RecyclerView.ViewHolder
abstract class RecyclerView.ViewHolder
FragmentViewHolder |
|
GuidedActionsStylist.ViewHolder |
ViewHolder caches information about the action item layouts' subviews. |
ItemBridgeAdapter.ViewHolder |
ViewHolder for the ItemBridgeAdapter. |
LeanbackListPreferenceDialogFragment.ViewHolder |
This class is deprecated. Ue LeanbackListPreferenceDialogFragmentCompat. |
LeanbackListPreferenceDialogFragmentCompat.ViewHolder |
ViewHolder for each Item in the List. |
PreferenceViewHolder |
A |
A ViewHolder describes an item view and metadata about its place within the RecyclerView.
Adapter implementations should subclass ViewHolder and add fields for caching potentially expensive findViewById results.
While LayoutParams belong to the LayoutManager, ViewHolders belong to the adapter. Adapters should feel free to use their own custom ViewHolder implementations to store data that makes binding view contents easier. Implementations should assume that individual item views will hold strong references to ViewHolder objects and that RecyclerView instances may hold strong references to extra off-screen item views for caching purposes
Summary
Public constructors |
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ViewHolder(itemView: View) |
Public functions |
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Int |
Returns the Adapter position of the item represented by this ViewHolder with respect to the |
Int |
This function is deprecated. This method is confusing when adapters nest other adapters. |
RecyclerView.Adapter<RecyclerView.ViewHolder!>? |
Returns the |
Int |
Returns the Adapter position of the item represented by this ViewHolder with respect to the |
Long |
Returns The itemId represented by this ViewHolder. |
Int |
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Int |
Returns the position of the ViewHolder in terms of the latest layout pass. |
Int |
When LayoutManager supports animations, RecyclerView tracks 3 positions for ViewHolders to perform animations. |
Int |
This function is deprecated. This method is deprecated because its meaning is ambiguous due to the async handling of adapter updates. |
Boolean |
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Unit |
setIsRecyclable(recyclable: Boolean)Informs the recycler whether this item can be recycled. |
String! |
toString() |
Public constructors
Public functions
getAbsoluteAdapterPosition
fun getAbsoluteAdapterPosition(): Int
Returns the Adapter position of the item represented by this ViewHolder with respect to the RecyclerView's Adapter. If the Adapter that bound this ViewHolder is inside another adapter (e.g. ConcatAdapter), this position might be different and will include the offsets caused by other adapters in the ConcatAdapter.
Note that this might be different than the getLayoutPosition if there are pending adapter updates but a new layout pass has not happened yet.
RecyclerView does not handle any adapter updates until the next layout traversal. This may create temporary inconsistencies between what user sees on the screen and what adapter contents have. This inconsistency is not important since it will be less than 16ms but it might be a problem if you want to use ViewHolder position to access the adapter. Sometimes, you may need to get the exact adapter position to do some actions in response to user events. In that case, you should use this method which will calculate the Adapter position of the ViewHolder.
Note that if you've called notifyDataSetChanged, until the next layout pass, the return value of this method will be NO_POSITION.
Note that if you are querying the position as RecyclerView sees, you should use getAbsoluteAdapterPosition (e.g. you want to use it to save scroll state). If you are querying the position to access the Adapter contents, you should use getBindingAdapterPosition.
| Returns | |
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Int |
The adapter position of the item from |
getBindingAdapter
fun getBindingAdapter(): RecyclerView.Adapter<RecyclerView.ViewHolder!>?
Returns the Adapter that last bound this ViewHolder. Might return null if this ViewHolder is not bound to any adapter.
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RecyclerView.Adapter<RecyclerView.ViewHolder!>? |
The |
getBindingAdapterPosition
fun getBindingAdapterPosition(): Int
Returns the Adapter position of the item represented by this ViewHolder with respect to the Adapter that bound it.
Note that this might be different than the getLayoutPosition if there are pending adapter updates but a new layout pass has not happened yet.
RecyclerView does not handle any adapter updates until the next layout traversal. This may create temporary inconsistencies between what user sees on the screen and what adapter contents have. This inconsistency is not important since it will be less than 16ms but it might be a problem if you want to use ViewHolder position to access the adapter. Sometimes, you may need to get the exact adapter position to do some actions in response to user events. In that case, you should use this method which will calculate the Adapter position of the ViewHolder.
Note that if you've called notifyDataSetChanged, until the next layout pass, the return value of this method will be NO_POSITION.
If the Adapter that bound this ViewHolder is inside another Adapter (e.g. ConcatAdapter), this position might be different than getAbsoluteAdapterPosition. If you would like to know the position that RecyclerView considers (e.g. for saved state), you should use getAbsoluteAdapterPosition.
| Returns | |
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Int |
The adapter position of the item if it still exists in the adapter. |
getItemViewType
fun getItemViewType(): Int
| Returns | |
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Int |
The view type of this ViewHolder. |
getLayoutPosition
fun getLayoutPosition(): Int
Returns the position of the ViewHolder in terms of the latest layout pass.
This position is mostly used by RecyclerView components to be consistent while RecyclerView lazily processes adapter updates.
For performance and animation reasons, RecyclerView batches all adapter updates until the next layout pass. This may cause mismatches between the Adapter position of the item and the position it had in the latest layout calculations.
LayoutManagers should always call this method while doing calculations based on item positions. All methods in RecyclerView.LayoutManager, RecyclerView.State, RecyclerView.Recycler that receive a position expect it to be the layout position of the item.
If LayoutManager needs to call an external method that requires the adapter position of the item, it can use getAbsoluteAdapterPosition or convertPreLayoutPositionToPostLayout.
| Returns | |
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Int |
Returns the adapter position of the ViewHolder in the latest layout pass. |
getOldPosition
fun getOldPosition(): Int
When LayoutManager supports animations, RecyclerView tracks 3 positions for ViewHolders to perform animations.
If a ViewHolder was laid out in the previous onLayout call, old position will keep its adapter index in the previous layout.
| Returns | |
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Int |
The previous adapter index of the Item represented by this ViewHolder or |
isRecyclable
fun isRecyclable(): Boolean
| Returns | |
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Boolean |
true if this item is available to be recycled, false otherwise. |
| See also | |
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setIsRecyclable |
setIsRecyclable
fun setIsRecyclable(recyclable: Boolean): Unit
Informs the recycler whether this item can be recycled. Views which are not recyclable will not be reused for other items until setIsRecyclable() is later set to true. Calls to setIsRecyclable() should always be paired (one call to setIsRecyclabe(false) should always be matched with a later call to setIsRecyclable(true)). Pairs of calls may be nested, as the state is internally reference-counted.
| Parameters | |
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recyclable: Boolean |
Whether this item is available to be recycled. Default value is true. |
| See also | |
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isRecyclable |