package org.argeo.eclipse.ui.specific;
   
   import java.io.IOException;
   import java.io.InputStream;
   
   import org.eclipse.rap.fileupload.FileDetails;
   import org.eclipse.rap.fileupload.FileUploadHandler;
   import org.eclipse.rap.fileupload.FileUploadReceiver;
   import org.eclipse.rap.rwt.RWT;
  import org.eclipse.rap.rwt.client.ClientFile;
  import org.eclipse.rap.rwt.client.service.ClientFileUploader;
  import org.eclipse.rap.rwt.dnd.ClientFileTransfer;
  import org.eclipse.swt.dnd.DND;
  import org.eclipse.swt.dnd.DropTarget;
  import org.eclipse.swt.dnd.DropTargetAdapter;
  import org.eclipse.swt.dnd.DropTargetEvent;
  import org.eclipse.swt.dnd.Transfer;
  import org.eclipse.swt.widgets.Control;
  
  /** Configures a {@link Control} to receive files drop from the client OS. */
  public class FileDropAdapter {
  
  	public void prepareDropTarget(Control control, DropTarget dropTarget) {
  		dropTarget.setTransfer(new Transfer[] { ClientFileTransfer.getInstance() });
  		dropTarget.addDropListener(new DropTargetAdapter() {
  			private static final long serialVersionUID = 5361645765549463168L;
  
  			@Override
  			public void dropAccept(DropTargetEvent event) {
  				if (!ClientFileTransfer.getInstance().isSupportedType(event.currentDataType)) {
  					event.detail = DND.DROP_NONE;
  				}
  			}
  
  			@Override
  			public void drop(DropTargetEvent event) {
  				handleFileDrop(control, event);
  			}
  		});
  	}
  
  	public void handleFileDrop(Control control, DropTargetEvent event) {
  		ClientFile[] clientFiles = (ClientFile[]) event.data;
  		ClientFileUploader service = RWT.getClient().getService(ClientFileUploader.class);
  //		DiskFileUploadReceiver receiver = new DiskFileUploadReceiver();
  		FileUploadReceiver receiver = new FileUploadReceiver() {
  
  			@Override
  			public void receive(InputStream stream, FileDetails details) throws IOException {
  				control.getDisplay().syncExec(() -> {
  					try {
  						processUpload(stream, details.getFileName(), details.getContentType());
  					} catch (IOException e) {
  						throw new IllegalStateException("Cannot process upload of " + details.getFileName(), e);
  					}
  				});
  			}
  		};
  		FileUploadHandler handler = new FileUploadHandler(receiver);
  //		    handler.setMaxFileSize( sizeLimit );
  //		    handler.setUploadTimeLimit( timeLimit );
  		service.submit(handler.getUploadUrl(), clientFiles);
  //		for (File file : receiver.getTargetFiles()) {
  //			paths.add(file.toPath());
  //		}
  	}
  
  	/** Executed in UI thread */
  	protected void processUpload(InputStream in, String fileName, String contentType) throws IOException {
  
  	}
  
  }