public void SetSelection(IEnumerable <IObject3D> items)
{
if (items.Count() == 1)
{
// Add a single item directly as the SelectedItem
SelectedItem = items.First();
}
else
{
// Add a range of items wrapped with a new SelectionGroup
var SelectionGroup = new SelectionGroupObject3D(items)
{
Name = "Selection".Localize()
};
// Move selected items into a new SelectionGroup
this.Children.Modify(list =>
{
foreach (var item in items)
{
list.Remove(item);
}
// Add the SeletionGroup as the first child
list.Insert(0, SelectionGroup);
});
SelectedItem = SelectionGroup;
}
}
public void AddToSelection(IObject3D itemToAdd)
{
var selectedItem = SelectedItem;
if (itemToAdd == selectedItem || selectedItem?.Children?.Contains(itemToAdd) == true)
{
return;
}
if (selectedItem != null)
{
if (selectedItem is SelectionGroupObject3D)
{
// Remove from the scene root
this.Children.Modify(list => list.Remove(itemToAdd));
// Move into the SelectionGroup
selectedItem.Children.Modify(list => list.Add(itemToAdd));
}
else // add a new selection group and add to its children
{
// We're adding a new item to the selection. To do so we wrap the selected item
// in a new group and with the new item. The selection will continue to grow in this
// way until it's applied, due to a loss of focus or until a group operation occurs
var newSelectionGroup = new SelectionGroupObject3D(new[] { selectedItem, itemToAdd })
{
Name = "Selection".Localize()
};
this.Children.Modify(list =>
{
list.Remove(itemToAdd);
list.Remove(selectedItem);
// add the seletionGroup as the first item so we can hit it first
list.Insert(0, newSelectionGroup);
});
SelectedItem = newSelectionGroup;
}
}
else if (Children.Contains(itemToAdd))
{
SelectedItem = itemToAdd;
}
else
{
throw new Exception("Unable to select external object. Item must be in the scene to be selected.");
}
}