JavaFX Tutorial - JavaFX Drag Drop








Example

/*//from   ww  w.  jav a2  s.c  o m
 * Copyright (c) 2011, Pro JavaFX Authors
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. Neither the name of JFXtras nor the names of its contributors may be used
 *    to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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 * POSSIBILITY OF SUCH DAMAGE.
 *
 * Metronome1Main.fx - A simple example of animation using a Timeline
 *
 *  Developed 2011 by James L. Weaver jim.weaver [at] javafxpert.com
 *  as a JavaFX SDK 2.0 example for the Pro JavaFX book.
 */


import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.input.ClipboardContent;
import javafx.scene.input.DataFormat;
import javafx.scene.input.DragEvent;
import javafx.scene.input.Dragboard;
import javafx.scene.input.MouseEvent;
import javafx.scene.input.TransferMode;
import javafx.scene.paint.Color;
import javafx.scene.text.Text;
import javafx.stage.Stage;

public class Main extends Application {
  final Text source = new Text(50, 100, "DRAG ME");
  final Text target = new Text(150, 100, "DROP HERE");
  private static final DataFormat customFormat =
      new DataFormat("helloworld.custom");
  public static void main(String[] args) {
    Application.launch(args);
  }

  @Override
  public void start(Stage primaryStage) {
    Group root = new Group();
    Scene scene = new Scene(root, 300, 250);
    root.getChildren().addAll(source,target);

    source.setOnDragDetected(new EventHandler<MouseEvent>() {
      public void handle(MouseEvent event) {
          /* drag was detected, start a drag-and-drop gesture*/
          /* allow any transfer mode */
          Dragboard db = source.startDragAndDrop(TransferMode.ANY);
          
          /* Put a string on a dragboard */
          ClipboardContent content = new ClipboardContent();
          content.putString(source.getText());
          db.setContent(content);
          
          event.consume();
      }
  });
  target.setOnDragOver(new EventHandler<DragEvent>() {
      public void handle(DragEvent event) {
          /* data is dragged over the target */
          /* accept it only if it is not dragged from the same node 
           * and if it has a string data */
          if (event.getGestureSource() != target &&
                  event.getDragboard().hasString()) {
              /* allow for moving */
              event.acceptTransferModes(TransferMode.MOVE);
          }
          
          event.consume();
      }
  });
  target.setOnDragEntered(new EventHandler<DragEvent>() {
      public void handle(DragEvent event) {
      /* the drag-and-drop gesture entered the target */
      /* show to the user that it is an actual gesture target */
           if (event.getGestureSource() != target &&
                   event.getDragboard().hasString()) {
               target.setFill(Color.GREEN);
           }
                  
           event.consume();
      }
  });
  target.setOnDragExited(new EventHandler<DragEvent>() {
      public void handle(DragEvent event) {
          /* mouse moved away, remove the graphical cues */
          target.setFill(Color.BLACK);

          event.consume();
      }
  });
  target.setOnDragDropped(new EventHandler<DragEvent>() {
      public void handle(DragEvent event) {
          /* data dropped */
          /* if there is a string data on dragboard, read it and use it */
          Dragboard db = event.getDragboard();
          boolean success = false;
          if (db.hasString()) {
             target.setText(db.getString());
             success = true;
          }
          /* let the source know whether the string was successfully 
           * transferred and used */
          event.setDropCompleted(success);
          
          event.consume();
       }
  });
  source.setOnDragDone(new EventHandler<DragEvent>() {
      public void handle(DragEvent event) {
          /* the drag and drop gesture ended */
          /* if the data was successfully moved, clear it */
          if (event.getTransferMode() == TransferMode.MOVE) {
              source.setText("");
          }
          event.consume();
      }
  });

    primaryStage.setScene(scene);
    primaryStage.show();
  }
}

The code above generates the following result.

null