Java Swing Tutorial - Java DropTargetListener .drop (DropTargetDropEvent dtde)








Syntax

DropTargetListener.drop(DropTargetDropEvent dtde) has the following syntax.

void drop(DropTargetDropEvent dtde)

Example

In the following code shows how to use DropTargetListener.drop(DropTargetDropEvent dtde) method.

/*  w ww.  j a  va2 s. co  m*/
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.dnd.DnDConstants;
import java.awt.dnd.DropTarget;
import java.awt.dnd.DropTargetDragEvent;
import java.awt.dnd.DropTargetDropEvent;
import java.awt.dnd.DropTargetEvent;
import java.awt.dnd.DropTargetListener;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextArea;

public class Main extends JFrame implements DropTargetListener {

  DropTarget dt;

  JTextArea ta = new JTextArea();

  public Main() {
    super("Drop Test");
    setSize(300, 300);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    add(new JLabel("Drop a list from your file chooser here:"), BorderLayout.NORTH);
    ta.setBackground(Color.white);
    getContentPane().add(ta, BorderLayout.CENTER);

    dt = new DropTarget(ta, this);
    setVisible(true);
  }

  public void dragEnter(DropTargetDragEvent dtde) {
    System.out.println("Drag Enter");
  }

  public void dragExit(DropTargetEvent dte) {
    System.out.println("Source: " + dte.getSource());
    System.out.println("Drag Exit");
  }

  public void dragOver(DropTargetDragEvent dtde) {
    System.out.println("Drag Over");
  }

  public void dropActionChanged(DropTargetDragEvent dtde) {
    System.out.println("Drop Action Changed");
  }

  public void drop(DropTargetDropEvent dtde) {
    try {
      Transferable tr = dtde.getTransferable();
      DataFlavor[] flavors = tr.getTransferDataFlavors();
      for (int i = 0; i < flavors.length; i++) {
        System.out.println("Possible flavor: " + flavors[i].getMimeType());
        if (flavors[i].isFlavorJavaFileListType()) {
          dtde.acceptDrop(DnDConstants.ACTION_COPY);
          ta.setText("Successful file list drop.\n\n");

          java.util.List list = (java.util.List) tr.getTransferData(flavors[i]);
          for (int j = 0; j < list.size(); j++) {
            ta.append(list.get(j) + "\n");
          }
          dtde.dropComplete(true);
          return;
        }
      }
      System.out.println("Drop failed: " + dtde);
      dtde.rejectDrop();
    } catch (Exception e) {
      e.printStackTrace();
      dtde.rejectDrop();
    }
  }

  public static void main(String args[]) {
    new Main();
  }
}