RecyclerView.Recycler recycler)` Called when this LayoutManager is detached from its parent RecyclerView or when its parent RecyclerView is detached from its window.
`void`	`onDetachedFromWindow(RecyclerView view)` This method is deprecated. override `onDetachedFromWindow(RecyclerView, Recycler)`
`View`	`onFocusSearchFailed(View focused, int direction, RecyclerView.Recycler recycler, RecyclerView.State state)` Called when searching for a focusable view in the given direction has failed for the current content of the RecyclerView.
`void`	`onInitializeAccessibilityEvent(AccessibilityEvent event)`
`void`	`onInitializeAccessibilityEvent(RecyclerView.Recycler recycler, RecyclerView.State state, AccessibilityEvent event)` Called by the accessibility delegate to initialize an accessibility event.
`void`	`onInitializeAccessibilityNodeInfo(RecyclerView.Recycler recycler, RecyclerView.State state, AccessibilityNodeInfoCompat info)` Called by the AccessibilityDelegate when the information about the current layout should be populated.
`void`	`onInitializeAccessibilityNodeInfoForItem(RecyclerView.Recycler recycler, RecyclerView.State state, View host, AccessibilityNodeInfoCompat info)` Called by the AccessibilityDelegate when the accessibility information for a specific item should be populated.
`View`	`onInterceptFocusSearch(View focused, int direction)` This method gives a LayoutManager an opportunity to intercept the initial focus search before the default behavior of `FocusFinder` is used.
`void`	`onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount)` Called when items have been added to the adapter.
`void`	`onItemsChanged(RecyclerView recyclerView)` Called when `notifyDataSetChanged()` is triggered instead of giving detailed information on what has actually changed.
`void`	`onItemsMoved(RecyclerView recyclerView, int from, int to, int itemCount)` Called when an item is moved withing the adapter.
`void`	`onItemsRemoved(RecyclerView recyclerView, int positionStart, int itemCount)` Called when items have been removed from the adapter.
`void`	`onItemsUpdated(RecyclerView recyclerView, int positionStart, int itemCount)` Called when items have been changed in the adapter.
`void`	`onItemsUpdated(RecyclerView recyclerView, int positionStart, int itemCount, Object payload)` Called when items have been changed in the adapter and with optional payload.
`void`	`onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state)` Lay out all relevant child views from the given adapter.
`void`	`onLayoutCompleted(RecyclerView.State state)` Called after a full layout calculation is finished.
`void`	`onMeasure(RecyclerView.Recycler recycler, RecyclerView.State state, int widthSpec, int heightSpec)` Measure the attached RecyclerView.
`boolean`	`onRequestChildFocus(RecyclerView parent, View child, View focused)` This method is deprecated. Use `onRequestChildFocus(RecyclerView, State, View, View)`
`boolean`	`onRequestChildFocus(RecyclerView parent, RecyclerView.State state, View child, View focused)` Called when a descendant view of the RecyclerView requests focus.
`void`	`onRestoreInstanceState(Parcelable state)`
`Parcelable`	`onSaveInstanceState()` Called when the LayoutManager should save its state.
`void`	`onScrollStateChanged(int state)` RecyclerView calls this method to notify LayoutManager that scroll state has changed.
`boolean`	`performAccessibilityAction(RecyclerView.Recycler recycler, RecyclerView.State state, int action, Bundle args)` Called by AccessibilityDelegate when an action is requested from the RecyclerView.
`boolean`	`performAccessibilityActionForItem(RecyclerView.Recycler recycler, RecyclerView.State state, View view, int action, Bundle args)` Called by AccessibilityDelegate when an accessibility action is requested on one of the children of LayoutManager.
`void`	`postOnAnimation(Runnable action)` Causes the Runnable to execute on the next animation time step.
`void`	`removeAllViews()` Remove all views from the currently attached RecyclerView.
`void`	`removeAndRecycleAllViews(RecyclerView.Recycler recycler)` Removes all views and recycles them using the given recycler.
`void`	`removeAndRecycleView(View child, RecyclerView.Recycler recycler)` Remove a child view and recycle it using the given Recycler.
`void`	`removeAndRecycleViewAt(int index, RecyclerView.Recycler recycler)` Remove a child view and recycle it using the given Recycler.
`boolean`	`removeCallbacks(Runnable action)` Removes the specified Runnable from the message queue.
`void`	`removeDetachedView(View child)` Finish removing a view that was previously temporarily `detached`.
`void`	`removeView(View child)` Remove a view from the currently attached RecyclerView if needed.
`void`	`removeViewAt(int index)` Remove a view from the currently attached RecyclerView if needed.
`boolean`	`requestChildRectangleOnScreen(RecyclerView parent, View child, Rect rect, boolean immediate)` Called when a child of the RecyclerView wants a particular rectangle to be positioned onto the screen.
`void`	`requestLayout()` Calls `RecyclerView#requestLayout` on the underlying RecyclerView
`void`	`requestSimpleAnimationsInNextLayout()` A LayoutManager can call this method to force RecyclerView to run simple animations in the next layout pass, even if there is not any trigger to do so.
`int`	`scrollHorizontallyBy(int dx, RecyclerView.Recycler recycler, RecyclerView.State state)` Scroll horizontally by dx pixels in screen coordinates and return the distance traveled.
`void`	`scrollToPosition(int position)` Scroll to the specified adapter position.
`int`	`scrollVerticallyBy(int dy, RecyclerView.Recycler recycler, RecyclerView.State state)` Scroll vertically by dy pixels in screen coordinates and return the distance traveled.
`void`	`setAutoMeasureEnabled(boolean enabled)` Defines whether the layout should be measured by the RecyclerView or the LayoutManager wants to handle the layout measurements itself.
`void`	`setMeasuredDimension(int widthSize, int heightSize)` `Set the measured dimensions` of the host RecyclerView.
`void`	`setMeasuredDimension(Rect childrenBounds, int wSpec, int hSpec)` Sets the measured dimensions from the given bounding box of the children and the measurement specs that were passed into `onMeasure(int, int)`.
`void`	`setMeasurementCacheEnabled(boolean measurementCacheEnabled)` Sets whether RecyclerView should use its own measurement cache for the children.
`void`	`smoothScrollToPosition(RecyclerView recyclerView, RecyclerView.State state, int position)` Smooth scroll to the specified adapter position.
`void`	`startSmoothScroll(RecyclerView.SmoothScroller smoothScroller)` Starts a smooth scroll using the provided SmoothScroller.
`void`	`stopIgnoringView(View view)` View can be scrapped and recycled again.
`boolean`	`supportsPredictiveItemAnimations()` Returns whether this LayoutManager supports automatic item animations.

Inherited methods

From class


  
    java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long millis, int nanos)` Causes the current thread to wait until another thread invokes the `notify()` method or the `notifyAll()` method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed.
`final void`	`wait(long millis)` Causes the current thread to wait until either another thread invokes the `notify()` method or the `notifyAll()` method for this object, or a specified amount of time has elapsed.
`final void`	`wait()` Causes the current thread to wait until another thread invokes the `notify()` method or the `notifyAll()` method for this object.

XML attributes

android.support.v7.recyclerview:reverseLayout

Related methods:

getProperties(Context,AttributeSet,int,int)

android.support.v7.recyclerview:spanCount

Related methods:

getProperties(Context,AttributeSet,int,int)

android.support.v7.recyclerview:stackFromEnd

Related methods:

getProperties(Context,AttributeSet,int,int)

android:orientation

Related methods:

getProperties(Context,AttributeSet,int,int)

Public constructors

RecyclerView.LayoutManager

RecyclerView.LayoutManager ()

Public methods

addDisappearingView

void addDisappearingView (View child, 
                int index)

To be called only during onLayoutChildren(Recycler, State) to add a view to the layout that is known to be going away, either because it has been removed or because it is actually not in the visible portion of the container but is being laid out in order to inform RecyclerView in how to animate the item out of view.

Views added via this method are going to be invisible to LayoutManager after the dispatchLayout pass is complete. They cannot be retrieved via getChildAt(int) or won't be included in getChildCount() method.

Parameters
`child`	`View`: View to add and then remove with animation.
`index`	`int`: Index of the view.

addDisappearingView

void addDisappearingView (View child)

Parameters
`child`	`View`: View to add and then remove with animation.

addView

void addView (View child, 
                int index)

Add a view to the currently attached RecyclerView if needed. LayoutManagers should use this method to add views obtained from a RecyclerView.Recycler using getViewForPosition(int).

Parameters
`child`	`View`: View to add
`index`	`int`: Index to add child at

addView

void addView (View child)

Add a view to the currently attached RecyclerView if needed. LayoutManagers should use this method to add views obtained from a RecyclerView.Recycler using getViewForPosition(int).

Parameters
`child`	`View`: View to add

assertInLayoutOrScroll

void assertInLayoutOrScroll (String message)

Checks if RecyclerView is in the middle of a layout or scroll and throws an IllegalStateException if it is not.

Parameters
`message`	`String`: The message for the exception. Can be null.

See also:

assertNotInLayoutOrScroll(String)

assertNotInLayoutOrScroll

void assertNotInLayoutOrScroll (String message)

Checks if RecyclerView is in the middle of a layout or scroll and throws an IllegalStateException if it is.

Parameters
`message`	`String`: The message for the exception. Can be null.

See also:

assertInLayoutOrScroll(String)

attachView

void attachView (View child)

Reattach a previously detached view. This method should not be used to reattach views that were previously detachAndScrapView(android.view.View, RecyclerView.Recycler) scrapped}.

Parameters
`child`	`View`: Child to reattach

attachView

void attachView (View child, 
                int index)

Reattach a previously detached view. This method should not be used to reattach views that were previously detachAndScrapView(android.view.View, RecyclerView.Recycler) scrapped}.

Parameters
`child`	`View`: Child to reattach
`index`	`int`: Intended child index for child

attachView

void attachView (View child, 
                int index, 
                RecyclerView.LayoutParams lp)

Reattach a previously detached view. This method should not be used to reattach views that were previously detachAndScrapView(android.view.View, RecyclerView.Recycler) scrapped}.

Parameters
`child`	`View`: Child to reattach
`index`	`int`: Intended child index for child
`lp`	`RecyclerView.LayoutParams`: LayoutParams for child

calculateItemDecorationsForChild

void calculateItemDecorationsForChild (View child, 
                Rect outRect)

Calculates the item decor insets applied to the given child and updates the provided Rect instance with the inset values.

The Rect's left is set to the total width of left decorations.
The Rect's top is set to the total height of top decorations.
The Rect's right is set to the total width of right decorations.
The Rect's bottom is set to total height of bottom decorations.

Note that item decorations are automatically calculated when one of the LayoutManager's measure child methods is called. If you need to measure the child with custom specs via measure(int, int), you can use this method to get decorations.

Parameters
`child`	`View`: The child view whose decorations should be calculated
`outRect`	`Rect`: The Rect to hold result values

canScrollHorizontally

boolean canScrollHorizontally ()

Query if horizontal scrolling is currently supported. The default implementation returns false.

Returns
`boolean`	True if this LayoutManager can scroll the current contents horizontally

canScrollVertically

boolean canScrollVertically ()

Query if vertical scrolling is currently supported. The default implementation returns false.

Returns
`boolean`	True if this LayoutManager can scroll the current contents vertically

checkLayoutParams

boolean checkLayoutParams (RecyclerView.LayoutParams lp)

Determines the validity of the supplied LayoutParams object.

This should check to make sure that the object is of the correct type and all values are within acceptable ranges. The default implementation returns true for non-null params.

Parameters
`lp`	`RecyclerView.LayoutParams`: LayoutParams object to check

Returns
`boolean`	true if this LayoutParams object is valid, false otherwise

chooseSize

int chooseSize (int spec, 
                int desired, 
                int min)

Chooses a size from the given specs and parameters that is closest to the desired size and also complies with the spec.

Parameters
`spec`	`int`: The measureSpec
`desired`	`int`: The preferred measurement
`min`	`int`: The minimum value

Returns
`int`	A size that fits to the given specs

computeHorizontalScrollExtent

int computeHorizontalScrollExtent (RecyclerView.State state)

Override this method if you want to support scroll bars.

Read computeHorizontalScrollExtent() for details.

Default implementation returns 0.

Parameters
`state`	`RecyclerView.State`: Current state of RecyclerView

Returns
`int`	The horizontal extent of the scrollbar's thumb

See also:

computeHorizontalScrollExtent()

computeHorizontalScrollOffset

int computeHorizontalScrollOffset (RecyclerView.State state)

Override this method if you want to support scroll bars.

Read computeHorizontalScrollOffset() for details.

Default implementation returns 0.

Parameters
`state`	`RecyclerView.State`: Current State of RecyclerView where you can find total item count

Returns
`int`	The horizontal offset of the scrollbar's thumb

See also:

computeHorizontalScrollOffset()

computeHorizontalScrollRange

int computeHorizontalScrollRange (RecyclerView.State state)

Override this method if you want to support scroll bars.

Read computeHorizontalScrollRange() for details.

Default implementation returns 0.

Parameters
`state`	`RecyclerView.State`: Current State of RecyclerView where you can find total item count

Returns
`int`	The total horizontal range represented by the vertical scrollbar

See also:

computeHorizontalScrollRange()

computeVerticalScrollExtent

int computeVerticalScrollExtent (RecyclerView.State state)

Override this method if you want to support scroll bars.

Read computeVerticalScrollExtent() for details.

Default implementation returns 0.

Parameters
`state`	`RecyclerView.State`: Current state of RecyclerView

Returns
`int`	The vertical extent of the scrollbar's thumb

See also:

computeVerticalScrollExtent()

computeVerticalScrollOffset

int computeVerticalScrollOffset (RecyclerView.State state)

Override this method if you want to support scroll bars.

Read computeVerticalScrollOffset() for details.

Default implementation returns 0.

Parameters
`state`	`RecyclerView.State`: Current State of RecyclerView where you can find total item count

Returns
`int`	The vertical offset of the scrollbar's thumb

See also:

computeVerticalScrollOffset()

computeVerticalScrollRange

int computeVerticalScrollRange (RecyclerView.State state)

Override this method if you want to support scroll bars.

Read computeVerticalScrollRange() for details.

Default implementation returns 0.

Parameters
`state`	`RecyclerView.State`: Current State of RecyclerView where you can find total item count

Returns
`int`	The total vertical range represented by the vertical scrollbar

See also:

computeVerticalScrollRange()

detachAndScrapAttachedViews

void detachAndScrapAttachedViews (RecyclerView.Recycler recycler)

Temporarily detach and scrap all currently attached child views. Views will be scrapped into the given Recycler. The Recycler may prefer to reuse scrap views before other views that were previously recycled.

Parameters
`recycler`	`RecyclerView.Recycler`: Recycler to scrap views into

detachAndScrapView

void detachAndScrapView (View child, 
                RecyclerView.Recycler recycler)

Detach a child view and add it to a Recycler's scrap heap.

Scrapping a view allows it to be rebound and reused to show updated or different data.

Parameters
`child`	`View`: Child to detach and scrap
`recycler`	`RecyclerView.Recycler`: Recycler to deposit the new scrap view into

detachAndScrapViewAt

void detachAndScrapViewAt (int index, 
                RecyclerView.Recycler recycler)

Detach a child view and add it to a Recycler's scrap heap.

Scrapping a view allows it to be rebound and reused to show updated or different data.

Parameters
`index`	`int`: Index of child to detach and scrap
`recycler`	`RecyclerView.Recycler`: Recycler to deposit the new scrap view into

detachView

void detachView (View child)

Temporarily detach a child view.

LayoutManagers may want to perform a lightweight detach operation to rearrange views currently attached to the RecyclerView. Generally LayoutManager implementations will want to use detachAndScrapView(android.view.View, RecyclerView.Recycler) so that the detached view may be rebound and reused.

If a LayoutManager uses this method to detach a view, it must reattach or fully remove the detached view before the LayoutManager entry point method called by RecyclerView returns.

Parameters
`child`	`View`: Child to detach

detachViewAt

void detachViewAt (int index)

Temporarily detach a child view.

If a LayoutManager uses this method to detach a view, it must reattach or fully remove the detached view before the LayoutManager entry point method called by RecyclerView returns.

Parameters
`index`	`int`: Index of the child to detach

endAnimation

void endAnimation (View view)

Ends all animations on the view created by the RecyclerView.ItemAnimator.

Parameters
`view`	`View`: The View for which the animations should be ended.

See also:

endAnimations()

findContainingItemView

View findContainingItemView (View view)

Traverses the ancestors of the given view and returns the item view that contains it and also a direct child of the LayoutManager.

Note that this method may return null if the view is a child of the RecyclerView but not a child of the LayoutManager (e.g. running a disappear animation).

Parameters
`view`	`View`: The view that is a descendant of the LayoutManager.

Returns
`View`	The direct child of the LayoutManager which contains the given view or null if the provided view is not a descendant of this LayoutManager.

See also:

findViewByPosition

View findViewByPosition (int position)

Finds the view which represents the given adapter position.

This method traverses each child since it has no information about child order. Override this method to improve performance if your LayoutManager keeps data about child views.

If a view is ignored via ignoreView(View), it is also ignored by this method.

Parameters
`position`	`int`: Position of the item in adapter

Returns
`View`	The child view that represents the given position or null if the position is not laid out

generateDefaultLayoutParams

RecyclerView.LayoutParams generateDefaultLayoutParams ()

Create a default LayoutParams object for a child of the RecyclerView.

LayoutManagers will often want to use a custom LayoutParams type to store extra information specific to the layout. Client code should subclass RecyclerView.LayoutParams for this purpose.

Important: if you use your own custom LayoutParams type you must also override checkLayoutParams(LayoutParams), generateLayoutParams(android.view.ViewGroup.LayoutParams) and generateLayoutParams(android.content.Context, android.util.AttributeSet).

Returns
`RecyclerView.LayoutParams`	A new LayoutParams for a child view

generateLayoutParams

RecyclerView.LayoutParams generateLayoutParams (Context c, 
                AttributeSet attrs)

Create a LayoutParams object suitable for this LayoutManager from an inflated layout resource.

Parameters
`c`	`Context`: Context for obtaining styled attributes
`attrs`	`AttributeSet`: AttributeSet describing the supplied arguments

Returns
`RecyclerView.LayoutParams`	a new LayoutParams object

generateLayoutParams

RecyclerView.LayoutParams generateLayoutParams (ViewGroup.LayoutParams lp)

Create a LayoutParams object suitable for this LayoutManager, copying relevant values from the supplied LayoutParams object if possible.

Parameters
`lp`	`ViewGroup.LayoutParams`: Source LayoutParams object to copy values from

Returns
`RecyclerView.LayoutParams`	a new LayoutParams object

getBaseline

int getBaseline ()

Returns offset of the RecyclerView's text baseline from the its top boundary.

Returns
`int`	The offset of the RecyclerView's text baseline from the its top boundary; -1 if there is no baseline.

getBottomDecorationHeight

int getBottomDecorationHeight (View child)

Returns the total height of item decorations applied to child's bottom.

Note that this value is not updated until the View is measured or calculateItemDecorationsForChild(View, Rect) is called.

Parameters
`child`	`View`: Child to query

Returns
`int`	The total height of item decorations applied to the child's bottom.

See also:

getChildAt

View getChildAt (int index)

Return the child view at the given index

Parameters
`index`	`int`: Index of child to return

Returns
`View`	Child view at index

getChildCount

int getChildCount ()

Return the current number of child views attached to the parent RecyclerView. This does not include child views that were temporarily detached and/or scrapped.

Returns
`int`	Number of attached children

getChildMeasureSpec

int getChildMeasureSpec (int parentSize, 
                int parentMode, 
                int padding, 
                int childDimension, 
                boolean canScroll)

Calculate a MeasureSpec value for measuring a child view in one dimension.

Parameters
`parentSize`	`int`: Size of the parent view where the child will be placed
`parentMode`	`int`: The measurement spec mode of the parent
`padding`	`int`: Total space currently consumed by other elements of parent
`childDimension`	`int`: Desired size of the child view, or FILL_PARENT/WRAP_CONTENT. Generally obtained from the child view's LayoutParams
`canScroll`	`boolean`: true if the parent RecyclerView can scroll in this dimension

Returns
`int`	a MeasureSpec value for the child view

getChildMeasureSpec

int getChildMeasureSpec (int parentSize, 
                int padding, 
                int childDimension, 
                boolean canScroll)

This method is deprecated.
use getChildMeasureSpec(int, int, int, int, boolean)

Calculate a MeasureSpec value for measuring a child view in one dimension.

Parameters
`parentSize`	`int`: Size of the parent view where the child will be placed
`padding`	`int`: Total space currently consumed by other elements of the parent
`childDimension`	`int`: Desired size of the child view, or FILL_PARENT/WRAP_CONTENT. Generally obtained from the child view's LayoutParams
`canScroll`	`boolean`: true if the parent RecyclerView can scroll in this dimension

Returns
`int`	a MeasureSpec value for the child view

getClipToPadding

boolean getClipToPadding ()

Check if the RecyclerView is configured to clip child views to its padding.

Returns
`boolean`	true if this RecyclerView clips children to its padding, false otherwise

getColumnCountForAccessibility

int getColumnCountForAccessibility (RecyclerView.Recycler recycler, 
                RecyclerView.State state)

Returns the number of columns for accessibility.

Default implementation returns the number of items in the adapter if LayoutManager supports horizontal scrolling or 1 if LayoutManager does not support horizontal scrolling.

Parameters
`recycler`	`RecyclerView.Recycler`: The Recycler that can be used to convert view positions into adapter positions
`state`	`RecyclerView.State`: The current state of RecyclerView

Returns
`int`	The number of rows in LayoutManager for accessibility.

getDecoratedBottom

int getDecoratedBottom (View child)

Returns the bottom edge of the given child view within its parent, offset by any applied ItemDecorations.

Parameters
`child`	`View`: Child to query

Returns
`int`	Child bottom edge with offsets applied

See also:

getBottomDecorationHeight(View)

getDecoratedBoundsWithMargins

void getDecoratedBoundsWithMargins (View view, 
                Rect outBounds)

Returns the bounds of the view including its decoration and margins.

Parameters
`view`	`View`: The view element to check
`outBounds`	`Rect`: A rect that will receive the bounds of the element including its decoration and margins.

getDecoratedLeft

int getDecoratedLeft (View child)

Returns the left edge of the given child view within its parent, offset by any applied ItemDecorations.

Parameters
`child`	`View`: Child to query

Returns
`int`	Child left edge with offsets applied

See also:

getLeftDecorationWidth(View)

getDecoratedMeasuredHeight

int getDecoratedMeasuredHeight (View child)

Returns the measured height of the given child, plus the additional size of any insets applied by ItemDecorations.

Parameters
`child`	`View`: Child view to query

Returns
`int`	child's measured height plus `ItemDecoration` insets

See also:

getMeasuredHeight()

getDecoratedMeasuredWidth

int getDecoratedMeasuredWidth (View child)

Returns the measured width of the given child, plus the additional size of any insets applied by ItemDecorations.

Parameters
`child`	`View`: Child view to query

Returns
`int`	child's measured width plus `ItemDecoration` insets

See also:

getMeasuredWidth()

getDecoratedRight

int getDecoratedRight (View child)

Returns the right edge of the given child view within its parent, offset by any applied ItemDecorations.

Parameters
`child`	`View`: Child to query

Returns
`int`	Child right edge with offsets applied

See also:

getRightDecorationWidth(View)

getDecoratedTop

int getDecoratedTop (View child)

Returns the top edge of the given child view within its parent, offset by any applied ItemDecorations.

Parameters
`child`	`View`: Child to query

Returns
`int`	Child top edge with offsets applied

See also:

getTopDecorationHeight(View)

getFocusedChild

View getFocusedChild ()

Returns the item View which has or contains focus.

Returns
`View`	A direct child of RecyclerView which has focus or contains the focused child.

getHeight

int getHeight ()

Return the height of the parent RecyclerView

Returns
`int`	Height in pixels

getHeightMode

int getHeightMode ()

Return the height measurement spec mode of the RecyclerView.

This value is set only if the LayoutManager opts into the auto measure api via setAutoMeasureEnabled(boolean).

When RecyclerView is running a layout, this value is always set to EXACTLY even if it was measured with a different spec mode.

Returns
`int`	Height measure spec mode.

See also:

getItemCount

int getItemCount ()

Returns the number of items in the adapter bound to the parent RecyclerView.

Note that this number is not necessarily equal to getItemCount(). In methods where State is available, you should use getItemCount() instead. For more details, check the documentation for getItemCount().

Returns
`int`	The number of items in the bound adapter

See also:

getItemCount()

getItemViewType

int getItemViewType (View view)

Returns the View type defined by the adapter.

Parameters
`view`	`View`: The view to query

Returns
`int`	The type of the view assigned by the adapter.

getLayoutDirection

int getLayoutDirection ()

Returns the resolved layout direction for this RecyclerView.

Returns
`int`	`LAYOUT_DIRECTION_RTL` if the layout direction is RTL or returns `LAYOUT_DIRECTION_LTR` if the layout direction is not RTL.

getLeftDecorationWidth

int getLeftDecorationWidth (View child)

Returns the total width of item decorations applied to child's left.

Note that this value is not updated until the View is measured or calculateItemDecorationsForChild(View, Rect) is called.

Parameters
`child`	`View`: Child to query

Returns
`int`	The total width of item decorations applied to the child's left.

See also:

getMinimumHeight

int getMinimumHeight ()

Returns
`int`	The host RecyclerView's `getMinimumHeight()`

getMinimumWidth

int getMinimumWidth ()

Returns
`int`	The host RecyclerView's `getMinimumWidth()`

getPaddingBottom

int getPaddingBottom ()

Return the bottom padding of the parent RecyclerView

Returns
`int`	Padding in pixels

getPaddingEnd

int getPaddingEnd ()

Return the end padding of the parent RecyclerView

Returns
`int`	Padding in pixels

getPaddingLeft

int getPaddingLeft ()

Return the left padding of the parent RecyclerView

Returns
`int`	Padding in pixels

getPaddingRight

int getPaddingRight ()

Return the right padding of the parent RecyclerView

Returns
`int`	Padding in pixels

getPaddingStart

int getPaddingStart ()

Return the start padding of the parent RecyclerView

Returns
`int`	Padding in pixels

getPaddingTop

int getPaddingTop ()

Return the top padding of the parent RecyclerView

Returns
`int`	Padding in pixels

getPosition

int getPosition (View view)

Returns the adapter position of the item represented by the given View. This does not contain any adapter changes that might have happened after the last layout.

Parameters
`view`	`View`: The view to query

Returns
`int`	The adapter position of the item which is rendered by this View.

getProperties

RecyclerView.LayoutManager.Properties getProperties (Context context, 
                AttributeSet attrs, 
                int defStyleAttr, 
                int defStyleRes)

Parse the xml attributes to get the most common properties used by layout managers.

Related XML Attributes:

Parameters
`context`	`Context`
`attrs`	`AttributeSet`
`defStyleAttr`	`int`
`defStyleRes`	`int`

Returns
`RecyclerView.LayoutManager.Properties`	an object containing the properties as specified in the attrs.

getRightDecorationWidth

int getRightDecorationWidth (View child)

Returns the total width of item decorations applied to child's right.

Note that this value is not updated until the View is measured or calculateItemDecorationsForChild(View, Rect) is called.

Parameters
`child`	`View`: Child to query

Returns
`int`	The total width of item decorations applied to the child's right.

See also:

getRowCountForAccessibility

int getRowCountForAccessibility (RecyclerView.Recycler recycler, 
                RecyclerView.State state)

Returns the number of rows for accessibility.

Default implementation returns the number of items in the adapter if LayoutManager supports vertical scrolling or 1 if LayoutManager does not support vertical scrolling.

Parameters
`recycler`	`RecyclerView.Recycler`: The Recycler that can be used to convert view positions into adapter positions
`state`	`RecyclerView.State`: The current state of RecyclerView

Returns
`int`	The number of rows in LayoutManager for accessibility.

getSelectionModeForAccessibility

int getSelectionModeForAccessibility (RecyclerView.Recycler recycler, 
                RecyclerView.State state)

Returns the selection mode for accessibility. Should be SELECTION_MODE_NONE, SELECTION_MODE_SINGLE or SELECTION_MODE_MULTIPLE.

Default implementation returns SELECTION_MODE_NONE.

Parameters
`recycler`	`RecyclerView.Recycler`: The Recycler that can be used to convert view positions into adapter positions
`state`	`RecyclerView.State`: The current state of RecyclerView

Returns
`int`	Selection mode for accessibility. Default implementation returns `SELECTION_MODE_NONE`.

getTopDecorationHeight

int getTopDecorationHeight (View child)

Returns the total height of item decorations applied to child's top.

Note that this value is not updated until the View is measured or calculateItemDecorationsForChild(View, Rect) is called.

Parameters
`child`	`View`: Child to query

Returns
`int`	The total height of item decorations applied to the child's top.

See also:

getTransformedBoundingBox

void getTransformedBoundingBox (View child, 
                boolean includeDecorInsets, 
                Rect out)

Calculates the bounding box of the View while taking into account its matrix changes (translation, scale etc) with respect to the RecyclerView.

If includeDecorInsets is true, they are applied first before applying the View's matrix so that the decor offsets also go through the same transformation.

Parameters
`child`	`View`: The ItemView whose bounding box should be calculated.
`includeDecorInsets`	`boolean`: True if the decor insets should be included in the bounding box
`out`	`Rect`: The rectangle into which the output will be written.

getWidth

int getWidth ()

Return the width of the parent RecyclerView

Returns
`int`	Width in pixels

getWidthMode

int getWidthMode ()

Return the width measurement spec mode of the RecyclerView.

This value is set only if the LayoutManager opts into the auto measure api via setAutoMeasureEnabled(boolean).

When RecyclerView is running a layout, this value is always set to EXACTLY even if it was measured with a different spec mode.

Returns
`int`	Width measure spec mode.

See also:

hasFocus

boolean hasFocus ()

Returns true if the RecyclerView this LayoutManager is bound to has or contains focus.

Returns
`boolean`	true if the RecyclerView has or contains focus

See also:

hasFocus()

ignoreView

void ignoreView (View view)

Flags a view so that it will not be scrapped or recycled.

Scope of ignoring a child is strictly restricted to position tracking, scrapping and recyling. Methods like removeAndRecycleAllViews(Recycler) will ignore the child whereas removeAllViews() or offsetChildrenHorizontal(int) will not ignore the child.

Before this child can be recycled again, you have to call stopIgnoringView(View).

You can call this method only if your LayoutManger is in onLayout or onScroll callback.

Parameters
`view`	`View`: View to ignore.

See also:

stopIgnoringView(View)

isAttachedToWindow

boolean isAttachedToWindow ()

Returns whether LayoutManager is currently attached to a RecyclerView which is attached to a window.

Returns
`boolean`	True if this LayoutManager is controlling a RecyclerView and the RecyclerView is attached to window.

isAutoMeasureEnabled

boolean isAutoMeasureEnabled ()

Returns whether the LayoutManager uses the automatic measurement API or not.

Returns
`boolean`	`True` if the LayoutManager is measured by the RecyclerView or `false` if it measures itself.

See also:

setAutoMeasureEnabled(boolean)

isFocused

boolean isFocused ()

Returns true if the RecyclerView this LayoutManager is bound to has focus.

Returns
`boolean`	True if the RecyclerView has focus, false otherwise.

See also:

isFocused()

isLayoutHierarchical

boolean isLayoutHierarchical (RecyclerView.Recycler recycler, 
                RecyclerView.State state)

Returns whether layout is hierarchical or not to be used for accessibility.

Default implementation returns false.

Parameters
`recycler`	`RecyclerView.Recycler`: The Recycler that can be used to convert view positions into adapter positions
`state`	`RecyclerView.State`: The current state of RecyclerView

Returns
`boolean`	True if layout is hierarchical.

isMeasurementCacheEnabled

boolean isMeasurementCacheEnabled ()

In addition to the View Framework's measurement cache, RecyclerView uses its own additional measurement cache for its children to avoid re-measuring them when not necessary. It is on by default but it can be turned off via setMeasurementCacheEnabled(boolean).

Returns
`boolean`	True if measurement cache is enabled, false otherwise.

See also:

setMeasurementCacheEnabled(boolean)

isSmoothScrolling

boolean isSmoothScrolling ()

Returns
`boolean`	true if RecycylerView is currently in the state of smooth scrolling.

layoutDecorated

void layoutDecorated (View child, 
                int left, 
                int top, 
                int right, 
                int bottom)

Lay out the given child view within the RecyclerView using coordinates that include any current ItemDecorations.

LayoutManagers should prefer working in sizes and coordinates that include item decoration insets whenever possible. This allows the LayoutManager to effectively ignore decoration insets within measurement and layout code. See the following methods:

Parameters
`child`	`View`: Child to lay out
`left`	`int`: Left edge, with item decoration insets included
`top`	`int`: Top edge, with item decoration insets included
`right`	`int`: Right edge, with item decoration insets included
`bottom`	`int`: Bottom edge, with item decoration insets included

See also:

layoutDecoratedWithMargins

void layoutDecoratedWithMargins (View child, 
                int left, 
                int top, 
                int right, 
                int bottom)

Lay out the given child view within the RecyclerView using coordinates that include any current ItemDecorations and margins.

Parameters
`child`	`View`: Child to lay out
`left`	`int`: Left edge, with item decoration insets and left margin included
`top`	`int`: Top edge, with item decoration insets and top margin included
`right`	`int`: Right edge, with item decoration insets and right margin included
`bottom`	`int`: Bottom edge, with item decoration insets and bottom margin included

See also:

measureChild

void measureChild (View child, 
                int widthUsed, 
                int heightUsed)

Measure a child view using standard measurement policy, taking the padding of the parent RecyclerView and any added item decorations into account.

If the RecyclerView can be scrolled in either dimension the caller may pass 0 as the widthUsed or heightUsed parameters as they will be irrelevant.

Parameters
`child`	`View`: Child view to measure
`widthUsed`	`int`: Width in pixels currently consumed by other views, if relevant
`heightUsed`	`int`: Height in pixels currently consumed by other views, if relevant

measureChildWithMargins

void measureChildWithMargins (View child, 
                int widthUsed, 
                int heightUsed)

Measure a child view using standard measurement policy, taking the padding of the parent RecyclerView, any added item decorations and the child margins into account.

If the RecyclerView can be scrolled in either dimension the caller may pass 0 as the widthUsed or heightUsed parameters as they will be irrelevant.

Parameters
`child`	`View`: Child view to measure
`widthUsed`	`int`: Width in pixels currently consumed by other views, if relevant
`heightUsed`	`int`: Height in pixels currently consumed by other views, if relevant

moveView

void moveView (int fromIndex, 
                int toIndex)

Moves a View from one position to another.

Parameters
`fromIndex`	`int`: The View's initial index
`toIndex`	`int`: The View's target index

offsetChildrenHorizontal

void offsetChildrenHorizontal (int dx)

Offset all child views attached to the parent RecyclerView by dx pixels along the horizontal axis.

Parameters
`dx`	`int`: Pixels to offset by

offsetChildrenVertical

void offsetChildrenVertical (int dy)

Offset all child views attached to the parent RecyclerView by dy pixels along the vertical axis.

Parameters
`dy`	`int`: Pixels to offset by

onAdapterChanged

void onAdapterChanged (Adapter oldAdapter, 
                Adapter newAdapter)

Called if the RecyclerView this LayoutManager is bound to has a different adapter set. The LayoutManager may use this opportunity to clear caches and configure state such that it can relayout appropriately with the new data and potentially new view types.

The default implementation removes all currently attached views.

Parameters
`oldAdapter`	`Adapter`: The previous adapter instance. Will be null if there was previously no adapter.
`newAdapter`	`Adapter`: The new adapter instance. Might be null if `setAdapter(RecyclerView.Adapter)` is called with `null`.

onAddFocusables

boolean onAddFocusables (RecyclerView recyclerView, 
                ArrayList<View> views, 
                int direction, 
                int focusableMode)

Called to populate focusable views within the RecyclerView.

The LayoutManager implementation should return true if the default behavior of addFocusables(java.util.ArrayList, int) should be suppressed.

The default implementation returns false to trigger RecyclerView to fall back to the default ViewGroup behavior.

Parameters
`recyclerView`	`RecyclerView`: The RecyclerView hosting this LayoutManager
`views`	`ArrayList`: List of output views. This method should add valid focusable views to this list.
`direction`	`int`: One of `FOCUS_UP`, `FOCUS_DOWN`, `FOCUS_LEFT`, `FOCUS_RIGHT`, `FOCUS_BACKWARD`, `FOCUS_FORWARD`
`focusableMode`	`int`: The type of focusables to be added.

Returns
`boolean`	true to suppress the default behavior, false to add default focusables after this method returns.

See also:

onAttachedToWindow

void onAttachedToWindow (RecyclerView view)

Called when this LayoutManager is both attached to a RecyclerView and that RecyclerView is attached to a window.

If the RecyclerView is re-attached with the same LayoutManager and Adapter, it may not call onLayoutChildren(Recycler, State) if nothing has changed and a layout was not requested on the RecyclerView while it was detached.

Subclass implementations should always call through to the superclass implementation.

Parameters
`view`	`RecyclerView`: The RecyclerView this LayoutManager is bound to

See also:

onDetachedFromWindow(RecyclerView, Recycler)

onDetachedFromWindow

void onDetachedFromWindow (RecyclerView view, 
                RecyclerView.Recycler recycler)

Called when this LayoutManager is detached from its parent RecyclerView or when its parent RecyclerView is detached from its window.

LayoutManager should clear all of its View references as another LayoutManager might be assigned to the RecyclerView.

If your LayoutManager has View references that it cleans in on-detach, it should also call requestLayout() to ensure that it is re-laid out when RecyclerView is re-attached.

Subclass implementations should always call through to the superclass implementation.

Parameters
`view`	`RecyclerView`: The RecyclerView this LayoutManager is bound to
`recycler`	`RecyclerView.Recycler`: The recycler to use if you prefer to recycle your children instead of keeping them around.

See also:

onAttachedToWindow(RecyclerView)

onDetachedFromWindow

void onDetachedFromWindow (RecyclerView view)

This method is deprecated.
override onDetachedFromWindow(RecyclerView, Recycler)

Parameters
`view`	`RecyclerView`

onFocusSearchFailed

View onFocusSearchFailed (View focused, 
                int direction, 
                RecyclerView.Recycler recycler, 
                RecyclerView.State state)

Called when searching for a focusable view in the given direction has failed for the current content of the RecyclerView.

This is the LayoutManager's opportunity to populate views in the given direction to fulfill the request if it can. The LayoutManager should attach and return the view to be focused. The default implementation returns null.

Parameters
`focused`	`View`: The currently focused view
`direction`	`int`: One of `FOCUS_UP`, `FOCUS_DOWN`, `FOCUS_LEFT`, `FOCUS_RIGHT`, `FOCUS_BACKWARD`, `FOCUS_FORWARD` or 0 for not applicable
`recycler`	`RecyclerView.Recycler`: The recycler to use for obtaining views for currently offscreen items
`state`	`RecyclerView.State`: Transient state of RecyclerView

Returns
`View`	The chosen view to be focused

onInitializeAccessibilityEvent

void onInitializeAccessibilityEvent (AccessibilityEvent event)

Parameters
`event`	`AccessibilityEvent`

onInitializeAccessibilityEvent

void onInitializeAccessibilityEvent (RecyclerView.Recycler recycler, 
                RecyclerView.State state, 
                AccessibilityEvent event)

Called by the accessibility delegate to initialize an accessibility event.

Default implementation adds item count and scroll information to the event.

Parameters
`recycler`	`RecyclerView.Recycler`: The Recycler that can be used to convert view positions into adapter positions
`state`	`RecyclerView.State`: The current state of RecyclerView
`event`	`AccessibilityEvent`: The event instance to initialize

See also:

onInitializeAccessibilityEvent(android.view.accessibility.AccessibilityEvent)

onInitializeAccessibilityNodeInfo

void onInitializeAccessibilityNodeInfo (RecyclerView.Recycler recycler, 
                RecyclerView.State state, 
                AccessibilityNodeInfoCompat info)

Called by the AccessibilityDelegate when the information about the current layout should be populated.

Default implementation adds a AccessibilityNodeInfoCompat.CollectionInfoCompat.

You should override getRowCountForAccessibility(RecyclerView.Recycler, RecyclerView.State), getColumnCountForAccessibility(RecyclerView.Recycler, RecyclerView.State), isLayoutHierarchical(RecyclerView.Recycler, RecyclerView.State) and getSelectionModeForAccessibility(RecyclerView.Recycler, RecyclerView.State) for more accurate accessibility information.

Parameters
`recycler`	`RecyclerView.Recycler`: The Recycler that can be used to convert view positions into adapter positions
`state`	`RecyclerView.State`: The current state of RecyclerView
`info`	`AccessibilityNodeInfoCompat`: The info that should be filled by the LayoutManager

See also:

onInitializeAccessibilityNodeInfoForItem

void onInitializeAccessibilityNodeInfoForItem (RecyclerView.Recycler recycler, 
                RecyclerView.State state, 
                View host, 
                AccessibilityNodeInfoCompat info)

Called by the AccessibilityDelegate when the accessibility information for a specific item should be populated.

Default implementation adds basic positioning information about the item.

Parameters
`recycler`	`RecyclerView.Recycler`: The Recycler that can be used to convert view positions into adapter positions
`state`	`RecyclerView.State`: The current state of RecyclerView
`host`	`View`: The child for which accessibility node info should be populated
`info`	`AccessibilityNodeInfoCompat`: The info to fill out about the item

See also:

onInitializeAccessibilityNodeInfoForItem(View, int, android.view.accessibility.AccessibilityNodeInfo)

onInterceptFocusSearch

View onInterceptFocusSearch (View focused, 
                int direction)

This method gives a LayoutManager an opportunity to intercept the initial focus search before the default behavior of FocusFinder is used. If this method returns null FocusFinder will attempt to find a focusable child view. If it fails then onFocusSearchFailed(View, int, RecyclerView.Recycler, RecyclerView.State) will be called to give the LayoutManager an opportunity to add new views for items that did not have attached views representing them. The LayoutManager should not add or remove views from this method.

Parameters
`focused`	`View`: The currently focused view
`direction`	`int`: One of `FOCUS_UP`, `FOCUS_DOWN`, `FOCUS_LEFT`, `FOCUS_RIGHT`, `FOCUS_BACKWARD`, `FOCUS_FORWARD`

Returns
`View`	A descendant view to focus or null to fall back to default behavior. The default implementation returns null.

onItemsAdded

void onItemsAdded (RecyclerView recyclerView, 
                int positionStart, 
                int itemCount)

Called when items have been added to the adapter. The LayoutManager may choose to requestLayout if the inserted items would require refreshing the currently visible set of child views. (e.g. currently empty space would be filled by appended items, etc.)

onItemsChanged

void onItemsChanged (RecyclerView recyclerView)

Called when notifyDataSetChanged() is triggered instead of giving detailed information on what has actually changed.

onItemsMoved

void onItemsMoved (RecyclerView recyclerView, 
                int from, 
                int to, 
                int itemCount)

Called when an item is moved withing the adapter.

Note that, an item may also change position in response to another ADD/REMOVE/MOVE operation. This callback is only called if and only if notifyItemMoved(int, int) is called.

onItemsRemoved

void onItemsRemoved (RecyclerView recyclerView, 
                int positionStart, 
                int itemCount)

Called when items have been removed from the adapter.

onItemsUpdated

void onItemsUpdated (RecyclerView recyclerView, 
                int positionStart, 
                int itemCount)

Called when items have been changed in the adapter. To receive payload, override onItemsUpdated(RecyclerView, int, int, Object) instead, then this callback will not be invoked.

onItemsUpdated

void onItemsUpdated (RecyclerView recyclerView, 
                int positionStart, 
                int itemCount, 
                Object payload)

Called when items have been changed in the adapter and with optional payload. Default implementation calls onItemsUpdated(RecyclerView, int, int).

onLayoutChildren

void onLayoutChildren (RecyclerView.Recycler recycler, 
                RecyclerView.State state)

Lay out all relevant child views from the given adapter. The LayoutManager is in charge of the behavior of item animations. By default, RecyclerView has a non-null ItemAnimator, and simple item animations are enabled. This means that add/remove operations on the adapter will result in animations to add new or appearing items, removed or disappearing items, and moved items. If a LayoutManager returns false from supportsPredictiveItemAnimations(), which is the default, and runs a normal layout operation during onLayoutChildren(Recycler, State), the RecyclerView will have enough information to run those animations in a simple way. For example, the default ItemAnimator, DefaultItemAnimator, will simply fade views in and out, whether they are actually added/removed or whether they are moved on or off the screen due to other add/remove operations.

A LayoutManager wanting a better item animation experience, where items can be animated onto and off of the screen according to where the items exist when they are not on screen, then the LayoutManager should return true from supportsPredictiveItemAnimations() and add additional logic to onLayoutChildren(Recycler, State). Supporting predictive animations means that onLayoutChildren(Recycler, State) will be called twice; once as a "pre" layout step to determine where items would have been prior to a real layout, and again to do the "real" layout. In the pre-layout phase, items will remember their pre-layout positions to allow them to be laid out appropriately. Also, removed items will be returned from the scrap to help determine correct placement of other items. These removed items should not be added to the child list, but should be used to help calculate correct positioning of other views, including views that were not previously onscreen (referred to as APPEARING views), but whose pre-layout offscreen position can be determined given the extra information about the pre-layout removed views.

The second layout pass is the real layout in which only non-removed views will be used. The only additional requirement during this pass is, if supportsPredictiveItemAnimations() returns true, to note which views exist in the child list prior to layout and which are not there after layout (referred to as DISAPPEARING views), and to position/layout those views appropriately, without regard to the actual bounds of the RecyclerView. This allows the animation system to know the location to which to animate these disappearing views.

The default LayoutManager implementations for RecyclerView handle all of these requirements for animations already. Clients of RecyclerView can either use one of these layout managers directly or look at their implementations of onLayoutChildren() to see how they account for the APPEARING and DISAPPEARING views.

Parameters
`recycler`	`RecyclerView.Recycler`: Recycler to use for fetching potentially cached views for a position
`state`	`RecyclerView.State`: Transient state of RecyclerView

onLayoutCompleted

void onLayoutCompleted (RecyclerView.State state)

Called after a full layout calculation is finished. The layout calculation may include multiple onLayoutChildren(Recycler, State) calls due to animations or layout measurement but it will include only one onLayoutCompleted(State) call. This method will be called at the end of layout(int, int, int, int) call.

This is a good place for the LayoutManager to do some cleanup like pending scroll position, saved state etc.

Parameters
`state`	`RecyclerView.State`: Transient state of RecyclerView

onMeasure

void onMeasure (RecyclerView.Recycler recycler, 
                RecyclerView.State state, 
                int widthSpec, 
                int heightSpec)

Measure the attached RecyclerView. Implementations must call setMeasuredDimension(int, int) before returning.

The default implementation will handle EXACTLY measurements and respect the minimum width and height properties of the host RecyclerView if measured as UNSPECIFIED. AT_MOST measurements will be treated as EXACTLY and the RecyclerView will consume all available space.

Parameters
`recycler`	`RecyclerView.Recycler`: Recycler
`state`	`RecyclerView.State`: Transient state of RecyclerView
`widthSpec`	`int`: Width `View.MeasureSpec`
`heightSpec`	`int`: Height `View.MeasureSpec`

onRequestChildFocus

boolean onRequestChildFocus (RecyclerView parent, 
                View child, 
                View focused)

This method is deprecated.
Use onRequestChildFocus(RecyclerView, State, View, View)

Parameters
`parent`	`RecyclerView`
`child`	`View`
`focused`	`View`

Returns
`boolean`

onRequestChildFocus

boolean onRequestChildFocus (RecyclerView parent, 
                RecyclerView.State state, 
                View child, 
                View focused)

Called when a descendant view of the RecyclerView requests focus.

A LayoutManager wishing to keep focused views aligned in a specific portion of the view may implement that behavior in an override of this method.

If the LayoutManager executes different behavior that should override the default behavior of scrolling the focused child on screen instead of running alongside it, this method should return true.

Parameters
`parent`	`RecyclerView`: The RecyclerView hosting this LayoutManager
`state`	`RecyclerView.State`: Current state of RecyclerView
`child`	`View`: Direct child of the RecyclerView containing the newly focused view
`focused`	`View`: The newly focused view. This may be the same view as child or it may be null

Returns
`boolean`	true if the default scroll behavior should be suppressed

onRestoreInstanceState

void onRestoreInstanceState (Parcelable state)

Parameters
`state`	`Parcelable`

onSaveInstanceState

Parcelable onSaveInstanceState ()

Called when the LayoutManager should save its state. This is a good time to save your scroll position, configuration and anything else that may be required to restore the same layout state if the LayoutManager is recreated.

RecyclerView does NOT verify if the LayoutManager has changed between state save and restore. This will let you share information between your LayoutManagers but it is also your responsibility to make sure they use the same parcelable class.

Returns
`Parcelable`	Necessary information for LayoutManager to be able to restore its state

onScrollStateChanged

void onScrollStateChanged (int state)

RecyclerView calls this method to notify LayoutManager that scroll state has changed.

Parameters
`state`	`int`: The new scroll state for RecyclerView

performAccessibilityAction

boolean performAccessibilityAction (RecyclerView.Recycler recycler, 
                RecyclerView.State state, 
                int action, 
                Bundle args)

Called by AccessibilityDelegate when an action is requested from the RecyclerView.

Parameters
`recycler`	`RecyclerView.Recycler`: The Recycler that can be used to convert view positions into adapter positions
`state`	`RecyclerView.State`: The current state of RecyclerView
`action`	`int`: The action to perform
`args`	`Bundle`: Optional action arguments

Returns
`boolean`

See also:

performAccessibilityAction(int, android.os.Bundle)

performAccessibilityActionForItem

boolean performAccessibilityActionForItem (RecyclerView.Recycler recycler, 
                RecyclerView.State state, 
                View view, 
                int action, 
                Bundle args)

Called by AccessibilityDelegate when an accessibility action is requested on one of the children of LayoutManager.

Default implementation does not do anything.

Parameters
`recycler`	`RecyclerView.Recycler`: The Recycler that can be used to convert view positions into adapter positions
`state`	`RecyclerView.State`: The current state of RecyclerView
`view`	`View`: The child view on which the action is performed
`action`	`int`: The action to perform
`args`	`Bundle`: Optional action arguments

Returns
`boolean`	true if action is handled

See also:

performAccessibilityAction(int, android.os.Bundle)

postOnAnimation

void postOnAnimation (Runnable action)

Causes the Runnable to execute on the next animation time step. The runnable will be run on the user interface thread.

Calling this method when LayoutManager is not attached to a RecyclerView has no effect.

Parameters
`action`	`Runnable`: The Runnable that will be executed.

See also:

removeCallbacks(Runnable)

removeAllViews

void removeAllViews ()

Remove all views from the currently attached RecyclerView. This will not recycle any of the affected views; the LayoutManager is responsible for doing so if desired.

removeAndRecycleAllViews

void removeAndRecycleAllViews (RecyclerView.Recycler recycler)

Removes all views and recycles them using the given recycler.

If you want to clean cached views as well, you should call clear() too.

If a View is marked as "ignored", it is not removed nor recycled.

Parameters
`recycler`	`RecyclerView.Recycler`: Recycler to use to recycle children

See also:

removeAndRecycleView

void removeAndRecycleView (View child, 
                RecyclerView.Recycler recycler)

Remove a child view and recycle it using the given Recycler.

Parameters
`child`	`View`: Child to remove and recycle
`recycler`	`RecyclerView.Recycler`: Recycler to use to recycle child

removeAndRecycleViewAt

void removeAndRecycleViewAt (int index, 
                RecyclerView.Recycler recycler)

Remove a child view and recycle it using the given Recycler.

Parameters
`index`	`int`: Index of child to remove and recycle
`recycler`	`RecyclerView.Recycler`: Recycler to use to recycle child

removeCallbacks

boolean removeCallbacks (Runnable action)

Removes the specified Runnable from the message queue.

Calling this method when LayoutManager is not attached to a RecyclerView has no effect.

Parameters
`action`	`Runnable`: The Runnable to remove from the message handling queue

Returns
`boolean`	true if RecyclerView could ask the Handler to remove the Runnable, false otherwise. When the returned value is true, the Runnable may or may not have been actually removed from the message queue (for instance, if the Runnable was not in the queue already.)

See also:

postOnAnimation(Runnable)

removeDetachedView

void removeDetachedView (View child)

Finish removing a view that was previously temporarily detached.

Parameters
`child`	`View`: Detached child to remove

removeView

void removeView (View child)

Remove a view from the currently attached RecyclerView if needed. LayoutManagers should use this method to completely remove a child view that is no longer needed. LayoutManagers should strongly consider recycling removed views using recycleView(android.view.View).

Parameters
`child`	`View`: View to remove

removeViewAt

void removeViewAt (int index)

Parameters
`index`	`int`: Index of the child view to remove

requestChildRectangleOnScreen

boolean requestChildRectangleOnScreen (RecyclerView parent, 
                View child, 
                Rect rect, 
                boolean immediate)

Called when a child of the RecyclerView wants a particular rectangle to be positioned onto the screen. See requestChildRectangleOnScreen(android.view.View, android.graphics.Rect, boolean) for more details.

The base implementation will attempt to perform a standard programmatic scroll to bring the given rect into view, within the padded area of the RecyclerView.

Parameters
`parent`	`RecyclerView`
`child`	`View`: The direct child making the request.
`rect`	`Rect`: The rectangle in the child's coordinates the child wishes to be on the screen.
`immediate`	`boolean`: True to forbid animated or delayed scrolling, false otherwise

Returns
`boolean`	Whether the group scrolled to handle the operation

requestLayout

void requestLayout ()

Calls RecyclerView#requestLayout on the underlying RecyclerView

requestSimpleAnimationsInNextLayout

void requestSimpleAnimationsInNextLayout ()

A LayoutManager can call this method to force RecyclerView to run simple animations in the next layout pass, even if there is not any trigger to do so. (e.g. adapter data change).

Note that, calling this method will not guarantee that RecyclerView will run animations at all. For example, if there is not any RecyclerView.ItemAnimator set, RecyclerView will not run any animations but will still clear this flag after the layout is complete.

scrollHorizontallyBy

int scrollHorizontallyBy (int dx, 
                RecyclerView.Recycler recycler, 
                RecyclerView.State state)

Scroll horizontally by dx pixels in screen coordinates and return the distance traveled. The default implementation does nothing and returns 0.

Parameters
`dx`	`int`: distance to scroll by in pixels. X increases as scroll position approaches the right.
`recycler`	`RecyclerView.Recycler`: Recycler to use for fetching potentially cached views for a position
`state`	`RecyclerView.State`: Transient state of RecyclerView

Returns
`int`	The actual distance scrolled. The return value will be negative if dx was negative and scrolling proceeeded in that direction. `Math.abs(result)` may be less than dx if a boundary was reached.

scrollToPosition

void scrollToPosition (int position)

Scroll to the specified adapter position. Actual position of the item on the screen depends on the LayoutManager implementation.

Parameters
`position`	`int`: Scroll to this adapter position.

scrollVerticallyBy

int scrollVerticallyBy (int dy, 
                RecyclerView.Recycler recycler, 
                RecyclerView.State state)

Scroll vertically by dy pixels in screen coordinates and return the distance traveled. The default implementation does nothing and returns 0.

Parameters
`dy`	`int`: distance to scroll in pixels. Y increases as scroll position approaches the bottom.
`recycler`	`RecyclerView.Recycler`: Recycler to use for fetching potentially cached views for a position
`state`	`RecyclerView.State`: Transient state of RecyclerView

Returns
`int`	The actual distance scrolled. The return value will be negative if dy was negative and scrolling proceeeded in that direction. `Math.abs(result)` may be less than dy if a boundary was reached.

setAutoMeasureEnabled

void setAutoMeasureEnabled (boolean enabled)

Defines whether the layout should be measured by the RecyclerView or the LayoutManager wants to handle the layout measurements itself.

This method is usually called by the LayoutManager with value true if it wants to support WRAP_CONTENT. If you are using a public LayoutManager but want to customize the measurement logic, you can call this method with false and override onMeasure(int, int) to implement your custom measurement logic.

AutoMeasure is a convenience mechanism for LayoutManagers to easily wrap their content or handle various specs provided by the RecyclerView's parent. It works by calling onLayoutChildren(Recycler, State) during an onMeasure(int, int) call, then calculating desired dimensions based on children's positions. It does this while supporting all existing animation capabilities of the RecyclerView.

AutoMeasure works as follows:

LayoutManager should call setAutoMeasureEnabled(true) to enable it. All of the framework LayoutManagers use auto-measure.
When onMeasure(int, int) is called, if the provided specs are exact, RecyclerView will only call LayoutManager's onMeasure and return without doing any layout calculation.
If one of the layout specs is not EXACT, the RecyclerView will start the layout process in onMeasure call. It will process all pending Adapter updates and decide whether to run a predictive layout or not. If it decides to do so, it will first call onLayoutChildren(Recycler, State) with isPreLayout() set to true. At this stage, getWidth() and getHeight() will still return the width and height of the RecyclerView as of the last layout calculation.
After handling the predictive case, RecyclerView will call onLayoutChildren(Recycler, State) with isMeasuring() set to true and isPreLayout() set to false. The LayoutManager can access the measurement specs via getHeight(), getHeightMode(), getWidth() and getWidthMode().
After the layout calculation, RecyclerView sets the measured width & height by calculating the bounding box for the children (+ RecyclerView's padding). The LayoutManagers can override setMeasuredDimension(Rect, int, int) to choose different values. For instance, GridLayoutManager overrides this value to handle the case where if it is vertical and has 3 columns but only 2 items, it should still measure its width to fit 3 items, not 2.
Any following on measure call to the RecyclerView will run onLayoutChildren(Recycler, State) with isMeasuring() set to true and isPreLayout() set to false. RecyclerView will take care of which views are actually added / removed / moved / changed for animations so that the LayoutManager should not worry about them and handle each onLayoutChildren(Recycler, State) call as if it is the last one.
When measure is complete and RecyclerView's onLayout(boolean, int, int, int, int) method is called, RecyclerView checks whether it already did layout calculations during the measure pass and if so, it re-uses that information. It may still decide to call onLayoutChildren(Recycler, State) if the last measure spec was different from the final dimensions or adapter contents have changed between the measure call and the layout call.
Finally, animations are calculated and run as usual.

Parameters
`enabled`	`boolean`: `True` if the Layout should be measured by the RecyclerView, `false` if the LayoutManager wants to measure itself.

See also:

setMeasuredDimension

void setMeasuredDimension (int widthSize, 
                int heightSize)

Set the measured dimensions of the host RecyclerView.

Parameters
`widthSize`	`int`: Measured width
`heightSize`	`int`: Measured height

setMeasuredDimension

void setMeasuredDimension (Rect childrenBounds, 
                int wSpec, 
                int hSpec)

Sets the measured dimensions from the given bounding box of the children and the measurement specs that were passed into onMeasure(int, int). It is called after the RecyclerView calls onLayoutChildren(Recycler, State) during a measurement pass.

This method should call setMeasuredDimension(int, int).

The default implementation adds the RecyclerView's padding to the given bounding box then caps the value to be within the given measurement specs.

This method is only called if the LayoutManager opted into the auto measurement API.

Parameters
`childrenBounds`	`Rect`: The bounding box of all children
`wSpec`	`int`: The widthMeasureSpec that was passed into the RecyclerView.
`hSpec`	`int`: The heightMeasureSpec that was passed into the RecyclerView.

See also:

setAutoMeasureEnabled(boolean)

setMeasurementCacheEnabled

void setMeasurementCacheEnabled (boolean measurementCacheEnabled)

Sets whether RecyclerView should use its own measurement cache for the children. This is a more aggressive cache than the framework uses.

Parameters
`measurementCacheEnabled`	`boolean`: True to enable the measurement cache, false otherwise.

See also:

isMeasurementCacheEnabled()

smoothScrollToPosition

void smoothScrollToPosition (RecyclerView recyclerView, 
                RecyclerView.State state, 
                int position)

Smooth scroll to the specified adapter position.

To support smooth scrolling, override this method, create your RecyclerView.SmoothScroller instance and call startSmoothScroll(SmoothScroller).

Parameters
`recyclerView`	`RecyclerView`: The RecyclerView to which this layout manager is attached
`state`	`RecyclerView.State`: Current State of RecyclerView
`position`	`int`: Scroll to this adapter position.

startSmoothScroll

void startSmoothScroll (RecyclerView.SmoothScroller smoothScroller)

Starts a smooth scroll using the provided SmoothScroller.

Calling this method will cancel any previous smooth scroll request.

Parameters
`smoothScroller`	`RecyclerView.SmoothScroller`: Unstance which defines how smooth scroll should be animated

stopIgnoringView

void stopIgnoringView (View view)

View can be scrapped and recycled again.

Note that calling this method removes all information in the view holder.

You can call this method only if your LayoutManger is in onLayout or onScroll callback.

Parameters
`view`	`View`: View to ignore.

supportsPredictiveItemAnimations

boolean supportsPredictiveItemAnimations ()

Returns whether this LayoutManager supports automatic item animations. A LayoutManager wishing to support item animations should obey certain rules as outlined in onLayoutChildren(Recycler, State). The default return value is false, so subclasses of LayoutManager will not get predictive item animations by default.

Whether item animations are enabled in a RecyclerView is determined both by the return value from this method and the ItemAnimator set on the RecyclerView itself. If the RecyclerView has a non-null ItemAnimator but this method returns false, then simple item animations will be enabled, in which views that are moving onto or off of the screen are simply faded in/out. If the RecyclerView has a non-null ItemAnimator and this method returns true, then there will be two calls to onLayoutChildren(Recycler, State) to setup up the information needed to more intelligently predict where appearing and disappearing views should be animated from/to.

Returns
`boolean`	true if predictive item animations should be enabled, false otherwise

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RecyclerView.LayoutManager

Summary

Nested classes

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XML attributes

android.support.v7.recyclerview:reverseLayout

android.support.v7.recyclerview:spanCount

android.support.v7.recyclerview:stackFromEnd

android:orientation

Public constructors

RecyclerView.LayoutManager

Public methods

addDisappearingView

addDisappearingView

addView

addView

assertInLayoutOrScroll

assertNotInLayoutOrScroll

attachView

attachView

attachView

calculateItemDecorationsForChild

canScrollHorizontally

canScrollVertically

checkLayoutParams

chooseSize

computeHorizontalScrollExtent

computeHorizontalScrollOffset

computeHorizontalScrollRange

computeVerticalScrollExtent

computeVerticalScrollOffset

computeVerticalScrollRange

detachAndScrapAttachedViews

detachAndScrapView

detachAndScrapViewAt

detachView

detachViewAt

endAnimation

findContainingItemView

findViewByPosition

generateDefaultLayoutParams

generateLayoutParams

generateLayoutParams

getBaseline

getBottomDecorationHeight

getChildAt

getChildCount

getChildMeasureSpec

getChildMeasureSpec

getClipToPadding

getColumnCountForAccessibility

getDecoratedBottom

getDecoratedBoundsWithMargins

getDecoratedLeft

getDecoratedMeasuredHeight

getDecoratedMeasuredWidth

getDecoratedRight

getDecoratedTop

getFocusedChild

getHeight

getHeightMode

getItemCount

getItemViewType

getLayoutDirection

getLeftDecorationWidth

getMinimumHeight

getMinimumWidth

getPaddingBottom

getPaddingEnd

getPaddingLeft

getPaddingRight

getPaddingStart

getPaddingTop

getPosition