# GridLayoutManager
Artifact: [androidx.leanback:leanback-grid](https://developer.android.com/jetpack/androidx/releases/leanback) [View Source](https://cs.android.com/search?q=file:androidx/leanback/widget/GridLayoutManager.java+class:androidx.leanback.widget.GridLayoutManager) Added in [1.0.0](https://developer.android.com/jetpack/androidx/releases/leanback#1.0.0)
*** ** * ** ***
```
public final class GridLayoutManager extends RecyclerView.LayoutManager
```
|---|---|---|
| [java.lang.Object](https://developer.android.com/reference/java/lang/Object.html) |||
| ↳ | [androidx.recyclerview.widget.RecyclerView.LayoutManager](https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager) ||
| | ↳ | [androidx.leanback.widget.GridLayoutManager](https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager) |
*** ** * ** ***
A `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager` implementation that lays out items in a grid for leanback `https://developer.android.com/reference/androidx/leanback/widget/VerticalGridView` and `https://developer.android.com/reference/androidx/leanback/widget/HorizontalGridView`.
## Summary
| ### Public constructors |
|---|
| `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#GridLayoutManager()()` |
| ### Public methods |
|---|---|
| `boolean` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#canScrollHorizontally()()` Query if horizontal scrolling is currently supported. |
| `boolean` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#canScrollVertically()()` Query if vertical scrolling is currently supported. |
| `boolean` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#checkLayoutParams(androidx.recyclerview.widget.RecyclerView.LayoutParams)(@https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutParams lp)` Determines the validity of the supplied LayoutParams object. |
| `void` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#collectAdjacentPrefetchPositions(int,int,androidx.recyclerview.widget.RecyclerView.State,androidx.recyclerview.widget.RecyclerView.LayoutManager.LayoutPrefetchRegistry)( int dx, int dy, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager.LayoutPrefetchRegistry layoutPrefetchRegistry )` Gather all positions from the LayoutManager to be prefetched, given specified momentum. |
| `void` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#collectInitialPrefetchPositions(int,androidx.recyclerview.widget.RecyclerView.LayoutManager.LayoutPrefetchRegistry)( int adapterItemCount, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager.LayoutPrefetchRegistry layoutPrefetchRegistry )` Gather all positions from the LayoutManager to be prefetched in preperation for its RecyclerView to come on screen, due to the movement of another, containing RecyclerView. |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutParams` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#generateDefaultLayoutParams()()` Create a default `LayoutParams` object for a child of the RecyclerView. |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutParams` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#generateLayoutParams(android.view.ViewGroup.LayoutParams)(@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/view/ViewGroup.LayoutParams.html lp)` Create a LayoutParams object suitable for this LayoutManager, copying relevant values from the supplied LayoutParams object if possible. |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutParams` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#generateLayoutParams(android.content.Context,android.util.AttributeSet)(@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/content/Context.html context, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/util/AttributeSet.html attrs)` Create a LayoutParams object suitable for this LayoutManager from an inflated layout resource. |
| `int` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#getColumnCountForAccessibility(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State)( @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state )` Returns the number of columns for accessibility. |
| `int` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#getDecoratedBottom(android.view.View)(@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/view/View.html child)` Returns the bottom edge of the given child view within its parent, offset by any applied `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.ItemDecoration`. |
| `void` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#getDecoratedBoundsWithMargins(android.view.View,android.graphics.Rect)(@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/view/View.html view, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/graphics/Rect.html outBounds)` Returns the bounds of the view including its decoration and margins. |
| `int` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#getDecoratedLeft(android.view.View)(@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/view/View.html child)` Returns the left edge of the given child view within its parent, offset by any applied `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.ItemDecoration`. |
| `int` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#getDecoratedRight(android.view.View)(@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/view/View.html child)` Returns the right edge of the given child view within its parent, offset by any applied `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.ItemDecoration`. |
| `int` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#getDecoratedTop(android.view.View)(@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/view/View.html child)` Returns the top edge of the given child view within its parent, offset by any applied `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.ItemDecoration`. |
| `int` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#getRowCountForAccessibility(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State)( @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state )` Returns the number of rows for accessibility. |
| `int` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#getViewCenter(android.view.View)(@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/view/View.html child)` Returns calculated center of the child view in the parent `https://developer.android.com/reference/androidx/leanback/widget/BaseGridView`. |
| `int` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#getWindowKeyLine()()` Returns calculated offset in pixels for alignment key line. |
| `void` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#onAdapterChanged(androidx.recyclerview.widget.RecyclerView.Adapter,androidx.recyclerview.widget.RecyclerView.Adapter)( @https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Adapter oldAdapter, @https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Adapter newAdapter )` Called if the RecyclerView this LayoutManager is bound to has a different adapter set via `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView#setAdapter(androidx.recyclerview.widget.RecyclerView.Adapter)` or `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView#swapAdapter(androidx.recyclerview.widget.RecyclerView.Adapter,boolean)`. |
| `boolean` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#onAddFocusables(androidx.recyclerview.widget.RecyclerView,java.util.ArrayList,int,int)( @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView recyclerView, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/java/util/ArrayList.html views, int direction, int focusableMode )` Called to populate focusable views within the RecyclerView. |
| `void` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#onInitializeAccessibilityNodeInfo(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State,androidx.core.view.accessibility.AccessibilityNodeInfoCompat)( @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/core/view/accessibility/AccessibilityNodeInfoCompat info )` Called by the AccessibilityDelegate when the information about the current layout should be populated. |
| `void` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#onInitializeAccessibilityNodeInfoForItem(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State,android.view.View,androidx.core.view.accessibility.AccessibilityNodeInfoCompat)( @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/view/View.html host, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/core/view/accessibility/AccessibilityNodeInfoCompat info )` Called by the AccessibilityDelegate when the accessibility information for a specific item should be populated. |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/android/view/View.html` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#onInterceptFocusSearch(android.view.View,int)(@https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/android/view/View.html focused, int direction)` This method gives a LayoutManager an opportunity to intercept the initial focus search before the default behavior of `https://developer.android.com/reference/android/view/FocusFinder.html` is used. |
| `void` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#onItemsAdded(androidx.recyclerview.widget.RecyclerView,int,int)( @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView recyclerView, int positionStart, int itemCount )` Called when items have been added to the adapter. |
| `void` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#onItemsChanged(androidx.recyclerview.widget.RecyclerView)(@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView recyclerView)` Called in response to a call to `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Adapter#notifyDataSetChanged()` or `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView#swapAdapter(androidx.recyclerview.widget.RecyclerView.Adapter,boolean)` ()} and signals that the the entire data set has changed. |
| `void` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#onItemsMoved(androidx.recyclerview.widget.RecyclerView,int,int,int)( @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView recyclerView, int fromPosition, int toPosition, int itemCount )` Called when an item is moved withing the adapter. |
| `void` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#onItemsRemoved(androidx.recyclerview.widget.RecyclerView,int,int)( @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView recyclerView, int positionStart, int itemCount )` Called when items have been removed from the adapter. |
| `void` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#onItemsUpdated(androidx.recyclerview.widget.RecyclerView,int,int)( @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView recyclerView, int positionStart, int itemCount )` Called when items have been changed in the adapter. |
| `void` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#onLayoutChildren(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State)( @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state )` Lay out all relevant child views from the given adapter. |
| `void` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#onLayoutCompleted(androidx.recyclerview.widget.RecyclerView.State)(@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state)` Called after a full layout calculation is finished. |
| `void` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#onMeasure(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State,int,int)( @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state, int widthSpec, int heightSpec )` Measure the attached RecyclerView. |
| `boolean` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#onRequestChildFocus(androidx.recyclerview.widget.RecyclerView,androidx.recyclerview.widget.RecyclerView.State,android.view.View,android.view.View)( @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView parent, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/view/View.html child, @https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/android/view/View.html focused )` Called when a descendant view of the RecyclerView requests focus. |
| `void` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#onRestoreInstanceState(android.os.Parcelable)(@https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/android/os/Parcelable.html state)` Called when the RecyclerView is ready to restore the state based on a previous RecyclerView. |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/os/Parcelable.html` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#onSaveInstanceState()()` Called when the LayoutManager should save its state. |
| `void` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#onScrollStateChanged(int)(int state)` RecyclerView calls this method to notify LayoutManager that scroll state has changed. |
| `boolean` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#performAccessibilityAction(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State,int,android.os.Bundle)( @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state, int action, @https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/android/os/Bundle.html args )` Called by AccessibilityDelegate when an action is requested from the RecyclerView. |
| `void` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#removeAndRecycleAllViews(androidx.recyclerview.widget.RecyclerView.Recycler)(@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler)` Removes all views and recycles them using the given recycler. |
| `boolean` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#requestChildRectangleOnScreen(androidx.recyclerview.widget.RecyclerView,android.view.View,android.graphics.Rect,boolean)( @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView parent, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/view/View.html child, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/graphics/Rect.html rect, boolean immediate )` Called when a child of the RecyclerView wants a particular rectangle to be positioned onto the screen. |
| `int` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#scrollHorizontallyBy(int,androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State)( int dx, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state )` Scroll horizontally by dx pixels in screen coordinates and return the distance traveled. |
| `void` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#scrollToPosition(int)(int position)` Scroll to the specified adapter position. |
| `int` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#scrollVerticallyBy(int,androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State)( int dy, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state )` Scroll vertically by dy pixels in screen coordinates and return the distance traveled. |
| `void` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#setFocusOutAllowed(boolean,boolean)(boolean throughFront, boolean throughBack)` Sets whether focus can move out from the front and/or back of the grid view. |
| `void` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#setOrientation(int)(int orientation)` Sets grid view orientation. |
| `void` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#smoothScrollToPosition(androidx.recyclerview.widget.RecyclerView,androidx.recyclerview.widget.RecyclerView.State,int)( @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView recyclerView, @https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state, int position )` Smooth scroll to the specified adapter position. |
| `void` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#startSmoothScroll(androidx.recyclerview.widget.RecyclerView.SmoothScroller)(@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.SmoothScroller smoothScroller)` Starts a smooth scroll using the provided `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.SmoothScroller`. |
| `boolean` | `https://developer.android.com/reference/androidx/leanback/widget/GridLayoutManager#supportsPredictiveItemAnimations()()` Returns whether this LayoutManager supports "predictive item animations". |
| ### Inherited methods |
|---|
| From [androidx.recyclerview.widget.RecyclerView.LayoutManager](https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager) |---|---| | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#addDisappearingView(android.view.View)(https://developer.android.com/reference/android/view/View.html child)` To be called only during `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#onLayoutChildren(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State)` to add a view to the layout that is known to be going away, either because it has been `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Adapter#notifyItemRemoved(int)` 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` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#addDisappearingView(android.view.View,int)(https://developer.android.com/reference/android/view/View.html child, int index)` To be called only during `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#onLayoutChildren(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State)` to add a view to the layout that is known to be going away, either because it has been `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Adapter#notifyItemRemoved(int)` 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` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#addView(android.view.View)(https://developer.android.com/reference/android/view/View.html child)` Add a view to the currently attached RecyclerView if needed. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#addView(android.view.View,int)(https://developer.android.com/reference/android/view/View.html child, int index)` Add a view to the currently attached RecyclerView if needed. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#assertInLayoutOrScroll(java.lang.String)(https://developer.android.com/reference/java/lang/String.html message)` Checks if RecyclerView is in the middle of a layout or scroll and throws an `https://developer.android.com/reference/java/lang/IllegalStateException.html` if it **is not**. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#assertNotInLayoutOrScroll(java.lang.String)(https://developer.android.com/reference/java/lang/String.html message)` Checks if RecyclerView is in the middle of a layout or scroll and throws an `https://developer.android.com/reference/java/lang/IllegalStateException.html` if it **is**. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#attachView(android.view.View)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html child)` Reattach a previously `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#detachView(android.view.View)` view. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#attachView(android.view.View,int)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html child, int index)` Reattach a previously `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#detachView(android.view.View)` view. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#attachView(android.view.View,int,androidx.recyclerview.widget.RecyclerView.LayoutParams)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html child, int index, https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutParams lp)` Reattach a previously `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#detachView(android.view.View)` view. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#calculateItemDecorationsForChild(android.view.View,android.graphics.Rect)( @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html child, @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/graphics/Rect.html outRect )` Calculates the item decor insets applied to the given child and updates the provided Rect instance with the inset values. | | `static int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#chooseSize(int,int,int)(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` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#computeHorizontalScrollExtent(androidx.recyclerview.widget.RecyclerView.State)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state)` Override this method if you want to support scroll bars. | | `int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#computeHorizontalScrollOffset(androidx.recyclerview.widget.RecyclerView.State)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state)` Override this method if you want to support scroll bars. | | `int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#computeHorizontalScrollRange(androidx.recyclerview.widget.RecyclerView.State)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state)` Override this method if you want to support scroll bars. | | `int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#computeVerticalScrollExtent(androidx.recyclerview.widget.RecyclerView.State)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state)` Override this method if you want to support scroll bars. | | `int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#computeVerticalScrollOffset(androidx.recyclerview.widget.RecyclerView.State)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state)` Override this method if you want to support scroll bars. | | `int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#computeVerticalScrollRange(androidx.recyclerview.widget.RecyclerView.State)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state)` Override this method if you want to support scroll bars. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#detachAndScrapAttachedViews(androidx.recyclerview.widget.RecyclerView.Recycler)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler)` Temporarily detach and scrap all currently attached child views. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#detachAndScrapView(android.view.View,androidx.recyclerview.widget.RecyclerView.Recycler)( @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html child, @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler )` Detach a child view and add it to a `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler` scrap heap. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#detachAndScrapViewAt(int,androidx.recyclerview.widget.RecyclerView.Recycler)(int index, @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler)` Detach a child view and add it to a `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler` scrap heap. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#detachView(android.view.View)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html child)` Temporarily detach a child view. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#detachViewAt(int)(int index)` Temporarily detach a child view. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#endAnimation(android.view.View)(https://developer.android.com/reference/android/view/View.html view)` Ends all animations on the view created by the `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.ItemAnimator`. | | `@https://developer.android.com/reference/androidx/annotation/Nullable https://developer.android.com/reference/android/view/View.html` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#findContainingItemView(android.view.View)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html view)` Traverses the ancestors of the given view and returns the item view that contains it and also a direct child of the LayoutManager. | | `@https://developer.android.com/reference/androidx/annotation/Nullable https://developer.android.com/reference/android/view/View.html` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#findViewByPosition(int)(int position)` Finds the view which represents the given adapter position. | | `int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getBaseline()()` Returns offset of the RecyclerView's text baseline from the its top boundary. | | `int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getBottomDecorationHeight(android.view.View)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html child)` Returns the total height of item decorations applied to child's bottom. | | `@https://developer.android.com/reference/androidx/annotation/Nullable https://developer.android.com/reference/android/view/View.html` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getChildAt(int)(int index)` Return the child view at the given index | | `int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getChildCount()()` Return the current number of child views attached to the parent RecyclerView. | | `static int` | `[getChildMeasureSpec](https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getChildMeasureSpec(int,int,int,boolean))( int parentSize, int padding, int childDimension, boolean canScroll )` **This method is deprecated.** use `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getChildMeasureSpec(int,int,int,int,boolean)`
| | `static int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getChildMeasureSpec(int,int,int,int,boolean)( int parentSize, int parentMode, int padding, int childDimension, boolean canScroll )` Calculate a MeasureSpec value for measuring a child view in one dimension. | | `boolean` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getClipToPadding()()` Check if the RecyclerView is configured to clip child views to its padding. | | `int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getDecoratedMeasuredHeight(android.view.View)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html child)` Returns the measured height of the given child, plus the additional size of any insets applied by `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.ItemDecoration`. | | `int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getDecoratedMeasuredWidth(android.view.View)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html child)` Returns the measured width of the given child, plus the additional size of any insets applied by `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.ItemDecoration`. | | `@https://developer.android.com/reference/androidx/annotation/Nullable https://developer.android.com/reference/android/view/View.html` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getFocusedChild()()` Returns the item View which has or contains focus. | | `@https://developer.android.com/reference/androidx/annotation/Px int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getHeight()()` Returns the height that is currently relevant to the LayoutManager. | | `int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getHeightMode()()` Return the height measurement spec mode that is currently relevant to the LayoutManager. | | `int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getItemCount()()` Returns the number of items in the adapter bound to the parent RecyclerView. | | `int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getItemViewType(android.view.View)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html view)` Returns the View type defined by the adapter. | | `int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getLayoutDirection()()` Returns the resolved layout direction for this RecyclerView. | | `int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getLeftDecorationWidth(android.view.View)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html child)` Returns the total width of item decorations applied to child's left. | | `@https://developer.android.com/reference/androidx/annotation/Px int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getMinimumHeight()()` | | `@https://developer.android.com/reference/androidx/annotation/Px int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getMinimumWidth()()` | | `@https://developer.android.com/reference/androidx/annotation/Px int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getPaddingBottom()()` Return the bottom padding of the parent RecyclerView | | `@https://developer.android.com/reference/androidx/annotation/Px int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getPaddingEnd()()` Return the end padding of the parent RecyclerView | | `@https://developer.android.com/reference/androidx/annotation/Px int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getPaddingLeft()()` Return the left padding of the parent RecyclerView | | `@https://developer.android.com/reference/androidx/annotation/Px int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getPaddingRight()()` Return the right padding of the parent RecyclerView | | `@https://developer.android.com/reference/androidx/annotation/Px int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getPaddingStart()()` Return the start padding of the parent RecyclerView | | `@https://developer.android.com/reference/androidx/annotation/Px int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getPaddingTop()()` Return the top padding of the parent RecyclerView | | `int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getPosition(android.view.View)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html view)` Returns the adapter position of the item represented by the given View. | | `static https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager.Properties` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getProperties(android.content.Context,android.util.AttributeSet,int,int)( @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/content/Context.html context, @https://developer.android.com/reference/androidx/annotation/Nullable https://developer.android.com/reference/android/util/AttributeSet.html attrs, int defStyleAttr, int defStyleRes )` Parse the xml attributes to get the most common properties used by layout managers. | | `int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getRightDecorationWidth(android.view.View)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html child)` Returns the total width of item decorations applied to child's right. | | `int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getSelectionModeForAccessibility(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State)( @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler, @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state )` Returns the selection mode for accessibility. | | `int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getTopDecorationHeight(android.view.View)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html child)` Returns the total height of item decorations applied to child's top. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getTransformedBoundingBox(android.view.View,boolean,android.graphics.Rect)( @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html child, boolean includeDecorInsets, @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/graphics/Rect.html out )` Calculates the bounding box of the View while taking into account its matrix changes (translation, scale etc) with respect to the RecyclerView. | | `@https://developer.android.com/reference/androidx/annotation/Px int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getWidth()()` Returns the width that is currently relevant to the LayoutManager. | | `int` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getWidthMode()()` Return the width measurement spec mode that is currently relevant to the LayoutManager. | | `boolean` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#hasFocus()()` Returns true if the RecyclerView this LayoutManager is bound to has or contains focus. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#ignoreView(android.view.View)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html view)` Flags a view so that it will not be scrapped or recycled. | | `boolean` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#isAttachedToWindow()()` Returns whether LayoutManager is currently attached to a RecyclerView which is attached to a window. | | `boolean` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#isAutoMeasureEnabled()()` Returns whether the measuring pass of layout should use the AutoMeasure mechanism of `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView` or if it should be done by the LayoutManager's implementation of `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#onMeasure(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State,int,int)`. | | `boolean` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#isFocused()()` Returns true if the RecyclerView this LayoutManager is bound to has focus. | | `final boolean` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#isItemPrefetchEnabled()()` Sets whether the LayoutManager should be queried for views outside of its viewport while the UI thread is idle between frames. | | `boolean` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#isLayoutHierarchical(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State)( @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler, @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state )` Returns whether layout is hierarchical or not to be used for accessibility. | | `boolean` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#isLayoutReversed()()` Query if the layout is in reverse order. | | `boolean` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#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` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#isSmoothScrolling()()` | | `boolean` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#isViewPartiallyVisible(android.view.View,boolean,boolean)( @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html child, boolean completelyVisible, boolean acceptEndPointInclusion )` Returns whether the given child view is partially or fully visible within the padded bounded area of RecyclerView, depending on the input parameters. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#layoutDecorated(android.view.View,int,int,int,int)( @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html child, int left, int top, int right, int bottom )` Lay out the given child view within the RecyclerView using coordinates that include any current `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.ItemDecoration`. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#layoutDecoratedWithMargins(android.view.View,int,int,int,int)( @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html child, int left, int top, int right, int bottom )` Lay out the given child view within the RecyclerView using coordinates that include any current `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.ItemDecoration` and margins. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#measureChild(android.view.View,int,int)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html 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` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#measureChildWithMargins(android.view.View,int,int)( @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html 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` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#moveView(int,int)(int fromIndex, int toIndex)` Moves a View from one position to another. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#offsetChildrenHorizontal(int)(@https://developer.android.com/reference/androidx/annotation/Px int dx)` Offset all child views attached to the parent RecyclerView by dx pixels along the horizontal axis. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#offsetChildrenVertical(int)(@https://developer.android.com/reference/androidx/annotation/Px int dy)` Offset all child views attached to the parent RecyclerView by dy pixels along the vertical axis. | | `void` | `@https://developer.android.com/reference/androidx/annotation/CallSuper https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#onAttachedToWindow(androidx.recyclerview.widget.RecyclerView)(https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView view)` Called when this LayoutManager is both attached to a RecyclerView and that RecyclerView is attached to a window. | | `void` | `[onDetachedFromWindow](https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#onDetachedFromWindow(androidx.recyclerview.widget.RecyclerView))(https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView view)` **This method is deprecated.** override `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#onDetachedFromWindow(androidx.recyclerview.widget.RecyclerView,androidx.recyclerview.widget.RecyclerView.Recycler)`
| | `void` | `@https://developer.android.com/reference/androidx/annotation/CallSuper https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#onDetachedFromWindow(androidx.recyclerview.widget.RecyclerView,androidx.recyclerview.widget.RecyclerView.Recycler)(https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView view, https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler)` Called when this LayoutManager is detached from its parent RecyclerView or when its parent RecyclerView is detached from its window. | | `@https://developer.android.com/reference/androidx/annotation/Nullable https://developer.android.com/reference/android/view/View.html` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#onFocusSearchFailed(android.view.View,int,androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State)( @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html focused, int direction, @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler, @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state )` Called when searching for a focusable view in the given direction has failed for the current content of the RecyclerView. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#onInitializeAccessibilityEvent(android.view.accessibility.AccessibilityEvent)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/accessibility/AccessibilityEvent.html event)` | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#onInitializeAccessibilityEvent(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State,android.view.accessibility.AccessibilityEvent)( @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler, @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state, @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/accessibility/AccessibilityEvent.html event )` Called by the accessibility delegate to initialize an accessibility event. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#onItemsUpdated(androidx.recyclerview.widget.RecyclerView,int,int,java.lang.Object)( @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView recyclerView, int positionStart, int itemCount, @https://developer.android.com/reference/androidx/annotation/Nullable https://developer.android.com/reference/java/lang/Object.html payload )` Called when items have been changed in the adapter and with optional payload. | | `boolean` | `[onRequestChildFocus](https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#onRequestChildFocus(androidx.recyclerview.widget.RecyclerView,android.view.View,android.view.View))( @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView parent, @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html child, @https://developer.android.com/reference/androidx/annotation/Nullable https://developer.android.com/reference/android/view/View.html focused )` **This method is deprecated.** Use `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#onRequestChildFocus(androidx.recyclerview.widget.RecyclerView,androidx.recyclerview.widget.RecyclerView.State,android.view.View,android.view.View)`
| | `boolean` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#performAccessibilityActionForItem(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State,android.view.View,int,android.os.Bundle)( @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler, @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state, @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html view, int action, @https://developer.android.com/reference/androidx/annotation/Nullable https://developer.android.com/reference/android/os/Bundle.html args )` Called by AccessibilityDelegate when an accessibility action is requested on one of the children of LayoutManager. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#postOnAnimation(java.lang.Runnable)(https://developer.android.com/reference/java/lang/Runnable.html action)` Causes the Runnable to execute on the next animation time step. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#removeAllViews()()` Remove all views from the currently attached RecyclerView. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#removeAndRecycleView(android.view.View,androidx.recyclerview.widget.RecyclerView.Recycler)( @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html child, @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler )` Remove a child view and recycle it using the given Recycler. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#removeAndRecycleViewAt(int,androidx.recyclerview.widget.RecyclerView.Recycler)( int index, @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler )` Remove a child view and recycle it using the given Recycler. | | `boolean` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#removeCallbacks(java.lang.Runnable)(https://developer.android.com/reference/java/lang/Runnable.html action)` Removes the specified Runnable from the message queue. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#removeDetachedView(android.view.View)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html child)` Finish removing a view that was previously temporarily `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#detachView(android.view.View)`. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#removeView(android.view.View)(https://developer.android.com/reference/android/view/View.html child)` Remove a view from the currently attached RecyclerView if needed. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#removeViewAt(int)(int index)` Remove a view from the currently attached RecyclerView if needed. | | `boolean` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#requestChildRectangleOnScreen(androidx.recyclerview.widget.RecyclerView,android.view.View,android.graphics.Rect,boolean,boolean)( @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView parent, @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html child, @https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/graphics/Rect.html rect, boolean immediate, boolean focusedChildVisible )` Requests that the given child of the RecyclerView be positioned onto the screen. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#requestLayout()()` Calls `RecyclerView#requestLayout` on the underlying RecyclerView | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#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. | | `void` | `[setAutoMeasureEnabled](https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#setAutoMeasureEnabled(boolean))(boolean enabled)` **This method is deprecated.** Implementors of LayoutManager should define whether or not it uses AutoMeasure by overriding `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#isAutoMeasureEnabled()`.
| | `final void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#setItemPrefetchEnabled(boolean)(boolean enabled)` Sets whether the LayoutManager should be queried for views outside of its viewport while the UI thread is idle between frames. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#setMeasuredDimension(int,int)(int widthSize, int heightSize)` `https://developer.android.com/reference/android/view/View.html#setMeasuredDimension(int, int)` of the host RecyclerView. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#setMeasuredDimension(android.graphics.Rect,int,int)(https://developer.android.com/reference/android/graphics/Rect.html 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 `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView#onMeasure(int,int)`. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#setMeasurementCacheEnabled(boolean)(boolean measurementCacheEnabled)` Sets whether RecyclerView should use its own measurement cache for the children. | | `void` | `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#stopIgnoringView(android.view.View)(@https://developer.android.com/reference/androidx/annotation/NonNull https://developer.android.com/reference/android/view/View.html view)` View can be scrapped and recycled again. | |
## Public constructors
### GridLayoutManager
Added in [1.0.0](https://developer.android.com/jetpack/androidx/releases/leanback#1.0.0)
```
public GridLayoutManager()
```
## Public methods
### canScrollHorizontally
```
public 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
```
public 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
```
public boolean checkLayoutParams(@Nullable 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 |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutParams lp` | LayoutParams object to check |
| Returns |
|---|---|
| `boolean` | true if this LayoutParams object is valid, false otherwise |
### collectAdjacentPrefetchPositions
```
public void collectAdjacentPrefetchPositions(
int dx,
int dy,
@NonNull RecyclerView.State state,
@NonNull RecyclerView.LayoutManager.LayoutPrefetchRegistry layoutPrefetchRegistry
)
```
Gather all positions from the LayoutManager to be prefetched, given specified momentum.
If item prefetch is enabled, this method is called in between traversals to gather which positions the LayoutManager will soon need, given upcoming movement in subsequent traversals.
The LayoutManager should call `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager.LayoutPrefetchRegistry#addPosition(int,int)` for each item to be prepared, and these positions will have their ViewHolders created and bound, if there is sufficient time available, in advance of being needed by a scroll or layout.
| Parameters |
|---|---|
| `int dx` | X movement component. |
| `int dy` | Y movement component. |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state` | State of RecyclerView |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager.LayoutPrefetchRegistry layoutPrefetchRegistry` | PrefetchRegistry to add prefetch entries into. |
| See also |
|---|---|
| `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#isItemPrefetchEnabled()` | |
| `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#collectInitialPrefetchPositions(int,androidx.recyclerview.widget.RecyclerView.LayoutManager.LayoutPrefetchRegistry)` | |
### collectInitialPrefetchPositions
```
public void collectInitialPrefetchPositions(
int adapterItemCount,
@NonNull RecyclerView.LayoutManager.LayoutPrefetchRegistry layoutPrefetchRegistry
)
```
Gather all positions from the LayoutManager to be prefetched in preperation for its RecyclerView to come on screen, due to the movement of another, containing RecyclerView.
This method is only called when a RecyclerView is nested in another RecyclerView.
If item prefetch is enabled for this LayoutManager, as well in another containing LayoutManager, this method is called in between draw traversals to gather which positions this LayoutManager will first need, once it appears on the screen.
For example, if this LayoutManager represents a horizontally scrolling list within a vertically scrolling LayoutManager, this method would be called when the horizontal list is about to come onscreen.
The LayoutManager should call `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager.LayoutPrefetchRegistry#addPosition(int,int)` for each item to be prepared, and these positions will have their ViewHolders created and bound, if there is sufficient time available, in advance of being needed by a scroll or layout.
| Parameters |
|---|---|
| `int adapterItemCount` | number of items in the associated adapter. |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager.LayoutPrefetchRegistry layoutPrefetchRegistry` | PrefetchRegistry to add prefetch entries into. |
| See also |
|---|---|
| `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#isItemPrefetchEnabled()` | |
| `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#collectAdjacentPrefetchPositions(int,int,androidx.recyclerview.widget.RecyclerView.State,androidx.recyclerview.widget.RecyclerView.LayoutManager.LayoutPrefetchRegistry)` | |
### generateDefaultLayoutParams
Added in [1.0.0](https://developer.android.com/jetpack/androidx/releases/leanback#1.0.0)
```
public @NonNull 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 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).
### generateLayoutParams
```
public @NonNull RecyclerView.LayoutParams generateLayoutParams(@NonNull ViewGroup.LayoutParams lp)
```
Create a LayoutParams object suitable for this LayoutManager, copying relevant values from the supplied LayoutParams object if possible.
*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).
### generateLayoutParams
```
public @NonNull RecyclerView.LayoutParams generateLayoutParams(@NonNull Context context, @NonNull AttributeSet attrs)
```
Create a LayoutParams object suitable for this LayoutManager from an inflated layout resource.
*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).
### getColumnCountForAccessibility
```
public int getColumnCountForAccessibility(
@NonNull RecyclerView.Recycler recycler,
@NonNull 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 |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler` | The Recycler that can be used to convert view positions into adapter positions |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state` | The current state of RecyclerView |
| Returns |
|---|---|
| `int` | The number of rows in LayoutManager for accessibility. |
### getDecoratedBottom
```
public int getDecoratedBottom(@NonNull View child)
```
Returns the bottom edge of the given child view within its parent, offset by any applied `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.ItemDecoration`.
| Parameters |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/view/View.html child` | Child to query |
| Returns |
|---|---|
| `int` | Child bottom edge with offsets applied |
| See also |
|---|---|
| `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getBottomDecorationHeight(android.view.View)` | |
### getDecoratedBoundsWithMargins
```
public void getDecoratedBoundsWithMargins(@NonNull View view, @NonNull Rect outBounds)
```
Returns the bounds of the view including its decoration and margins.
| Parameters |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/view/View.html view` | The view element to check |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/graphics/Rect.html outBounds` | A rect that will receive the bounds of the element including its decoration and margins. |
### getDecoratedLeft
```
public int getDecoratedLeft(@NonNull View child)
```
Returns the left edge of the given child view within its parent, offset by any applied `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.ItemDecoration`.
| Parameters |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/view/View.html child` | Child to query |
| Returns |
|---|---|
| `int` | Child left edge with offsets applied |
| See also |
|---|---|
| `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getLeftDecorationWidth(android.view.View)` | |
### getDecoratedRight
```
public int getDecoratedRight(@NonNull View child)
```
Returns the right edge of the given child view within its parent, offset by any applied `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.ItemDecoration`.
| Parameters |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/view/View.html child` | Child to query |
| Returns |
|---|---|
| `int` | Child right edge with offsets applied |
| See also |
|---|---|
| `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getRightDecorationWidth(android.view.View)` | |
### getDecoratedTop
```
public int getDecoratedTop(@NonNull View child)
```
Returns the top edge of the given child view within its parent, offset by any applied `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.ItemDecoration`.
| Parameters |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/view/View.html child` | Child to query |
| Returns |
|---|---|
| `int` | Child top edge with offsets applied |
| See also |
|---|---|
| `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getTopDecorationHeight(android.view.View)` | |
### getRowCountForAccessibility
```
public int getRowCountForAccessibility(
@NonNull RecyclerView.Recycler recycler,
@NonNull 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 |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler` | The Recycler that can be used to convert view positions into adapter positions |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state` | The current state of RecyclerView |
| Returns |
|---|---|
| `int` | The number of rows in LayoutManager for accessibility. |
### getViewCenter
Added in [1.1.0-alpha02](https://developer.android.com/jetpack/androidx/releases/leanback#1.1.0-alpha02)
```
public int getViewCenter(@NonNull View child)
```
Returns calculated center of the child view in the parent `https://developer.android.com/reference/androidx/leanback/widget/BaseGridView`. The value is calculated from item alignment settings. A default value is center of the child view.
| Returns |
|---|---|
| `int` | The calculated center of the child view in the parent `https://developer.android.com/reference/androidx/leanback/widget/BaseGridView`. |
### getWindowKeyLine
Added in [1.1.0-alpha02](https://developer.android.com/jetpack/androidx/releases/leanback#1.1.0-alpha02)
```
public int getWindowKeyLine()
```
Returns calculated offset in pixels for alignment key line. The value is calculated from `https://developer.android.com/reference/androidx/leanback/widget/BaseGridView`'s window alignment settings. A default value is center of the `https://developer.android.com/reference/androidx/leanback/widget/BaseGridView`.
| Returns |
|---|---|
| `int` | The calculated offset in pixels for alignment key line. |
### onAdapterChanged
```
public void onAdapterChanged(
@Nullable RecyclerView.Adapter oldAdapter,
@Nullable RecyclerView.Adapter newAdapter
)
```
Called if the RecyclerView this LayoutManager is bound to has a different adapter set via `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView#setAdapter(androidx.recyclerview.widget.RecyclerView.Adapter)` or `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView#swapAdapter(androidx.recyclerview.widget.RecyclerView.Adapter,boolean)`. 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 |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Adapter oldAdapter` | The previous adapter instance. Will be null if there was previously no adapter. |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Adapter newAdapter` | The new adapter instance. Might be null if `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView#setAdapter(androidx.recyclerview.widget.RecyclerView.Adapter)` is called with `null`. |
### onAddFocusables
```
public boolean onAddFocusables(
@NonNull RecyclerView recyclerView,
@NonNull ArrayList views,
int direction,
int focusableMode
)
```
Called to populate focusable views within the RecyclerView.
The LayoutManager implementation should return `true` if the default behavior of `https://developer.android.com/reference/android/view/View.html#addFocusables(java.util.ArrayList<android.view.View>, int)` should be suppressed.
The default implementation returns `false` to trigger RecyclerView to fall back to the default ViewGroup behavior.
| Parameters |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView recyclerView` | The RecyclerView hosting this LayoutManager |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/java/util/ArrayList.html views` | List of output views. This method should add valid focusable views to this list. |
| `int direction` | One of `https://developer.android.com/reference/android/view/View.html#FOCUS_UP`, `https://developer.android.com/reference/android/view/View.html#FOCUS_DOWN`, `https://developer.android.com/reference/android/view/View.html#FOCUS_LEFT`, `https://developer.android.com/reference/android/view/View.html#FOCUS_RIGHT`, `https://developer.android.com/reference/android/view/View.html#FOCUS_BACKWARD`, `https://developer.android.com/reference/android/view/View.html#FOCUS_FORWARD` |
| `int focusableMode` | 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 |
|---|---|
| `https://developer.android.com/reference/android/view/View.html#FOCUSABLES_ALL` | |
| `https://developer.android.com/reference/android/view/View.html#FOCUSABLES_TOUCH_MODE` | |
### onInitializeAccessibilityNodeInfo
```
public void onInitializeAccessibilityNodeInfo(
@NonNull RecyclerView.Recycler recycler,
@NonNull RecyclerView.State state,
@NonNull AccessibilityNodeInfoCompat info
)
```
Called by the AccessibilityDelegate when the information about the current layout should be populated.
Default implementation adds a `https://developer.android.com/reference/androidx/core/view/accessibility/AccessibilityNodeInfoCompat.CollectionInfoCompat`.
You should override `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getRowCountForAccessibility(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State)`, `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getColumnCountForAccessibility(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State)`, `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#isLayoutHierarchical(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State)` and `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getSelectionModeForAccessibility(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State)` for more accurate accessibility information.
| Parameters |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler` | The Recycler that can be used to convert view positions into adapter positions |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state` | The current state of RecyclerView |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/core/view/accessibility/AccessibilityNodeInfoCompat info` | The info that should be filled by the LayoutManager |
| See also |
|---|---|
| `https://developer.android.com/reference/android/view/View.html#onInitializeAccessibilityNodeInfo(android.view.accessibility.AccessibilityNodeInfo)` | |
| `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getRowCountForAccessibility(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State)` | |
| `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getColumnCountForAccessibility(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State)` | |
| `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#isLayoutHierarchical(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State)` | |
| `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#getSelectionModeForAccessibility(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State)` | |
### onInitializeAccessibilityNodeInfoForItem
```
public void onInitializeAccessibilityNodeInfoForItem(
@NonNull RecyclerView.Recycler recycler,
@NonNull RecyclerView.State state,
@NonNull View host,
@NonNull 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 |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler` | The Recycler that can be used to convert view positions into adapter positions |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state` | The current state of RecyclerView |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/view/View.html host` | The child for which accessibility node info should be populated |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/core/view/accessibility/AccessibilityNodeInfoCompat info` | The info to fill out about the item |
| See also |
|---|---|
| `https://developer.android.com/reference/android/widget/AbsListView.html#onInitializeAccessibilityNodeInfoForItem(android.view.View, int, android.view.accessibility.AccessibilityNodeInfo)` | |
### onInterceptFocusSearch
```
public @Nullable View onInterceptFocusSearch(@Nullable View focused, int direction)
```
This method gives a LayoutManager an opportunity to intercept the initial focus search before the default behavior of `https://developer.android.com/reference/android/view/FocusFinder.html` is used. If this method returns null FocusFinder will attempt to find a focusable child view. If it fails then `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#onFocusSearchFailed(android.view.View,int,androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.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 |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/android/view/View.html focused` | The currently focused view |
| `int direction` | One of `https://developer.android.com/reference/android/view/View.html#FOCUS_UP`, `https://developer.android.com/reference/android/view/View.html#FOCUS_DOWN`, `https://developer.android.com/reference/android/view/View.html#FOCUS_LEFT`, `https://developer.android.com/reference/android/view/View.html#FOCUS_RIGHT`, `https://developer.android.com/reference/android/view/View.html#FOCUS_BACKWARD`, `https://developer.android.com/reference/android/view/View.html#FOCUS_FORWARD` |
| Returns |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/android/view/View.html` | A descendant view to focus or null to fall back to default behavior. The default implementation returns null. |
### onItemsAdded
```
public void onItemsAdded(
@NonNull 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
```
public void onItemsChanged(@NonNull RecyclerView recyclerView)
```
Called in response to a call to `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Adapter#notifyDataSetChanged()` or `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView#swapAdapter(androidx.recyclerview.widget.RecyclerView.Adapter,boolean)` ()} and signals that the the entire data set has changed.
### onItemsMoved
```
public void onItemsMoved(
@NonNull RecyclerView recyclerView,
int fromPosition,
int toPosition,
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 `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Adapter#notifyItemMoved(int,int)` is called.
### onItemsRemoved
```
public void onItemsRemoved(
@NonNull RecyclerView recyclerView,
int positionStart,
int itemCount
)
```
Called when items have been removed from the adapter.
### onItemsUpdated
```
public void onItemsUpdated(
@NonNull RecyclerView recyclerView,
int positionStart,
int itemCount
)
```
Called when items have been changed in the adapter. To receive payload, override `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#onItemsUpdated(androidx.recyclerview.widget.RecyclerView,int,int,java.lang.Object)` instead, then this callback will not be invoked.
### onLayoutChildren
```
public void onLayoutChildren(
@NonNull RecyclerView.Recycler recycler,
@NonNull 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 `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView#getItemAnimator()`, 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 `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#supportsPredictiveItemAnimations()`, which is the default, and runs a normal layout operation during `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#onLayoutChildren(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State)`, the RecyclerView will have enough information to run those animations in a simple way. For example, the default ItemAnimator, `https://developer.android.com/reference/androidx/recyclerview/widget/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 `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#supportsPredictiveItemAnimations()` and add additional logic to `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#onLayoutChildren(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State)`. Supporting predictive animations means that `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#onLayoutChildren(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.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, `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutParams#isItemRemoved()` 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 `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#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 |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler` | Recycler to use for fetching potentially cached views for a position |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state` | Transient state of RecyclerView |
### onLayoutCompleted
```
public void onLayoutCompleted(@NonNull RecyclerView.State state)
```
Called after a full layout calculation is finished. The layout calculation may include multiple `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#onLayoutChildren(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State)` calls due to animations or layout measurement but it will include only one `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#onLayoutCompleted(androidx.recyclerview.widget.RecyclerView.State)` call. This method will be called at the end of `https://developer.android.com/reference/android/view/View.html#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 |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state` | Transient state of RecyclerView |
### onMeasure
```
public void onMeasure(
@NonNull RecyclerView.Recycler recycler,
@NonNull RecyclerView.State state,
int widthSpec,
int heightSpec
)
```
Measure the attached RecyclerView. Implementations must call `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#setMeasuredDimension(int,int)` before returning.
It is strongly advised to use the AutoMeasure mechanism by overriding `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#isAutoMeasureEnabled()` to return true as AutoMeasure handles all the standard measure cases including when the RecyclerView's layout_width or layout_height have been set to wrap_content. If `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#isAutoMeasureEnabled()` is overridden to return true, this method should not be overridden.
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 |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler` | Recycler |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state` | Transient state of RecyclerView |
| `int widthSpec` | Width `https://developer.android.com/reference/android/view/View.MeasureSpec.html` |
| `int heightSpec` | Height `https://developer.android.com/reference/android/view/View.MeasureSpec.html` |
| See also |
|---|---|
| `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#isAutoMeasureEnabled()` | |
| `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#setMeasuredDimension(int,int)` | |
### onRequestChildFocus
```
public boolean onRequestChildFocus(
@NonNull RecyclerView parent,
@NonNull RecyclerView.State state,
@NonNull View child,
@Nullable 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 |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView parent` | The RecyclerView hosting this LayoutManager |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state` | Current state of RecyclerView |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/view/View.html child` | Direct child of the RecyclerView containing the newly focused view |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/android/view/View.html focused` | 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
```
public void onRestoreInstanceState(@Nullable Parcelable state)
```
Called when the RecyclerView is ready to restore the state based on a previous RecyclerView. Notice that this might happen after an actual layout, based on how Adapter prefers to restore State. See `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Adapter#getStateRestorationPolicy()` for more information.
| Parameters |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/android/os/Parcelable.html state` | The parcelable that was returned by the previous LayoutManager's `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#onSaveInstanceState()` method. |
### onSaveInstanceState
```
public @NonNull 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 |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/os/Parcelable.html` | Necessary information for LayoutManager to be able to restore its state |
### onScrollStateChanged
```
public void onScrollStateChanged(int state)
```
RecyclerView calls this method to notify LayoutManager that scroll state has changed.
| Parameters |
|---|---|
| `int state` | The new scroll state for RecyclerView |
### performAccessibilityAction
```
public boolean performAccessibilityAction(
@NonNull RecyclerView.Recycler recycler,
@NonNull RecyclerView.State state,
int action,
@Nullable Bundle args
)
```
Called by AccessibilityDelegate when an action is requested from the RecyclerView.
| Parameters |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler` | The Recycler that can be used to convert view positions into adapter positions |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state` | The current state of RecyclerView |
| `int action` | The action to perform |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/Nullable.html https://developer.android.com/reference/android/os/Bundle.html args` | Optional action arguments |
| See also |
|---|---|
| `https://developer.android.com/reference/android/view/View.html#performAccessibilityAction(int, android.os.Bundle)` | |
### removeAndRecycleAllViews
```
public void removeAndRecycleAllViews(@NonNull 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 `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler#clear()` too.
If a View is marked as "ignored", it is not removed nor recycled.
| Parameters |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler` | Recycler to use to recycle children |
| See also |
|---|---|
| `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#removeAndRecycleView(android.view.View,androidx.recyclerview.widget.RecyclerView.Recycler)` | |
| `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#removeAndRecycleViewAt(int,androidx.recyclerview.widget.RecyclerView.Recycler)` | |
| `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#ignoreView(android.view.View)` | |
### requestChildRectangleOnScreen
```
public boolean requestChildRectangleOnScreen(
@NonNull RecyclerView parent,
@NonNull View child,
@NonNull Rect rect,
boolean immediate
)
```
Called when a child of the RecyclerView wants a particular rectangle to be positioned onto the screen. See `https://developer.android.com/reference/android/view/ViewParent.html#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 |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView parent` | The parent RecyclerView. |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/view/View.html child` | The direct child making the request. |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/android/graphics/Rect.html rect` | The rectangle in the child's coordinates the child wishes to be on the screen. |
| `boolean immediate` | True to forbid animated or delayed scrolling, false otherwise |
| Returns |
|---|---|
| `boolean` | Whether the group scrolled to handle the operation |
### scrollHorizontallyBy
```
public int scrollHorizontallyBy(
int dx,
@NonNull RecyclerView.Recycler recycler,
@NonNull 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 |
|---|---|
| `int dx` | distance to scroll by in pixels. X increases as scroll position approaches the right. |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler` | Recycler to use for fetching potentially cached views for a position |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State 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
```
public void scrollToPosition(int position)
```
Scroll to the specified adapter position. Actual position of the item on the screen depends on the LayoutManager implementation.
| Parameters |
|---|---|
| `int position` | Scroll to this adapter position. |
### scrollVerticallyBy
```
public int scrollVerticallyBy(
int dy,
@NonNull RecyclerView.Recycler recycler,
@NonNull 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 |
|---|---|
| `int dy` | distance to scroll in pixels. Y increases as scroll position approaches the bottom. |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.Recycler recycler` | Recycler to use for fetching potentially cached views for a position |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State 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. |
### setFocusOutAllowed
Added in [1.0.0](https://developer.android.com/jetpack/androidx/releases/leanback#1.0.0)
```
public void setFocusOutAllowed(boolean throughFront, boolean throughBack)
```
Sets whether focus can move out from the front and/or back of the grid view.
| Parameters |
|---|---|
| `boolean throughFront` | For the vertical orientation, this controls whether focus can move out from the top of the grid. For the horizontal orientation, this controls whether focus can move out the front side of the grid. |
| `boolean throughBack` | For the vertical orientation, this controls whether focus can move out from the bottom of the grid. For the horizontal orientation, this controls whether focus can move out the back side of the grid. |
### setOrientation
Added in [1.0.0](https://developer.android.com/jetpack/androidx/releases/leanback#1.0.0)
```
public void setOrientation(int orientation)
```
Sets grid view orientation.
### smoothScrollToPosition
```
public void smoothScrollToPosition(
@NonNull RecyclerView recyclerView,
@NonNull RecyclerView.State state,
int position
)
```
Smooth scroll to the specified adapter position.
To support smooth scrolling, override this method, create your `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.SmoothScroller` instance and call `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#startSmoothScroll(androidx.recyclerview.widget.RecyclerView.SmoothScroller)`.
| Parameters |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView recyclerView` | The RecyclerView to which this layout manager is attached |
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.State state` | Current State of RecyclerView |
| `int position` | Scroll to this adapter position. |
### startSmoothScroll
```
public void startSmoothScroll(@NonNull RecyclerView.SmoothScroller smoothScroller)
```
Starts a smooth scroll using the provided `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.SmoothScroller`.
Each instance of SmoothScroller is intended to only be used once. Provide a new SmoothScroller instance each time this method is called.
Calling this method will cancel any previous smooth scroll request.
| Parameters |
|---|---|
| `@https://jspecify.dev/docs/api/org/jspecify/annotations/NonNull.html https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.SmoothScroller smoothScroller` | Instance which defines how smooth scroll should be animated |
### supportsPredictiveItemAnimations
```
public boolean supportsPredictiveItemAnimations()
```
Returns whether this LayoutManager supports "predictive item animations".
"Predictive item animations" are automatically created animations that show where items came from, and where they are going to, as items are added, removed, or moved within a layout.
A LayoutManager wishing to support predictive item animations must override this method to return true (the default implementation returns false) and must obey certain behavioral contracts outlined in `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView.LayoutManager#onLayoutChildren(androidx.recyclerview.widget.RecyclerView.Recycler,androidx.recyclerview.widget.RecyclerView.State)`.
Whether item animations actually occur in a RecyclerView is actually determined by both the return value from this method and the `https://developer.android.com/reference/androidx/recyclerview/widget/RecyclerView#setItemAnimator(androidx.recyclerview.widget.RecyclerView.ItemAnimator)` set on the RecyclerView itself. If the RecyclerView has a non-null ItemAnimator but this method returns false, then only "simple item animations" will be enabled in the RecyclerView, in which views whose position are changing are simply faded in/out. If the RecyclerView has a non-null ItemAnimator and this method returns true, then predictive item animations will be enabled in the RecyclerView.
| Returns |
|---|---|
| `boolean` | true if this LayoutManager supports predictive item animations, false otherwise. |