void EnsureLayoutInitialized()
{
if (_initialized)
{
return;
}
if (!ItemsView.IsVisible)
{
// If the CollectionView starts out invisible, we'll get a layout pass with a size of 1,1 and everything will
// go pear-shaped. So until the first time this CollectionView is visible, we do nothing.
return;
}
_initialized = true;
ItemsViewLayout.GetPrototype = GetPrototype;
Delegator = CreateDelegator();
CollectionView.Delegate = Delegator;
ItemsViewLayout.SetInitialConstraints(CollectionView.Bounds.Size);
CollectionView.SetCollectionViewLayout(ItemsViewLayout, false);
UpdateEmptyView();
}
public override void ViewDidLoad()
{
base.ViewDidLoad();
ItemsSource = CreateItemsViewSource();
ItemsViewLayout.GetPrototype = GetPrototype;
Delegator = CreateDelegator();
CollectionView.Delegate = Delegator;
if (!Forms.IsiOS11OrNewer)
{
AutomaticallyAdjustsScrollViewInsets = false;
}
else
{
// We set this property to keep iOS from trying to be helpful about insetting all the
// CollectionView content when we're in landscape mode (to avoid the notch)
// The SetUseSafeArea Platform Specific is already taking care of this for us
// That said, at some point it's possible folks will want a PS for controlling this behavior
CollectionView.ContentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentBehavior.Never;
}
RegisterViewTypes();
}
void EnsureLayoutInitialized()
{
if (_initialized)
{
return;
}
_initialized = true;
ItemsViewLayout.GetPrototype = GetPrototype;
Delegator = CreateDelegator();
CollectionView.Delegate = Delegator;
ItemsViewLayout.SetInitialConstraints(CollectionView.Bounds.Size);
CollectionView.SetCollectionViewLayout(ItemsViewLayout, false);
UpdateEmptyView();
}
public void UpdateLayout(ItemsViewLayout newLayout)
{
// Ignore calls to this method if the new layout is the same as the old one
if (CollectionView.CollectionViewLayout == newLayout)
{
return;
}
ItemsViewLayout = newLayout;
ItemsViewLayout.GetPrototype = GetPrototype;
Delegator = CreateDelegator();
CollectionView.Delegate = Delegator;
// Make sure the new layout is sized properly
ItemsViewLayout.ConstrainTo(CollectionView.Bounds.Size);
CollectionView.SetCollectionViewLayout(ItemsViewLayout, false);
// Reload the data so the currently visible cells get laid out according to the new layout
CollectionView.ReloadData();
}
public void UpdateLayout(ItemsViewLayout layout)
{
ItemsViewLayout = layout;
ItemsViewLayout.GetPrototype = GetPrototype;
Delegator = CreateDelegator();
CollectionView.Delegate = Delegator;
if (CollectionView.CollectionViewLayout != ItemsViewLayout)
{
// We're updating from a previous layout
// Make sure the new layout is sized properly
ItemsViewLayout.ConstrainTo(CollectionView.Bounds.Size);
CollectionView.SetCollectionViewLayout(ItemsViewLayout, false);
// Reload the data so the currently visible cells get laid out according to the new layout
CollectionView.ReloadData();
}
}
