controllerForIndex method
Implementation
NodeController? controllerForIndex(int index) {
if (this.index == index) {
return this;
}
if (!treeNode.expanded) {
return null;
}
for (NodeController controller in childControllers) {
var result = controller.controllerForIndex(index);
if (result != null) {
return result;
}
}
return null;
}