Android RemoteViews ListView Scroll

Question

Im trying to scroll a ListView to a particular position in an AppWidget.

However it does not do anything, i also tried the setPosit

Answer 1

Two things:

views.setScrollPosition(R.id.lvWidget, 3);

is the correct call. Internally, setScrollPosition(int, int) calls RemoteViews#setInt(viewId, "smoothScrollToPosition", position);.

viewId                   :    your ListView's id
"smoothScrollToPosition" :    method name to invoke on the ListView
position                 :    position to scroll to

So, you are calling the correct method.

Following is a comment for the method AppWidgetManager#partiallyUpdateAppWidget(int, RemoteViews) - taken from the source code of AppWidgetManager.java. I believe it answers your question: ... Use with {RemoteViews#showNext(int)}, {RemoteViews#showPrevious(int)},{RemoteViews#setScrollPosition(int, int)} and similar commands...

/**
 * Perform an incremental update or command on the widget specified by appWidgetId.
 *
 * This update  differs from {@link #updateAppWidget(int, RemoteViews)} in that the RemoteViews
 * object which is passed is understood to be an incomplete representation of the widget, and
 * hence is not cached by the AppWidgetService. Note that because these updates are not cached,
 * any state that they modify that is not restored by restoreInstanceState will not persist in
 * the case that the widgets are restored using the cached version in AppWidgetService.
 *
 * Use with {RemoteViews#showNext(int)}, {RemoteViews#showPrevious(int)},
 * {RemoteViews#setScrollPosition(int, int)} and similar commands.
 *
 * 

 * It is okay to call this method both inside an {@link #ACTION_APPWIDGET_UPDATE} broadcast,
 * and outside of the handler.
 * This method will only work when called from the uid that owns the AppWidget provider.
 *
 * 

 * This method will be ignored if a widget has not received a full update via
 * {@link #updateAppWidget(int[], RemoteViews)}.
 *
 * @param appWidgetId      The AppWidget instance for which to set the RemoteViews.
 * @param views            The RemoteViews object containing the incremental update / command.
 */
public void partiallyUpdateAppWidget(int appWidgetId, RemoteViews views) {
    partiallyUpdateAppWidget(new int[] { appWidgetId }, views);
}

As the comment indicates, call partiallyUpdateAppWidget(appWidgetId, views) after views.setScrollPosition(R.id.lvWidget, 3).

The comment also warns you: This method will be ignored if a widget has not received a full update via {#updateAppWidget(int[], RemoteViews)}. This might mean that the following calls:

views.setRemoteAdapter(R.id.lvWidget, svcIntent);
views.setScrollPosition(R.id.lvWidget, 3);

should not be made in one update. I suggest that you break these calls into two separate updates:

First:

views.setRemoteAdapter(R.id.lvWidget, svcIntent);
mAppWidgetManager.updateAppWidget(appWidgetIds, views);

Second:

views.setScrollPosition(R.id.lvWidget, 3);
mAppWidgetManager.partiallyUpdateAppWidget(appWidgetId, views);

Note that the first one is a full update, while the second one is only partial.