GridLayoutManager

Artifact: androidx.recyclerview:recyclerview

Added in 1.0.0

Kotlin |Java

class GridLayoutManager : LinearLayoutManager

kotlin.Any
↳	androidx.recyclerview.widget.RecyclerView.LayoutManager
	↳	androidx.recyclerview.widget.LinearLayoutManager
		↳	androidx.recyclerview.widget.GridLayoutManager

A RecyclerView.LayoutManager implementations that lays out items in a grid.

By default, each item occupies 1 span. You can change it by providing a custom SpanSizeLookup instance via setSpanSizeLookup.

Summary

Nested types
`class GridLayoutManager.DefaultSpanSizeLookup : GridLayoutManager.SpanSizeLookup` Default implementation for `SpanSizeLookup`.
`class GridLayoutManager.LayoutParams : RecyclerView.LayoutParams` LayoutParams used by GridLayoutManager.
`abstract class GridLayoutManager.SpanSizeLookup` A helper class to provide the number of spans each item occupies.

Constants
`const Int`	`DEFAULT_SPAN_COUNT = -1`

Public constructors
`GridLayoutManager(context: Context!, spanCount: Int)` Creates a vertical GridLayoutManager
`GridLayoutManager( context: Context!, attrs: AttributeSet!, defStyleAttr: Int, defStyleRes: Int )` Constructor used when layout manager is set in XML by RecyclerView attribute "layoutManager".
`GridLayoutManager( context: Context!, spanCount: Int, orientation: Int, reverseLayout: Boolean )`

Public functions
`Boolean`	`checkLayoutParams(lp: RecyclerView.LayoutParams!)` Determines the validity of the supplied LayoutParams object.
`Int`	`computeHorizontalScrollOffset(state: RecyclerView.State!)` Override this method if you want to support scroll bars.
`Int`	`computeHorizontalScrollRange(state: RecyclerView.State!)` Override this method if you want to support scroll bars.
`Int`	`computeVerticalScrollOffset(state: RecyclerView.State!)` Override this method if you want to support scroll bars.
`Int`	`computeVerticalScrollRange(state: RecyclerView.State!)` Override this method if you want to support scroll bars.
`RecyclerView.LayoutParams!`	`generateDefaultLayoutParams()` Create a default `LayoutParams` object for a child of the RecyclerView.
`RecyclerView.LayoutParams!`	`generateLayoutParams(lp: ViewGroup.LayoutParams!)` Create a LayoutParams object suitable for this LayoutManager, copying relevant values from the supplied LayoutParams object if possible.
`RecyclerView.LayoutParams!`	`generateLayoutParams(c: Context!, attrs: AttributeSet!)` Create a LayoutParams object suitable for this LayoutManager from an inflated layout resource.
`Int`	`getColumnCountForAccessibility( recycler: RecyclerView.Recycler!, state: RecyclerView.State! )` Returns the number of columns for accessibility.
`Int`	`getRowCountForAccessibility( recycler: RecyclerView.Recycler!, state: RecyclerView.State! )` Returns the number of rows for accessibility.
`Int`	`getSpanCount()` Returns the number of spans laid out by this grid.
`GridLayoutManager.SpanSizeLookup!`	`getSpanSizeLookup()` Returns the current `SpanSizeLookup` used by the GridLayoutManager.
`Boolean`	`isUsingSpansToEstimateScrollbarDimensions()` Returns true if the scroll offset and scroll range calculations take account of span information.
`View!`	`onFocusSearchFailed( focused: View!, direction: Int, recycler: RecyclerView.Recycler!, state: RecyclerView.State! )` Called when searching for a focusable view in the given direction has failed for the current content of the RecyclerView.
`Unit`	`onInitializeAccessibilityNodeInfo( recycler: RecyclerView.Recycler, state: RecyclerView.State, info: AccessibilityNodeInfoCompat )` Called by the AccessibilityDelegate when the information about the current layout should be populated.
`Unit`	`onInitializeAccessibilityNodeInfoForItem( recycler: RecyclerView.Recycler!, state: RecyclerView.State!, host: View!, info: AccessibilityNodeInfoCompat! )` Called by the AccessibilityDelegate when the accessibility information for a specific item should be populated.
`Unit`	`onItemsAdded( recyclerView: RecyclerView!, positionStart: Int, itemCount: Int )` Called when items have been added to the adapter.
`Unit`	`onItemsChanged(recyclerView: RecyclerView!)` Called in response to a call to `notifyDataSetChanged` or `swapAdapter` ()} and signals that the the entire data set has changed.
`Unit`	`onItemsMoved(recyclerView: RecyclerView!, from: Int, to: Int, itemCount: Int)` Called when an item is moved withing the adapter.
`Unit`	`onItemsRemoved( recyclerView: RecyclerView!, positionStart: Int, itemCount: Int )` Called when items have been removed from the adapter.
`Unit`	`onItemsUpdated( recyclerView: RecyclerView!, positionStart: Int, itemCount: Int, payload: Any! )` Called when items have been changed in the adapter and with optional payload.
`Unit`	`onLayoutChildren( recycler: RecyclerView.Recycler!, state: RecyclerView.State! )` Lay out all relevant child views from the given adapter.
`Unit`	`onLayoutCompleted(state: RecyclerView.State!)` Called after a full layout calculation is finished.
`Int`	`scrollHorizontallyBy( dx: Int, recycler: RecyclerView.Recycler!, state: RecyclerView.State! )` Scroll horizontally by dx pixels in screen coordinates and return the distance traveled.
`Int`	`scrollVerticallyBy( dy: Int, recycler: RecyclerView.Recycler!, state: RecyclerView.State! )` Scroll vertically by dy pixels in screen coordinates and return the distance traveled.
`Unit`	`setMeasuredDimension(childrenBounds: Rect!, wSpec: Int, hSpec: Int)` Sets the measured dimensions from the given bounding box of the children and the measurement specs that were passed into `onMeasure`.
`Unit`	`setSpanCount(spanCount: Int)` Sets the number of spans to be laid out.
`Unit`	`setSpanSizeLookup(spanSizeLookup: GridLayoutManager.SpanSizeLookup!)` Sets the source to get the number of spans occupied by each item in the adapter.
`Unit`	`setStackFromEnd(stackFromEnd: Boolean)` stackFromEnd is not supported by GridLayoutManager.
`Unit`	`setUsingSpansToEstimateScrollbarDimensions( useSpansToEstimateScrollBarDimensions: Boolean )` When this flag is set, the scroll offset and scroll range calculations will take account of span information.
`Boolean`	`supportsPredictiveItemAnimations()` Returns whether this LayoutManager supports "predictive item animations".

Inherited Constants

From androidx.recyclerview.widget.LinearLayoutManager

`const Int`	`HORIZONTAL = 0`
`const Int`	`INVALID_OFFSET = -2147483648`
`const Int`	`VERTICAL = 1`

Inherited functions

From androidx.recyclerview.widget.LinearLayoutManager

`Unit`	`assertNotInLayoutOrScroll(message: String!)` Checks if RecyclerView is in the middle of a layout or scroll and throws an `IllegalStateException` if it is.
`Unit`	`calculateExtraLayoutSpace( state: RecyclerView.State, extraLayoutSpace: IntArray )` Calculates the amount of extra space (in pixels) that should be laid out by and stores the result in `extraLayoutSpace`.
`Boolean`	`canScrollHorizontally()`
`Boolean`	`canScrollVertically()`
`Unit`	`collectAdjacentPrefetchPositions( dx: Int, dy: Int, state: RecyclerView.State!, layoutPrefetchRegistry: RecyclerView.LayoutManager.LayoutPrefetchRegistry! )` Gather all positions from the LayoutManager to be prefetched, given specified momentum.
`Unit`	`collectInitialPrefetchPositions( adapterItemCount: Int, layoutPrefetchRegistry: RecyclerView.LayoutManager.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.
`Int`	`computeHorizontalScrollExtent(state: RecyclerView.State!)` Override this method if you want to support scroll bars.
`PointF!`	`computeScrollVectorForPosition(targetPosition: Int)` Should calculate the vector that points to the direction where the target position can be found.
`Int`	`computeVerticalScrollExtent(state: RecyclerView.State!)` Override this method if you want to support scroll bars.
`Int`	`findFirstCompletelyVisibleItemPosition()` Returns the adapter position of the first fully visible view.
`Int`	`findFirstVisibleItemPosition()` Returns the adapter position of the first visible view.
`Int`	`findLastCompletelyVisibleItemPosition()` Returns the adapter position of the last fully visible view.
`Int`	`findLastVisibleItemPosition()` Returns the adapter position of the last visible view.
`View!`	`findViewByPosition(position: Int)` Finds the view which represents the given adapter position.
`Int`	`getExtraLayoutSpace(state: RecyclerView.State!)` This function is deprecated. Use `calculateExtraLayoutSpace` instead.
`Int`	`getInitialPrefetchItemCount()` Gets the number of items to prefetch in `collectInitialPrefetchPositions`, which defines how many inner items should be prefetched when this LayoutManager's RecyclerView is nested inside another RecyclerView.
`Int`	`getOrientation()` Returns the current orientation of the layout.
`Boolean`	`getRecycleChildrenOnDetach()` Returns whether LayoutManager will recycle its children when it is detached from RecyclerView.
`Boolean`	`getReverseLayout()` Returns if views are laid out from the opposite direction of the layout.
`Boolean`	`getStackFromEnd()`
`Boolean`	`isAutoMeasureEnabled()` Returns whether the measuring pass of layout should use the AutoMeasure mechanism of `RecyclerView` or if it should be done by the LayoutManager's implementation of `onMeasure`.
`Boolean`	`isLayoutRTL()`
`Boolean`	`isLayoutReversed()` Query if the layout is in reverse order.
`Boolean`	`isSmoothScrollbarEnabled()` Returns the current state of the smooth scrollbar feature.
`Unit`	`onDetachedFromWindow(view: RecyclerView!, recycler: RecyclerView.Recycler!)` Called when this LayoutManager is detached from its parent RecyclerView or when its parent RecyclerView is detached from its window.
`Unit`	`onInitializeAccessibilityEvent(event: AccessibilityEvent!)`
`Unit`	`onRestoreInstanceState(state: Parcelable!)` Called when the RecyclerView is ready to restore the state based on a previous RecyclerView.
`Parcelable!`	`onSaveInstanceState()` Called when the LayoutManager should save its state.
`Unit`	`prepareForDrop(view: View, target: View, x: Int, y: Int)` Called by the after a View is dropped over another View.
`Unit`	`scrollToPosition(position: Int)` Scroll the RecyclerView to make the position visible.
`Unit`	`scrollToPositionWithOffset(position: Int, offset: Int)` Scroll to the specified adapter position with the given offset from resolved layout start.
`Unit`	`setInitialPrefetchItemCount(itemCount: Int)` Sets the number of items to prefetch in `collectInitialPrefetchPositions`, which defines how many inner items should be prefetched when this LayoutManager's RecyclerView is nested inside another RecyclerView.
`Unit`	`setOrientation(orientation: Int)` Sets the orientation of the layout.
`Unit`	`setRecycleChildrenOnDetach(recycleChildrenOnDetach: Boolean)` Set whether LayoutManager will recycle its children when it is detached from RecyclerView.
`Unit`	`setReverseLayout(reverseLayout: Boolean)` Used to reverse item traversal and layout order.
`Unit`	`setSmoothScrollbarEnabled(enabled: Boolean)` When smooth scrollbar is enabled, the position and size of the scrollbar thumb is computed based on the number of visible pixels in the visible items.
`Unit`	`smoothScrollToPosition( recyclerView: RecyclerView!, state: RecyclerView.State!, position: Int )` Smooth scroll to the specified adapter position.

From androidx.recyclerview.widget.RecyclerView.LayoutManager

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

Constants

DEFAULT_SPAN_COUNT

Added in 1.0.0

const val DEFAULT_SPAN_COUNT = -1: Int

Public constructors

GridLayoutManager

Added in 1.0.0

GridLayoutManager(context: Context!, spanCount: Int)

Creates a vertical GridLayoutManager

Parameters
`context: Context!`	Current context, will be used to access resources.
`spanCount: Int`	The number of columns in the grid

GridLayoutManager

Added in 1.0.0

GridLayoutManager(
    context: Context!,
    attrs: AttributeSet!,
    defStyleAttr: Int,
    defStyleRes: Int
)

Constructor used when layout manager is set in XML by RecyclerView attribute "layoutManager". If spanCount is not specified in the XML, it defaults to a single column. spanCount

GridLayoutManager

Added in 1.0.0

GridLayoutManager(
    context: Context!,
    spanCount: Int,
    orientation: Int,
    reverseLayout: Boolean
)

Parameters
`context: Context!`	Current context, will be used to access resources.
`spanCount: Int`	The number of columns or rows in the grid
`orientation: Int`	Layout orientation. Should be `HORIZONTAL` or `VERTICAL`.
`reverseLayout: Boolean`	When set to true, layouts from end to start.

Public functions

fun checkLayoutParams(lp: RecyclerView.LayoutParams!): Boolean

Determines the validity of the supplied LayoutParams object.

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

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

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

fun computeHorizontalScrollOffset(state: RecyclerView.State!): Int

Override this method if you want to support scroll bars.

Read computeHorizontalScrollOffset for details.

Default implementation returns 0.

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

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

See also
`computeHorizontalScrollOffset`

fun computeHorizontalScrollRange(state: RecyclerView.State!): Int

Override this method if you want to support scroll bars.

Read computeHorizontalScrollRange for details.

Default implementation returns 0.

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

Returns
`Int`	The total horizontal range represented by the horizontal scrollbar

See also
`computeHorizontalScrollRange`

fun computeVerticalScrollOffset(state: RecyclerView.State!): Int

Override this method if you want to support scroll bars.

Read computeVerticalScrollOffset for details.

Default implementation returns 0.

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

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

See also
`computeVerticalScrollOffset`

fun computeVerticalScrollRange(state: RecyclerView.State!): Int

Override this method if you want to support scroll bars.

Read computeVerticalScrollRange for details.

Default implementation returns 0.

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

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

See also
`computeVerticalScrollRange`

generateDefaultLayoutParams

fun generateDefaultLayoutParams(): RecyclerView.LayoutParams!

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

fun generateLayoutParams(lp: ViewGroup.LayoutParams!): RecyclerView.LayoutParams!

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, generateLayoutParams and generateLayoutParams.

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

Returns
`RecyclerView.LayoutParams!`	a new LayoutParams object

generateLayoutParams

fun generateLayoutParams(c: Context!, attrs: AttributeSet!): RecyclerView.LayoutParams!

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, generateLayoutParams and generateLayoutParams.

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

Returns
`RecyclerView.LayoutParams!`	a new LayoutParams object

fun getColumnCountForAccessibility(
    recycler: RecyclerView.Recycler!,
    state: RecyclerView.State!
): Int

Returns the number of columns for accessibility.

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

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

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

fun getRowCountForAccessibility(
    recycler: RecyclerView.Recycler!,
    state: RecyclerView.State!
): Int

Returns the number of rows for accessibility.

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

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

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

getSpanCount

Added in 1.0.0

fun getSpanCount(): Int

Returns the number of spans laid out by this grid.

Returns
`Int`	The number of spans

See also
`setSpanCount`

getSpanSizeLookup

Added in 1.0.0

fun getSpanSizeLookup(): GridLayoutManager.SpanSizeLookup!

Returns the current SpanSizeLookup used by the GridLayoutManager.

Returns
`GridLayoutManager.SpanSizeLookup!`	The current `SpanSizeLookup` used by the GridLayoutManager.

isUsingSpansToEstimateScrollbarDimensions

Added in 1.1.0

fun isUsingSpansToEstimateScrollbarDimensions(): Boolean

Returns true if the scroll offset and scroll range calculations take account of span information. See setUsingSpansToEstimateScrollbarDimensions for more information on this topic. Defaults to false.

Returns
`Boolean`	true if the scroll offset and scroll range calculations take account of span information.

fun onFocusSearchFailed(
    focused: View!,
    direction: Int,
    recycler: RecyclerView.Recycler!,
    state: RecyclerView.State!
): View!

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

This is the LayoutManager's opportunity to populate views in the given direction to fulfill the request if it can. The LayoutManager should attach and return the view to be focused, if a focusable view in the given direction is found. Otherwise, if all the existing (or the newly populated views) are unfocusable, it returns the next unfocusable view to become visible on the screen. This unfocusable view is typically the first view that's either partially or fully out of RV's padded bounded area in the given direction. The default implementation returns null.

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

Returns
`View!`	The chosen view to be focused if a focusable view is found, otherwise an unfocusable view to become visible onto the screen, else null.

fun onInitializeAccessibilityNodeInfo(
    recycler: RecyclerView.Recycler,
    state: RecyclerView.State,
    info: AccessibilityNodeInfoCompat
): Unit

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

Default implementation adds a .

You should override getRowCountForAccessibility, getColumnCountForAccessibility, isLayoutHierarchical and getSelectionModeForAccessibility for more accurate accessibility information.

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

See also
`onInitializeAccessibilityNodeInfo`
`getRowCountForAccessibility`
`getColumnCountForAccessibility`
`isLayoutHierarchical`
`getSelectionModeForAccessibility`

fun onInitializeAccessibilityNodeInfoForItem(
    recycler: RecyclerView.Recycler!,
    state: RecyclerView.State!,
    host: View!,
    info: AccessibilityNodeInfoCompat!
): Unit

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

Default implementation adds basic positioning information about the item.

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

See also
`onInitializeAccessibilityNodeInfoForItem`

fun onItemsAdded(
    recyclerView: RecyclerView!,
    positionStart: Int,
    itemCount: Int
): Unit

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.)

fun onItemsChanged(recyclerView: RecyclerView!): Unit

Called in response to a call to notifyDataSetChanged or swapAdapter ()} and signals that the the entire data set has changed.

fun onItemsMoved(recyclerView: RecyclerView!, from: Int, to: Int, itemCount: Int): Unit

Called when an item is moved withing the adapter.

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

fun onItemsRemoved(
    recyclerView: RecyclerView!,
    positionStart: Int,
    itemCount: Int
): Unit

Called when items have been removed from the adapter.

fun onItemsUpdated(
    recyclerView: RecyclerView!,
    positionStart: Int,
    itemCount: Int,
    payload: Any!
): Unit

Called when items have been changed in the adapter and with optional payload. Default implementation calls onItemsUpdated.

fun onLayoutChildren(
    recycler: RecyclerView.Recycler!,
    state: RecyclerView.State!
): Unit

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

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

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

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

fun onLayoutCompleted(state: RecyclerView.State!): Unit

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

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

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

fun scrollHorizontallyBy(
    dx: Int,
    recycler: RecyclerView.Recycler!,
    state: RecyclerView.State!
): Int

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

fun scrollVerticallyBy(
    dy: Int,
    recycler: RecyclerView.Recycler!,
    state: RecyclerView.State!
): Int

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

setMeasuredDimension

fun setMeasuredDimension(childrenBounds: Rect!, wSpec: Int, hSpec: Int): Unit

Sets the measured dimensions from the given bounding box of the children and the measurement specs that were passed into onMeasure. It is only called if a LayoutManager returns true from isAutoMeasureEnabled and it is called after the RecyclerView calls onLayoutChildren in the execution of onMeasure.

This method must call setMeasuredDimension.

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

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

See also
`isAutoMeasureEnabled`
`setMeasuredDimension`

setSpanCount

Added in 1.0.0

fun setSpanCount(spanCount: Int): Unit

Sets the number of spans to be laid out.

If getOrientation is VERTICAL, this is the number of columns. If getOrientation is HORIZONTAL, this is the number of rows.

Parameters
`spanCount: Int`	The total number of spans in the grid

See also
`getSpanCount`

Added in 1.0.0

fun setSpanSizeLookup(spanSizeLookup: GridLayoutManager.SpanSizeLookup!): Unit

Sets the source to get the number of spans occupied by each item in the adapter.

Parameters
`spanSizeLookup: GridLayoutManager.SpanSizeLookup!`	`SpanSizeLookup` instance to be used to query number of spans occupied by each item

setStackFromEnd

fun setStackFromEnd(stackFromEnd: Boolean): Unit

stackFromEnd is not supported by GridLayoutManager. Consider using setReverseLayout.

setUsingSpansToEstimateScrollbarDimensions

Added in 1.1.0

fun setUsingSpansToEstimateScrollbarDimensions(
    useSpansToEstimateScrollBarDimensions: Boolean
): Unit

When this flag is set, the scroll offset and scroll range calculations will take account of span information.

This is will increase the accuracy of the scroll bar's size and offset but will require more calls to getSpanGroupIndex".

This additional accuracy may or may not be needed, depending on the characteristics of your layout. You will likely benefit from this accuracy when:

The variation in item span sizes is large.
The size of your data set is small (if your data set is large, the scrollbar will likely be very small anyway, and thus the increased accuracy has less impact).
Calls to getSpanGroupIndex are fast.

If you decide to enable this feature, you should be sure that calls to getSpanGroupIndex are fast, that set span group index caching is set to true via a call to and span index caching is also enabled via a call to { }.

supportsPredictiveItemAnimations

fun supportsPredictiveItemAnimations(): Boolean

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 onLayoutChildren.

Whether item animations actually occur in a RecyclerView is actually determined by both the return value from this method and the ItemAnimator set on the RecyclerView itself. If the RecyclerView has a non-null ItemAnimator but this method returns false, then 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.

GridLayoutManager

Summary

Nested types

Constants

Public constructors

Public functions

Inherited Constants

Inherited functions

Constants

DEFAULT_SPAN_COUNT

Public constructors

GridLayoutManager

GridLayoutManager

GridLayoutManager

Public functions

checkLayoutParams

computeHorizontalScrollOffset

computeHorizontalScrollRange

computeVerticalScrollOffset

computeVerticalScrollRange

generateDefaultLayoutParams

generateLayoutParams

generateLayoutParams

getColumnCountForAccessibility

getRowCountForAccessibility

getSpanCount

getSpanSizeLookup

isUsingSpansToEstimateScrollbarDimensions

onFocusSearchFailed

onInitializeAccessibilityNodeInfo

onInitializeAccessibilityNodeInfoForItem

onItemsAdded

onItemsChanged

onItemsMoved

onItemsRemoved

onItemsUpdated

onLayoutChildren

onLayoutCompleted

scrollHorizontallyBy

scrollVerticallyBy

setMeasuredDimension

setSpanCount

setSpanSizeLookup

setStackFromEnd

setUsingSpansToEstimateScrollbarDimensions

supportsPredictiveItemAnimations