CustomToolBarExample2.java

import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.ToolBar;
import javafx.scene.layout.HBox;
import javafx.scene.layout.Priority;
import javafx.stage.Stage;

public class ToolbarCustomExample2 extends Application
{

  @Override
  public void start( final Stage primaryStage )
  {
    final Button left = new Button( "left button" );
    final Button left1 = new Button( "left1 button" );
    final Button left2 = new Button( "left2 button" );
    final Button right = new Button( "right button" );
    final Button right1 = new Button( "right1 button" );
    final Button right2 = new Button( "right2 button" );
    final Button right3 = new Button( "right3 button" );
    final Button center = new Button( "center button" );
    final Button center1 = new Button( "center1 button" );

    /*
     * Extending the default ToolBar has the benefit, that you inherit useful features, like auto-collapse
     * (try resizing the window to something small).
     */
    final ToolBar toolBar = new ToolBar();
    final HBox leftSection = new HBox( left, left1, left2 );
    final HBox centerSection = new HBox( center, center1 );
    final HBox rightSection = new HBox( right, right1, right2, right3 );


    /* Center all sections and always grow them. Has the effect known as JUSTIFY. */
    HBox.setHgrow( leftSection, Priority.ALWAYS );
    HBox.setHgrow( centerSection, Priority.ALWAYS );
    HBox.setHgrow( rightSection, Priority.ALWAYS );

    leftSection.setAlignment( Pos.CENTER_LEFT );
    centerSection.setAlignment( Pos.CENTER );
    rightSection.setAlignment( Pos.CENTER_RIGHT );

    /* It might be harder to propagate some properties: */
    final int spacing = 8;
    toolBar.setPadding( new Insets( 0, spacing, 0, spacing ) );
    leftSection.setSpacing( spacing );
    centerSection.setSpacing( spacing );
    rightSection.setSpacing( spacing );

    toolBar.getItems().addAll( leftSection, centerSection, rightSection );

    left.setOnAction( event -> System.out.println( "left" ) );
    right.setOnAction( event -> System.out.println( "right" ) );
    center.setOnAction( event -> System.out.println( "center" ) );

    final Scene scene = new Scene( toolBar );

    primaryStage.setScene( scene );
    primaryStage.show();
  }

  public static void main( final String[] args )
  {
    launch( args );
  }
}