PathFinding.java: SettingsPane class

Question

Intro

I am still working on PathFinding.java. This time I need to get reviewed the class responsible for choosing the heuristic function, the finder implementation, just to mention a few of settings options.

Code

io.github.coderodde.pathfinding.app.SettingsPane.java:

package io.github.coderodde.pathfinding.app;
import static io.github.coderodde.pathfinding.app.Configuration.FREQUENCIES;
import static io.github.coderodde.pathfinding.finders.Finder.computePathCost;
import io.github.coderodde.pathfinding.controller.GridController;
import io.github.coderodde.pathfinding.finders.AStarFinder;
import io.github.coderodde.pathfinding.finders.BFSFinder;
import io.github.coderodde.pathfinding.finders.BIDDFSFinder;
import io.github.coderodde.pathfinding.finders.BeamSearchFinder;
import io.github.coderodde.pathfinding.finders.BestFirstSearchFinder;
import io.github.coderodde.pathfinding.finders.BidirectionalBFSFinder;
import io.github.coderodde.pathfinding.finders.BidirectionalDijkstra;
import io.github.coderodde.pathfinding.finders.DijkstraFinder;
import io.github.coderodde.pathfinding.finders.Finder;
import io.github.coderodde.pathfinding.finders.NBAStarFinder;
import io.github.coderodde.pathfinding.heuristics.ChebyshevHeuristicFunction;
import io.github.coderodde.pathfinding.heuristics.EuclideanHeuristicFunction;
import io.github.coderodde.pathfinding.heuristics.HeuristicFunction;
import io.github.coderodde.pathfinding.heuristics.ManhattanHeuristicFunction;
import io.github.coderodde.pathfinding.heuristics.OctileHeuristicFunction;
import io.github.coderodde.pathfinding.logic.GridCellNeighbourIterable;
import io.github.coderodde.pathfinding.logic.GridNodeExpander;
import io.github.coderodde.pathfinding.logic.PathfindingSettings;
import io.github.coderodde.pathfinding.logic.PathfindingSettings.DiagonalWeight;
import io.github.coderodde.pathfinding.logic.SearchState;
import io.github.coderodde.pathfinding.logic.SearchState.CurrentState;
import io.github.coderodde.pathfinding.logic.SearchStatistics;
import io.github.coderodde.pathfinding.model.GridModel;
import io.github.coderodde.pathfinding.utils.Cell;
import io.github.coderodde.pathfinding.view.GridView;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.concurrent.ExecutionException;
import javafx.application.Platform;
import javafx.concurrent.Task;
import javafx.geometry.Rectangle2D;
import javafx.scene.control.Accordion;
import javafx.scene.control.Button;
import javafx.scene.control.CheckBox;
import javafx.scene.control.ComboBox;
import javafx.scene.control.Label;
import javafx.scene.control.TitledPane;
import javafx.scene.layout.Pane;
import javafx.scene.layout.VBox;
import javafx.stage.Screen;
/**
 *
 * @author Rodion "rodde" EFremov
 * @version 1.0.0 (Aug 27, 2025)
 * @since 1.0.0 (Aug 27, 2025)
 */
public final class SettingsPane extends Pane {
 
 private static final String EUCLIDEAN = "Euclidean";
 private static final String MANHATTAN = "Manhattan";
 private static final String OCTILE = "Octile";
 private static final String CHEBYSHEV = "Chebyshev";
 
 private static final String ASTAR = "A* search";
 private static final String DIJKSTRA = "Dijkstra";
 private static final String BI_DIJKSTRA = "Bidirectional Dijkstra";
 private static final String BFS = "BFS";
 private static final String BI_BFS = "Bidirectional BFS";
 private static final String BEST_FIRST_SEARCH = "Best First search";
 private static final String BEAM_SEARCH = "Beam search";
 private static final String BIDDFS = "Bidirectional IDDFS";
 private static final String NBASTAR = "NBA* search";
 
 private static final String[] HEURISTIC_NAMES = {
 MANHATTAN,
 EUCLIDEAN,
 OCTILE,
 CHEBYSHEV,
 };
 
 private static final String[] FINDER_NAMES = {
 ASTAR,
 DIJKSTRA,
 BI_DIJKSTRA,
 BFS,
 BI_BFS,
 BEST_FIRST_SEARCH,
 BEAM_SEARCH,
 BIDDFS,
 NBASTAR,
 };
 
 private static final Map<String, HeuristicFunction> HEURISTIC_MAP =
 new HashMap<>();
 
 private static final Map<String, Finder> FINDER_MAP = 
 new HashMap<>();
 
 static {
 HEURISTIC_MAP.put(EUCLIDEAN, new EuclideanHeuristicFunction());
 HEURISTIC_MAP.put(MANHATTAN, new ManhattanHeuristicFunction());
 HEURISTIC_MAP.put(OCTILE, new OctileHeuristicFunction());
 HEURISTIC_MAP.put(CHEBYSHEV, new ChebyshevHeuristicFunction());
 
 FINDER_MAP.put(ASTAR, new AStarFinder());
 FINDER_MAP.put(DIJKSTRA, new DijkstraFinder());
 FINDER_MAP.put(BI_DIJKSTRA, new BidirectionalDijkstra());
 FINDER_MAP.put(BFS, new BFSFinder());
 FINDER_MAP.put(BI_BFS, new BidirectionalBFSFinder());
 FINDER_MAP.put(BEST_FIRST_SEARCH, new BestFirstSearchFinder());
 FINDER_MAP.put(BEAM_SEARCH, new BeamSearchFinder()); 
 FINDER_MAP.put(BIDDFS, new BIDDFSFinder());
 FINDER_MAP.put(NBASTAR, new NBAStarFinder());
 }
 
 private static final int PIXELS_WIDTH = 300;
 private static final int PIXELS_HEIGHT = 200;
 private static final int PIXELS_MARGIN = 20;
 private final double[] offset = new double[2];
 private GridModel gridModel;
 private GridView gridView;
 private GridController gridController;
 private GridNodeExpander gridNodeExpander;
 private final SearchState searchState;
 private Finder finder;
 private List<Cell> path = new ArrayList<>();
 
 private final ComboBox<String> comboBoxFrequency = new ComboBox<>();
 private final ComboBox<String> comboBoxDiagonalWeight = new ComboBox<>();
 private final ComboBox<String> comboBoxFinder = new ComboBox<>();
 private final ComboBox<String> comboBoxHeuristic = new ComboBox<>();
 private final ComboBox<String> comboBoxBeamWidth = new ComboBox<>();
 
 private final CheckBox checkBoxAllowDiagonals = 
 new CheckBox("Allow diagonals");
 
 private final CheckBox checkBoxDontCrossCorners = 
 new CheckBox("Don't cross corners");
 
 private final TitledPane titledPaneFrequency = 
 new TitledPane("Frequency", comboBoxFrequency);
 
 private final TitledPane titledPaneDiagonalWeight = 
 new TitledPane("Diagonal weight", comboBoxDiagonalWeight);
 
 private final TitledPane titledPaneFinder = 
 new TitledPane("Finder", comboBoxFinder);
 
 private final TitledPane titledPaneHeuristic = 
 new TitledPane("Heuristic", comboBoxHeuristic);
 
 private final TitledPane titledPaneBeamWidth = 
 new TitledPane("Beam width", comboBoxBeamWidth);
 
 private final TitledPane titledPaneDiagonalSettings;
 
 private final Label labelPathLength = new Label("Path cost: N/A");
 private final Label labelVisitedCount = new Label("Visited cells: N/A");
 private final Label labelOpenedCount = new Label("Opened cells: N/A");
 
 private final VBox vboxDiagonalSettings = new VBox();
 
 private final Button buttonStartPause = new Button("Start");
 private final Button buttonReset = new Button("Reset");
 private final Button buttonClearWalls = new Button("Clear walls");
 
 private volatile boolean searchIsRunning = false;
 
 public SettingsPane(GridModel gridModel,
 GridView gridView,
 GridController gridController,
 SearchState searchState) {
 this.gridModel = 
 Objects.requireNonNull(
 gridModel, 
 "The input grid model is null");
 
 this.gridView = 
 Objects.requireNonNull(
 gridView, 
 "The input grid view is null");
 
 this.searchState = searchState;
 this.searchState.setCurrentState(CurrentState.IDLE);
 
 this.labelPathLength.setStyle("-fx-background-color: white;" + 
 "-fx-font-size: 13px;");
 
 this.labelPathLength.setPrefWidth(PIXELS_WIDTH);
 
 this.labelVisitedCount.setStyle("-fx-background-color: white;" + 
 "-fx-font-size: 13px;");
 
 this.labelVisitedCount.setPrefWidth(PIXELS_WIDTH);
 
 this.labelOpenedCount.setStyle("-fx-background-color: white;" + 
 "-fx-font-size: 13px;");
 
 this.labelOpenedCount.setPrefWidth(PIXELS_WIDTH);
 
 this.vboxDiagonalSettings
 .getChildren()
 .addAll(checkBoxAllowDiagonals,
 checkBoxDontCrossCorners);
 
 this.titledPaneDiagonalSettings =
 new TitledPane(
 "Diagonal settings",
 this.vboxDiagonalSettings);
 
 setPrefSize(PIXELS_WIDTH,
 PIXELS_HEIGHT);
 
 setMinSize(PIXELS_WIDTH, 
 PIXELS_HEIGHT);
 
 setMaxSize(PIXELS_WIDTH, 
 PIXELS_HEIGHT);
 
 Rectangle2D screenRectangle = Screen.getPrimary().getBounds();
 
 setLayoutX(screenRectangle.getWidth() - PIXELS_WIDTH - PIXELS_MARGIN);
 setLayoutY(PIXELS_MARGIN);
 
 VBox mainVBox = new VBox();
 
 mainVBox.setPrefSize(PIXELS_WIDTH,
 PIXELS_HEIGHT);
 
 mainVBox.setMinSize(PIXELS_WIDTH,
 PIXELS_HEIGHT); 
 
 mainVBox.setMaxSize(PIXELS_WIDTH,
 PIXELS_HEIGHT); 
 
 for (int beamWidth = 1; beamWidth <= 8; ++beamWidth) {
 comboBoxBeamWidth.getItems()
 .add(String.format("%d", beamWidth));
 }
 
 comboBoxBeamWidth.setValue("8");
 
 for (String heuristicName : HEURISTIC_NAMES) {
 comboBoxHeuristic.getItems().add(heuristicName);
 }
 
 comboBoxFrequency.setPrefWidth(PIXELS_WIDTH);
 
 for (Integer frequency : FREQUENCIES) {
 comboBoxFrequency.getItems()
 .add(String.format("%d Hz", frequency));
 }
 
 for (String finder : FINDER_NAMES) {
 comboBoxFinder.getItems().add(finder);
 }
 
 comboBoxFinder.setValue(FINDER_NAMES[0]);
 comboBoxFinder.setPrefWidth(PIXELS_WIDTH);
 
 comboBoxFrequency.setValue(
 String.format("%d Hz", FREQUENCIES.getLast()));
 
 comboBoxDiagonalWeight .getItems().add("1");
 comboBoxDiagonalWeight .getItems().add("SQRT2");
 comboBoxDiagonalWeight .setPrefWidth(PIXELS_WIDTH);
 comboBoxDiagonalWeight .setValue("SQRT2");
 
 checkBoxAllowDiagonals.setSelected(true);
 checkBoxDontCrossCorners.setSelected(true);
 
 comboBoxBeamWidth.setValue("3");
 comboBoxHeuristic.setValue(MANHATTAN);
 
 comboBoxBeamWidth.setPrefWidth(PIXELS_WIDTH);
 comboBoxHeuristic.setPrefWidth(PIXELS_WIDTH);
 
 Accordion accordion = new Accordion(); 
 accordion.setPrefWidth(PIXELS_WIDTH);
 accordion.getPanes().addAll(titledPaneFrequency,
 titledPaneDiagonalSettings,
 titledPaneDiagonalWeight,
 titledPaneFinder,
 titledPaneHeuristic,
 titledPaneBeamWidth);
 
 accordion.setExpandedPane(titledPaneFinder);
 
 mainVBox.getChildren().addAll(accordion, 
 labelPathLength,
 labelVisitedCount,
 labelOpenedCount);
 
 getChildren().add(mainVBox);
 
 VBox buttonVBox = new VBox();
 
 buttonStartPause.setPrefWidth(PIXELS_WIDTH);
 buttonReset .setPrefWidth(PIXELS_WIDTH);
 buttonClearWalls.setPrefWidth(PIXELS_WIDTH);
 
 buttonStartPause.setOnAction(event -> {
 
 PathfindingSettings pathfindingSettings = 
 computePathfindingSettings();
 
 if (searchState.getCurrentState().equals(CurrentState.IDLE)) {
 // Once here, start search:
 gridView.clearPath(path); // Clear the possible previous path!
 searchState.setCurrentState(CurrentState.SEARCHING);
 gridController.disableUserInteraction();
 gridModel.clearStateCells();
 buttonStartPause.setText("Pause");
 buttonClearWalls.setDisable(true);
 buttonReset.setDisable(false);
 
 finder = pathfindingSettings.getFinder();
 gridNodeExpander = new GridNodeExpander(gridModel,
 pathfindingSettings);
 
 SearchStatistics searchStatistics = new SearchStatistics();
 
 Task<List<Cell>> task = new Task<>() {
 
 @Override
 protected List<Cell> call() throws Exception {
 searchIsRunning = true;
 
 List<Cell> path = finder.findPath(
 gridModel,
 new GridCellNeighbourIterable(
 gridModel,
 gridNodeExpander, 
 pathfindingSettings),
 pathfindingSettings,
 searchState,
 searchStatistics);
 
 searchIsRunning = false;
 
 searchState.setCurrentState(CurrentState.IDLE);
 buttonReset.setDisable(false);
 buttonClearWalls.setDisable(true);
 
 return path;
 }
 };
 
 task.setOnSucceeded(e -> {
 try {
 this.path.clear();
 this.path.addAll(task.get());
 System.out.println(this.path);
 
 labelPathLength.setText(
 "Path cost: " + computePathCost(
 this.path,
 pathfindingSettings));
 
 labelVisitedCount.setText(
 "Visited: " + searchStatistics.getVisited());
 
 labelOpenedCount.setText(
 "Opened: " + searchStatistics.getOpened());
 
 } catch (InterruptedException | ExecutionException ex) {
 System.getLogger(
 SettingsPane.class.getName()).log(
 System.Logger.Level.ERROR,
 (String) null,
 ex);
 Platform.exit();
 }
 
 gridView.drawPath(this.path);
 gridController.enableUserInteraction();
 searchState.setCurrentState(CurrentState.IDLE);
 buttonStartPause.setText("Search");
 searchState.resetState();
 labelPathLength.setText(
 "Path cost: " + 
 computePathCost(path, pathfindingSettings));
 });
 
 new Thread(task).start();
 
 } else if (searchState
 .getCurrentState()
 .equals(CurrentState.SEARCHING)) {
 
 // Once here, we need to pause the search:
 searchState.requestPause();
 searchState.setCurrentState(CurrentState.PAUSED);
 buttonStartPause.setText("Continue");
 } else if (searchState.getCurrentState()
 .equals(CurrentState.PAUSED)) {
 
 searchState.resetState();
 searchState.setCurrentState(CurrentState.SEARCHING);
 buttonStartPause.setText("Pause");
 }
 });
 
 buttonClearWalls.setOnAction(event -> {
 gridModel.clearWalls();
 }); 
 
 buttonReset.setOnAction(event -> {
 searchState.requestHalt();
 
 while (searchIsRunning) {
 try {
 Thread.sleep(10L);
 } catch (InterruptedException ex) {
 
 }
 }
 
 buttonReset.setDisable(true);
 buttonStartPause.setText("Search");
 buttonClearWalls.setDisable(false);
 gridModel.clearStateCells();
 gridView.drawBorders();
 gridView.drawAllCels();
 });
 
 buttonVBox.getChildren().addAll(buttonStartPause,
 buttonReset,
 buttonClearWalls);
 
 mainVBox.getChildren().add(buttonVBox);
 
 setOnMousePressed(event -> {
 offset[0] = event.getSceneX() - getLayoutX();
 offset[1] = event.getSceneY() - getLayoutY();
 });
 
 setOnMouseDragged(event -> {
 setLayoutX(event.getSceneX() - offset[0]);
 setLayoutY(event.getSceneY() - offset[1]);
 });
 
 Label emptyLabel = new Label("");
 emptyLabel.setPrefSize(PIXELS_WIDTH, 40.0);
 mainVBox.getChildren().add(emptyLabel);
 // after: VBox mainVBox = new VBox();
 mainVBox.setFillWidth(true);
 mainVBox.prefWidthProperty().bind(widthProperty());
 mainVBox.prefHeightProperty().bind(heightProperty()); // optional
 // Make children take full width of the VBox:
 accordion.setMaxWidth(Double.MAX_VALUE);
 buttonStartPause.setMaxWidth(Double.MAX_VALUE);
 buttonClearWalls.setMaxWidth(Double.MAX_VALUE);
 // If you keep Pane as the root, explicitly place the VBox at (0,0):
 mainVBox.relocate(0, 0);
 }
 
 public SearchState getSearchState() {
 return searchState;
 }
 
 @Override
 public boolean isResizable() {
 return false;
 }
 
 private PathfindingSettings computePathfindingSettings() {
 PathfindingSettings ps = new PathfindingSettings();
 
 ps.setAllowDiagonals(checkBoxAllowDiagonals.isSelected());
 ps.setDontCrossCorners(checkBoxDontCrossCorners.isSelected());
 ps.setBeamWidth(Integer.parseInt(comboBoxBeamWidth.getValue()));
 ps.setDiagonalWeight(
 DiagonalWeight.convert(comboBoxDiagonalWeight.getValue()));
 
 ps.setHeuristicFunction(
 HEURISTIC_MAP.get(comboBoxHeuristic.getValue()));
 
 ps.setFinder(FINDER_MAP.get(comboBoxFinder.getValue()));
 
 return ps;
 }
}

How it looks like

PathFinding.java: the settings pane

Critique request

As you can see, that is not that much OOP than Spagetti Oriented Programming. Can you suggest a better way of designing that functionality?

Also, how can I style the JavaFX components such that it would mimic qiao/PathFinding.js: enter image description here