BaseGridView

Kotlin |Java

abstract class BaseGridView : RecyclerView

kotlin.Any
↳	android.view.View
	↳	android.view.ViewGroup
		↳	androidx.recyclerview.widget.RecyclerView
			↳	androidx.leanback.widget.BaseGridView

Known Direct Subclasses

HorizontalGridView, VerticalGridView

HorizontalGridView	A `android.view.ViewGroup` that shows items in a horizontal scrolling list.
VerticalGridView	A `android.view.ViewGroup` that shows items in a vertically scrolling list.

An abstract base class for vertically and horizontally scrolling lists. The items come from the RecyclerView.Adapter associated with this view. Do not directly use this class, use VerticalGridView and HorizontalGridView. The class is not intended to be subclassed other than VerticalGridView and HorizontalGridView.

Summary

Nested classes
abstract	`OnKeyInterceptListener` Listener for intercepting key dispatch events.
abstract	`OnLayoutCompletedListener` Interface for receiving notification when BaseGridView has completed a full layout calculation.
abstract	`OnMotionInterceptListener` Listener for intercepting generic motion dispatch events.
abstract	`OnTouchInterceptListener` Listener for intercepting touch dispatch events.
abstract	`OnUnhandledKeyListener`
abstract	`SmoothScrollByBehavior` Defines behavior of duration and interpolator for smoothScrollBy().

Constants
static Float	`ITEM_ALIGN_OFFSET_PERCENT_DISABLED` Value indicates that percent is not used.
static Int	`SAVE_ALL_CHILD` Save on screen views plus save off screen child views without any limitation.
static Int	`SAVE_LIMITED_CHILD` Save on screen views plus save off screen child views states up to `getSaveChildrenLimitNumber()`.
static Int	`SAVE_NO_CHILD` Dont save states of any child views.
static Int	`SAVE_ON_SCREEN_CHILD` Only save on screen child views, the states are lost when they become off screen.
static Int	`WINDOW_ALIGN_BOTH_EDGE` The first item and last item are aligned with the two edges of the viewport.
static Int	`WINDOW_ALIGN_HIGH_EDGE` The last item is aligned with the high edge of the viewport when navigating to the end of list.
static Int	`WINDOW_ALIGN_LOW_EDGE` The first item is aligned with the low edge of the viewport.
static Int	`WINDOW_ALIGN_NO_EDGE` The focused item always stays in a key line location.
static Float	`WINDOW_ALIGN_OFFSET_PERCENT_DISABLED` Value indicates that percent is not used.

Inherited constants

From class RecyclerView

`Int`	`HORIZONTAL`
`Int`	`INVALID_TYPE`
`Long`	`NO_ID`
`Int`	`NO_POSITION`
`Int`	`SCROLL_STATE_DRAGGING` The RecyclerView is currently being dragged by outside input such as user touch input.
`Int`	`SCROLL_STATE_IDLE` The RecyclerView is not currently scrolling.
`Int`	`SCROLL_STATE_SETTLING` The RecyclerView is currently animating to a final position while not under outside control.
`Int`	`TOUCH_SLOP_DEFAULT` Constant for use with `setScrollingTouchSlop(int)`. Indicates that the RecyclerView should use the standard touch slop for smooth, continuous scrolling.
`Int`	`TOUCH_SLOP_PAGING` Constant for use with `setScrollingTouchSlop(int)`. Indicates that the RecyclerView should use the standard touch slop for scrolling widgets that snap to a page or other coarse-grained barrier.
`Int`	`UNDEFINED_DURATION` Constant that represents that a duration has not been defined.
`Int`	`VERTICAL`

Public methods
open Unit	`addOnChildViewHolderSelectedListener(listener: OnChildViewHolderSelectedListener!)` Registers a callback to be invoked when an item in BaseGridView has been selected.
Unit	`addOnLayoutCompletedListener(@NonNull listener: BaseGridView.OnLayoutCompletedListener)` Registers a callback to be invoked when the BaseGridView completes a full layout calculation.
open Unit	`animateIn()` Undo animateOut() and slide in child views.
open Unit	`animateOut()` Temporarily slide out child views to bottom (for VerticalGridView) or end (for HorizontalGridView).
open Boolean	`dispatchKeyEvent(event: KeyEvent!)`
open Boolean	`dispatchTouchEvent(event: MotionEvent!)`
open View!	`focusSearch(direction: Int)`
open Int	`getChildDrawingOrder(childCount: Int, i: Int)`
open Int	`getHorizontalMargin()` Returns the spacing in pixels between two child items horizontally.
open Int	`getHorizontalSpacing()` Returns the horizontal spacing in pixels between two child items.
open Int	`getInitialPrefetchItemCount()` Gets the number of items to prefetch in `RecyclerView.LayoutManager#collectInitialPrefetchPositions(int, RecyclerView.LayoutManager.LayoutPrefetchRegistry)`, which defines how many inner items should be prefetched when this GridView is nested inside another RecyclerView.
open Int	`getItemAlignmentOffset()` Returns number of pixels to the end of low edge.
open Float	`getItemAlignmentOffsetPercent()` Returns the offset percent for item alignment in addition to .
open Int	`getItemAlignmentViewId()` Returns the id of the view to align with, or `android.view.View#NO_ID` for the root `RecyclerView.ViewHolder#itemView`.
open BaseGridView.OnUnhandledKeyListener!	`getOnUnhandledKeyListener()` Returns the unhandled key listener.
Int	`getSaveChildrenLimitNumber()` Returns the limit used when when `getSaveChildrenPolicy()` is `SAVE_LIMITED_CHILD`
Int	`getSaveChildrenPolicy()` Returns the policy for saving children.
open Int	`getSelectedPosition()` Returns the adapter position of selected item.
open BaseGridView.SmoothScrollByBehavior?	`getSmoothScrollByBehavior()` Returns custom behavior for smoothScrollBy().
Int	`getSmoothScrollMaxPendingMoves()` When holding DPAD, DPAD events are generated faster than the grid view can scroll.
Float	`getSmoothScrollSpeedFactor()`
open Int	`getVerticalMargin()` Returns the spacing in pixels between two child items vertically.
open Int	`getVerticalSpacing()` Returns the vertical spacing in pixels between two child items.
open Unit	`getViewSelectedOffsets(view: View!, offsets: IntArray!)` Returns the x/y offsets to final position from current position if the view is selected.
open Int	`getWindowAlignment()` Returns the method for focused item alignment in the view.
open Int	`getWindowAlignmentOffset()` Returns the offset in pixels for window alignment key line.
open Float	`getWindowAlignmentOffsetPercent()` Returns the offset percent for window alignment key line in addition to `getWindowAlignmentOffset()`.
open Boolean	`hasOverlappingRendering()`
open Boolean	`hasPreviousViewInSameRow(position: Int)` Returns true if the view at the given position has a same row sibling in front of it.
open Boolean	`isChildLayoutAnimated()` Returns true if an animation will run when a child changes size or when adding or removing a child.
open Boolean	`isFocusDrawingOrderEnabled()` Returns true if draws selected child at last, false otherwise.
Boolean	`isFocusSearchDisabled()` Returns true if focus search is disabled.
open Boolean	`isItemAlignmentOffsetWithPadding()` Returns true if applies padding to item alignment when `getItemAlignmentOffsetPercent()` is 0 or 100; returns false otherwise.
open Boolean	`isScrollEnabled()` Returns true if scrolling is enabled, false otherwise.
open Boolean	`isWindowAlignmentPreferKeyLineOverHighEdge()` Returns whether prefer key line over high edge when `WINDOW_ALIGN_HIGH_EDGE` is used.
open Boolean	`isWindowAlignmentPreferKeyLineOverLowEdge()` Returns whether prefer key line over low edge when `WINDOW_ALIGN_LOW_EDGE` is used.
open Boolean	`onRequestFocusInDescendants(direction: Int, previouslyFocusedRect: Rect!)`
open Unit	`onRtlPropertiesChanged(layoutDirection: Int)` Notify layout manager that layout directionality has been updated
open Unit	`removeOnChildViewHolderSelectedListener(listener: OnChildViewHolderSelectedListener!)` Remove the callback invoked when an item in BaseGridView has been selected.
Unit	`removeOnLayoutCompletedListener(@NonNull listener: BaseGridView.OnLayoutCompletedListener)` Removes a callback to be invoked when the BaseGridView completes a full layout calculation.
open Unit	`removeView(view: View!)`
open Unit	`removeViewAt(index: Int)`
open Unit	`scrollToPosition(position: Int)`
open Unit	`setAnimateChildLayout(animateChildLayout: Boolean)` Sets whether ItemAnimator should run when a child changes size or when adding or removing a child.
open Unit	`setChildrenVisibility(visibility: Int)` Changes and overrides children's visibility.
open Unit	`setFocusDrawingOrderEnabled(enabled: Boolean)` Enables or disables the default "focus draw at last" order rule.
Unit	`setFocusSearchDisabled(disabled: Boolean)` Disables or enables focus search.
open Unit	`setGravity(gravity: Int)` Sets the gravity used for child view positioning.
open Unit	`setHasOverlappingRendering(hasOverlapping: Boolean)`
open Unit	`setHorizontalMargin(margin: Int)` Sets the spacing in pixels between two child items horizontally.
open Unit	`setHorizontalSpacing(spacing: Int)` Sets the horizontal spacing in pixels between two child items.
open Unit	`setInitialPrefetchItemCount(itemCount: Int)` Sets the number of items to prefetch in `RecyclerView.LayoutManager#collectInitialPrefetchPositions(int, RecyclerView.LayoutManager.LayoutPrefetchRegistry)`, which defines how many inner items should be prefetched when this GridView is nested inside another RecyclerView.
open Unit	`setItemAlignmentOffset(offset: Int)` Sets number of pixels to the end of low edge.
open Unit	`setItemAlignmentOffsetPercent(offsetPercent: Float)` Sets the offset percent for item alignment in addition to .
open Unit	`setItemAlignmentOffsetWithPadding(withPadding: Boolean)` Sets whether applies padding to item alignment when `getItemAlignmentOffsetPercent()` is 0 or 100.
open Unit	`setItemAlignmentViewId(viewId: Int)` Sets the id of the view to align with.
open Unit	`setItemMargin(margin: Int)` Sets the spacing in pixels between two child items.
open Unit	`setItemSpacing(spacing: Int)` Sets the vertical and horizontal spacing in pixels between two child items.
open Unit	`setLayoutEnabled(layoutEnabled: Boolean)` Enables or disables layout.
open Unit	`setOnChildLaidOutListener(listener: OnChildLaidOutListener!)` Registers a callback to be invoked when an item in BaseGridView has been laid out.
open Unit	`setOnChildSelectedListener(listener: OnChildSelectedListener!)` Registers a callback to be invoked when an item in BaseGridView has been selected.
open Unit	`setOnChildViewHolderSelectedListener(listener: OnChildViewHolderSelectedListener!)` Registers a callback to be invoked when an item in BaseGridView has been selected.
open Unit	`setOnKeyInterceptListener(listener: BaseGridView.OnKeyInterceptListener!)` Sets the key intercept listener.
open Unit	`setOnMotionInterceptListener(listener: BaseGridView.OnMotionInterceptListener!)` Sets the generic motion intercept listener.
open Unit	`setOnTouchInterceptListener(listener: BaseGridView.OnTouchInterceptListener!)` Sets the touch intercept listener.
open Unit	`setOnUnhandledKeyListener(listener: BaseGridView.OnUnhandledKeyListener!)` Sets the unhandled key listener.
open Unit	`setPruneChild(pruneChild: Boolean)` Enables or disables pruning of children.
open Unit	`setRecyclerListener(listener: RecyclerView.RecyclerListener?)`
Unit	`setSaveChildrenLimitNumber(limitNumber: Int)` Sets the limit number when `getSaveChildrenPolicy()` is `SAVE_LIMITED_CHILD`.
Unit	`setSaveChildrenPolicy(savePolicy: Int)` Sets the policy for saving children.
open Unit	`setScrollEnabled(scrollEnabled: Boolean)` Enables or disables scrolling.
open Unit	`setSelectedPosition(position: Int)` Changes the selected item immediately without animation.
open Unit	`setSelectedPosition(position: Int, scrollExtra: Int)` Changes the selected item immediately without animation, scrollExtra is applied in primary scroll direction.
open Unit	`setSelectedPosition(position: Int, task: ViewHolderTask!)` Perform a task on ViewHolder at given position after scroll to it.
open Unit	`setSelectedPositionSmooth(position: Int)` Changes the selected item and run an animation to scroll to the target position.
open Unit	`setSelectedPositionSmooth(position: Int, task: ViewHolderTask!)` Perform a task on ViewHolder at given position after smooth scrolling to it.
Unit	`setSmoothScrollByBehavior(@Nullable behavior: BaseGridView.SmoothScrollByBehavior?)` Set custom behavior for smoothScrollBy().
Unit	`setSmoothScrollMaxPendingMoves(maxPendingMoves: Int)` When holding DPAD, DPAD events are generated faster than the grid view can scroll.
Unit	`setSmoothScrollSpeedFactor(smoothScrollSpeedFactor: Float)` Set factor of how slow the smoothScroller should run.
open Unit	`setVerticalMargin(margin: Int)` Sets the spacing in pixels between two child items vertically.
open Unit	`setVerticalSpacing(spacing: Int)` Sets the vertical spacing in pixels between two child items.
open Unit	`setWindowAlignment(windowAlignment: Int)` Sets the method for focused item alignment in the view.
open Unit	`setWindowAlignmentOffset(offset: Int)` Sets the offset in pixels for window alignment key line.
open Unit	`setWindowAlignmentOffsetPercent(offsetPercent: Float)` Sets the offset percent for window alignment key line in addition to .
open Unit	`setWindowAlignmentPreferKeyLineOverHighEdge(preferKeyLineOverHighEdge: Boolean)` Returns whether prefer key line over high edge when `WINDOW_ALIGN_HIGH_EDGE` is used.
open Unit	`setWindowAlignmentPreferKeyLineOverLowEdge(preferKeyLineOverLowEdge: Boolean)` Sets whether prefer key line over low edge when `WINDOW_ALIGN_LOW_EDGE` is used.
open Unit	`smoothScrollBy(dx: Int, dy: Int)`
open Unit	`smoothScrollBy(dx: Int, dy: Int, @Nullable interpolator: Interpolator?)`
open Unit	`smoothScrollToPosition(position: Int)`

Protected methods
open Boolean	`dispatchGenericFocusedEvent(event: MotionEvent!)`
open Unit	`onFocusChanged(gainFocus: Boolean, direction: Int, previouslyFocusedRect: Rect!)`

Inherited functions

From class RecyclerView

`Unit`	`addFocusables(views: ArrayList<View!>!, direction: Int, focusableMode: Int)`
`Unit`	`addItemDecoration(@NonNull decor: RecyclerView.ItemDecoration, index: Int)` Add an `ItemDecoration` to this RecyclerView. Item decorations can affect both measurement and drawing of individual item views. Item decorations are ordered. Decorations placed earlier in the list will be run/queried/drawn first for their effects on item views. Padding added to views will be nested; a padding added by an earlier decoration will mean further item decorations in the list will be asked to draw/pad within the previous decoration's given area.
`Unit`	`addItemDecoration(@NonNull decor: RecyclerView.ItemDecoration)` Add an `ItemDecoration` to this RecyclerView. Item decorations can affect both measurement and drawing of individual item views. Item decorations are ordered. Decorations placed earlier in the list will be run/queried/drawn first for their effects on item views. Padding added to views will be nested; a padding added by an earlier decoration will mean further item decorations in the list will be asked to draw/pad within the previous decoration's given area.
`Unit`	`addOnChildAttachStateChangeListener(@NonNull listener: RecyclerView.OnChildAttachStateChangeListener)` Register a listener that will be notified whenever a child view is attached to or detached from RecyclerView. This listener will be called when a LayoutManager or the RecyclerView decides that a child view is no longer needed. If an application associates expensive or heavyweight data with item views, this may be a good place to release or free those resources.
`Unit`	`addOnItemTouchListener(@NonNull listener: RecyclerView.OnItemTouchListener)` Add an `OnItemTouchListener` to intercept touch events before they are dispatched to child views or this view's standard scrolling behavior. Client code may use listeners to implement item manipulation behavior. Once a listener returns true from `OnItemTouchListener#onInterceptTouchEvent(RecyclerView, MotionEvent)` its `OnItemTouchListener#onTouchEvent(RecyclerView, MotionEvent)` method will be called for each incoming MotionEvent until the end of the gesture.
`Unit`	`addOnScrollListener(@NonNull listener: RecyclerView.OnScrollListener)` Add a listener that will be notified of any changes in scroll state or position. Components that add a listener should take care to remove it when finished. Other components that take ownership of a view may call `clearOnScrollListeners()` to remove all attached listeners.
`Boolean`	`checkLayoutParams(p: LayoutParams!)`
`Unit`	`clearOnChildAttachStateChangeListeners()` Removes all listeners that were added via `addOnChildAttachStateChangeListener(OnChildAttachStateChangeListener)`.
`Unit`	`clearOnScrollListeners()` Remove all secondary listener that were notified of any changes in scroll state or position.
`Int`	`computeHorizontalScrollExtent()` Compute the horizontal extent of the horizontal scrollbar's thumb within the horizontal range. This value is used to compute the length of the thumb within the scrollbar's track. The range is expressed in arbitrary units that must be the same as the units used by `computeHorizontalScrollRange()` and `computeHorizontalScrollOffset()`. Default implementation returns 0. If you want to support scroll bars, override `RecyclerView.LayoutManager#computeHorizontalScrollExtent(RecyclerView.State)` in your LayoutManager.
`Int`	`computeHorizontalScrollOffset()` Compute the horizontal offset of the horizontal scrollbar's thumb within the horizontal range. This value is used to compute the length of the thumb within the scrollbar's track. The range is expressed in arbitrary units that must be the same as the units used by `computeHorizontalScrollRange()` and `computeHorizontalScrollExtent()`. Default implementation returns 0. If you want to support scroll bars, override `RecyclerView.LayoutManager#computeHorizontalScrollOffset(RecyclerView.State)` in your LayoutManager.
`Int`	`computeHorizontalScrollRange()` Compute the horizontal range that the horizontal scrollbar represents. The range is expressed in arbitrary units that must be the same as the units used by `computeHorizontalScrollExtent()` and `computeHorizontalScrollOffset()`. Default implementation returns 0. If you want to support scroll bars, override `RecyclerView.LayoutManager#computeHorizontalScrollRange(RecyclerView.State)` in your LayoutManager.
`Int`	`computeVerticalScrollExtent()` Compute the vertical extent of the vertical scrollbar's thumb within the vertical range. This value is used to compute the length of the thumb within the scrollbar's track. The range is expressed in arbitrary units that must be the same as the units used by `computeVerticalScrollRange()` and `computeVerticalScrollOffset()`. Default implementation returns 0. If you want to support scroll bars, override `RecyclerView.LayoutManager#computeVerticalScrollExtent(RecyclerView.State)` in your LayoutManager.
`Int`	`computeVerticalScrollOffset()` Compute the vertical offset of the vertical scrollbar's thumb within the vertical range. This value is used to compute the length of the thumb within the scrollbar's track. The range is expressed in arbitrary units that must be the same as the units used by `computeVerticalScrollRange()` and `computeVerticalScrollExtent()`. Default implementation returns 0. If you want to support scroll bars, override `RecyclerView.LayoutManager#computeVerticalScrollOffset(RecyclerView.State)` in your LayoutManager.
`Int`	`computeVerticalScrollRange()` Compute the vertical range that the vertical scrollbar represents. The range is expressed in arbitrary units that must be the same as the units used by `computeVerticalScrollExtent()` and `computeVerticalScrollOffset()`. Default implementation returns 0. If you want to support scroll bars, override `RecyclerView.LayoutManager#computeVerticalScrollRange(RecyclerView.State)` in your LayoutManager.
`Boolean`	`dispatchNestedFling(velocityX: Float, velocityY: Float, consumed: Boolean)`
`Boolean`	`dispatchNestedPreFling(velocityX: Float, velocityY: Float)`
`Boolean`	`dispatchNestedPreScroll(dx: Int, dy: Int, consumed: IntArray?, offsetInWindow: IntArray?)`
`Boolean`	`dispatchNestedPreScroll(dx: Int, dy: Int, consumed: IntArray?, offsetInWindow: IntArray?, type: Int)`
`Boolean`	`dispatchNestedScroll(dxConsumed: Int, dyConsumed: Int, dxUnconsumed: Int, dyUnconsumed: Int, offsetInWindow: IntArray?)`
`Boolean`	`dispatchNestedScroll(dxConsumed: Int, dyConsumed: Int, dxUnconsumed: Int, dyUnconsumed: Int, offsetInWindow: IntArray?, type: Int)`
`Unit`	`dispatchNestedScroll(dxConsumed: Int, dyConsumed: Int, dxUnconsumed: Int, dyUnconsumed: Int, offsetInWindow: IntArray?, type: Int, @NonNull consumed: IntArray)`
`Boolean`	`dispatchPopulateAccessibilityEvent(event: AccessibilityEvent!)`
`Unit`	`dispatchRestoreInstanceState(container: SparseArray<Parcelable!>!)` Override to prevent thawing of any views created by the adapter.
`Unit`	`dispatchSaveInstanceState(container: SparseArray<Parcelable!>!)` Override to prevent freezing of any views created by the adapter.
`Unit`	`draw(c: Canvas!)`
`Boolean`	`drawChild(canvas: Canvas!, child: View!, drawingTime: Long)`
`View?`	`findChildViewUnder(x: Float, y: Float)` Find the topmost view under the given point.
`View?`	`findContainingItemView(@NonNull view: View)` Traverses the ancestors of the given view and returns the item view that contains it and also a direct child of the RecyclerView. This returned view can be used to get the ViewHolder by calling `getChildViewHolder(View)`.
`RecyclerView.ViewHolder?`	`findContainingViewHolder(@NonNull view: View)` Returns the ViewHolder that contains the given view.
`RecyclerView.ViewHolder?`	`findViewHolderForAdapterPosition(position: Int)` Return the ViewHolder for the item in the given position of the data set. Unlike `findViewHolderForLayoutPosition(int)` this method takes into account any pending adapter changes that may not be reflected to the layout yet. On the other hand, if `Adapter#notifyDataSetChanged()` has been called but the new layout has not been calculated yet, this method will return `null` since the new positions of views are unknown until the layout is calculated. This method checks only the children of RecyclerView. If the item at the given `position` is not laid out, it will not create a new one. When the ItemAnimator is running a change animation, there might be 2 ViewHolders representing the same Item. In this case, the updated ViewHolder will be returned.
`RecyclerView.ViewHolder!`	`findViewHolderForItemId(id: Long)` Return the ViewHolder for the item with the given id. The RecyclerView must use an Adapter with `stableIds` to return a non-null value. This method checks only the children of RecyclerView. If the item with the given `id` is not laid out, it will not create a new one. When the ItemAnimator is running a change animation, there might be 2 ViewHolders with the same id. In this case, the updated ViewHolder will be returned.
`RecyclerView.ViewHolder?`	`findViewHolderForLayoutPosition(position: Int)` Return the ViewHolder for the item in the given position of the data set as of the latest layout pass. This method checks only the children of RecyclerView. If the item at the given `position` is not laid out, it will not create a new one. Note that when Adapter contents change, ViewHolder positions are not updated until the next layout calculation. If there are pending adapter updates, the return value of this method may not match your adapter contents. You can use #`ViewHolder#getBindingAdapterPosition()` to get the current adapter position of a ViewHolder. If the `Adapter` that is assigned to the RecyclerView is an adapter that combines other adapters (e.g. `MergeAdapter`), you can use the `ViewHolder#getBindingAdapter()`) to find the position relative to the `Adapter` that bound the `ViewHolder`. When the ItemAnimator is running a change animation, there might be 2 ViewHolders with the same layout position representing the same Item. In this case, the updated ViewHolder will be returned.
`RecyclerView.ViewHolder?`	`findViewHolderForPosition(position: Int)`
`Boolean`	`fling(velocityX: Int, velocityY: Int)` Begin a standard fling with an initial velocity along each axis in pixels per second. If the velocity given is below the system-defined minimum this method will return false and no fling will occur.
`View!`	`focusSearch(focused: View!, direction: Int)` Since RecyclerView is a collection ViewGroup that includes virtual children (items that are in the Adapter but not visible in the UI), it employs a more involved focus search strategy that differs from other ViewGroups. It first does a focus search within the RecyclerView. If this search finds a View that is in the focus direction with respect to the currently focused View, RecyclerView returns that child as the next focus target. When it cannot find such child, it calls `LayoutManager#onFocusSearchFailed(View, int, Recycler, State)` to layout more Views in the focus search direction. If LayoutManager adds a View that matches the focus search criteria, it will be returned as the focus search result. Otherwise, RecyclerView will call parent to handle the focus search like a regular ViewGroup. When the direction is `View#FOCUS_FORWARD` or `View#FOCUS_BACKWARD`, a View that is not in the focus direction is still valid focus target which may not be the desired behavior if the Adapter has more children in the focus direction. To handle this case, RecyclerView converts the focus direction to an absolute direction and makes a preliminary focus search in that direction. If there are no Views to gain focus, it will call `LayoutManager#onFocusSearchFailed(View, int, Recycler, State)` before running a focus search with the original (relative) direction. This allows RecyclerView to provide better candidates to the focus search while still allowing the view system to take focus from the RecyclerView and give it to a more suitable child if such child exists.
`LayoutParams!`	`generateDefaultLayoutParams()`
`LayoutParams!`	`generateLayoutParams(attrs: AttributeSet!)`
`LayoutParams!`	`generateLayoutParams(p: LayoutParams!)`
`CharSequence!`	`getAccessibilityClassName()`
`RecyclerView.Adapter<RecyclerView.ViewHolder!>?`	`getAdapter()` Retrieves the previously set adapter or null if no adapter is set.
`Int`	`getBaseline()` Return the offset of the RecyclerView's text baseline from the its top boundary. If the LayoutManager of this RecyclerView does not support baseline alignment, this method returns -1.
`Int`	`getChildAdapterPosition(@NonNull child: View)` Return the adapter position that the given child view corresponds to.
`Long`	`getChildItemId(@NonNull child: View)` Return the stable item id that the given child view corresponds to.
`Int`	`getChildLayoutPosition(@NonNull child: View)` Return the adapter position of the given child view as of the latest completed layout pass. This position may not be equal to Item's adapter position if there are pending changes in the adapter which have not been reflected to the layout yet.
`Int`	`getChildPosition(@NonNull child: View)`
`RecyclerView.ViewHolder!`	`getChildViewHolder(@NonNull child: View)` Retrieve the `ViewHolder` for the given child view.
`Boolean`	`getClipToPadding()` Returns whether this RecyclerView will clip its children to its padding, and resize (but not clip) any EdgeEffect to the padded region, if padding is present. By default, children are clipped to the padding of their parent RecyclerView. This clipping behavior is only enabled if padding is non-zero.
`RecyclerViewAccessibilityDelegate?`	`getCompatAccessibilityDelegate()` Returns the accessibility delegate compatibility implementation used by the RecyclerView.
`Unit`	`getDecoratedBoundsWithMargins(@NonNull view: View, @NonNull outBounds: Rect)` Returns the bounds of the view including its decoration and margins.
`RecyclerView.EdgeEffectFactory`	`getEdgeEffectFactory()` Retrieves the previously set `EdgeEffectFactory` or the default factory if nothing was set.
`RecyclerView.ItemAnimator?`	`getItemAnimator()` Gets the current ItemAnimator for this RecyclerView. A null return value indicates that there is no animator and that item changes will happen without any animations. By default, RecyclerView instantiates and uses an instance of `DefaultItemAnimator`.
`RecyclerView.ItemDecoration`	`getItemDecorationAt(index: Int)` Returns an `ItemDecoration` previously added to this RecyclerView.
`Int`	`getItemDecorationCount()` Returns the number of `ItemDecoration` currently added to this RecyclerView.
`RecyclerView.LayoutManager?`	`getLayoutManager()` Return the `LayoutManager` currently responsible for layout policy for this RecyclerView.
`Int`	`getMaxFlingVelocity()` Returns the maximum fling velocity used by this RecyclerView.
`Int`	`getMinFlingVelocity()` Returns the minimum velocity to start a fling.
`RecyclerView.OnFlingListener?`	`getOnFlingListener()` Get the current `OnFlingListener` from this `RecyclerView`.
`Boolean`	`getPreserveFocusAfterLayout()` Returns true if the RecyclerView should attempt to preserve currently focused Adapter Item's focus even if the View representing the Item is replaced during a layout calculation. By default, this value is `true`.
`RecyclerView.RecycledViewPool`	`getRecycledViewPool()` Retrieve this RecyclerView's `RecycledViewPool`. This method will never return null; if no pool is set for this view a new one will be created. See `setRecycledViewPool` for more information.
`Int`	`getScrollState()` Return the current scrolling state of the RecyclerView.
`Boolean`	`hasFixedSize()`
`Boolean`	`hasNestedScrollingParent()`
`Boolean`	`hasNestedScrollingParent(type: Int)`
`Boolean`	`hasPendingAdapterUpdates()` Returns whether there are pending adapter updates which are not yet applied to the layout. If this method returns `true`, it means that what user is currently seeing may not reflect them adapter contents (depending on what has changed). You may use this information to defer or cancel some operations. This method returns true if RecyclerView has not yet calculated the first layout after it is attached to the Window or the Adapter has been replaced.
`Unit`	`invalidateItemDecorations()` Invalidates all ItemDecorations. If RecyclerView has item decorations, calling this method will trigger a `requestLayout()` call.
`Boolean`	`isAnimating()` Returns true if RecyclerView is currently running some animations. If you want to be notified when animations are finished, use `ItemAnimator#isRunning(ItemAnimator.ItemAnimatorFinishedListener)`.
`Boolean`	`isAttachedToWindow()` Returns true if RecyclerView is attached to window.
`Boolean`	`isComputingLayout()` Returns whether RecyclerView is currently computing a layout. If this method returns true, it means that RecyclerView is in a lockdown state and any attempt to update adapter contents will result in an exception because adapter contents cannot be changed while RecyclerView is trying to compute the layout. It is very unlikely that your code will be running during this state as it is called by the framework when a layout traversal happens or RecyclerView starts to scroll in response to system events (touch, accessibility etc). This case may happen if you have some custom logic to change adapter contents in response to a View callback (e.g. focus change callback) which might be triggered during a layout calculation. In these cases, you should just postpone the change using a Handler or a similar mechanism.
`Boolean`	`isLayoutFrozen()`
`Boolean`	`isLayoutSuppressed()` Returns whether layout and scroll calls on this container are currently being suppressed, due to an earlier call to `suppressLayout(boolean)`.
`Boolean`	`isNestedScrollingEnabled()`
`Unit`	`offsetChildrenHorizontal(@Px dx: Int)` Offset the bounds of all child views by `dx` pixels. Useful for implementing simple scrolling in `LayoutManagers`.
`Unit`	`offsetChildrenVertical(@Px dy: Int)` Offset the bounds of all child views by `dy` pixels. Useful for implementing simple scrolling in `LayoutManagers`.
`Unit`	`onAttachedToWindow()`
`Unit`	`onChildAttachedToWindow(@NonNull child: View)` Called when an item view is attached to this RecyclerView. Subclasses of RecyclerView may want to perform extra bookkeeping or modifications of child views as they become attached. This will be called before a `LayoutManager` measures or lays out the view and is a good time to perform these changes.
`Unit`	`onChildDetachedFromWindow(@NonNull child: View)` Called when an item view is detached from this RecyclerView. Subclasses of RecyclerView may want to perform extra bookkeeping or modifications of child views as they become detached. This will be called as a `LayoutManager` fully detaches the child view from the parent and its window.
`Unit`	`onDetachedFromWindow()`
`Unit`	`onDraw(c: Canvas!)`
`Boolean`	`onGenericMotionEvent(event: MotionEvent!)`
`Boolean`	`onInterceptTouchEvent(e: MotionEvent!)`
`Unit`	`onLayout(changed: Boolean, l: Int, t: Int, r: Int, b: Int)`
`Unit`	`onMeasure(widthSpec: Int, heightSpec: Int)`
`Unit`	`onRestoreInstanceState(state: Parcelable!)`
`Parcelable!`	`onSaveInstanceState()`
`Unit`	`onScrollStateChanged(state: Int)` Called when the scroll state of this RecyclerView changes. Subclasses should use this method to respond to state changes instead of an explicit listener. This method will always be invoked before listeners, but after the LayoutManager responds to the scroll state change.
`Unit`	`onScrolled(@Px dx: Int, @Px dy: Int)` Called when the scroll position of this RecyclerView changes. Subclasses should use this method to respond to scrolling within the adapter's data set instead of an explicit listener. This method will always be invoked before listeners. If a subclass needs to perform any additional upkeep or bookkeeping after scrolling but before listeners run, this is a good place to do so. This differs from `View#onScrollChanged(int, int, int, int)` in that it receives the distance scrolled in either direction within the adapter's data set instead of absolute scroll coordinates. Since RecyclerView cannot compute the absolute scroll position from any arbitrary point in the data set, `onScrollChanged` will always receive the current `View#getScrollX()` and `View#getScrollY()` values which do not correspond to the data set scroll position. However, some subclasses may choose to use these fields as special offsets.
`Unit`	`onSizeChanged(w: Int, h: Int, oldw: Int, oldh: Int)`
`Boolean`	`onTouchEvent(e: MotionEvent!)`
`Unit`	`removeDetachedView(child: View!, animate: Boolean)`
`Unit`	`removeItemDecoration(@NonNull decor: RecyclerView.ItemDecoration)` Remove an `ItemDecoration` from this RecyclerView. The given decoration will no longer impact the measurement and drawing of item views.
`Unit`	`removeItemDecorationAt(index: Int)` Removes the `ItemDecoration` associated with the supplied index position.
`Unit`	`removeOnChildAttachStateChangeListener(@NonNull listener: RecyclerView.OnChildAttachStateChangeListener)` Removes the provided listener from child attached state listeners list.
`Unit`	`removeOnItemTouchListener(@NonNull listener: RecyclerView.OnItemTouchListener)` Remove an `OnItemTouchListener`. It will no longer be able to intercept touch events.
`Unit`	`removeOnScrollListener(@NonNull listener: RecyclerView.OnScrollListener)` Remove a listener that was notified of any changes in scroll state or position.
`Unit`	`requestChildFocus(child: View!, focused: View!)`
`Boolean`	`requestChildRectangleOnScreen(child: View!, rect: Rect!, immediate: Boolean)`
`Unit`	`requestDisallowInterceptTouchEvent(disallowIntercept: Boolean)`
`Unit`	`requestLayout()`
`Unit`	`scrollBy(x: Int, y: Int)`
`Unit`	`scrollTo(x: Int, y: Int)`
`Unit`	`sendAccessibilityEventUnchecked(event: AccessibilityEvent!)`
`Unit`	`setAccessibilityDelegateCompat(@Nullable accessibilityDelegate: RecyclerViewAccessibilityDelegate?)` Sets the accessibility delegate compatibility implementation used by RecyclerView.
`Unit`	`setAdapter(@Nullable adapter: RecyclerView.Adapter<RecyclerView.ViewHolder!>?)` Set a new adapter to provide child views on demand. When adapter is changed, all existing views are recycled back to the pool. If the pool has only one adapter, it will be cleared.
`Unit`	`setChildDrawingOrderCallback(@Nullable childDrawingOrderCallback: RecyclerView.ChildDrawingOrderCallback?)` Sets the `ChildDrawingOrderCallback` to be used for drawing children. See `ViewGroup#getChildDrawingOrder(int, int)` for details. Calling this method will always call `ViewGroup#setChildrenDrawingOrderEnabled(boolean)`. The parameter will be true if childDrawingOrderCallback is not null, false otherwise. Note that child drawing order may be overridden by View's elevation.
`Unit`	`setClipToPadding(clipToPadding: Boolean)`
`Unit`	`setEdgeEffectFactory(@NonNull edgeEffectFactory: RecyclerView.EdgeEffectFactory)` Set a `EdgeEffectFactory` for this `RecyclerView`. When a new `EdgeEffectFactory` is set, any existing over-scroll effects are cleared and new effects are created as needed using `EdgeEffectFactory#createEdgeEffect(RecyclerView, int)`
`Unit`	`setHasFixedSize(hasFixedSize: Boolean)` RecyclerView can perform several optimizations if it can know in advance that RecyclerView's size is not affected by the adapter contents. RecyclerView can still change its size based on other factors (e.g. its parent's size) but this size calculation cannot depend on the size of its children or contents of its adapter (except the number of items in the adapter). If your use of RecyclerView falls into this category, set this to `true`. It will allow RecyclerView to avoid invalidating the whole layout when its adapter contents change.
`Unit`	`setItemAnimator(@Nullable animator: RecyclerView.ItemAnimator?)` Sets the `ItemAnimator` that will handle animations involving changes to the items in this RecyclerView. By default, RecyclerView instantiates and uses an instance of `DefaultItemAnimator`. Whether item animations are enabled for the RecyclerView depends on the ItemAnimator and whether the LayoutManager `supports item animations`.
`Unit`	`setItemViewCacheSize(size: Int)` Set the number of offscreen views to retain before adding them to the potentially shared `recycled view pool`. The offscreen view cache stays aware of changes in the attached adapter, allowing a LayoutManager to reuse those views unmodified without needing to return to the adapter to rebind them.
`Unit`	`setLayoutFrozen(frozen: Boolean)` Enable or disable layout and scroll. After `setLayoutFrozen(true)` is called, Layout requests will be postponed until `setLayoutFrozen(false)` is called; child views are not updated when RecyclerView is frozen, `smoothScrollBy(int, int)`, `scrollBy(int, int)`, `scrollToPosition(int)` and `smoothScrollToPosition(int)` are dropped; TouchEvents and GenericMotionEvents are dropped; `LayoutManager#onFocusSearchFailed(View, int, Recycler, State)` will not be called. `setLayoutFrozen(true)` does not prevent app from directly calling , `LayoutManager#smoothScrollToPosition( * RecyclerView, State, int)`. `setAdapter(Adapter)` and `swapAdapter(Adapter, boolean)` will automatically stop frozen. Note: Running ItemAnimator is not stopped automatically, it's caller's responsibility to call ItemAnimator.end().
`Unit`	`setLayoutManager(@Nullable layout: RecyclerView.LayoutManager?)` Set the `LayoutManager` that this RecyclerView will use. In contrast to other adapter-backed views such as `android.widget.ListView` or `android.widget.GridView`, RecyclerView allows client code to provide custom layout arrangements for child views. These arrangements are controlled by the `LayoutManager`. A LayoutManager must be provided for RecyclerView to function. Several default strategies are provided for common uses such as lists and grids.
`Unit`	`setLayoutTransition(transition: LayoutTransition!)`
`Unit`	`setNestedScrollingEnabled(enabled: Boolean)`
`Unit`	`setOnFlingListener(@Nullable onFlingListener: RecyclerView.OnFlingListener?)` Set a `OnFlingListener` for this `RecyclerView`. If the `OnFlingListener` is set then it will receive calls to `fling(int,int)` and will be able to intercept them.
`Unit`	`setOnScrollListener(@Nullable listener: RecyclerView.OnScrollListener?)` Set a listener that will be notified of any changes in scroll state or position.
`Unit`	`setPreserveFocusAfterLayout(preserveFocusAfterLayout: Boolean)` Set whether the RecyclerView should try to keep the same Item focused after a layout calculation or not. Usually, LayoutManagers keep focused views visible before and after layout but sometimes, views may lose focus during a layout calculation as their state changes or they are replaced with another view due to type change or animation. In these cases, RecyclerView can request focus on the new view automatically.
`Unit`	`setRecycledViewPool(@Nullable pool: RecyclerView.RecycledViewPool?)` Recycled view pools allow multiple RecyclerViews to share a common pool of scrap views. This can be useful if you have multiple RecyclerViews with adapters that use the same view types, for example if you have several data sets with the same kinds of item views displayed by a `androidx.viewpager.widget.ViewPager`.
`Unit`	`setScrollingTouchSlop(slopConstant: Int)` Configure the scrolling touch slop for a specific use case. Set up the RecyclerView's scrolling motion threshold based on common usages. Valid arguments are `TOUCH_SLOP_DEFAULT` and `TOUCH_SLOP_PAGING`.
`Unit`	`setViewCacheExtension(@Nullable extension: RecyclerView.ViewCacheExtension?)` Sets a new `ViewCacheExtension` to be used by the Recycler.
`Unit`	`smoothScrollBy(@Px dx: Int, @Px dy: Int, @Nullable interpolator: Interpolator?, duration: Int)` Smooth scrolls the RecyclerView by a given distance.
`Boolean`	`startNestedScroll(axes: Int)`
`Boolean`	`startNestedScroll(axes: Int, type: Int)`
`Unit`	`stopNestedScroll()`
`Unit`	`stopNestedScroll(type: Int)`
`Unit`	`stopScroll()` Stop any current scroll in progress, such as one started by `smoothScrollBy(int, int)`, `fling(int, int)` or a touch-initiated fling.
`Unit`	`suppressLayout(suppress: Boolean)` Tells this RecyclerView to suppress all layout and scroll calls until layout suppression is disabled with a later call to suppressLayout(false). When layout suppression is disabled, a requestLayout() call is sent if requestLayout() was attempted while layout was being suppressed. In addition to the layout suppression `smoothScrollBy(int, int)`, `scrollBy(int, int)`, `scrollToPosition(int)` and `smoothScrollToPosition(int)` are dropped; TouchEvents and GenericMotionEvents are dropped; `LayoutManager#onFocusSearchFailed(View, int, Recycler, State)` will not be called. `suppressLayout(true)` does not prevent app from directly calling , `LayoutManager#smoothScrollToPosition( * RecyclerView, State, int)`. `setAdapter(Adapter)` and `swapAdapter(Adapter, boolean)` will automatically stop suppressing. Note: Running ItemAnimator is not stopped automatically, it's caller's responsibility to call ItemAnimator.end().
`Unit`	`swapAdapter(@Nullable adapter: RecyclerView.Adapter<RecyclerView.ViewHolder!>?, removeAndRecycleExistingViews: Boolean)` Swaps the current adapter with the provided one. It is similar to `setAdapter(Adapter)` but assumes existing adapter and the new adapter uses the same `ViewHolder` and does not clear the RecycledViewPool. Note that it still calls onAdapterChanged callbacks.

Constants

ITEM_ALIGN_OFFSET_PERCENT_DISABLED

static val ITEM_ALIGN_OFFSET_PERCENT_DISABLED: Float

Value indicates that percent is not used.

Value: ItemAlignmentFacet.ITEM_ALIGN_OFFSET_PERCENT_DISABLED

SAVE_ALL_CHILD

static val SAVE_ALL_CHILD: Int

Save on screen views plus save off screen child views without any limitation. This might cause out of memory, only use it when you are dealing with limited data.

Value: 3

SAVE_LIMITED_CHILD

static val SAVE_LIMITED_CHILD: Int

Save on screen views plus save off screen child views states up to getSaveChildrenLimitNumber().

Value: 2

SAVE_NO_CHILD

static val SAVE_NO_CHILD: Int

Dont save states of any child views.

Value: 0

SAVE_ON_SCREEN_CHILD

static val SAVE_ON_SCREEN_CHILD: Int

Only save on screen child views, the states are lost when they become off screen.

Value: 1

WINDOW_ALIGN_BOTH_EDGE

static val WINDOW_ALIGN_BOTH_EDGE: Int

The first item and last item are aligned with the two edges of the viewport. When navigating in the middle of list, the focus maintains a key line location.

The key line location is calculated by "windowAlignOffset" and "windowAlignOffsetPercent"; if neither of these two is defined, the default value is 1/2 of the size.

Value: WINDOW_ALIGN_LOW_EDGE | WINDOW_ALIGN_HIGH_EDGE

WINDOW_ALIGN_HIGH_EDGE

static val WINDOW_ALIGN_HIGH_EDGE: Int

The last item is aligned with the high edge of the viewport when navigating to the end of list. When navigating away from the end, the focus item is aligned to a key line location.

For HorizontalGridView, high edge refers to getWidth() - getPaddingRight() when RTL is false or getPaddingLeft() when RTL is true. For VerticalGridView, high edge refers to getHeight() - getPaddingBottom().

The key line location is calculated by "windowAlignOffset" and "windowAlignOffsetPercent"; if neither of these two is defined, the default value is 1/2 of the size.

Note if there are very few items between high edge and key line, use setWindowAlignmentPreferKeyLineOverHighEdge(boolean) to control whether you prefer to align the items to key line or high edge. Default is preferring key line.

Value: 1 << 1

WINDOW_ALIGN_LOW_EDGE

static val WINDOW_ALIGN_LOW_EDGE: Int

The first item is aligned with the low edge of the viewport. When navigating away from the first item, the focus item is aligned to a key line location.

For HorizontalGridView, low edge refers to getPaddingLeft() when RTL is false or getWidth() - getPaddingRight() when RTL is true. For VerticalGridView, low edge refers to getPaddingTop().

The key line location is calculated by "windowAlignOffset" and "windowAlignOffsetPercent"; if neither of these two is defined, the default value is 1/2 of the size.

Note if there are very few items between low edge and key line, use setWindowAlignmentPreferKeyLineOverLowEdge(boolean) to control whether you prefer to align the items to key line or low edge. Default is preferring low edge.

Value: 1

WINDOW_ALIGN_NO_EDGE

static val WINDOW_ALIGN_NO_EDGE: Int

The focused item always stays in a key line location.

The key line location is calculated by "windowAlignOffset" and "windowAlignOffsetPercent"; if neither of these two is defined, the default value is 1/2 of the size.

Value: 0

WINDOW_ALIGN_OFFSET_PERCENT_DISABLED

static val WINDOW_ALIGN_OFFSET_PERCENT_DISABLED: Float

Value indicates that percent is not used.

Value: -1

Public methods

addOnChildViewHolderSelectedListener

open fun addOnChildViewHolderSelectedListener(listener: OnChildViewHolderSelectedListener!): Unit

Registers a callback to be invoked when an item in BaseGridView has been selected. Note that the listener may be invoked when there is a layout pending on the view, affording the listener an opportunity to adjust the upcoming layout based on the selection state.

Parameters
`listener`	OnChildViewHolderSelectedListener!: The listener to be invoked.

addOnLayoutCompletedListener

fun addOnLayoutCompletedListener(@NonNull listener: BaseGridView.OnLayoutCompletedListener): Unit

Registers a callback to be invoked when the BaseGridView completes a full layout calculation.

Parameters
`listener`	BaseGridView.OnLayoutCompletedListener: The listener to be invoked.

animateIn

open fun animateIn(): Unit

Undo animateOut() and slide in child views.

animateOut

open fun animateOut(): Unit

Temporarily slide out child views to bottom (for VerticalGridView) or end (for HorizontalGridView). Layout and scrolling will be suppressed until animateIn() is called.

dispatchKeyEvent

open fun dispatchKeyEvent(event: KeyEvent!): Boolean

dispatchTouchEvent

open fun dispatchTouchEvent(event: MotionEvent!): Boolean

focusSearch

open fun focusSearch(direction: Int): View!

getChildDrawingOrder

open fun getChildDrawingOrder(
    childCount: Int, 
    i: Int
): Int

getHorizontalMargin

open fun getHorizontalMargin(): Int

Deprecated: Use getHorizontalSpacing()

Returns the spacing in pixels between two child items horizontally.

getHorizontalSpacing

open fun getHorizontalSpacing(): Int

Returns the horizontal spacing in pixels between two child items.

Return
`Int`	The Horizontal spacing in pixels between two child items.

getInitialPrefetchItemCount

open fun getInitialPrefetchItemCount(): Int

Gets the number of items to prefetch in RecyclerView.LayoutManager#collectInitialPrefetchPositions(int, RecyclerView.LayoutManager.LayoutPrefetchRegistry), which defines how many inner items should be prefetched when this GridView is nested inside another RecyclerView.

Return
`Int`	number of items to prefetch.

See Also

RecyclerView.LayoutManager#isItemPrefetchEnabled()#setInitialPrefetchItemCount(int)RecyclerView.LayoutManager#collectInitialPrefetchPositions(int, RecyclerView.LayoutManager.LayoutPrefetchRegistry)

getItemAlignmentOffset

open fun getItemAlignmentOffset(): Int

Returns number of pixels to the end of low edge. Supports right to left layout direction. In left to right or vertical case, it's the offset added to left/top edge. In right to left case, it's the offset subtracted from right edge. Item alignment settings are ignored for the child if ItemAlignmentFacet is provided by RecyclerView.ViewHolder or FacetProviderAdapter.

Return
`Int`	The number of pixels to the end of low edge.

getItemAlignmentOffsetPercent

open fun getItemAlignmentOffsetPercent(): Float

Returns the offset percent for item alignment in addition to .

Return
`Float`	Percentage to offset. E.g., 40 means 40% of the width from the low edge, or `ITEM_ALIGN_OFFSET_PERCENT_DISABLED` if disabled. Default value is 50.

getItemAlignmentViewId

open fun getItemAlignmentViewId(): Int

Returns the id of the view to align with, or android.view.View#NO_ID for the root RecyclerView.ViewHolder#itemView.

Return
`Int`	The id of the view to align with, or `android.view.View#NO_ID` for the root `RecyclerView.ViewHolder#itemView`.

getOnUnhandledKeyListener

open fun getOnUnhandledKeyListener(): BaseGridView.OnUnhandledKeyListener!

Returns the unhandled key listener.

Return
`BaseGridView.OnUnhandledKeyListener!`	The unhandled key listener.

getSaveChildrenLimitNumber

fun getSaveChildrenLimitNumber(): Int

Returns the limit used when when getSaveChildrenPolicy() is SAVE_LIMITED_CHILD

getSaveChildrenPolicy

fun getSaveChildrenPolicy(): Int

Returns the policy for saving children.

Return
`Int`	policy, one of `SAVE_NO_CHILD` `SAVE_ON_SCREEN_CHILD` `SAVE_LIMITED_CHILD` `SAVE_ALL_CHILD`.

getSelectedPosition

open fun getSelectedPosition(): Int

Returns the adapter position of selected item.

Return
`Int`	The adapter position of selected item.

getSmoothScrollByBehavior

@Nullable open fun getSmoothScrollByBehavior(): BaseGridView.SmoothScrollByBehavior?

Returns custom behavior for smoothScrollBy().

Return
`BaseGridView.SmoothScrollByBehavior?`	Custom behavior for SmoothScrollBy(). Null for default behavior.

getSmoothScrollMaxPendingMoves

fun getSmoothScrollMaxPendingMoves(): Int

When holding DPAD, DPAD events are generated faster than the grid view can scroll. The grid view counts unhandled DPAD events and complete the movement after user release DPAD. If the value is set too high, the scrolling will last very long after DPAD is released. If the value is set too low, it may miss many DPAD events. The default value is 10. If app increases setSmoothScrollSpeedFactor(float), it may need decrease the max pending DPAD events to avoid scrolling too long after DPAD release.

Return
`Int`	Maximum number of pending DPAD events to be remembered when smooth scroll cannot catch up speed of DPAD events being sent.

getSmoothScrollSpeedFactor

fun getSmoothScrollSpeedFactor(): Float

Return
`Float`	Factor of how slow the smoothScroller runs. Default value is 1f.

getVerticalMargin

open fun getVerticalMargin(): Int

Deprecated: Use getVerticalSpacing()

Returns the spacing in pixels between two child items vertically.

getVerticalSpacing

open fun getVerticalSpacing(): Int

Returns the vertical spacing in pixels between two child items.

Return
`Int`	The vertical spacing in pixels between two child items.

getViewSelectedOffsets

open fun getViewSelectedOffsets(
    view: View!, 
    offsets: IntArray!
): Unit

Returns the x/y offsets to final position from current position if the view is selected.

Parameters
`view`	View!: The view to get offsets.
`offsets`	IntArray!: offsets[0] holds offset of X, offsets[1] holds offset of Y.

getWindowAlignment

open fun getWindowAlignment(): Int

Returns the method for focused item alignment in the view.

Return
`Int`	`WINDOW_ALIGN_BOTH_EDGE`, `WINDOW_ALIGN_LOW_EDGE`, `WINDOW_ALIGN_HIGH_EDGE` or `WINDOW_ALIGN_NO_EDGE`.

getWindowAlignmentOffset

open fun getWindowAlignmentOffset(): Int

Returns the offset in pixels for window alignment key line.

Return
`Int`	The number of pixels to offset. If the offset is positive, it is distance from low edge (see `WINDOW_ALIGN_LOW_EDGE`); if the offset is negative, the absolute value is distance from high edge (see `WINDOW_ALIGN_HIGH_EDGE`). Default value is 0.

getWindowAlignmentOffsetPercent

open fun getWindowAlignmentOffsetPercent(): Float

Returns the offset percent for window alignment key line in addition to getWindowAlignmentOffset().

Return
`Float`	Percentage to offset. E.g., 40 means 40% of the width from the low edge, or `WINDOW_ALIGN_OFFSET_PERCENT_DISABLED` if disabled. Default value is 50.

hasOverlappingRendering

open fun hasOverlappingRendering(): Boolean

hasPreviousViewInSameRow

open fun hasPreviousViewInSameRow(position: Int): Boolean

Returns true if the view at the given position has a same row sibling in front of it. This will return true if first item view is not created.

Parameters
`position`	Int: Position in adapter.

Return
`Boolean`	True if the view at the given position has a same row sibling in front of it.

isChildLayoutAnimated

open fun isChildLayoutAnimated(): Boolean

Returns true if an animation will run when a child changes size or when adding or removing a child.

Return
`Boolean`	True if ItemAnimator is enabled, false otherwise.

isFocusDrawingOrderEnabled

open fun isFocusDrawingOrderEnabled(): Boolean

Returns true if draws selected child at last, false otherwise. Default is enabled.

Return
`Boolean`	True if draws selected child at last, false otherwise.

isFocusSearchDisabled

fun isFocusSearchDisabled(): Boolean

Returns true if focus search is disabled.

Return
`Boolean`	True if focus search is disabled.

isItemAlignmentOffsetWithPadding

open fun isItemAlignmentOffsetWithPadding(): Boolean

Returns true if applies padding to item alignment when getItemAlignmentOffsetPercent() is 0 or 100; returns false otherwise.

When true: Applies start/top padding when getItemAlignmentOffsetPercent() is 0. Applies end/bottom padding when getItemAlignmentOffsetPercent() is 100. Does not apply padding if getItemAlignmentOffsetPercent() is neither 0 nor 100.

When false: does not apply padding

isScrollEnabled

open fun isScrollEnabled(): Boolean

Returns true if scrolling is enabled, false otherwise.

Return
`Boolean`	True if scrolling is enabled, false otherwise.

isWindowAlignmentPreferKeyLineOverHighEdge

open fun isWindowAlignmentPreferKeyLineOverHighEdge(): Boolean

Returns whether prefer key line over high edge when WINDOW_ALIGN_HIGH_EDGE is used. When true, if there are very few items between high edge and key line, align items to key line instead of align items to high edge. Default value is true (aka prefer align to key line).

Return
`Boolean`	True to prefer key line over high edge, false otherwise.

isWindowAlignmentPreferKeyLineOverLowEdge

open fun isWindowAlignmentPreferKeyLineOverLowEdge(): Boolean

Returns whether prefer key line over low edge when WINDOW_ALIGN_LOW_EDGE is used. When true, if there are very few items between low edge and key line, align items to key line instead of align items to low edge. Default value is false (aka prefer align to low edge).

Return
`Boolean`	True to prefer key line over low edge, false otherwise.

onRequestFocusInDescendants

open fun onRequestFocusInDescendants(
    direction: Int, 
    previouslyFocusedRect: Rect!
): Boolean

onRtlPropertiesChanged

open fun onRtlPropertiesChanged(layoutDirection: Int): Unit

Notify layout manager that layout directionality has been updated

removeOnChildViewHolderSelectedListener

open fun removeOnChildViewHolderSelectedListener(listener: OnChildViewHolderSelectedListener!): Unit

Remove the callback invoked when an item in BaseGridView has been selected.

Parameters
`listener`	OnChildViewHolderSelectedListener!: The listener to be removed.

removeOnLayoutCompletedListener

fun removeOnLayoutCompletedListener(@NonNull listener: BaseGridView.OnLayoutCompletedListener): Unit

Removes a callback to be invoked when the BaseGridView completes a full layout calculation.

Parameters
`listener`	BaseGridView.OnLayoutCompletedListener: The listener to be invoked.

removeView

open fun removeView(view: View!): Unit

removeViewAt

open fun removeViewAt(index: Int): Unit

scrollToPosition

open fun scrollToPosition(position: Int): Unit

setAnimateChildLayout

open fun setAnimateChildLayout(animateChildLayout: Boolean): Unit

Sets whether ItemAnimator should run when a child changes size or when adding or removing a child.

Parameters
`animateChildLayout`	Boolean: True to enable ItemAnimator, false to disable.

setChildrenVisibility

open fun setChildrenVisibility(visibility: Int): Unit

Changes and overrides children's visibility.

Parameters
`visibility`	Int: See `View#getVisibility()`.

setFocusDrawingOrderEnabled

open fun setFocusDrawingOrderEnabled(enabled: Boolean): Unit

Enables or disables the default "focus draw at last" order rule. Default is enabled.

Parameters
`enabled`	Boolean: True to draw the selected child at last, false otherwise.

setFocusSearchDisabled

fun setFocusSearchDisabled(disabled: Boolean): Unit

Disables or enables focus search.

Parameters
`disabled`	Boolean: True to disable focus search, false to enable.

setGravity

open fun setGravity(gravity: Int): Unit

Sets the gravity used for child view positioning. Defaults to GRAVITY_TOP|GRAVITY_START.

Parameters
`gravity`	Int: See `android.view.Gravity`

setHasOverlappingRendering

open fun setHasOverlappingRendering(hasOverlapping: Boolean): Unit

setHorizontalMargin

open fun setHorizontalMargin(margin: Int): Unit

Deprecated: Use setHorizontalSpacing(int)

Sets the spacing in pixels between two child items horizontally.

setHorizontalSpacing

open fun setHorizontalSpacing(spacing: Int): Unit

Sets the horizontal spacing in pixels between two child items.

Parameters
`spacing`	Int: Horizontal spacing in pixels between two child items.

setInitialPrefetchItemCount

open fun setInitialPrefetchItemCount(itemCount: Int): Unit

Sets the number of items to prefetch in RecyclerView.LayoutManager#collectInitialPrefetchPositions(int, RecyclerView.LayoutManager.LayoutPrefetchRegistry), which defines how many inner items should be prefetched when this GridView is nested inside another RecyclerView.

Set this value to the number of items this inner GridView will display when it is first scrolled into the viewport. RecyclerView will attempt to prefetch that number of items so they are ready, avoiding jank as the inner GridView is scrolled into the viewport.

For example, take a VerticalGridView of scrolling HorizontalGridViews. The rows always have 6 items visible in them (or 7 if not aligned). Passing 6 to this method for each inner GridView will enable RecyclerView's prefetching feature to do create/bind work for 6 views within a row early, before it is scrolled on screen, instead of just the default 4.

Calling this method does nothing unless the LayoutManager is in a RecyclerView nested in another RecyclerView.

Note: Setting this value to be larger than the number of views that will be visible in this view can incur unnecessary bind work, and an increase to the number of Views created and in active use.

Parameters
`itemCount`	Int: Number of items to prefetch

See Also

#getInitialPrefetchItemCount()RecyclerView.LayoutManager#isItemPrefetchEnabled()RecyclerView.LayoutManager#collectInitialPrefetchPositions(int, RecyclerView.LayoutManager.LayoutPrefetchRegistry)

setItemAlignmentOffset

open fun setItemAlignmentOffset(offset: Int): Unit

Sets number of pixels to the end of low edge. Supports right to left layout direction. Item alignment settings are ignored for the child if ItemAlignmentFacet is provided by RecyclerView.ViewHolder or FacetProviderAdapter.

Parameters
`offset`	Int: In left to right or vertical case, it's the offset added to left/top edge. In right to left case, it's the offset subtracted from right edge.

setItemAlignmentOffsetPercent

open fun setItemAlignmentOffsetPercent(offsetPercent: Float): Unit

Sets the offset percent for item alignment in addition to . Item alignment settings are ignored for the child if ItemAlignmentFacet is provided by RecyclerView.ViewHolder or FacetProviderAdapter.

Parameters
`offsetPercent`	Float: Percentage to offset. E.g., 40 means 40% of the width from the low edge. Use `ITEM_ALIGN_OFFSET_PERCENT_DISABLED` to disable.

setItemAlignmentOffsetWithPadding

open fun setItemAlignmentOffsetWithPadding(withPadding: Boolean): Unit

Sets whether applies padding to item alignment when getItemAlignmentOffsetPercent() is 0 or 100.

When true: Applies start/top padding if getItemAlignmentOffsetPercent() is 0. Applies end/bottom padding if getItemAlignmentOffsetPercent() is 100. Does not apply padding if getItemAlignmentOffsetPercent() is neither 0 nor 100.

When false: does not apply padding

setItemAlignmentViewId

open fun setItemAlignmentViewId(viewId: Int): Unit

Sets the id of the view to align with. Use android.view.View#NO_ID (default) for the root RecyclerView.ViewHolder#itemView. Item alignment settings on BaseGridView are if ItemAlignmentFacet is provided by RecyclerView.ViewHolder or FacetProviderAdapter.

setItemMargin

open fun setItemMargin(margin: Int): Unit

Deprecated: use setItemSpacing(int)

Sets the spacing in pixels between two child items.

setItemSpacing

open fun setItemSpacing(spacing: Int): Unit

Sets the vertical and horizontal spacing in pixels between two child items.

Parameters
`spacing`	Int: Vertical and horizontal spacing in pixels between two child items.

setLayoutEnabled

open fun setLayoutEnabled(layoutEnabled: Boolean): Unit

Enables or disables layout. All children will be removed when layout is disabled.

Parameters
`layoutEnabled`	Boolean: True to enable layout, false otherwise.

setOnChildLaidOutListener

open fun setOnChildLaidOutListener(listener: OnChildLaidOutListener!): Unit

Registers a callback to be invoked when an item in BaseGridView has been laid out.

Parameters
`listener`	OnChildLaidOutListener!: The listener to be invoked.

setOnChildSelectedListener

open fun setOnChildSelectedListener(listener: OnChildSelectedListener!): Unit

Parameters
`listener`	OnChildSelectedListener!: The listener to be invoked.

setOnChildViewHolderSelectedListener

open fun setOnChildViewHolderSelectedListener(listener: OnChildViewHolderSelectedListener!): Unit

Parameters
`listener`	OnChildViewHolderSelectedListener!: The listener to be invoked.

setOnKeyInterceptListener

open fun setOnKeyInterceptListener(listener: BaseGridView.OnKeyInterceptListener!): Unit

Sets the key intercept listener.

Parameters
`listener`	BaseGridView.OnKeyInterceptListener!: The key intercept listener.

setOnMotionInterceptListener

open fun setOnMotionInterceptListener(listener: BaseGridView.OnMotionInterceptListener!): Unit

Sets the generic motion intercept listener.

Parameters
`listener`	BaseGridView.OnMotionInterceptListener!: The motion intercept listener.

setOnTouchInterceptListener

open fun setOnTouchInterceptListener(listener: BaseGridView.OnTouchInterceptListener!): Unit

Sets the touch intercept listener.

Parameters
`listener`	BaseGridView.OnTouchInterceptListener!: The touch intercept listener.

setOnUnhandledKeyListener

open fun setOnUnhandledKeyListener(listener: BaseGridView.OnUnhandledKeyListener!): Unit

Sets the unhandled key listener.

Parameters
`listener`	BaseGridView.OnUnhandledKeyListener!: The unhandled key intercept listener.

setPruneChild

open fun setPruneChild(pruneChild: Boolean): Unit

Enables or disables pruning of children. Disable is useful during transition.

Parameters
`pruneChild`	Boolean: True to prune children out side visible area, false to enable.

setRecyclerListener

open fun setRecyclerListener(listener: RecyclerView.RecyclerListener?): Unit

setSaveChildrenLimitNumber

fun setSaveChildrenLimitNumber(limitNumber: Int): Unit

Sets the limit number when getSaveChildrenPolicy() is SAVE_LIMITED_CHILD.

setSaveChildrenPolicy

fun setSaveChildrenPolicy(savePolicy: Int): Unit

Sets the policy for saving children.

Parameters
`savePolicy`	Int: One of `SAVE_NO_CHILD` `SAVE_ON_SCREEN_CHILD` `SAVE_LIMITED_CHILD` `SAVE_ALL_CHILD`.

setScrollEnabled

open fun setScrollEnabled(scrollEnabled: Boolean): Unit

Enables or disables scrolling. Disable is useful during transition.

Parameters
`scrollEnabled`	Boolean: True to enable scroll, false to disable.

setSelectedPosition

open fun setSelectedPosition(position: Int): Unit

Changes the selected item immediately without animation.

setSelectedPosition

open fun setSelectedPosition(
    position: Int, 
    scrollExtra: Int
): Unit

Changes the selected item immediately without animation, scrollExtra is applied in primary scroll direction. The scrollExtra will be kept until another setSelectedPosition or setSelectedPositionSmooth call.

setSelectedPosition

open fun setSelectedPosition(
    position: Int, 
    task: ViewHolderTask!
): Unit

Perform a task on ViewHolder at given position after scroll to it.

Parameters
`position`	Int: Position of item in adapter.
`task`	ViewHolderTask!: Task to executed on the ViewHolder at a given position.

setSelectedPositionSmooth

open fun setSelectedPositionSmooth(position: Int): Unit

Changes the selected item and run an animation to scroll to the target position.

Parameters
`position`	Int: Adapter position of the item to select.

setSelectedPositionSmooth

open fun setSelectedPositionSmooth(
    position: Int, 
    task: ViewHolderTask!
): Unit

Perform a task on ViewHolder at given position after smooth scrolling to it.

Parameters
`position`	Int: Position of item in adapter.
`task`	ViewHolderTask!: Task to executed on the ViewHolder at a given position.

setSmoothScrollByBehavior

fun setSmoothScrollByBehavior(@Nullable behavior: BaseGridView.SmoothScrollByBehavior?): Unit

Set custom behavior for smoothScrollBy().

Parameters
`behavior`	BaseGridView.SmoothScrollByBehavior?: Custom behavior of SmoothScrollBy(). Null for default behavior.

setSmoothScrollMaxPendingMoves

fun setSmoothScrollMaxPendingMoves(maxPendingMoves: Int): Unit

When holding DPAD, DPAD events are generated faster than the grid view can scroll. The grid view counts unhandled DPAD events and completes the movement after user release DPAD. If the value is set too high, the scrolling will last very long after DPAD is released. If the value is set too low, it may miss many DPAD events. The default value is 10. If app increases setSmoothScrollSpeedFactor(float), it may need decrease the max pending DPAD events to avoid scrolling too long after DPAD release.

Parameters
`maxPendingMoves`	Int: Maximum number of pending DPAD events to be remembered.

setSmoothScrollSpeedFactor

fun setSmoothScrollSpeedFactor(smoothScrollSpeedFactor: Float): Unit

Set factor of how slow the smoothScroller should run. For example when set to 2f, the smooth scroller is twice slower. The value is 1f by default.

Parameters
`smoothScrollSpeedFactor`	Float: Factor of how slow the smooth scroll is.

setVerticalMargin

open fun setVerticalMargin(margin: Int): Unit

Deprecated: Use setVerticalSpacing(int)

Sets the spacing in pixels between two child items vertically.

setVerticalSpacing

open fun setVerticalSpacing(spacing: Int): Unit

Sets the vertical spacing in pixels between two child items.

Parameters
`spacing`	Int: Vertical spacing between two child items.

setWindowAlignment

open fun setWindowAlignment(windowAlignment: Int): Unit

Sets the method for focused item alignment in the view.

Parameters
`windowAlignment`	Int: `WINDOW_ALIGN_BOTH_EDGE`, `WINDOW_ALIGN_LOW_EDGE`, `WINDOW_ALIGN_HIGH_EDGE` or `WINDOW_ALIGN_NO_EDGE`.

setWindowAlignmentOffset

open fun setWindowAlignmentOffset(offset: Int): Unit

Sets the offset in pixels for window alignment key line.

Parameters
`offset`	Int: The number of pixels to offset. If the offset is positive, it is distance from low edge (see `WINDOW_ALIGN_LOW_EDGE`); if the offset is negative, the absolute value is distance from high edge (see `WINDOW_ALIGN_HIGH_EDGE`). Default value is 0.

setWindowAlignmentOffsetPercent

open fun setWindowAlignmentOffsetPercent(offsetPercent: Float): Unit

Sets the offset percent for window alignment key line in addition to .

Parameters
`offsetPercent`	Float: Percentage to offset. E.g., 40 means 40% of the width from low edge. Use `WINDOW_ALIGN_OFFSET_PERCENT_DISABLED` to disable. Default value is 50.

setWindowAlignmentPreferKeyLineOverHighEdge

open fun setWindowAlignmentPreferKeyLineOverHighEdge(preferKeyLineOverHighEdge: Boolean): Unit

Parameters
`preferKeyLineOverHighEdge`	Boolean: True to prefer key line over high edge, false otherwise.

setWindowAlignmentPreferKeyLineOverLowEdge

open fun setWindowAlignmentPreferKeyLineOverLowEdge(preferKeyLineOverLowEdge: Boolean): Unit

Sets whether prefer key line over low edge when WINDOW_ALIGN_LOW_EDGE is used. When true, if there are very few items between low edge and key line, align items to key line instead of align items to low edge. Default value is false (aka prefer align to low edge).

Parameters
`preferKeyLineOverLowEdge`	Boolean: True to prefer key line over low edge, false otherwise.

smoothScrollBy

open fun smoothScrollBy(
    dx: Int, 
    dy: Int
): Unit

smoothScrollBy

open fun smoothScrollBy(
    dx: Int, 
    dy: Int, 
    @Nullable interpolator: Interpolator?
): Unit

smoothScrollToPosition

open fun smoothScrollToPosition(position: Int): Unit

Protected methods

dispatchGenericFocusedEvent

protected open fun dispatchGenericFocusedEvent(event: MotionEvent!): Boolean

onFocusChanged

protected open fun onFocusChanged(
    gainFocus: Boolean, 
    direction: Int, 
    previouslyFocusedRect: Rect!
): Unit

BaseGridView

Summary

Nested classes

Constants

Inherited constants

Public methods

Protected methods

Inherited functions

Constants

ITEM_ALIGN_OFFSET_PERCENT_DISABLED

SAVE_ALL_CHILD

SAVE_LIMITED_CHILD

SAVE_NO_CHILD

SAVE_ON_SCREEN_CHILD

WINDOW_ALIGN_BOTH_EDGE

WINDOW_ALIGN_HIGH_EDGE

WINDOW_ALIGN_LOW_EDGE

WINDOW_ALIGN_NO_EDGE

WINDOW_ALIGN_OFFSET_PERCENT_DISABLED

Public methods

addOnChildViewHolderSelectedListener

addOnLayoutCompletedListener

animateIn

animateOut

dispatchKeyEvent

dispatchTouchEvent

focusSearch

getChildDrawingOrder

getHorizontalMargin

getHorizontalSpacing

getInitialPrefetchItemCount

getItemAlignmentOffset

getItemAlignmentOffsetPercent

getItemAlignmentViewId

getOnUnhandledKeyListener

getSaveChildrenLimitNumber

getSaveChildrenPolicy

getSelectedPosition

getSmoothScrollByBehavior

getSmoothScrollMaxPendingMoves

getSmoothScrollSpeedFactor

getVerticalMargin

getVerticalSpacing

getViewSelectedOffsets

getWindowAlignment

getWindowAlignmentOffset

getWindowAlignmentOffsetPercent

hasOverlappingRendering

hasPreviousViewInSameRow

isChildLayoutAnimated

isFocusDrawingOrderEnabled

isFocusSearchDisabled

isItemAlignmentOffsetWithPadding

isScrollEnabled

isWindowAlignmentPreferKeyLineOverHighEdge

isWindowAlignmentPreferKeyLineOverLowEdge

onRequestFocusInDescendants

onRtlPropertiesChanged

removeOnChildViewHolderSelectedListener

removeOnLayoutCompletedListener

removeView

removeViewAt

scrollToPosition

setAnimateChildLayout

setChildrenVisibility

setFocusDrawingOrderEnabled

setFocusSearchDisabled

setGravity

setHasOverlappingRendering

setHorizontalMargin

setHorizontalSpacing

setInitialPrefetchItemCount

setItemAlignmentOffset

setItemAlignmentOffsetPercent

setItemAlignmentOffsetWithPadding

setItemAlignmentViewId

setItemMargin

setItemSpacing

setLayoutEnabled

setOnChildLaidOutListener