belongs to Maven artifact com.android.support:recyclerview-v7:28.0.0-alpha1
AsyncListUtil.ViewCallback
public
static
abstract
class
AsyncListUtil.ViewCallback
extends Object
java.lang.Object | |
↳ | android.support.v7.util.AsyncListUtil.ViewCallback |
The callback that links AsyncListUtil
with the list view.
All methods are called on the main thread.
Summary
Constants | |
---|---|
int |
HINT_SCROLL_ASC
Scrolling in ascending order (from lower to higher positions in the order of the backing storage). |
int |
HINT_SCROLL_DESC
Scrolling in descending order (from higher to lower positions in the order of the backing storage). |
int |
HINT_SCROLL_NONE
No scroll direction hint available. |
Public constructors | |
---|---|
AsyncListUtil.ViewCallback()
|
Public methods | |
---|---|
void
|
extendRangeInto(int[] range, int[] outRange, int scrollHint)
Compute a wider range of items that will be loaded for smoother scrolling. |
abstract
void
|
getItemRangeInto(int[] outRange)
Compute the range of visible item positions. |
abstract
void
|
onDataRefresh()
Called when the entire data set has changed. |
abstract
void
|
onItemLoaded(int position)
Called when an item at the given position is loaded. |
Inherited methods | |
---|---|
From
class
java.lang.Object
|
Constants
HINT_SCROLL_ASC
int HINT_SCROLL_ASC
Scrolling in ascending order (from lower to higher positions in the order of the backing storage).
Constant Value: 2 (0x00000002)
HINT_SCROLL_DESC
int HINT_SCROLL_DESC
Scrolling in descending order (from higher to lower positions in the order of the backing storage).
Constant Value: 1 (0x00000001)
HINT_SCROLL_NONE
int HINT_SCROLL_NONE
No scroll direction hint available.
Constant Value: 0 (0x00000000)
Public constructors
Public methods
extendRangeInto
void extendRangeInto (int[] range, int[] outRange, int scrollHint)
Compute a wider range of items that will be loaded for smoother scrolling.
If there is no scroll hint, the default implementation extends the visible range by half its length in both directions. If there is a scroll hint, the range is extended by its full length in the scroll direction, and by half in the other direction.
For example, if range
is {100, 200}
and scrollHint
is HINT_SCROLL_ASC
, then outRange
will be {50, 300}
.
However, if scrollHint
is HINT_SCROLL_NONE
, then
outRange
will be {50, 250}
Parameters | |
---|---|
range |
int : Visible item range. |
outRange |
int : Extended range. |
scrollHint |
int : The scroll direction hint.
|
getItemRangeInto
void getItemRangeInto (int[] outRange)
Compute the range of visible item positions.
outRange[0] is the position of the first visible item (in the order of the backing storage).
outRange[1] is the position of the last visible item (in the order of the backing storage).
Negative positions and positions greater or equal to getItemCount()
are invalid.
If the returned range contains invalid positions it is ignored (no item will be loaded).
Parameters | |
---|---|
outRange |
int : The visible item range.
|
onDataRefresh
void onDataRefresh ()
Called when the entire data set has changed.
onItemLoaded
void onItemLoaded (int position)
Called when an item at the given position is loaded.
Parameters | |
---|---|
position |
int : Item position.
|