Improve code readability and structure

- Fix exception when trying to place an item without one selected
- Add access modifiers to all class members
- Add `final` to all variables if applicable
- Add `TestBehaviour` to the machines to test the event system
- Convert classes to records where appropriate
- Change `Function<T, T>` to `Consumer<T>`
- Change non generic methods in the `EventHandler` class to generic methods
- Remove unused imports
- Other minor improvements

src/main/java/com/yes/yes/MainController.java

@@ -1,6 +1,8 @@
 package com.yes.yes;
 
-import com.yes.yes.managers.*;
+import com.yes.yes.managers.GameManager;
+import com.yes.yes.managers.PlayerManager;
+import com.yes.yes.managers.UiManager;
 import javafx.application.Platform;
 import javafx.fxml.FXML;
 import javafx.scene.layout.VBox;
@@ -8,7 +10,7 @@ import javafx.scene.layout.VBox;
 
 public class MainController {
     @FXML
-    VBox root;
+    private VBox root;
 
     public void initialize() {
         GameManager gameManager = new GameManager(root);

src/main/java/com/yes/yes/YesApplication.java

@@ -2,12 +2,15 @@ package com.yes.yes;
 
 import javafx.fxml.FXMLLoader;
 import javafx.scene.Scene;
-import javafx.scene.transform.Scale;
 import javafx.stage.Stage;
 
 import java.io.IOException;
 
 public class YesApplication extends javafx.application.Application {
+    public static void main(String[] args) {
+        launch();
+    }
+
     @Override
     public void start(Stage stage) throws IOException {
         FXMLLoader fxmlLoader = new FXMLLoader(YesApplication.class.getResource("main-view.fxml"));
@@ -21,8 +24,4 @@ public class YesApplication extends javafx.application.Application {
         stage.setMaximized(true);
         stage.show();
     }
-
-    public static void main(String[] args) {
-        launch();
-    }
 }

src/main/java/com/yes/yes/behaviours/PlaceBehaviour.java

@@ -12,8 +12,7 @@ public class PlaceBehaviour extends Component {
     }
 
     @Override
-    public void initialize()
-    {
+    public void initialize() {
         for (int x = -1; x < 2; x++) {
             for (int y = -1; y < 2; y++) {
                 try {
@@ -21,7 +20,6 @@ public class PlaceBehaviour extends Component {
 
                     if (entity != null) {
                         entity.trigger("placed", parent);
-                        System.out.println(entity.getClass().getSimpleName());
                     }
                 } catch (IllegalAccessException ex) {
                     ex.printStackTrace();

src/main/java/com/yes/yes/behaviours/TestBehaviour.java

@@ -11,9 +11,13 @@ public class TestBehaviour extends Component {
         super(entity, blockContainer);
     }
 
+    private void onNeighborPlaced(Entity entity) {
+        System.out.println(parent.getClass().getSimpleName() + " > \"" + entity.getClass().getSimpleName() + "\" got placed in the radius.");
+    }
+
     @Override
     public void initialize() {
-
+        parent.addListener("placed", this::onNeighborPlaced);
     }
 
     @Override

src/main/java/com/yes/yes/entities/machines/TestMachine.java

@@ -1,7 +1,9 @@
 package com.yes.yes.entities.machines;
 
 import com.yes.yes.behaviours.PlaceBehaviour;
-import com.yes.yes.utils.*;
+import com.yes.yes.behaviours.TestBehaviour;
+import com.yes.yes.utils.BlockContainer;
+import com.yes.yes.utils.Entity;
 import javafx.scene.shape.Circle;
 
 public class TestMachine extends Entity {
@@ -13,5 +15,6 @@ public class TestMachine extends Entity {
     public TestMachine(BlockContainer blockContainer) {
         this();
         this.addBehaviour(new PlaceBehaviour(this, blockContainer));
+        this.addBehaviour(new TestBehaviour(this, blockContainer));
     }
 }

src/main/java/com/yes/yes/entities/machines/TestMachine2.java

@@ -1,6 +1,7 @@
 package com.yes.yes.entities.machines;
 
 import com.yes.yes.behaviours.PlaceBehaviour;
+import com.yes.yes.behaviours.TestBehaviour;
 import com.yes.yes.utils.BlockContainer;
 import com.yes.yes.utils.Entity;
 import javafx.scene.shape.Rectangle;
@@ -14,5 +15,6 @@ public class TestMachine2 extends Entity {
     public TestMachine2(BlockContainer blockContainer) {
         this();
         this.addBehaviour(new PlaceBehaviour(this, blockContainer));
+        this.addBehaviour(new TestBehaviour(this, blockContainer));
     }
 }

src/main/java/com/yes/yes/managers/GameManager.java

@@ -2,7 +2,6 @@ package com.yes.yes.managers;
 
 import com.yes.yes.entities.machines.TestMachine;
 import com.yes.yes.entities.machines.TestMachine2;
-import com.yes.yes.utils.Coordinate;
 import com.yes.yes.utils.EntityRegistry;
 import com.yes.yes.utils.RegistryEntry;
 import com.yes.yes.utils.exceptions.AlreadyExistsException;
@@ -10,17 +9,17 @@ import com.yes.yes.world.World;
 import javafx.scene.layout.VBox;
 
 public class GameManager {
-    VBox root;
-    World world;
-
-    public World getWorld() {
-        return world;
-    }
+    private final VBox root;
+    private World world;
 
     public GameManager(VBox root) {
         this.root = root;
     }
 
+    public World getWorld() {
+        return world;
+    }
+
     public void initialize() {
         world = new World();
 
@@ -28,8 +27,8 @@ public class GameManager {
         world.toBack();
 
         try {
-            EntityRegistry.register(new RegistryEntry("test","test machine", TestMachine.class));
-            EntityRegistry.register(new RegistryEntry("test2","test machine", TestMachine2.class));
+            EntityRegistry.register(new RegistryEntry("test", "test machine", TestMachine.class));
+            EntityRegistry.register(new RegistryEntry("test2", "test machine", TestMachine2.class));
         } catch (AlreadyExistsException e) {
             e.printStackTrace();
         }

src/main/java/com/yes/yes/managers/PlayerManager.java

@@ -1,10 +1,7 @@
 package com.yes.yes.managers;
 
 import com.yes.yes.ui.BuildBox;
-import com.yes.yes.utils.BlockContainer;
-import com.yes.yes.utils.Coordinate;
-import com.yes.yes.utils.Entity;
-import com.yes.yes.utils.EntityRegistry;
+import com.yes.yes.utils.*;
 import com.yes.yes.world.Chunk;
 import com.yes.yes.world.World;
 import javafx.scene.Scene;
@@ -15,14 +12,14 @@ import javafx.scene.input.KeyEvent;
 
 public class PlayerManager {
 
-    static final KeyCombination LEFT_KEY = new KeyCodeCombination(KeyCode.A);
-    static final KeyCombination RIGHT_KEY = new KeyCodeCombination(KeyCode.D);
-    static final KeyCombination UP_KEY = new KeyCodeCombination(KeyCode.W);
-    static final KeyCombination DOWN_KEY = new KeyCodeCombination(KeyCode.S);
+    private static final KeyCombination LEFT_KEY = new KeyCodeCombination(KeyCode.A);
+    private static final KeyCombination RIGHT_KEY = new KeyCodeCombination(KeyCode.D);
+    private static final KeyCombination UP_KEY = new KeyCodeCombination(KeyCode.W);
+    private static final KeyCombination DOWN_KEY = new KeyCodeCombination(KeyCode.S);
 
-    World world;
-    BuildBox buildBox;
-    Coordinate chunkPos = new Coordinate(0, 0);
+    private final World world;
+    private final BuildBox buildBox;
+    private Coordinate chunkPos = new Coordinate(0, 0);
 
     public PlayerManager(World world, BuildBox buildBox) {
         this.world = world;
@@ -40,11 +37,16 @@ public class PlayerManager {
                     Coordinate blockCoordinate = Coordinate.WorldToChunkBlock(mouseCoordinate);
 
                     try {
-                        Class[] types = new Class[1];
+                        Class<?>[] types = new Class<?>[1];
                         types[0] = BlockContainer.class;
 
                         BlockContainer blockContainer = new BlockContainer(world, blockCoordinate, chunkCoordinate);
-                        Entity entity = (Entity) EntityRegistry.getEntity(buildBox.getSelectedEntity()).getEntity().getConstructor(types).newInstance(blockContainer);
+                        RegistryEntry registryEntry = EntityRegistry.getEntry(buildBox.getSelectedEntity());
+
+                        if (registryEntry == null)
+                            return;
+
+                        Entity entity = (Entity) registryEntry.getEntity().getConstructor(types).newInstance(blockContainer);
 
                         world.getChunk(chunkCoordinate).setEntity(entity, blockCoordinate);
                     } catch (Exception ex) {
@@ -53,11 +55,11 @@ public class PlayerManager {
                 }
         );
 
-        world.setTranslateX(Integer.MAX_VALUE / -5000);
-        world.setTranslateY(Integer.MAX_VALUE / -5000);
+        world.setTranslateX(Integer.MAX_VALUE / -5000d);
+        world.setTranslateY(Integer.MAX_VALUE / -5000d);
     }
 
-    void ProcessKeyPress(KeyEvent key) {
+    private void ProcessKeyPress(KeyEvent key) {
         if (LEFT_KEY.match(key)) {
             world.setTranslateX(world.getTranslateX() + 45);
         }

src/main/java/com/yes/yes/managers/UiManager.java

@@ -4,8 +4,8 @@ import com.yes.yes.ui.BuildBox;
 import javafx.scene.layout.VBox;
 
 public class UiManager {
-    VBox root;
-    BuildBox buildBox;
+    private final VBox root;
+    private BuildBox buildBox;
 
     public UiManager(VBox root) {
         this.root = root;

src/main/java/com/yes/yes/ui/BuildBox.java

@@ -5,18 +5,10 @@ import javafx.application.Platform;
 import javafx.scene.control.ScrollPane;
 import javafx.scene.layout.HBox;
 
-import java.util.function.Function;
-
 public class BuildBox extends javafx.scene.Group {
     String selectedEntity;
 
 
-    Function<String, Void> changeItem = i -> {
-        System.out.println(i);
-        this.selectedEntity = i;
-        return null;
-    };
-
     public BuildBox() {
         ScrollPane pane = new ScrollPane();
         HBox hbox = new HBox();
@@ -32,7 +24,12 @@ public class BuildBox extends javafx.scene.Group {
 
         Platform.runLater(() -> pane.prefWidthProperty().bind(this.getScene().getWindow().widthProperty()));
 
-        EntityRegistry.getKeys().forEach(e -> hbox.getChildren().add(new BuildItem(e, changeItem)));
+        EntityRegistry.getKeys().forEach(e -> hbox.getChildren().add(new BuildItem(e, this::changeItem)));
+    }
+
+    private void changeItem(String name) {
+        System.out.println(name);
+        this.selectedEntity = name;
     }
 
     public String getSelectedEntity() {

src/main/java/com/yes/yes/ui/BuildItem.java

@@ -5,18 +5,17 @@ import com.yes.yes.world.Chunk;
 import javafx.scene.Node;
 import javafx.scene.control.Button;
 
-import java.util.function.Function;
+import java.util.function.Consumer;
 
 public class BuildItem extends javafx.scene.layout.StackPane {
-    String display_name;
-    String name;
-    Class<?> entity;
+    private final String display_name;
+    private final String name;
 
-    public BuildItem(String name, Function<String, Void> onClick) {
+    public BuildItem(String name, Consumer<String> onClick) {
         super();
 
-        this.display_name = EntityRegistry.getEntity(name).getDisplayName();
-        this.entity = EntityRegistry.getEntity(name).getEntity();
+        this.display_name = EntityRegistry.getEntry(name).getDisplayName();
+        Class<?> entity = EntityRegistry.getEntry(name).getEntity();
         this.name = name;
 
         this.prefWidth(Chunk.ENTITY_SIZE);
@@ -33,7 +32,7 @@ public class BuildItem extends javafx.scene.layout.StackPane {
         button.setStyle("-fx-background-color: null; -fx-border-color: null");
         button.setPrefSize(Chunk.ENTITY_SIZE, Chunk.ENTITY_SIZE);
         button.setMinSize(Chunk.ENTITY_SIZE, Chunk.ENTITY_SIZE);
-        button.setOnAction((e) -> onClick.apply(this.name));
+        button.setOnAction((e) -> onClick.accept(this.name));
 
         this.getChildren().add(button);
     }

src/main/java/com/yes/yes/utils/BlockContainer.java

@@ -3,18 +3,9 @@ package com.yes.yes.utils;
 import com.yes.yes.world.Chunk;
 import com.yes.yes.world.World;
 
-public class BlockContainer {
-    final World world;
-    final Coordinate blockCoordinate;
-    final Coordinate chunkCoordinate;
+public record BlockContainer(World world, Coordinate blockCoordinate, Coordinate chunkCoordinate) {
     final static int MAX_RADIUS = 2;
 
-    public BlockContainer(World world, Coordinate blockCoordinate, Coordinate chunkCoordinate) {
-        this.world = world;
-        this.blockCoordinate = blockCoordinate;
-        this.chunkCoordinate = chunkCoordinate;
-    }
-
     public Entity getBlock(Coordinate offset) throws IllegalAccessException {
         if (Math.abs(offset.x) > MAX_RADIUS || Math.abs(offset.y) > MAX_RADIUS)
             throw new IllegalAccessException();

src/main/java/com/yes/yes/utils/Component.java

@@ -1,7 +1,7 @@
 package com.yes.yes.utils;
 
 public abstract class Component {
-    protected Entity parent;
+    protected final Entity parent;
     protected final BlockContainer blockContainer;
 
     public Component(Entity entity, BlockContainer blockContainer) {
@@ -10,5 +10,6 @@ public abstract class Component {
     }
 
     public abstract void initialize();
+
     public abstract void update();
 }

src/main/java/com/yes/yes/utils/Coordinate.java

@@ -13,23 +13,6 @@ public class Coordinate {
         this.y = y;
     }
 
-    public Coordinate() {
-    }
-
-
-    @Override
-    public boolean equals(Object o) {
-        if (this == o) return true;
-        if (!(o instanceof Coordinate)) return false;
-        Coordinate that = (Coordinate) o;
-        return x == that.x && y == that.y;
-    }
-
-    @Override
-    public int hashCode() {
-        return Objects.hash(x, y);
-    }
-
     public static Coordinate WorldToChunkCoordinate(Coordinate worldPos) {
         int chunkSize = Chunk.CHUNK_SIZE * Chunk.ENTITY_SIZE;
 
@@ -43,4 +26,16 @@ public class Coordinate {
 
         return new Coordinate(worldPos.x / Chunk.ENTITY_SIZE, worldPos.y / Chunk.ENTITY_SIZE);
     }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (!(o instanceof Coordinate that)) return false;
+        return x == that.x && y == that.y;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(x, y);
+    }
 }

src/main/java/com/yes/yes/utils/Entity.java

@@ -2,12 +2,13 @@ package com.yes.yes.utils;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.function.Consumer;
 import java.util.function.Function;
 
 public abstract class Entity extends javafx.scene.Group {
-    private ArrayList<Component> behaviours = new ArrayList<>();
-    private final HashMap<String, Object> data = new HashMap<String, Object>();
+    private final HashMap<String, Object> data = new HashMap<>();
     private final EventHandler handler = new EventHandler();
+    private ArrayList<Component> behaviours = new ArrayList<>();
     private int rotation;
 
     public final void addBehaviour(Component behaviour) {
@@ -40,7 +41,7 @@ public abstract class Entity extends javafx.scene.Group {
         return (T) data.get(key);
     }
 
-    public final void addListener(String eventName, Function<Object, Void> function) {
+    public final <T> void addListener(String eventName, Consumer<T> function) {
         handler.addListener(eventName, function);
     }
 

src/main/java/com/yes/yes/utils/EntityRegistry.java

@@ -6,7 +6,7 @@ import java.util.ArrayList;
 import java.util.HashMap;
 
 public abstract class EntityRegistry {
-    static HashMap<String, RegistryEntry> entities = new HashMap<>();
+    private static final HashMap<String, RegistryEntry> entities = new HashMap<>();
 
     public static void register(RegistryEntry entry) throws AlreadyExistsException {
         if (entities.containsKey(entry.getName())) {
@@ -16,7 +16,7 @@ public abstract class EntityRegistry {
         }
     }
 
-    public static RegistryEntry getEntity(String name) {
+    public static RegistryEntry getEntry(String name) {
         return entities.get(name);
     }
 

src/main/java/com/yes/yes/utils/EventHandler.java

@@ -2,18 +2,19 @@ package com.yes.yes.utils;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.function.Consumer;
 import java.util.function.Function;
 
 public class EventHandler {
-    private final HashMap<String, ArrayList<Function<Object, Void>>> events = new HashMap<>();
+    private final HashMap<String, ArrayList<Consumer<Object>>> events = new HashMap<>();
 
 
-
-    public void addListener(String eventName, Function<Object, Void> function) {
+    public <T> void addListener(String eventName, Consumer<T> function) {
         if (!events.containsKey(eventName)) {
             events.put(eventName, new ArrayList<>());
         }
-        events.get(eventName).add(function);
+
+        events.get(eventName).add((e) -> function.accept((T) e));
     }
 
     public void removeListener(String eventName, Function<Object, Void> function) throws IllegalArgumentException {
@@ -21,13 +22,13 @@ public class EventHandler {
         if (!events.containsKey(eventName)) {
             throw new IllegalArgumentException("Event " + eventName + " does not exist!");
         }
+        //noinspection SuspiciousMethodCalls
         events.get(eventName).remove(function);
     }
 
-    public void trigger(String eventName, Object parameter) {
-        //TODO: Check if this needs null checking
+    public <T> void trigger(String eventName, T parameter) {
         if (events.containsKey(eventName)) {
-            events.get(eventName).forEach(e -> e.apply(parameter));
+            events.get(eventName).forEach(e -> e.accept(parameter));
         }
     }
 }

src/main/java/com/yes/yes/utils/GlobalEventHandler.java

@@ -1,11 +1,12 @@
 package com.yes.yes.utils;
 
+import java.util.function.Consumer;
 import java.util.function.Function;
 
 public abstract class GlobalEventHandler {
     private static final EventHandler handler = new EventHandler();
 
-    public static void addListener(String eventName, Function<Object, Void> function) {
+    public static <T> void addListener(String eventName, Consumer<T> function) {
         handler.addListener(eventName, function);
     }
 

src/main/java/com/yes/yes/utils/RegistryEntry.java

@@ -1,15 +1,6 @@
 package com.yes.yes.utils;
 
-public class RegistryEntry {
-    String name;
-    String displayName;
-    Class<?> entity;
-
-    public RegistryEntry(String name, String displayName, Class<?> entity) {
-        this.name = name;
-        this.displayName = displayName;
-        this.entity = entity;
-    }
+public record RegistryEntry(String name, String displayName, Class<?> entity) {
 
     public String getName() {
         return name;

src/main/java/com/yes/yes/utils/Size.java

@@ -3,17 +3,14 @@ package com.yes.yes.utils;
 import java.util.Objects;
 
 public class Size {
-    public int x;
-    public int y;
+    public final int x;
+    public final int y;
 
     public Size(int x, int y) {
         this.x = x;
         this.y = y;
     }
 
-    public Size() {
-    }
-
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;

src/main/java/com/yes/yes/world/Chunk.java

@@ -3,7 +3,6 @@ package com.yes.yes.world;
 import com.yes.yes.utils.Coordinate;
 import com.yes.yes.utils.Entity;
 import javafx.geometry.HPos;
-import javafx.geometry.Pos;
 import javafx.geometry.VPos;
 import javafx.scene.layout.*;
 import javafx.scene.paint.Color;

src/main/java/com/yes/yes/world/World.java

@@ -16,9 +16,9 @@ public class World extends GridPane {
         super();
         //HACK: Move the world by Integer.MAX_VALUE/-1000 in order to avoid -indexes
         //      So we need to generate all the column indexes to make alignment correct
-        for (int i = 0; i < (Integer.MAX_VALUE/1000/(Chunk.CHUNK_SIZE*Chunk.ENTITY_SIZE)); i++) {
-            this.getRowConstraints().add(new RowConstraints(Chunk.CHUNK_SIZE*Chunk.ENTITY_SIZE));
-            this.getColumnConstraints().add(new ColumnConstraints(Chunk.CHUNK_SIZE*Chunk.ENTITY_SIZE));
+        for (int i = 0; i < (Integer.MAX_VALUE / 1000 / (Chunk.CHUNK_SIZE * Chunk.ENTITY_SIZE)); i++) {
+            this.getRowConstraints().add(new RowConstraints(Chunk.CHUNK_SIZE * Chunk.ENTITY_SIZE));
+            this.getColumnConstraints().add(new ColumnConstraints(Chunk.CHUNK_SIZE * Chunk.ENTITY_SIZE));
         }
     }
 
@@ -29,7 +29,7 @@ public class World extends GridPane {
     }
 
     public void load(Coordinate pos) {
-        if(loadedChunks.containsKey(pos)) return;
+        if (loadedChunks.containsKey(pos)) return;
 
         Chunk chunk = getChunk(pos);
         this.add(chunk, pos.x, pos.y);

src/main/resources/com/yes/yes/main-view.fxml

@@ -1,10 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
-<?import javafx.geometry.Insets?>
-<?import javafx.scene.control.Label?>
 <?import javafx.scene.layout.VBox?>
-
-<?import javafx.scene.control.Button?>
 <VBox spacing="20.0" xmlns:fx="http://javafx.com/fxml"
       fx:controller="com.yes.yes.MainController" fx:id="root">
 </VBox>