private View FindFocusView(View root, View current, FocusDirection direction)
{
int index = root.IndexOf(current);
Debug.Assert(index != -1);
if (direction == FocusDirection.Down || direction == FocusDirection.Right)
{
for (int i = index + 1; i < root.ChildCount(); ++i)
{
View child = root.ViewAt(i);
View view = FindFocusView(child, direction);
if (view != null)
{
return view;
}
}
}
else if (direction == FocusDirection.Up || direction == FocusDirection.Left)
{
for (int i = index - 1; i >= 0; --i)
{
View child = root.ViewAt(i);
View view = FindFocusView(child, direction);
if (view != null)
{
return view;
}
}
}
View parent = root.Parent();
if (parent != null)
{
return FindFocusView(parent, root, direction);
}
return null;
}
private View FindFocusView(View root, FocusDirection direction)
{
if (direction == FocusDirection.Down || direction == FocusDirection.Right)
{
for (int i = 0; i < root.ChildCount(); ++i)
{
View child = root.ViewAt(i);
View view = FindFocusView(child, direction);
if (view != null)
{
return view;
}
if (child.CanFocus())
{
return child;
}
}
}
else if (direction == FocusDirection.Up || direction == FocusDirection.Left)
{
for (int i = root.ChildCount() - 1; i >= 0; --i)
{
View child = root.ViewAt(i);
View view = FindFocusView(child, direction);
if (view != null)
{
return view;
}
if (child.CanFocus())
{
return child;
}
}
}
return root.focusable ? root : null;
}