protected override void OnPause()
{
base.OnPause();
if (IsHandlingException)
{
return;
}
// https://futurestud.io/tutorials/how-to-save-and-restore-the-scroll-position-and-state-of-a-android-listview
if (BrowseViewState != null)
{
BrowseViewState.Dispose();
BrowseViewState = null;
}
if (_abandonViewState == false)
{
BrowseViewState = AbstractBrowseView.OnSaveInstanceState();
}
if (ColumnCount == 1)
{
FirstVisiblePosition = AbstractBrowseView.FirstVisiblePosition;
}
FirstVisibleRow = AbstractBrowseView.FirstVisiblePosition / ColumnCount;
PositionsInRow = ColumnCount;
}
protected override void OnResume()
{
base.OnResume();
if (IsHandlingException)
{
return;
}
BrowseFooterFragment = FragmentManager.FindFragmentById <AndroidBrowseFooterFragment>
(
Resource.Id.BrowseFooterFragment
);
AbstractBrowseView = FindViewById <AbsListView>(BrowseViewId);
BrowseViewAdapter = GetBrowseAdapter();
BrowseFooterFragment.ConfigureBrowsingFor
(
AbstractBrowseView,
getThumbnailWidth: () =>
{
return(BrowseViewAdapter.GetThumbnailWidth());
},
viewTypeChanged: () =>
{
ToggleBrowseActivity();
},
scaleTypeChanged: () =>
{
BrowseViewAdapter.NotifyDataSetChanged();
}
);
if (AbstractBrowseView.Adapter == null)
{
AbstractBrowseView.Adapter = BrowseViewAdapter;
}
if (BrowseViewState != null)
{
AbstractBrowseView.OnRestoreInstanceState(BrowseViewState);
}
else
{
TryRestoreFirstPosition();
}
//_browseObjectsList.ChoiceMode = ChoiceMode.Multiple;
//AbsListView.IMultiChoiceModeListener multiChoiceModeListener = new MultiChoiceModeListener();
//_browseObjectsList.SetMultiChoiceModeListener(multiChoiceModeListener);
}
private void TryRestoreFirstPosition()
{
if (PositionsInRow == null)
{
return;
}
int firstPositionInRow = FirstVisibleRow * PositionsInRow.Value;
int lastPositionInRow = firstPositionInRow + PositionsInRow.Value - 1;
int firstVisiblePosition = ((FirstVisiblePosition < firstPositionInRow) ||
(lastPositionInRow < FirstVisiblePosition))
? firstPositionInRow
: FirstVisiblePosition;
if (AbstractBrowseView.FirstVisiblePosition != firstVisiblePosition)
{
AbstractBrowseView.SetSelection(firstVisiblePosition);
}
}
