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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

AsyncListUtil.ViewCallback

AsyncListUtil.ViewCallback ()

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.

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