transferabletreenode.java

JGraph扩展应用。自定义Renderer,自定义视图View实现自定义工作流控件

/*
 * $Id: TransferableTreeNode.java,v 1.3 2006/05/07 11:56:33 aviva Exp $
 * Read the "license.txt" file for licensing information.
 * (C) Antonio Vieiro. All rights reserved.
 */
package net.antonioshome.swing.treewrapper;

import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.swing.JTree;
import javax.swing.tree.MutableTreeNode;

/**
 * TransferableTreeNode is a Transferable object used to transfer
 *   TreeNodes or Strings in drag and drop operations.
 * @author Antonio Vieiro ([e-mail]), $Author: aviva $
 * @version $Revision: 1.3 $
 */
class TransferableTreeNode
  implements Transferable
{
  /**
   * The local JVM DataFlavor.
   */
  private static DataFlavor javaJVMLocalObjectFlavor;
  /**
   * The supported data flavors.
   */
  private static DataFlavor [] supportedDataFlavors;
  /**
   * Returns the Java JVM LocalObject Flavor.
   */
  public static DataFlavor getJavaJVMLocalObjectFlavor()
  {
    if ( javaJVMLocalObjectFlavor == null )
    {
      try
      {
        javaJVMLocalObjectFlavor = new DataFlavor( DataFlavor.javaJVMLocalObjectMimeType );
      }
      catch( ClassNotFoundException cnfe )
      {
        System.err.println( "Cannot create JVM Local Object Flavor " + cnfe.getMessage() );
      }
    }
    return javaJVMLocalObjectFlavor;
  }
  /**
   * Returns the supported data flavors.
   */
  private static DataFlavor [] getSupportedDataFlavors()
  {
    if ( supportedDataFlavors == null )
    {
      DataFlavor localJVMFlavor = getJavaJVMLocalObjectFlavor();
      supportedDataFlavors =
        localJVMFlavor == null ?
          new DataFlavor[] { DataFlavor.stringFlavor } :
          new DataFlavor[] { localJVMFlavor, DataFlavor.stringFlavor };
    }
    return supportedDataFlavors;
  }
  /**
   * Creates a new instance of TransferableTreeNode.
   * @param aTree the JTree that contains de dragged node.
   * @param aNode the MutableTreeNode in JTree that is to be dragged.
   * @param wasExpanded true if the source node was expanded, false otherwise.
   */
  public TransferableTreeNode( JTree aTree, MutableTreeNode aNode, boolean wasExpanded )
  {
    setSourceTree( aTree );
    setSourceNode( aNode );
    setNodeWasExpanded( wasExpanded );
  }
  
  public boolean isDataFlavorSupported(DataFlavor flavor)
  {
    DataFlavor [] flavors = getSupportedDataFlavors();
    for( int i=0; i<flavors.length; i++ )
    {
      if ( flavor.equals( flavors[i] ) )
        return true;
    }
    return false;
  }
  
  public Object getTransferData(DataFlavor flavor) throws UnsupportedFlavorException, IOException
  {
    if ( flavor.equals( javaJVMLocalObjectFlavor ) )
    {
      return this;
    }
    else if ( flavor.equals( DataFlavor.stringFlavor ) )
    {
      return getSourceNode().toString();
    }
    else
      throw new UnsupportedFlavorException( flavor );
  }
  
  public DataFlavor[] getTransferDataFlavors()
  {
    return getSupportedDataFlavors();
  }

  /**
   * Holds value of property sourceTree.
   */
  private JTree sourceTree;

  /**
   * Getter for property sourceTree.
   * @return Value of property sourceTree.
   */
  public JTree getSourceTree()
  {
    return this.sourceTree;
  }

  /**
   * Setter for property sourceTree.
   * @param sourceTree New value of property sourceTree.
   */
  public void setSourceTree(JTree sourceTree)
  {
    this.sourceTree = sourceTree;
  }

  /**
   * Holds value of property sourceNode.
   */
  private MutableTreeNode sourceNode;

  /**
   * Getter for property sourceNode.
   * @return Value of property sourceNode.
   */
  public MutableTreeNode getSourceNode()
  {
    return this.sourceNode;
  }

  /**
   * Setter for property sourceNode.
   * @param sourceNode New value of property sourceNode.
   */
  public void setSourceNode(MutableTreeNode sourceNode)
  {
    this.sourceNode = sourceNode;
  }

  /**
   * Holds value of property nodeWasExpanded.
   */
  private boolean nodeWasExpanded;

  /**
   * Getter for property nodeWasExpanded.
   * @return Value of property nodeWasExpanded.
   */
  public boolean isNodeWasExpanded()
  {
    return this.nodeWasExpanded;
  }

  /**
   * Setter for property nodeWasExpanded.
   * @param nodeWasExpanded New value of property nodeWasExpanded.
   */
  public void setNodeWasExpanded(boolean nodeWasExpanded)
  {
    this.nodeWasExpanded = nodeWasExpanded;
  }

}