Various methods of laying out buttons in association with JavaFX TabPanes

ButtonsInTabArea.java

import javafx.application.Application;
import javafx.event.*;
import javafx.scene.*;
import javafx.scene.control.*;
import javafx.scene.layout.*;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;

/** https://forums.oracle.com/forums/thread.jspa?messageID=10573836 "Thread: Adding button next to tab " */
public class ButtonsInTabArea extends Application {
  public static void main(String[] args) { launch(args); }
  @Override public void start(Stage stage) {
    final VBox layout = new VBox(10);
    layout.getChildren().addAll(
      createTabPane(), 
      createButtonInTabsTabPane(),
      createSideBySideButtonAndTabPane(),
      createFixedWidthTabPaneWithButtonOnTop(),
      createVariableWidthTabPaneWithButtonOnTop()
    );
    layout.setStyle("-fx-background-color: cornsilk; -fx-padding: 10;");
    
    stage.setScene(new Scene(layout));
    stage.show();
  }
  
  private TabPane createTabPane() {
    TabPane tabPane = new TabPane();
    tabPane.getTabs().addAll(createTab("red"), createTab("green"), createTab("blue"));
    tabPane.setTabClosingPolicy(TabPane.TabClosingPolicy.UNAVAILABLE);
    tabPane.setMaxWidth(Control.USE_PREF_SIZE);
    
    return tabPane;
  }
  
  private Tab createTab(final String color) {
    Tab tab = new Tab(color);
    tab.setContent(new Rectangle(500, 75, Color.valueOf(color)));
    return tab;
  }

  private TabPane createButtonInTabsTabPane() {
    final TabPane tabPane = createTabPane();
    int i = 1;
    for (final Tab tab: tabPane.getTabs()) {
      placeButtonInTab("ButtonInTab " + i, tab);
      i++;
    }
    return tabPane;
  }

  private void placeButtonInTab(final String buttonText, final Tab tab) {
    Button button = new Button(buttonText);
    button.setOnAction(new EventHandler<ActionEvent>() {
      @Override public void handle(ActionEvent event) {
        tab.getTabPane().getSelectionModel().select(tab);
      }
    });
    tab.setGraphic(button);
  }
  
  private Pane createSideBySideButtonAndTabPane() {
    final HBox    hbox    = new HBox(5);
    final TabPane tabPane = createTabPane();
    final Button  button  = new Button("Button beside TabPane");
    hbox.getChildren().addAll(tabPane, button);
    
    return hbox;
  }

  private Group createFixedWidthTabPaneWithButtonOnTop() {
    final TabPane tabPane = createTabPane();
    final Button  button  = new Button("Button on top of fixed size TabPane");

    final Group   layout = new Group(tabPane, button);
    button.layoutXProperty().bind(
      tabPane.widthProperty().subtract(button.widthProperty().add(10.0))
    );
    button.setLayoutY(5);
    
    return layout;
  }
  
  private Pane createVariableWidthTabPaneWithButtonOnTop() {
    final TabPane tabPane = createTabPane();
    final Button  button  = new Button("Button on top of variable size TabPane");
    button.setMinWidth(Control.USE_PREF_SIZE);

    final Pane   layout = new AnchorPane();
    layout.getChildren().addAll(tabPane, button);
    AnchorPane.setTopAnchor(button, 5.0);
    AnchorPane.setRightAnchor(button, 10.0);
    layout.maxWidthProperty().bind(tabPane.widthProperty());
    
    return layout;
  }  
}