refactor: removed MainFXMLController from dependencies

Replaced MainFXMLController-based scene-changing with event-based scene-changing to remove cyclic dependency

src/main/java/ch/zhaw/gartenverwaltung/HelloApplication.java

@@ -1,8 +1,7 @@
 package ch.zhaw.gartenverwaltung;
 
+import ch.zhaw.gartenverwaltung.bootstrap.AppLoader;
 import javafx.application.Application;
-import javafx.fxml.FXMLLoader;
-import javafx.scene.Scene;
 import javafx.stage.Stage;
 
 import java.io.IOException;
@@ -10,10 +9,11 @@ import java.io.IOException;
 public class HelloApplication extends Application {
     @Override
     public void start(Stage stage) throws IOException {
-        FXMLLoader fxmlLoader = new FXMLLoader(HelloApplication.class.getResource("MainFXML.fxml"));
-        Scene scene = new Scene(fxmlLoader.load());
+        AppLoader appLoader = new AppLoader();
+
+        appLoader.loadSceneToStage("MainFXML.fxml", stage);
+
         stage.setTitle("Gartenverwaltung");
-        stage.setScene(scene);
         stage.show();
     }
 

src/main/java/ch/zhaw/gartenverwaltung/MainFXMLController.java

@@ -1,21 +1,25 @@
 package ch.zhaw.gartenverwaltung;
 
+import ch.zhaw.gartenverwaltung.bootstrap.AfterInject;
 import ch.zhaw.gartenverwaltung.bootstrap.AppLoader;
+import ch.zhaw.gartenverwaltung.bootstrap.ChangeViewEvent;
+import ch.zhaw.gartenverwaltung.bootstrap.Inject;
+import javafx.event.EventHandler;
 import javafx.fxml.FXML;
-import javafx.fxml.Initializable;
 import javafx.scene.control.Button;
 import javafx.scene.layout.AnchorPane;
 import javafx.scene.layout.Pane;
 
 import java.io.IOException;
-import java.net.URL;
-import java.util.ResourceBundle;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
-public class MainFXMLController implements Initializable {
+public class MainFXMLController {
     private static final Logger LOG = Logger.getLogger(MainFXMLController.class.getName());
-    private final AppLoader appLoader = new AppLoader(this);
+
+    @Inject
+    AppLoader appLoader;
+
     @FXML
     private Button home_button;
 
@@ -31,29 +35,26 @@ public class MainFXMLController implements Initializable {
     @FXML
     private Button plants_button;
 
-    public MainFXMLController() throws IOException {
-    }
-
     @FXML
-    void goToHome() throws IOException {
+    void goToHome() {
         showPaneAsMainView("Home.fxml");
         styleChangeButton(home_button);
     }
 
     @FXML
-    void goToMyPlants() throws IOException {
+    void goToMyPlants() {
         showPaneAsMainView("MyGarden.fxml");
         styleChangeButton(myGarden_button);
     }
 
     @FXML
-    void goToMySchedule() throws IOException {
+    void goToMySchedule() {
         showPaneAsMainView("MySchedule.fxml");
         styleChangeButton(mySchedule_button);
     }
 
     @FXML
-    void goToPlants() throws IOException {
+    void goToPlants() {
         showPaneAsMainView("Plants.fxml");
         styleChangeButton(plants_button);
     }
@@ -63,15 +64,22 @@ public class MainFXMLController implements Initializable {
      * set HGrow and VGrow to parent AnchorPane.
      * Sends MainController to other Controllers.
      * @param fxmlFile string of fxml file
-     * @throws IOException exception when file does not exist
      */
-    public void showPaneAsMainView(String fxmlFile) throws IOException {
+    public void showPaneAsMainView(String fxmlFile) {
+        try {
             Pane anchorPane = appLoader.loadPane(fxmlFile);
             mainPane.getChildren().setAll(anchorPane);
             anchorPane.prefWidthProperty().bind(mainPane.widthProperty());
             anchorPane.prefHeightProperty().bind(mainPane.heightProperty());
+
+            anchorPane.removeEventHandler(ChangeViewEvent.CHANGE_MAIN_VIEW, changeMainViewHandler);
+            anchorPane.addEventHandler(ChangeViewEvent.CHANGE_MAIN_VIEW, changeMainViewHandler);
+        } catch (IOException e) {
+            LOG.log(Level.SEVERE, "Could not load pane.", e);
+        }
     }
 
+    private final EventHandler<ChangeViewEvent> changeMainViewHandler = (ChangeViewEvent event) -> showPaneAsMainView(event.view());
 
     private void preloadPanes() throws IOException {
         appLoader.loadAndCacheFxml("MyGarden.fxml");
@@ -87,8 +95,9 @@ public class MainFXMLController implements Initializable {
      * loads the default FXML File
      * {@inheritDoc}
      */
-    @Override
-    public void initialize(URL url, ResourceBundle resourceBundle) {
+    @AfterInject
+    @SuppressWarnings("unused")
+    public void init() {
         try {
             preloadPanes();
             showPaneAsMainView("Home.fxml");

src/main/java/ch/zhaw/gartenverwaltung/MyGardenController.java

@@ -2,6 +2,7 @@ package ch.zhaw.gartenverwaltung;
 
 import ch.zhaw.gartenverwaltung.bootstrap.AfterInject;
 import ch.zhaw.gartenverwaltung.bootstrap.AppLoader;
+import ch.zhaw.gartenverwaltung.bootstrap.ChangeViewEvent;
 import ch.zhaw.gartenverwaltung.bootstrap.Inject;
 import ch.zhaw.gartenverwaltung.io.PlantList;
 import ch.zhaw.gartenverwaltung.models.Garden;
@@ -17,6 +18,7 @@ import javafx.scene.control.Button;
 import javafx.scene.control.ButtonType;
 import javafx.scene.control.Label;
 import javafx.scene.image.ImageView;
+import javafx.scene.layout.AnchorPane;
 import javafx.scene.layout.HBox;
 import javafx.scene.layout.Priority;
 import javafx.scene.layout.VBox;
@@ -30,16 +32,15 @@ import java.util.logging.Logger;
 
 public class MyGardenController {
     private static final Logger LOG = Logger.getLogger(MyGardenController.class.getName());
-
     @Inject
     AppLoader appLoader;
     @Inject
-    MainFXMLController mainController;
-    @Inject
     private Garden garden;
     @Inject
     private PlantList plantList;
 
+    @FXML
+    public AnchorPane myGardenRoot;
     @FXML
     private VBox myPlants_vbox;
 
@@ -61,8 +62,8 @@ public class MyGardenController {
     }
 
     @FXML
-    void addPlant(ActionEvent event) throws IOException {
-        mainController.showPaneAsMainView("Plants.fxml");
+    void addPlant() {
+        myGardenRoot.fireEvent(new ChangeViewEvent(ChangeViewEvent.CHANGE_MAIN_VIEW, "Plants.fxml"));
     }
 
     private void createPlantView(List<Crop> crops) throws HardinessZoneNotSetException, IOException {

src/main/java/ch/zhaw/gartenverwaltung/PlantsController.java

@@ -2,6 +2,7 @@ package ch.zhaw.gartenverwaltung;
 
 import ch.zhaw.gartenverwaltung.bootstrap.AfterInject;
 import ch.zhaw.gartenverwaltung.bootstrap.AppLoader;
+import ch.zhaw.gartenverwaltung.bootstrap.ChangeViewEvent;
 import ch.zhaw.gartenverwaltung.bootstrap.Inject;
 import ch.zhaw.gartenverwaltung.io.HardinessZoneNotSetException;
 import ch.zhaw.gartenverwaltung.models.PlantListModel;
@@ -16,6 +17,7 @@ import javafx.geometry.Insets;
 import javafx.scene.control.*;
 import javafx.scene.image.Image;
 import javafx.scene.image.ImageView;
+import javafx.scene.layout.AnchorPane;
 import javafx.scene.layout.VBox;
 import javafx.stage.Modality;
 import javafx.stage.Stage;
@@ -39,6 +41,9 @@ public class PlantsController {
     // TODO: move to model
     private final ListProperty<Plant> plantListProperty = new SimpleListProperty<>(FXCollections.observableArrayList());
 
+    @FXML
+    public AnchorPane plantsRoot;
+
     @FXML
     private VBox seasons;
 
@@ -73,6 +78,8 @@ public class PlantsController {
         stage.initModality(Modality.APPLICATION_MODAL);
         stage.setResizable(false);
         stage.showAndWait();
+        // TODO: change to dialog
+        plantsRoot.fireEvent(new ChangeViewEvent(ChangeViewEvent.CHANGE_MAIN_VIEW, "MyGarden.fxml"));
     }
 
     /**

src/main/java/ch/zhaw/gartenverwaltung/bootstrap/AfterInject.java

@@ -5,6 +5,10 @@ import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
+/**
+ * Annotates a method to be executed after all dependencies annotates with {@link Inject}
+ * have been injected.
+ */
 @Retention(RetentionPolicy.RUNTIME)
 @Target(ElementType.METHOD)
 public @interface AfterInject { }

src/main/java/ch/zhaw/gartenverwaltung/bootstrap/AppLoader.java

@@ -1,7 +1,6 @@
 package ch.zhaw.gartenverwaltung.bootstrap;
 
 import ch.zhaw.gartenverwaltung.HelloApplication;
-import ch.zhaw.gartenverwaltung.MainFXMLController;
 import ch.zhaw.gartenverwaltung.io.CropList;
 import ch.zhaw.gartenverwaltung.io.JsonCropList;
 import ch.zhaw.gartenverwaltung.io.JsonPlantList;
@@ -13,7 +12,6 @@ import ch.zhaw.gartenverwaltung.models.GardenSchedule;
 import ch.zhaw.gartenverwaltung.models.PlantListModel;
 import javafx.fxml.FXMLLoader;
 import javafx.scene.Scene;
-import javafx.scene.layout.AnchorPane;
 import javafx.scene.layout.Pane;
 import javafx.stage.Stage;
 
@@ -39,14 +37,19 @@ public class AppLoader {
 
     private final GardenSchedule gardenSchedule = new GardenSchedule(taskList, plantList);
     private final Garden garden = new Garden(gardenSchedule, cropList);
-    private final MainFXMLController mainController;
 
 
-    public AppLoader(MainFXMLController mainController) throws IOException {
-        this.mainController = mainController;
+    public AppLoader() throws IOException {
     }
 
 
+    /**
+     * Loads and returns a {@link Pane} (cached).
+     *
+     * @param fxmlFile The file name to be loaded
+     * @return The loaded Pane
+     * @throws IOException if the file could not be loaded
+     */
     public Pane loadPane(String fxmlFile) throws IOException {
         Pane pane = panes.get(fxmlFile);
         if (pane == null) {
@@ -56,6 +59,16 @@ public class AppLoader {
         return pane;
     }
 
+    /**
+     * Loads the given fxml-file from resources (no caching) and creates a new {@link Scene},
+     * which is then appended to the given {@link Stage}.
+     * Performs dependency-injection.
+     *
+     * @param fxmlFile The file name to be loaded
+     * @param appendee The {@link Stage} to which the new {@link Scene} is appended.
+     * @return The controller of the loaded scene.
+     * @throws IOException if the file could not be loaded
+     */
     public Object loadSceneToStage(String fxmlFile, Stage appendee) throws IOException {
         FXMLLoader loader = new FXMLLoader(Objects.requireNonNull(HelloApplication.class.getResource(fxmlFile)));
         Pane root = loader.load();
@@ -65,13 +78,27 @@ public class AppLoader {
         return controller;
     }
 
+    /**
+     * Loads the given fxml-file from resources and caches the pane.
+     * Performs dependency-injection.
+     *
+     * @param fxmlFile The file name to be loaded
+     * @throws IOException if the file could not be loaded
+     */
     public void loadAndCacheFxml(String fxmlFile) throws IOException {
         FXMLLoader loader = new FXMLLoader(Objects.requireNonNull(HelloApplication.class.getResource(fxmlFile)));
-        AnchorPane anchorPane = loader.load();
-        panes.put(fxmlFile, anchorPane);
+        Pane pane = loader.load();
+        panes.put(fxmlFile, pane);
         annotationInject(loader.getController());
     }
 
+    /**
+     * Injects the applications dependencies into the given object's fields annotated with {@link Inject}.
+     * Afterwards, all methods on the objects annotated with {@link AfterInject} are executed.
+     * (Success of the injections is not guaranteed!)
+     *
+     * @param controller The class containing the injectable fields
+     */
     public void annotationInject(Object controller) {
         Arrays.stream(controller.getClass().getDeclaredFields())
                 .filter(field -> field.isAnnotationPresent(Inject.class))
@@ -104,7 +131,6 @@ public class AppLoader {
             case "PlantList" -> plantList;
             case "PlantListModel" -> new PlantListModel(plantList);
             case "GardenSchedule" -> gardenSchedule;
-            case "MainFXMLController" -> mainController;
             case "AppLoader" -> this;
             default -> null;
         };

src/main/java/ch/zhaw/gartenverwaltung/bootstrap/ChangeViewEvent.java

@@ -0,0 +1,19 @@
+package ch.zhaw.gartenverwaltung.bootstrap;
+
+import javafx.event.Event;
+import javafx.event.EventType;
+
+public class ChangeViewEvent extends Event {
+    private final String view;
+
+    public static final EventType<ChangeViewEvent> CHANGE_MAIN_VIEW = new EventType<>("CHANGE_MAIN_VIEW");
+
+    public ChangeViewEvent(EventType<? extends Event> eventType, String view) {
+        super(eventType);
+        this.view = view;
+    }
+
+    public String view() {
+        return view;
+    }
+}

src/main/java/ch/zhaw/gartenverwaltung/bootstrap/Inject.java

@@ -5,6 +5,9 @@ import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
+/**
+ * Annotates a Field to be injected from the application-dependencies
+ */
 @Retention(RetentionPolicy.RUNTIME)
 @Target(ElementType.FIELD)
 public @interface Inject { }

src/main/resources/ch/zhaw/gartenverwaltung/MyGarden.fxml

@@ -7,7 +7,7 @@
 <?import javafx.scene.layout.VBox?>
 <?import javafx.scene.text.Font?>
 
-<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="655.0" prefWidth="1175.0" xmlns="http://javafx.com/javafx/17" xmlns:fx="http://javafx.com/fxml/1" fx:controller="ch.zhaw.gartenverwaltung.MyGardenController">
+<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="655.0" prefWidth="1175.0" xmlns="http://javafx.com/javafx/17" xmlns:fx="http://javafx.com/fxml/1" fx:controller="ch.zhaw.gartenverwaltung.MyGardenController" fx:id="myGardenRoot">
    <children>
       <VBox layoutY="49.0" prefHeight="655.0" prefWidth="1175.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
          <children>

src/main/resources/ch/zhaw/gartenverwaltung/Plants.fxml

@@ -15,7 +15,8 @@
 
 <AnchorPane maxHeight="-Infinity" maxWidth="1.7976931348623157E308" minHeight="-Infinity" minWidth="1000.0" prefHeight="853.0"
             prefWidth="1219.0" xmlns="http://javafx.com/javafx/17" xmlns:fx="http://javafx.com/fxml/1"
-            fx:controller="ch.zhaw.gartenverwaltung.PlantsController">
+            fx:controller="ch.zhaw.gartenverwaltung.PlantsController"
+            fx:id="plantsRoot">
    <children>
       <SplitPane dividerPositions="0.7377363661277062" layoutX="539.0" layoutY="266.0" prefHeight="853.0" prefWidth="1219.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
         <items>