Android APIs
public static abstract class

AsyncListUtil.ViewCallback

extends Object
java.lang.Object
   ↳ android.support.v7.util.AsyncListUtil.ViewCallback

Class Overview

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.
[Expand]
Inherited Methods
From class java.lang.Object

Constants

public static final int HINT_SCROLL_ASC

Scrolling in ascending order (from lower to higher positions in the order of the backing storage).

Constant Value: 2 (0x00000002)

public static final int HINT_SCROLL_DESC

Scrolling in descending order (from higher to lower positions in the order of the backing storage).

Constant Value: 1 (0x00000001)

public static final int HINT_SCROLL_NONE

No scroll direction hint available.

Constant Value: 0 (0x00000000)

Public Constructors

public AsyncListUtil.ViewCallback ()

Public Methods

public 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 Visible item range.
outRange Extended range.
scrollHint The scroll direction hint.

public abstract 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 The visible item range.

public abstract void onDataRefresh ()

Called when the entire data set has changed.

public abstract void onItemLoaded (int position)

Called when an item at the given position is loaded.

Parameters
position Item position.