recyclerview/androidx.recyclerview.widget/StaggeredGridLayoutManager

StaggeredGridLayoutManager

open class StaggeredGridLayoutManager : RecyclerView.LayoutManager, RecyclerView.SmoothScroller.ScrollVectorProvider(source)

A LayoutManager that lays out children in a staggered grid formation. It supports horizontal &vertical layout as well as an ability to layout children in reverse.

Staggered grids are likely to have gaps at the edges of the layout. To avoid these gaps, StaggeredGridLayoutManager can offset spans independently or move items between spans. You can control this behavior via setGapStrategy.

Constructors

StaggeredGridLayoutManager

constructor(context: Context, attrs: AttributeSet, defStyleAttr: Int, defStyleRes: Int)

Constructor used when layout manager is set in XML by RecyclerView attribute "layoutManager".

constructor(spanCount: Int, orientation: Int)

Creates a StaggeredGridLayoutManager with given parameters.

Types

open class LayoutParams : RecyclerView.LayoutParams

LayoutParams used by StaggeredGridLayoutManager.

@RestrictTo(value = LIBRARY)

open class SavedState : Parcelable

Properties

GAP_HANDLING_LAZY

val ~~GAP_HANDLING_LAZY~~: Int = 1

GAP_HANDLING_MOVE_ITEMS_BETWEEN_SPANS

val GAP_HANDLING_MOVE_ITEMS_BETWEEN_SPANS: Int = 2

When scroll state is changed to SCROLL_STATE_IDLE, StaggeredGrid will check if there are gaps in the because of full span items.

GAP_HANDLING_NONE

val GAP_HANDLING_NONE: Int = 0

Does not do anything to hide gaps.

val HORIZONTAL: Int = 0

val VERTICAL: Int = 1

Functions

assertNotInLayoutOrScroll

open fun assertNotInLayoutOrScroll(message: String)

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

canScrollHorizontally

open fun canScrollHorizontally(): Boolean

Query if horizontal scrolling is currently supported.

canScrollVertically

open fun canScrollVertically(): Boolean

Query if vertical scrolling is currently supported.

checkLayoutParams

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

Determines the validity of the supplied LayoutParams object.

collectAdjacentPrefetchPositions

@RestrictTo(value = LIBRARY)

open fun collectAdjacentPrefetchPositions(dx: Int, dy: Int, state: RecyclerView.State, layoutPrefetchRegistry: RecyclerView.LayoutManager.LayoutPrefetchRegistry)

Gather all positions from the LayoutManager to be prefetched, given specified momentum.

computeHorizontalScrollExtent

open fun computeHorizontalScrollExtent(state: RecyclerView.State): Int

Override this method if you want to support scroll bars.

computeHorizontalScrollOffset

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

Override this method if you want to support scroll bars.

computeHorizontalScrollRange

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

Override this method if you want to support scroll bars.

computeScrollVectorForPosition

open fun computeScrollVectorForPosition(targetPosition: Int): PointF

Should calculate the vector that points to the direction where the target position can be found.

computeVerticalScrollExtent

open fun computeVerticalScrollExtent(state: RecyclerView.State): Int

Override this method if you want to support scroll bars.

computeVerticalScrollOffset

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

Override this method if you want to support scroll bars.

computeVerticalScrollRange

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

Override this method if you want to support scroll bars.

findFirstCompletelyVisibleItemPositions

open fun findFirstCompletelyVisibleItemPositions(into: Array<Int>): Array<Int>

Returns the adapter position of the first completely visible view for each span.

findFirstVisibleItemPositions

open fun findFirstVisibleItemPositions(into: Array<Int>): Array<Int>

Returns the adapter position of the first visible view for each span.

findLastCompletelyVisibleItemPositions

open fun findLastCompletelyVisibleItemPositions(into: Array<Int>): Array<Int>

Returns the adapter position of the last completely visible view for each span.

findLastVisibleItemPositions

open fun findLastVisibleItemPositions(into: Array<Int>): Array<Int>

Returns the adapter position of the last visible view for each span.

generateDefaultLayoutParams

open fun generateDefaultLayoutParams(): RecyclerView.LayoutParams

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

generateLayoutParams

open 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.

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

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

getColumnCountForAccessibility

open fun getColumnCountForAccessibility(@NonNull recycler: RecyclerView.Recycler, @NonNull state: RecyclerView.State): Int

Returns the number of columns for accessibility.

open fun getGapStrategy(): Int

Returns the current gap handling strategy for StaggeredGridLayoutManager.

open fun getOrientation(): Int

getReverseLayout

open fun getReverseLayout(): Boolean

Returns whether views are laid out in reverse order or not.

getRowCountForAccessibility

open fun getRowCountForAccessibility(@NonNull recycler: RecyclerView.Recycler, @NonNull state: RecyclerView.State): Int

Returns the number of rows for accessibility.

open fun getSpanCount(): Int

Returns the number of spans laid out by StaggeredGridLayoutManager.

invalidateSpanAssignments

open fun invalidateSpanAssignments()

For consistency, StaggeredGridLayoutManager keeps a mapping between spans and items.

isAutoMeasureEnabled

open fun isAutoMeasureEnabled(): Boolean

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.

isLayoutReversed

open fun isLayoutReversed(): Boolean

Query if the layout is in reverse order.

offsetChildrenHorizontal

open fun offsetChildrenHorizontal(dx: Int)

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

offsetChildrenVertical

open fun offsetChildrenVertical(dy: Int)

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

onAdapterChanged

open fun onAdapterChanged(@Nullable oldAdapter: RecyclerView.Adapter, @Nullable newAdapter: RecyclerView.Adapter)

Called if the RecyclerView this LayoutManager is bound to has a different adapter set via setAdapter or swapAdapter.

onDetachedFromWindow

open fun 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.

onFocusSearchFailed

open 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.

onInitializeAccessibilityEvent

open fun onInitializeAccessibilityEvent(event: AccessibilityEvent)

onInitializeAccessibilityNodeInfo

open fun onInitializeAccessibilityNodeInfo(@NonNull recycler: RecyclerView.Recycler, @NonNull state: RecyclerView.State, @NonNull info: AccessibilityNodeInfoCompat)

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

onInitializeAccessibilityNodeInfoForItem

open fun onInitializeAccessibilityNodeInfoForItem(@NonNull recycler: RecyclerView.Recycler, @NonNull state: RecyclerView.State, @NonNull host: View, @NonNull info: AccessibilityNodeInfoCompat)

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

open fun onItemsAdded(recyclerView: RecyclerView, positionStart: Int, itemCount: Int)

Called when items have been added to the adapter.

open fun onItemsChanged(recyclerView: RecyclerView)

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

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

Called when an item is moved withing the adapter.

open fun onItemsRemoved(recyclerView: RecyclerView, positionStart: Int, itemCount: Int)

Called when items have been removed from the adapter.

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

Called when items have been changed in the adapter and with optional payload.

onLayoutChildren

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

Lay out all relevant child views from the given adapter.

onLayoutCompleted

open fun onLayoutCompleted(state: RecyclerView.State)

Called after a full layout calculation is finished.

onRestoreInstanceState

open fun onRestoreInstanceState(state: Parcelable)

Called when the RecyclerView is ready to restore the state based on a previous RecyclerView.

onSaveInstanceState

open fun onSaveInstanceState(): Parcelable

Called when the LayoutManager should save its state.

onScrollStateChanged

open fun onScrollStateChanged(state: Int)

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

scrollHorizontallyBy

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

Scroll horizontally by dx pixels in screen coordinates and return the distance traveled.

scrollToPosition

open fun scrollToPosition(position: Int)

Scroll to the specified adapter position.

scrollToPositionWithOffset

open fun scrollToPositionWithOffset(position: Int, offset: Int)

Scroll to the specified adapter position with the given offset from layout start.

scrollVerticallyBy

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

Scroll vertically by dy pixels in screen coordinates and return the distance traveled.

open fun setGapStrategy(gapStrategy: Int)

Sets the gap handling strategy for StaggeredGridLayoutManager.

setMeasuredDimension

open fun 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.

open fun setOrientation(orientation: Int)

Sets the orientation of the layout.

setReverseLayout

open fun setReverseLayout(reverseLayout: Boolean)

Sets whether LayoutManager should start laying out items from the end of the UI.

open fun setSpanCount(spanCount: Int)

Sets the number of spans for the layout.

smoothScrollToPosition

open fun smoothScrollToPosition(recyclerView: RecyclerView, state: RecyclerView.State, position: Int)

Smooth scroll to the specified adapter position.

supportsPredictiveItemAnimations

open fun supportsPredictiveItemAnimations(): Boolean

Returns whether this LayoutManager supports "predictive item animations".