- override
Adds a child DisplayObject to this DisplayObjectContainer.
The child is added to the front (top) of all other children. (To add a child to a specific index position, use addChildAt.)
If you add a child object that already has a different display object container as a parent, the object is removed from the child list of the other display object container.
Source
@override
void addChild(DisplayObject child) {
if (child == this) {
throw new ArgumentError("An object cannot be added as a child of itself.");
} else if (child.parent == this) {
_addLocalChild(child);
} else {
child.removeFromParent();
_throwIfAncestors(child);
_children.add(child);
_setChildParent(child);
}
}