SortedList
class SortedList<T>
A Sorted list implementation that can keep items in order and also notify for changes in the list such that it can be bound to a RecyclerView.Adapter.
It keeps items ordered using the compare method and uses binary search to retrieve items. If the sorting criteria of your items may change, make sure you call appropriate methods while editing them to avoid data inconsistencies.
You can control the order of items and change notifications via the Callback parameter.
Summary
Nested types |
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class SortedList.BatchedCallback<T2> : SortedList.CallbackA callback implementation that can batch notify events dispatched by the SortedList. |
abstract class SortedList.Callback<T2> : Comparator, ListUpdateCallbackThe class that controls the behavior of the |
Constants |
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const Int |
INVALID_POSITION = -1Used by |
Public constructors |
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SortedList(klass: Class<T!>, callback: SortedList.Callback<T!>)Creates a new SortedList of type T. |
SortedList(Creates a new SortedList of type T. |
Public functions |
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Int |
add(item: T!)Adds the given item to the list. |
Unit |
Adds the given items to the list. |
Unit |
addAll(items: (Mutable)Collection<T!>)Adds the given items to the list. |
Unit |
Adds the given items to the list. |
Unit |
Batches adapter updates that happen after calling this method and before calling |
Unit |
clear()Removes all items from the SortedList. |
Unit |
Ends the update transaction and dispatches any remaining event to the callback. |
T! |
Returns the item at the given index. |
Int |
indexOf(item: T!)Returns the position of the provided item. |
Unit |
recalculatePositionOfItemAt(index: Int)This method can be used to recalculate the position of the item at the given index, without triggering an |
Boolean |
remove(item: T!)Removes the provided item from the list and calls |
T! |
removeItemAt(index: Int)Removes the item at the given index and calls |
Unit |
replaceAll(items: Array<T!>)Replaces the current items with the new items, dispatching |
Unit |
replaceAll(items: (Mutable)Collection<T!>)Replaces the current items with the new items, dispatching |
Unit |
replaceAll(items: Array<T!>, mayModifyInput: Boolean)Replaces the current items with the new items, dispatching |
Int |
size()The number of items in the list. |
Unit |
updateItemAt(index: Int, item: T!)Updates the item at the given index and calls |
Constants
INVALID_POSITION
const val INVALID_POSITION = -1: Int
Used by indexOf when the item cannot be found in the list.
Public constructors
SortedList
SortedList(klass: Class<T!>, callback: SortedList.Callback<T!>)
Creates a new SortedList of type T.
| Parameters | |
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klass: Class<T!> |
The class of the contents of the SortedList. |
callback: SortedList.Callback<T!> |
The callback that controls the behavior of SortedList. |
SortedList
SortedList(
klass: Class<T!>,
callback: SortedList.Callback<T!>,
initialCapacity: Int
)
Creates a new SortedList of type T.
| Parameters | |
|---|---|
klass: Class<T!> |
The class of the contents of the SortedList. |
callback: SortedList.Callback<T!> |
The callback that controls the behavior of SortedList. |
initialCapacity: Int |
The initial capacity to hold items. |
Public functions
add
fun add(item: T!): Int
Adds the given item to the list. If this is a new item, SortedList calls onInserted.
If the item already exists in the list and its sorting criteria is not changed, it is replaced with the existing Item. SortedList uses areItemsTheSame to check if two items are the same item and uses areContentsTheSame to decide whether it should call onChanged or not. In both cases, it always removes the reference to the old item and puts the new item into the backing array even if areContentsTheSame returns false.
If the sorting criteria of the item is changed, SortedList won't be able to find its duplicate in the list which will result in having a duplicate of the Item in the list. If you need to update sorting criteria of an item that already exists in the list, use updateItemAt. You can find the index of the item using indexOf before you update the object.
| Parameters | |
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item: T! |
The item to be added into the list. |
| Returns | |
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Int |
The index of the newly added item. |
| See also | |
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compare |
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areItemsTheSame |
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areContentsTheSame |
} |
addAll
fun addAll(items: Array<T!>): Unit
Adds the given items to the list. Does not modify or retain the input.
| Parameters | |
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items: Array<T!> |
Array of items to be added into the list. |
| See also | |
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addAll |
addAll
fun addAll(items: (Mutable)Collection<T!>): Unit
Adds the given items to the list. Does not modify or retain the input.
| Parameters | |
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items: (Mutable)Collection<T!> |
Collection of items to be added into the list. |
| See also | |
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addAll |
addAll
fun addAll(items: Array<T!>, mayModifyInput: Boolean): Unit
Adds the given items to the list. Equivalent to calling add in a loop, except the callback events may be in a different order/granularity since addAll can batch them for better performance.
If allowed, will reference the input array during, and possibly after, the operation to avoid extra memory allocation, in which case you should not continue to reference or modify the array yourself.
| Parameters | |
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items: Array<T!> |
Array of items to be added into the list. |
mayModifyInput: Boolean |
If true, SortedList is allowed to modify and permanently reference the input array. |
| See also | |
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addAll |
beginBatchedUpdates
fun beginBatchedUpdates(): Unit
Batches adapter updates that happen after calling this method and before calling endBatchedUpdates. For example, if you add multiple items in a loop and they are placed into consecutive indices, SortedList calls onInserted only once with the proper item count. If an event cannot be merged with the previous event, the previous event is dispatched to the callback instantly.
After running your data updates, you must call endBatchedUpdates which will dispatch any deferred data change event to the current callback.
A sample implementation may look like this:
mSortedList.beginBatchedUpdates(); try { mSortedList.add(item1) mSortedList.add(item2) mSortedList.remove(item3) ... } finally { mSortedList.endBatchedUpdates(); }
Instead of using this method to batch calls, you can use a Callback that extends BatchedCallback. In that case, you must make sure that you are manually calling dispatchLastEvent right after you complete your data changes. Failing to do so may create data inconsistencies with the Callback.
If the current Callback is an instance of BatchedCallback, calling this method has no effect.
endBatchedUpdates
fun endBatchedUpdates(): Unit
Ends the update transaction and dispatches any remaining event to the callback.
get
fun get(index: Int): T!
Returns the item at the given index.
| Parameters | |
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index: Int |
The index of the item to retrieve. |
| Returns | |
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T! |
The item at the given index. |
| Throws | |
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java.lang.IndexOutOfBoundsException |
if provided index is negative or larger than the size of the list. |
indexOf
fun indexOf(item: T!): Int
Returns the position of the provided item.
| Parameters | |
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item: T! |
The item to query for position. |
| Returns | |
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Int |
The position of the provided item or |
recalculatePositionOfItemAt
fun recalculatePositionOfItemAt(index: Int): Unit
This method can be used to recalculate the position of the item at the given index, without triggering an onChanged callback.
If you are editing objects in the list such that their position in the list may change but you don't want to trigger an onChange animation, you can use this method to re-position it. If the item changes position, SortedList will call onMoved without calling onChanged.
A sample usage may look like:
final int position = mSortedList.indexOf(item); item.incrementPriority(); // assume items are sorted by priority mSortedList.recalculatePositionOfItemAt(position);
| Parameters | |
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index: Int |
The current index of the Item whose position should be re-calculated. |
| See also | |
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updateItemAt |
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add |
remove
fun remove(item: T!): Boolean
Removes the provided item from the list and calls onRemoved.
| Parameters | |
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item: T! |
The item to be removed from the list. |
| Returns | |
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Boolean |
True if item is removed, false if item cannot be found in the list. |
removeItemAt
fun removeItemAt(index: Int): T!
Removes the item at the given index and calls onRemoved.
| Parameters | |
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index: Int |
The index of the item to be removed. |
| Returns | |
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T! |
The removed item. |
replaceAll
fun replaceAll(items: Array<T!>): Unit
Replaces the current items with the new items, dispatching ListUpdateCallback events for each change detected as appropriate. Does not modify or retain the input.
| Parameters | |
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items: Array<T!> |
Array of items to replace current items. |
| See also | |
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replaceAll |
replaceAll
fun replaceAll(items: (Mutable)Collection<T!>): Unit
Replaces the current items with the new items, dispatching ListUpdateCallback events for each change detected as appropriate. Does not modify or retain the input.
| Parameters | |
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items: (Mutable)Collection<T!> |
Array of items to replace current items. |
| See also | |
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replaceAll |
replaceAll
fun replaceAll(items: Array<T!>, mayModifyInput: Boolean): Unit
Replaces the current items with the new items, dispatching ListUpdateCallback events for each change detected as appropriate.
If allowed, will reference the input array during, and possibly after, the operation to avoid extra memory allocation, in which case you should not continue to reference or modify the array yourself.
Note: this method does not detect moves or dispatch onMoved events. It instead treats moves as a remove followed by an add and therefore dispatches onRemoved and onRemoved events. See DiffUtil if you want your implementation to dispatch move events.
| Parameters | |
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items: Array<T!> |
Array of items to replace current items. |
mayModifyInput: Boolean |
If true, SortedList is allowed to modify and permanently reference the input array. |
| See also | |
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replaceAll |
size
fun size(): Int
The number of items in the list.
| Returns | |
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Int |
The number of items in the list. |
updateItemAt
fun updateItemAt(index: Int, item: T!): Unit
Updates the item at the given index and calls onChanged and/or onMoved if necessary.
You can use this method if you need to change an existing Item such that its position in the list may change.
If the new object is a different object (get(index) != item) and areContentsTheSame returns true, SortedList avoids calling onChanged otherwise it calls onChanged.
If the new position of the item is different than the provided index, SortedList calls onMoved.
| Parameters | |
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index: Int |
The index of the item to replace |
item: T! |
The item to replace the item at the given Index. |
| See also | |
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add |