When I try to initiate a multiple selection drag gesture on a ListView it works as expected. I can use Shift or Ctrl to multiselect and then click and drag. The drag gesture starts with all my items still selected.

When I try the same thing with a TableView my multiple selection is lost as soon as I click to start my drag gesture. The only way I can make it work is to start the drag gesture at the same time as I Shift select my multiple items.

Run the following test code and try to initiate a drag with multiple rows selected:

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import java.util.Iterator;
import java.util.List;

import javafx.application.Application;
import javafx.beans.property.ReadOnlyStringWrapper;
import javafx.beans.value.ObservableValue;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.SelectionMode;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableColumn.CellDataFeatures;
import javafx.scene.control.TableView;
import javafx.scene.input.ClipboardContent;
import javafx.scene.input.DataFormat;
import javafx.scene.input.Dragboard;
import javafx.scene.input.MouseEvent;
import javafx.scene.input.TransferMode;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
import javafx.util.Callback;

public class TableBlankCells extends Application {

   @Override public void start(Stage primaryStage) {
   
      final TableView<String> table = new TableView<>();
      final TableColumn<String, String> column1 = new TableColumn<>("Column 1");
      column1.setCellValueFactory(new Callback<CellDataFeatures<String,String>,
       ObservableValue<String>>() {
       public ObservableValue<String> call(CellDataFeatures<String, String> p){
       return new ReadOnlyStringWrapper(p.getValue());
       }
});
      
      column1.setPrefWidth( 200 );
      table.getColumns().add( column1 );
      table.getItems().addAll("one", "two", "three", "four");
      table.getSelectionModel().setSelectionMode(SelectionMode.MULTIPLE);
      
      table.setOnDragDetected(new EventHandler<MouseEvent>() {
       @Override public void handle(MouseEvent event) {
       List<String> strings = table.getSelectionModel().getSelectedItems();
       if ( !strings.isEmpty() ) {
       Dragboard db = table.startDragAndDrop(TransferMode.COPY);
       ClipboardContent content = new ClipboardContent();
       StringBuilder sb = new StringBuilder();
       for ( Iterator<String> it = strings.iterator(); it.hasNext(); ){
       sb.append( it.next() );
       if ( it.hasNext() ) {
       sb.append(", ");
       }
       }
       content.put(DataFormat.PLAIN_TEXT, sb.toString());
       db.setContent(content);
       event.consume();
       }
       }
});
       
      primaryStage.setScene( new Scene(new StackPane(table)) );
      primaryStage.show();
   }
    
   public static void main(String[] args) {
    launch(args);
   }
   
    
}