public override void ViewDidLayoutSubviews()
{
base.ViewDidLayoutSubviews();
if (isViewAppearing || isViewRotating)
{
// Force the UICollectionViewFlowLayout to get laid out again with the new size if
// a) The view is appearing. This ensures that
// collectionView:layout:sizeForItemAtIndexPath: is called for a second time
// when the view is shown and when the view *frame(s)* are actually set
// (we need the view frame's to have been set to work out the size's and on the
// first call to collectionView:layout:sizeForItemAtIndexPath: the view frame(s)
// aren't set correctly)
// b) The view is rotating. This ensures that
// collectionView:layout:sizeForItemAtIndexPath: is called again and can use the views
// *new* frame so that the buttonBarView cell's actually get resized correctly
CachedCellWidths = CalculateWidths();
ButtonBarView.CollectionViewLayout.InvalidateLayout();
// When the view first appears or is rotated we also need to ensure that the barButtonView's
// selectedBar is resized and its contentOffset/scroll is set correctly (the selected
// tab/cell may end up either skewed or off screen after a rotation otherwise)
ButtonBarView.MoveToIndex((int)CurrentIndex, animated: false, swipeDirection: SwipeDirection.None, pagerScroll: PagerScroll.ScrollOnlyIfOutOfScreen);
ButtonBarView.SelectItem(NSIndexPath.FromRowSection((System.nint)CurrentIndex, 0), false, UICollectionViewScrollPosition.None);
}
}
public override void ReloadPagerTabStripView()
{
base.ReloadPagerTabStripView();
if (IsViewLoaded)
{
ButtonBarView.ReloadData();
cachedCellWidths = CalculateWidths();
ButtonBarView.MoveToIndex((int)CurrentIndex, animated: false, swipeDirection: SwipeDirection.None, pagerScroll: PagerScroll.Yes);
}
}
public void PagerTabStripViewController(PagerTabStripViewController pagerTabStripViewController, int fromIndex, int toIndex)
{
if (shouldUpdateButtonBarView)
{
ButtonBarView.MoveToIndex(toIndex, animated: true, swipeDirection: toIndex < fromIndex ? SwipeDirection.Right : SwipeDirection.Left, pagerScroll: PagerScroll.Yes);
if (ChangeCurrentIndex != null)
{
var oldCell = ButtonBarView.CellForItem(NSIndexPath.FromItemSection(new nint(CurrentIndex != fromIndex ? fromIndex : toIndex), 0)) as ButtonBarViewCell;
var newCell = ButtonBarView.CellForItem(NSIndexPath.FromItemSection(new nint(CurrentIndex), 0)) as ButtonBarViewCell;
ChangeCurrentIndex(oldCell, newCell, true);
}
}
}
public void ItemSelected(UICollectionView collectionView, NSIndexPath indexPath)
{
if (indexPath.Item != CurrentIndex)
{
ButtonBarView.MoveToIndex((int)indexPath.Item, true, SwipeDirection.None, PagerScroll.Yes);
shouldUpdateButtonBarView = false;
var oldCell = ButtonBarView.CellForItem(NSIndexPath.FromItemSection(new nint(CurrentIndex), 0)) as ButtonBarViewCell;
var newCell = ButtonBarView.CellForItem(NSIndexPath.FromItemSection(indexPath.Item, 0)) as ButtonBarViewCell;
if (PagerBehaviour.IsProgressiveIndicator)
{
ChangeCurrentIndexProgressive?.Invoke(oldCell, newCell, 1, true, true);
}
else
{
ChangeCurrentIndex?.Invoke(oldCell, newCell, true);
}
MoveToViewControllerAtIndex((uint)indexPath.Item);
}
}