title: Dialog causes drag done events to not propagate
body: <p>I'm using a popup dialog during a drag and drop operation. When the drop happens a dialog pops up and when it is dismissed the event chain should continue and allow something to happen when the drag operation ends. If the popup dialog is FX then there is no problem but if it's Gluon the drag done operation doesn't happen.</p>
  
  <p>Here is a sample code:</p>
  
  <pre><code>import javafx.scene.control.Alert.AlertType;
  import javafx.scene.control.Label;
  import javafx.scene.input.ClipboardContent;
  import javafx.scene.input.DataFormat;
  import javafx.scene.input.Dragboard;
  import javafx.scene.input.TransferMode;
  import javafx.scene.layout.Background;
  import javafx.scene.layout.BackgroundFill;
  import javafx.scene.layout.HBox;
  import javafx.scene.paint.Color;
  
  import com.gluonhq.charm.glisten.mvc.View;
  
  public class MainView extends View {
  
      HBox root;
  
      public MainView(String name) {
          super(name);
  
          Label source = new Label("Source");
          configureDragSource(source);
          Label target = new Label("Target");
          configureDragTarget(target);
          Label popupTarget = new Label("Popup Target");
          configureDragPopupTarget(popupTarget);
          root = new HBox(40, source, target, popupTarget);
          setCenter(root);
      }
  
      private void configureDragSource(Label source) {
          source.setOnDragDetected(e -&gt; {
              root.setBackground(new Background(new BackgroundFill(Color.RED, null, null)));
              Dragboard db = source.startDragAndDrop(TransferMode.ANY);
              ClipboardContent content = new ClipboardContent();
              content.put(DataFormat.PLAIN_TEXT, source.getText());
              db.setContent(content);
          });
          source.setOnDragDone(e -&gt; root.setBackground(new Background(new BackgroundFill(null, null, null))));
      }
  
      private void configureDragTarget(Label target) {
          target.setOnDragOver(e -&gt; e.acceptTransferModes(TransferMode.ANY));
  
      }
  
      private void configureDragPopupTarget(Label popupTarget) {
          popupTarget.setOnDragOver(e -&gt; e.acceptTransferModes(TransferMode.ANY));
          popupTarget.setOnDragDropped(e -&gt; {
              javafx.scene.control.Alert popup1 = new javafx.scene.control.Alert(AlertType.INFORMATION);
              com.gluonhq.charm.glisten.control.Alert popup2 = new com.gluonhq.charm.glisten.control.Alert(AlertType.INFORMATION);
              popup1.showAndWait();
          });
      }
  }
  </code></pre>
  
  <p>The source should be dragged upon which the background changes to red. When the drag operation is done the backgrounds should return to default. The regular drop target does nothing and the color change works. But when dropping on the popup target the dialog appears and when it is closed the color changes only for the FX dialog and not for the gluon dialog. Change <code>popup1.showAndWait();</code> to <code>popup2</code>.</p>
  
  <p>If important this is the application class</p>
  
  <pre><code>import com.gluonhq.charm.glisten.application.MobileApplication;
  
  public class TestApplication extends MobileApplication {
  
      @Override
      public void init() {
          addViewFactory(HOME_VIEW, () -&gt; new MainView(HOME_VIEW));
      }
  
      public static void main(String[] args) {
          launch(args);
      }
  }
  </code></pre>
  
  <p>and this is the gradle build file:</p>
  
  <pre><code>buildscript {
      repositories {
          jcenter()
      }
      dependencies {
          classpath 'org.javafxports:jfxmobile-plugin:1.3.5'
      }
  }
  
  apply plugin: 'org.javafxports.jfxmobile'
  apply plugin: 'eclipse'
  
  jar {
      manifest {
          attributes 'Main-Class': 'com.test.TestApplication'
      }
  }
  
  jfxmobile {
      downConfig {
          version = '3.3.0'
          plugins 'display', 'lifecycle', 'statusbar', 'storage'
      }
      android {
          compileSdkVersion = 19
  //      manifest = 'src/android/AndroidManifest.xml'
      }
      ios {
          infoPList = file('src/ios/Default-Info.plist')
          forceLinkClasses = [
                  'com.gluonhq.**.*',
                  'javax.annotations.**.*',
                  'javax.inject.**.*',
                  'javax.json.**.*',
                  'org.glassfish.json.**.*'
          ]
      }
  }
  
  eclipse {
      classpath {
          downloadJavadoc = true
          downloadSources = true
      }
  }
  
  repositories {
      jcenter()
      maven {
          url 'http://nexus.gluonhq.com/nexus/content/repositories/releases'
      }
  }
  
  mainClassName = 'com.test.TestApplication'
  
  dependencies {
      compile 'com.gluonhq:charm:4.3.5'
  }
  
  task wrapper(type: Wrapper) {
      gradleVersion = '4.2'
  }
  </code></pre>
  
  <p>Happens also on <code>compile 'com.gluonhq:charm:4.3.7'</code> and 4.4.0.</p>
  
  <p>Running on Java 8 b141. Why does this happen? Is this a bug?</p>