import java.util.*;
    
  String event = arg("workerEvent");
  if ( event == "done" || event =="alreadyRunning" || event == "longRunningTask")
    return;
  
  final WindowContext context = argObj("windowContext");
  Worker worker = argObj("worker");
  final HashObject profile = context.get("profile");
  
  Tree tree = context.get("/schemaTree");
  NodeInfo root = (NodeInfo)tree.getModel().getRoot();
  
  if ( event == "init" )
  {
    if ( root.getText().equals("A Tree") )
    {
      // we are new and not in a refresh
      tree.setCellRenderer(new IconicCellRenderer("images/schema.gif", "images/instance.gif", "images/table.gif"));
      root.setText(profile.get("user") + "@" + profile.get("host"));
      root.setIcon("instance");
    } 
    else 
    {
       tree.saveState();
    }
    root.removeAllChildren();
  }
  else if ( event == "backgroundTask" )
  {
    final DB db = new SQLLoggingDB((SQLLoggingDB)context.get("db"));
    worker.setProperty("db", db);
    worker.setProperty("waitOperation", "select lower(owner) from all_objects where object_type = 'TABLE' and object_name not like 'BIN$%' group by owner");
    
    DB.AutoCleanupTX tx = new DB.AutoCleanupTX() {
      public void execute() 
      {
        String dbs = profile.get("dbs");
    
        String sql = null;
        if ( dbs == null || dbs.length() == 0 )
        {
           sql = "select lower(owner) owner, lower(object_name) object from all_objects where object_type = 'TABLE' and object_name not like 'BIN$%'  order by owner, object";
        }
        else
        {
          String[] dbArray = dbs.split(";");
          sql = "select lower(owner), lower(object_name) object from all_objects where object_type = 'TABLE' and object_name in (";
          String sep="";
          for (String aDb: dbArray)
          {
            sql+=sep+"'"+aDb + "'";
            sep=",";
          }
          sql+=")";
        }
        
        DB.Result r = db.execute(sql);
        log.info("schema objects: " + r.size());

        Map allObjects = r.remap("owner");

        HashObject taskResult = new HashObject();
        taskResult.put("allObjects", allObjects);
    
        publish(taskResult);
      }
    };
    
    db.execute(tx);

  }
  else if ( event == "update" )
  {
    HashObject taskResult = (HashObject)((List)argObj("taskResult")).get(0);
    
    Map<String, List<HashObject>> allObjects = taskResult.getObject("allObjects");
    HashObject schemaNodes = new HashObject();

    List<String> schemas = new ArrayList();
    schemas.addAll(allObjects.keySet());

    context.put("dbsOrSchemas", schemas);
    
    if ( "true".equals(profile.get("sort")))
    {
      Collections.sort(schemas);
    }

    schemaNodes = TreeUtils.populateList(root, schemas, "schema");

    for (String schema: schemas)
    {
      List<HashObject> tables = allObjects.get(schema);
     
      log.info("populating table list: " + tables.size());

      TreeUtils.populateList((NodeInfo)schemaNodes.getObject(schema), (ArrayList<HashObject>)tables, 1, "table");
    }

    tree.updateUI();
    tree.restoreState();
  }
  else if ( event == "cancelled" ) 
  {
    DB db = worker.getProperty("db");
    if ( db != null )
    {
      db.cancel();
    }
  }