FULL PRODUCT VERSION :
java version "1.8.0_77"
Java(TM) SE Runtime Environment (build 1.8.0_77-b03)
Java HotSpot(TM) 64-Bit Server VM (build 25.77-b03, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Linux den-pc 4.2.0-35-generic #40~14.04.1-Ubuntu SMP Fri Mar 18 16:37:35 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

A DESCRIPTION OF THE PROBLEM :
If you execute the example PhotoViewer.java from the book "JavaFX Introduction by example" and drag some image files into the photo viewer they won't be displayed there. However this example works in Windows.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Execute the example PhotoViewer.java from the book "JavaFX Introduction by example" and drag some image files from Dolphin (linux file explorer) into the photo viewer

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The images can be seen in the photoviewer
ACTUAL -
The images cannot be seen in the photoviewer

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
package jfx8ibe;
import java.net.MalformedURLException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Vector;
import java.util.concurrent.atomic.AtomicBoolean;
import javafx.application.Application;
import javafx.application.Platform;
import javafx.beans.property.ReadOnlyDoubleProperty;
import javafx.concurrent.Task;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.ProgressIndicator;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
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.shape.Arc;
import javafx.scene.shape.ArcType;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;

/**
 * A photo viewer application to demonstrate the JavaFX ImageView node.
 * <p>
 * Instructions:
 * 1. Drag and drop an image file onto the application window.
 * 2. Repeat step 1 so more than 2 images are loaded.
 * 3. Click the left and right arrow controls to advance.
 * </p>
 * @author cdea
 */
public class PhotoViewer extends Application {
    // List of URL strings
    private final List<String> imageFiles = new Vector<String>();
    // The current index into the imageFile
    private int currentIndex = -1;
    // Enumeration of next and previous button directions
    public enum ButtonMove {NEXT, PREV};
    // Current image view display
    private ImageView currentImageView;
    // Loading progress indicator
    private ProgressIndicator progressIndicator;
    // mutex */
    private AtomicBoolean loading = new AtomicBoolean();
    
    @Override
    public void start(Stage primaryStage) {
        primaryStage.setTitle("Chapter 5 Photo Viewer");
        Group root = new Group();
        Scene scene = new Scene(root, 551, 400, Color.BLACK);
 // scene.getStylesheets()
 // .add(getClass()
 // .getResource("photo-viewer.css")
 // .toExternalForm());
        primaryStage.setScene(scene);
        
        // set up the current image view area
        currentImageView = createImageView(scene.widthProperty());
        
        // set up drag and drop file abilities
        setupDragNDrop(scene);
        
        // create button panel controls (left & right arrows)
        Group buttonGroup = createButtonPanel(scene);
        
        // create a progress indicator
        progressIndicator = createProgressIndicator(scene);
        
        root.getChildren().addAll(currentImageView,
                                  buttonGroup,
                                  progressIndicator);
        
        primaryStage.show();
    }
    /*
     * A factory function returning an ImageView instance to
     * preserve the aspect ratio and bind the instance to the width
     * of the scene for resizing the image.
     *
     * @param widthProperty is the Scene's read only width property.
     * @return ImageView newly created image view for current display.
     */
    private ImageView createImageView(ReadOnlyDoubleProperty widthProperty) {
        // maintain aspect ratio
        ImageView imageView = new ImageView();
        // set aspect ratio
        imageView.setPreserveRatio(true);
        // resize based on the scene
        imageView.fitWidthProperty().bind(widthProperty);
        return imageView;
    }
    
    /*
     * Sets up the drag and drop capability for files and URLs to be
     * dragged and dropped onto the scene. This will load the image into
     * the current image view area.
     * @param scene The primary application scene.
     */
    private void setupDragNDrop(Scene scene) {
        
        // Dragging over surface
        scene.setOnDragOver((DragEvent event) -> {
            Dragboard db = event.getDragboard();
            if ( db.hasFiles()
                    || (db.hasUrl() && isValidImageFile(db.getUrl()))) {
                //System.out.println("url " + db.getUrl());
                event.acceptTransferModes(TransferMode.LINK);
            } else {
                event.consume();
            }
        });
        
        // Dropping over surface
        scene.setOnDragDropped((DragEvent event) -> {
            Dragboard db = event.getDragboard();
            // image from the local file system.
            if (db.hasFiles() && !db.hasUrl()) {
                db.getFiles()
                  .stream()
                  .forEach( file -> {
                    try {
                        System.out.println("dropped file: "+ file.toURI().toURL().toString());
                        addImage(file.toURI().toURL().toString());
                    } catch (MalformedURLException ex) {
                        ex.printStackTrace();
                    }
                  });
            } else {
                System.out.println("dropped url: "+ db.getUrl());
                // image from some host
                addImage(db.getUrl());
            }
            if (currentIndex > -1) {
                loadImage(imageFiles.get(currentIndex));
            }

            event.setDropCompleted(true);
            event.consume();
        });
    }
    /*
     * Returns a custom created button panel
     * containing left and right buttons to
     * see previous and next images.
     * @param scene The main application scene
     * @return Group A custom button panel with
     * previous and next buttons
     */
    private Group createButtonPanel(Scene scene){
        // create button panel
        Group buttonGroup = new Group();
        
        Rectangle buttonArea = new Rectangle(0, 0, 60, 30);
        buttonArea.getStyleClass().add("button-panel");
        buttonGroup.getChildren().add(buttonArea);

        // left arrow button
        Arc leftButton = new Arc(12,16, 15, 15, -30, 60);
        leftButton.setType(ArcType.ROUND);
        leftButton.getStyleClass().add("left-arrow");
        
        // return to previous image
        leftButton.addEventHandler(MouseEvent.MOUSE_PRESSED,
            (mouseEvent) -> {
                System.out.println("busy loading? " + loading.get());
                // if no previous image or currently loading.
                if (currentIndex == 0 || loading.get()) return;
                int indx = gotoImageIndex(ButtonMove.PREV);
                if (indx > -1) {
                    loadImage(imageFiles.get(indx));
                }
        });
        
        // right arrow button
        Arc rightButton = new Arc(12,16, 15, 15, 180-30, 60);
        rightButton.setType(ArcType.ROUND);
        rightButton.getStyleClass().add("right-arrow");
        
        // advance to next image
        rightButton.addEventHandler(MouseEvent.MOUSE_PRESSED,
            (mouseEvent) -> {
                System.out.println("busy loading? " + loading.get());
                // if no next image or currently loading.
                if (currentIndex == imageFiles.size()-1
                        || loading.get()) return;
                
                int indx = gotoImageIndex(ButtonMove.NEXT);
                if (indx > -1) {
                    loadImage(imageFiles.get(indx));
                }
        });
        // add buttons to button group
        buttonGroup.getChildren().addAll(leftButton, rightButton);
        
        // move button group when scene is resized
        buttonGroup.translateXProperty()
                .bind(scene.widthProperty()
                           .subtract(buttonArea.getWidth() + 6));
        buttonGroup.translateYProperty()
                .bind(scene.heightProperty()
                           .subtract(buttonArea.getHeight() + 6));
        return buttonGroup;
    }
    
    /*
     * Create a progress indicator control to be centered.
     * @param scene The primary application scene.
     * @return ProgressIndicator a new progress indicator centered.
     */
    private ProgressIndicator createProgressIndicator(Scene scene) {
        ProgressIndicator progress = new ProgressIndicator(0);
        progress.setVisible(false);
        progress.layoutXProperty()
                .bind(scene.widthProperty()
                           .subtract(progress.widthProperty())
                           .divide(2));
        progress.layoutYProperty()
                .bind(scene.heightProperty()
                           .subtract(progress.heightProperty())
                           .divide(2));
        return progress;
    }
    
    /*
     * Returns true if URL's file extensions match jpg, jpeg, png, gif and bmp.
     * @param url standard URL path to image file.
     * @return boolean returns true if URL's extension matches jpg,jpeg,
     * png and gif.
     */
    private boolean isValidImageFile(String url) {
        List<String> imgTypes = Arrays.asList(".jpg", ".jpeg", ".png", ".gif", ".bmp");
        return imgTypes.stream()
                       .anyMatch(t -> url.endsWith(t));
    }
    
    /* Adds the URL string representation of the path to the image file.
     * Based on a URL the method will check if it matches supported
     * image format.
     * @param url string representation of the path to the image file.
     */
    private void addImage(String url) {
        if (isValidImageFile(url)) {
            currentIndex +=1;
            imageFiles.add(currentIndex, url);
        }
    }
    
    /*
     * Returns the next index in the list of files to go to next.
     *
     * @param direction PREV and NEXT to move backward or forward
     * in the list of pictures.
     * @return int the index to the previous or next picture to be shown.
     */
    private int gotoImageIndex(ButtonMove direction) {
        int size = imageFiles.size();
        if (size == 0) {
            currentIndex = -1;
        } else if (direction == ButtonMove.NEXT
                && size > 1
                && currentIndex < size - 1) {
            currentIndex += 1;
        } else if (direction == ButtonMove.PREV
                && size > 1
                && currentIndex > 0) {
            currentIndex -= 1;
        }

        return currentIndex;
    
    }
    
    /*
     * Returns a worker task (Task) which will off-load the image
     * on a separate thread when finished; the current image will
     * be displayed on the JavaFX application thread.
     * @param url string representation of the path to the image file.
     * @return
     */
    private Task createWorker(final String url) {
        return new Task() {
            @Override
            protected Object call() throws Exception {
                // on the worker thread...
                Image image = new Image(url, false);
                Platform.runLater(() -> {
                    // on the JavaFX Application Thread....
                    System.out.println("done loading image " + url);
                    currentImageView.setImage(image);
                    progressIndicator.setVisible(false);
                    loading.set(false); // free lock
                });
                return true;
            }
        };
    }
    
    /*
     * This method does the following loads an image,
     * updates a progress bar and spawns a new thread.
     * If another process is already loading
     * the method will return without loading.
     * @param url string representation of the path to the image file.
     */
    private void loadImage(String url) {
        // do not begin task until current
        // task is finished loading (atomic)
        if (!loading.getAndSet(true)) {
            System.out.println("loadImage spawned ");
            Task loadImage = createWorker(url);
            progressIndicator.setVisible(true);
            progressIndicator.progressProperty().unbind();
            progressIndicator.progressProperty()
                             .bind(loadImage.progressProperty());
            new Thread(loadImage).start();
        }
    }
    public static void main(String[] args) {
        launch(args);
    }
}
---------- END SOURCE ----------