package io.github.magwas.inez.ui;
   
   import javafx.collections.FXCollections;
   import javafx.collections.ObservableList;
   import javafx.scene.control.TreeItem;
   
   import io.github.magwas.inez.element.BridiElement;
   
   public class BridiElementTreeItem extends TreeItem<BridiElement> {
  
  	private boolean isFirstTimeChildren = true;
  	private boolean isFirstTimeLeaf = true;
  	private boolean isLeaf;
  
  	public BridiElementTreeItem(BridiElement rootElement) {
  		super(rootElement);
  	}
  
  	@Override
  	public ObservableList getChildren() {
  		if (isFirstTimeChildren) {
  			isFirstTimeChildren = false;
  			// First call: load children dynamically
  			super.getChildren().setAll(buildChildren(this));
  		}
  		return super.getChildren();
  	}
  
  	@Override
  	public boolean isLeaf() {
  		if (isFirstTimeLeaf) {
  			isFirstTimeLeaf = false;
  			isLeaf = 0 == getValue().getChildren().count();
  		}
  		return isLeaf;
  	}
  
  	private ObservableList buildChildren(BridiElementTreeItem treeItem) {
  		ObservableList<BridiElementTreeItem> children = FXCollections.observableArrayList();
  		treeItem.getValue().getChildren().forEach(x -> children.add(new BridiElementTreeItem(x)));
  		return children;
  	}
  }