java - java中需要的BST图形表示

Question

我正在使用Model–view–controller设计模式，我需要一个用于我的 BST/AVL 模型的 UI 查看器，我已经开发了模型和 Controller 逻辑，我只需要查看器，我现在不需要处理图形，它会如果有人有一个 Viewer 类，该类的方法可以获取树的根并绘制它，而不需要高级动画或效果

类似的东西

SimpleBSTreeViewer.draw(myTree.getRoot());

树的节点结构

public class NodeBST <T extends Comparable<T>> {
 private T data;
 private NodeBST<T> left;
 private NodeBST<T> right;
 private NodeBST<T> parent;
 
 //other methods go here ...
}

这将有助于集中精力编写逻辑部分，

我搜索并找到了其他代表树的java小程序，但它们在同一个类中具有模型逻辑和 View ，我正在模型- View - Controller 模式(MVC模式)中工作，最好将模型与 View 分开尽可能地，我只想要一个适合我的模型的查看器

-注意:这是我需要的示例(我已经使用 JTree，但它并不令人满意。)

Answer 1

• 获取 Jgraphx库并从 HelloWorld 开始 我编写此类的示例

• 使用this计算节点坐标的问题。

  package algorithms.searching.bst;
  
  import java.util.Random;
  
  import javax.swing.JFrame;
  
  import log.Logger;
  
  import algorithms.searching.bst.avl.AVL;
  
  import com.mxgraph.swing.mxGraphComponent;
  import com.mxgraph.view.mxGraph;
  
  @SuppressWarnings("serial")
  
  public class TreeViewer<T extends Comparable<T>> extends JFrame {
  
  static private int CANVAS_HEIGHT = 600;
  static private int CANVAS_WIDTH = 1000;
  
  private int rootY = 10;
  private int NODE_SIZE = 25;
  private int ROW_HEIGHT = 50;
  mxGraph graph = new mxGraph();
  Object parent = graph.getDefaultParent();
  
  /**
   * draws a tree starting from this root
   * 
   * @param root
   * @param depth
   *            number of nodes to the root (including root)
   * @param index
   *            index of node in this level (leftChildIndex = parentIndex * 2
   *            - 1) and (rightChildIndex = parentIndex * 2)
   * @return
   */
  public Object drawTree(NodeBST<T> root, int depth, int index) {
      if (root == null) {
          return null;
      }
  
      // draw root
  
      /*
       * leftChildIndex = parentIndex * 2 - 1 
       * rightChildIndex = parentIndex *2
       *
       *
       * x = index * canvasWidth / (2^depth + 1)
       *
       * y = depth * canvasHeight / treeDepth
       */
  
      int myX = (int) ((CANVAS_WIDTH * (index)) / (Math.pow(2, depth - 1) + 1));
  
      Object rootVertex = graph.insertVertex(parent, null, root.getData(),
              myX, depth * ROW_HEIGHT + rootY, NODE_SIZE, NODE_SIZE);
  
      Logger.log("new x coordinate=" + myX);
  
      // recurse for right child
  
      Object rightChildVertex = drawTree(root.getRight(), depth + 1,
              index * 2);
  
      if (rightChildVertex != null) {// edge
          graph.insertEdge(parent, null, "R", rootVertex, rightChildVertex,
                  "startArrow=none;endArrow=none;strokeWidth=1;strokeColor=green");
      }
  
      Object leftChildVertex = drawTree(root.getLeft(), depth + 1,
              index * 2 - 1);
  
      // recurse for right child
  
      if (leftChildVertex != null) { // edge
          graph.insertEdge(parent, null, "L", rootVertex, leftChildVertex,
                  "startArrow=none;endArrow=none;strokeWidth=1;strokeColor=green");
      }
  
      return rootVertex;
  
  }
  
  /**
   * Redraw the whole tree
   * 
   * @param root
   *            the root of tree to be drawn
   */
  
  public void update(NodeBST<T> root) {
  
      graph.getModel().beginUpdate();
  
      try {
  
          Object[] cells = graph.getChildCells(parent, true, false);
          graph.removeCells(cells, true);
          drawTree(root, 1, 1);
  
      } finally {
          graph.getModel().endUpdate();
      }
  }
  
  public TreeViewer(NodeBST<T> root) {
      // super("Hello, World!");
  
      this.update(root);
  
      mxGraphComponent graphComponent = new mxGraphComponent(graph);
  
      getContentPane().add(graphComponent);
  }
  
  public static void main(String[] args) {
  
      AVL<Integer> bst = new AVL<Integer>();//use AVL tree class 
  
      Random randomGenerator = new Random();
      for (int i = 0; i < 20; i++) {//try generating 20 random integers
          bst.insert(randomGenerator.nextInt(1000));
      }
  
      TreeViewer<Integer> myTreeViewer=new TreeViewer<Integer>(bst.getRoot());
      JFrame frame = myTreeViewer;
  
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.setSize(CANVAS_WIDTH, CANVAS_HEIGHT);
      frame.setVisible(true);
  
  }
  
  
  
  }
  

• 只需修改此类即可获取您的树类

• 非常感谢NeplatnyUdaj !