Drag and drop to other applications and OS?

Question

I'm using JavaFX's Drag and Drop system in my application, and it has been working well so far.

Now I want to support drag and drop to outside applications, eg. dragging files from my application to the explorer. How would I achieve that?

Answer 1

Here is a sample source for an action listener on an ImageView image extraction to OS' explorer (With a custom process for jpg image to remove alpha-channel to display it correctly):

inputImageView.setOnDragDetected(new EventHandler <MouseEvent>() {
               @Override
               public void handle(MouseEvent event) {


                   // for paste as file, e.g. in Windows Explorer
                    try {

            Clipboard clipboard Clipboard.getSystemClipboard();     
                   Dragboard db = inputImageView.startDragAndDrop(TransferMode.ANY);

                   ClipboardContent content = new ClipboardContent();

                   Image sourceImage = inputImageView.getImage();

                   ImageInfo imageInfo = (ImageInfo) inputImageView.getUserData();

                   String name = FilenameUtils.getBaseName(imageInfo.getName());
                   String ext = FilenameUtils.getExtension(imageInfo.getName());


                   ///Avoid get "prefix lenght too short" error when file name lenght <= 3
                   if (name.length() < 4){
                       name = name+Long.toHexString(Double.doubleToLongBits(Math.random()));;
                       }

                   File temp = File.createTempFile(name, "."+ext);

                   if (ext.contentEquals("jpg")|| ext.contentEquals("jpeg")){
                       BufferedImage image = SwingFXUtils.fromFXImage(sourceImage, null); // Get buffered image.
                       BufferedImage imageRGB = new BufferedImage(image.getWidth(),image.getHeight(),
BufferedImage.OPAQUE);
                       Graphics2D graphics = imageRGB.createGraphics();
                       graphics.drawImage(image, 0, 0, null);
                       ImageIO.write(imageRGB, ext, temp);
                       graphics.dispose();

                       ImageIO.write(imageRGB,
                               ext, temp);  

                   }else{

                       ImageIO.write(SwingFXUtils.fromFXImage(sourceImage, null),
                               ext, temp);  
                   }




                   content.putFiles(java.util.Collections.singletonList(temp));
                   db.setContent(content);
                   clipboard.setContent(content);
                   event.consume();

                   temp.deleteOnExit();

                    } catch (IOException ex) {
                           System.out.println(ex.getMessage());
                     }

               }
           });

With the help of use of an Object that is passed to the imageView's setUserData method, it helps me to retrieve database id and pic name:

  public class ImageInfo {
    private String imageInfo;
    private int inputId;

    @Override
    public String toString() {
        return imageInfo;
    }

    public ImageInfo(String imageInfo, int inputId) {
        this.imageInfo = imageInfo;
        this.inputId = inputId;
    }

    public String getName() {
        return imageInfo;
    }

    public void setName(String imageInfo) {
        this.imageInfo = imageInfo;
    }

    public int getIndex() {
        return inputId;
    }

    public void setIndex(int areaindex) {
        this.inputId = inputId;
    }
}

I hope it will help somenone at an expected time :-)

Regards

Answer 2

I've achieved what you described by using:

Vector<File> files = new Vector<File>();
private ClipboardContent filesToCopyClipboard = new ClipboardContent();

...

final ObjectWithAReturnablePathField draggableObj = new ObjectWithAReturnablePathField();

...

draggableObj.setOnDragDetected(new EventHandler<MouseEvent>()
{

    @Override
    public void handle(MouseEvent me) 
    {
        Dragboard db = draggableObj.startDragAndDrop(TransferMode.ANY);
        try 
        {
           File f = new File(new URI(draggableObj.getFilePath()));
           files.add(f);
           filesToCopyClipboard.putFiles(files);
        } 
        catch (URISyntaxException e) 
        {
           e.printStackTrace();
        }
        db.setContent(filesToCopyClipboard);
        me.consume();
    }

 });
 draggableObj.setOnDragDone(new EventHandler<DragEvent>() 
 {
     @Override 
     public void handle(DragEvent me) 
     {

        me.consume();
      }
 });

Which means:

It's possible to achieve file transference between JavaFX 2 and a native application by filling a ClipboardContent with a list using the TransferMode.ANY on the setOnDragDetected method of any Draggable Object (Any Node) which can return a Path for a file. In my case, I've created a class called Thumb extending ImageView and (among others things) I made a method called getFilePath() which returns the Path from the Image used to initialize the ImageView(). I'm sorry BTW for the poor example and the poor english, but I'm running out of time to give a more detailed answer as of now. I hope it helps. Cheers