//　Add/Remove



import java.awt.*;

import java.applet.*;

import vrml.external.field.*;

import vrml.external.Node;

import vrml.external.Browser;

import vrml.external.exception.*;



public class vrml54 extends Applet  {

  //　テキストの設定。

  TextArea output = null;

  boolean error = false;

  

  Browser browser;

  Node root;

  Node[] shape;

  

  EventInMFNode addChildren;

  EventInMFNode removeChildren;

  

  public void init()  {

    System.out.println("AddRemoveTest init()...");

    

    add(new Button("Add Sphere"));

    add(new Button("Remove Sphere"));

    

    output = new TextArea(5, 40);

    add(output);

  }

  

  public void start() {

    System.out.println("AddRemoveTest start()...");

    output.appendText("\nAddRemoveTest start()...\n");

    

    //　ブラウザの取得。

    browser = (Browser) vrml.external.Browser.getBrowser(this);

    

    output.appendText("Got the browser\n");

    System.out.println("Got the browser: " + browser);

    

    try {

      //　wrlの中身の、ROOTノードを取得。

      root = browser.getNode("ROOT");

      //　球を表示する。

      addChildren = (EventInMFNode) root.getEventIn("addChildren");

      //　球を消去する。

      removeChildren = (EventInMFNode) root.getEventIn("removeChildren");

      

      //　球をJavaでも作成することができる。

      shape = browser.createVrmlFromString("Shape  {\n" +

         "  appearance Appearance  {\n" +

         "    material Material  {\n" +

         "      diffuseColor 0.2 0.2 0.8\n" +

         "    }\n" +

         "  }\n" +

         "  geometry Sphere  {}\n" +

         "}\n");

    }

    catch (InvalidNodeException e)  {

      output.appendText("PROBLEMS! : " + e + "\n");

      error = true;

    }

    catch (InvalidEventInException e) {

      output.appendText("PROBLEMS! : " + e + "\n");

      error = true;

    }

    catch (InvalidVrmlException e)  {

      output.appendText("PROBLEMS! : " + e + "\n");

      error = true;

    }

    

    if (error == false)

      output.appendText("Initialization OK\n");

  }

  

  //　ボタンが押されたときの設定

  public boolean action(Event event, Object what) {

    if (event.target instanceof Button) {

      Button b = (Button) event.target;

      if (b.getLabel() == "Add Sphere") {

        output.appendText("Sending addChildren event...\n");

        addChildren.setValue(shape);

      }

      else if (b.getLabel() == "Remove Sphere") {

        output.appendText("Sending removeChildren event...\n");

        removeChildren.setValue(shape);

      }

    }

    return true;

  }

}