public override Fragment GetItem(int position)
{
var fragment = FragmentContainer.CreateInstance(_page.Children[position]);
_fragments.Add(fragment);
return(fragment);
}
Fragment GetFragment(Page page, bool removed, bool popToRoot)
{
// pop
if (removed)
{
return(_fragmentStack[_fragmentStack.Count - 2]);
}
// pop to root
if (popToRoot)
{
return(_fragmentStack[0]);
}
// push
return(FragmentContainer.CreateInstance(page));
}
void InsertPageBefore(Page page, Page before)
{
if (!_isAttachedToWindow)
{
PushCurrentPages();
}
UpdateToolbar();
int index = PageController.InternalChildren.IndexOf(before);
if (index == -1)
{
throw new InvalidOperationException("This should never happen, please file a bug");
}
Fragment fragment = FragmentContainer.CreateInstance(page);
_fragmentStack.Insert(index, fragment);
}
protected override void AddChildView(VisualElement childView)
{
_pageContainer = null;
Page page = childView as NavigationPage ?? (Page)(childView as TabbedPage);
if (page == null)
{
// The thing we're adding is not a NavigationPage or TabbedPage, so we can just use the old AddChildView
if (_currentFragment != null)
{
if (!_parent.IsAttachedToRoot())
{
return;
}
// But first, if the previous occupant of this container was a fragment, we need to remove it properly
FragmentTransaction transaction = FragmentManager.BeginTransactionEx();
transaction.RemoveEx(_currentFragment);
transaction.SetTransitionEx((int)FragmentTransit.None);
if (IsAttachedToWindow)
{
ExecuteTransaction(transaction);
}
else
{
_transaction = transaction;
}
_currentFragment = null;
}
base.AddChildView(childView);
}
else
{
if (!_parent.IsAttachedToRoot())
{
return;
}
// The renderers for NavigationPage and TabbedPage both host fragments, so they need to be wrapped in a
// FragmentContainer in order to get isolated fragment management
Fragment fragment = FragmentContainer.CreateInstance(page);
var fc = fragment as FragmentContainer;
fc?.SetOnCreateCallback(pc =>
{
_pageContainer = pc;
UpdateFlowDirection();
SetDefaultBackgroundColor(pc.Child);
});
FragmentTransaction transaction = FragmentManager.BeginTransactionEx();
if (_currentFragment != null)
{
transaction.RemoveEx(_currentFragment);
}
transaction.AddEx(Id, fragment);
transaction.SetTransitionEx((int)FragmentTransit.None);
if (IsAttachedToWindow)
{
ExecuteTransaction(transaction);
}
else
{
_transaction = transaction;
}
_currentFragment = fragment;
}
}