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  1. JDK
  2. JDK-8165749

java.lang.RuntimeException: dndGesture.dragboard is null in dragDrop

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    • Subcomponent:
    • CPU:
      x86_64
    • OS:
      os_x

      Description

      FULL PRODUCT VERSION :
      java version "1.8.0_60"
      Java(TM) SE Runtime Environment (build 1.8.0_60-b27)
      Java HotSpot(TM) 64-Bit Server VM (build 25.60-b23, mixed mode)

      ADDITIONAL OS VERSION INFORMATION :
      Mac OS X' Version '10.11.6' Arch 'x86_64'

      A DESCRIPTION OF THE PROBLEM :
      Using the demo javafx drag and drop example from here: http://docs.oracle.com/javafx/2/drag_drop/HelloDragAndDrop.java.html (source included below)

      If you drag a file onto the window and before letting go of the left button, press the right mouse button you get a java crash.

      Only happens on MacOSX, have tried the same on Windows 7 & 10 and Linux Mint and they are OK.

      STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
      1. Run demo app
      2. Drag a file onto the window
      3. Before releasing left mouse button, press the right mouse button.

      EXPECTED VERSUS ACTUAL BEHAVIOR :
      EXPECTED -
      Shouldn't crash
      ACTUAL -
      Crashes

      ERROR MESSAGES/STACK TRACES THAT OCCUR :
      java.lang.RuntimeException: dndGesture.dragboard is null in dragDrop
          at javafx.scene.Scene$DropTargetListener.drop(Scene.java:2863) ~[jfxrt.jar:?]
          at com.sun.javafx.tk.quantum.GlassSceneDnDEventHandler.lambda$handleDragDrop$309(GlassSceneDnDEventHandler.java:95) ~[jfxrt.jar:?]
          at java.security.AccessController.doPrivileged(Native Method) ~[?:1.8.0_101]
          at com.sun.javafx.tk.quantum.GlassSceneDnDEventHandler.handleDragDrop(GlassSceneDnDEventHandler.java:92) ~[jfxrt.jar:?]
          at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleDragDrop$363(GlassViewEventHandler.java:700) ~[jfxrt.jar:?]
          at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389) ~[jfxrt.jar:?]
          at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleDragDrop(GlassViewEventHandler.java:699) ~[jfxrt.jar:?]
          at com.sun.glass.ui.View.handleDragDrop(View.java:712) ~[jfxrt.jar:?]
          at com.sun.glass.ui.View.notifyDragDrop(View.java:1037) ~[jfxrt.jar:?]

      REPRODUCIBILITY :
      This bug can be reproduced always.

      ---------- BEGIN SOURCE ----------
      package hellodraganddrop;

      import javafx.application.Application;
      import javafx.event.EventHandler;
      import javafx.scene.Group;
      import javafx.scene.Scene;
      import javafx.scene.input.*;
      import javafx.scene.paint.Color;
      import javafx.scene.text.Text;
      import javafx.stage.Stage;

      /**
       * Demonstrates a drag-and-drop feature.
       */
      public class HelloDragAndDrop extends Application {

          @Override public void start(Stage stage) {
              stage.setTitle("Hello Drag And Drop");

              Group root = new Group();
              Scene scene = new Scene(root, 400, 200);
              scene.setFill(Color.LIGHTGREEN);

              final Text source = new Text(50, 100, "DRAG ME");
              source.setScaleX(2.0);
              source.setScaleY(2.0);

              final Text target = new Text(250, 100, "DROP HERE");
              target.setScaleX(2.0);
              target.setScaleY(2.0);

              source.setOnDragDetected(new EventHandler <MouseEvent>() {
                  public void handle(MouseEvent event) {
                      /* drag was detected, start drag-and-drop gesture*/
                      System.out.println("onDragDetected");
                      
                      /* allow any transfer mode */
                      Dragboard db = source.startDragAndDrop(TransferMode.ANY);
                      
                      /* put a string on 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 */
                      System.out.println("onDragOver");
                      
                      /* 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 both copying and moving, whatever user chooses */
                          event.acceptTransferModes(TransferMode.COPY_OR_MOVE);
                      }
                      
                      event.consume();
                  }
              });

              target.setOnDragEntered(new EventHandler <DragEvent>() {
                  public void handle(DragEvent event) {
                      /* the drag-and-drop gesture entered the target */
                      System.out.println("onDragEntered");
                      /* 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 */
                      System.out.println("onDragDropped");
                      /* 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 */
                      System.out.println("onDragDone");
                      /* if the data was successfully moved, clear it */
                      if (event.getTransferMode() == TransferMode.MOVE) {
                          source.setText("");
                      }
                      
                      event.consume();
                  }
              });

              root.getChildren().add(source);
              root.getChildren().add(target);
              stage.setScene(scene);
              stage.show();
          }

          public static void main(String[] args) {
              Application.launch(args);
          }
      }
      ---------- END SOURCE ----------

        Attachments

        1. HelloDragAndDrop.java
          5 kB
        2. os_x.PNG
          os_x.PNG
          50 kB
        3. Win7.PNG
          Win7.PNG
          51 kB

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              Assignee:
              jpereda Jose Pereda
              Reporter:
              webbuggrp Webbug Group
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                Updated:
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