Make nullable paths explicitly nullable

src/main/java/app/controllers/EditorController.java

@@ -146,8 +146,7 @@ public class EditorController implements Initializable, Controller {
    * 
    * @param filePath The path of the file
    */
-  public void setEditorContent(Path filePath) {
-      String newContent = FileOperations.readFile(filePath);
+  public void setEditorContent(String newContent) {
       editor.clear();
       editor.appendText(newContent);
   }
@@ -182,7 +181,12 @@ public class EditorController implements Initializable, Controller {
    */
   @Subscribe
   public void handle(FileSelectedEvent event) {
-      this.setEditorContent(event.getPath());
+    String newContent =
+      event
+        .getPath()
+        .map(path -> FileOperations.readFile(path))
+        .orElse("");
+    this.setEditorContent(newContent);
   }
 
   /**

src/main/java/app/controllers/FiletreeController.java

@@ -10,6 +10,7 @@ import java.io.File;
 import java.net.URL;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.Optional;
 import java.util.ResourceBundle;
 
 import com.google.common.eventbus.EventBus;
@@ -75,9 +76,7 @@ public class FiletreeController implements Initializable, Controller {
       Path path = FiletreeOperations.getPathOfTreeItem(item);
 
       if (!Files.isDirectory(path)) {
-        // TODO: Add setActiveFilePath Model modification into FileSelectedEvent
-        Model.setActiveFilePath(path);
-        this.eventBus.post(new FileSelectedEvent(path));
+        this.eventBus.post(new FileSelectedEvent(Optional.ofNullable(path)));
       }
     }
   }

src/main/java/app/controllers/MenubarController.java

@@ -3,6 +3,7 @@ package app.controllers;
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.net.URL;
+import java.util.Optional;
 import java.util.ResourceBundle;
 
 import com.google.common.eventbus.EventBus;
@@ -33,6 +34,7 @@ import javafx.scene.control.MenuBar;
 import javafx.scene.control.RadioMenuItem;
 import javafx.scene.control.ToggleGroup;
 import javafx.stage.Stage;
+import java.util.Optional;
 
 /**
  * A FXML controller that controls the menubar component of the UI
@@ -65,9 +67,7 @@ public class MenubarController implements Initializable, Controller {
   /* ------------------------------------------------------------------------ */
   @FXML
   private void handleNewFile() {
-    // TODO: Move Model modification inside event
-    Model.setActiveFilePath(null);
-    this.eventBus.post(new FileSelectedEvent(null));
+    this.eventBus.post(new FileSelectedEvent(Optional.empty()));
   }
 
   @FXML
@@ -89,9 +89,7 @@ public class MenubarController implements Initializable, Controller {
     try {
       File file = FileOperations.openFileWithDialog(stage);
 
-      // TODO: Move Model modification inside event
-      Model.setActiveFilePath(file.toPath());
-      this.eventBus.post(new FileSelectedEvent(file.toPath()));
+      this.eventBus.post(new FileSelectedEvent(Optional.ofNullable(file.toPath())));
     } catch (FileNotFoundException e) {
       DialogBoxes.showErrorMessage("File not found!");
     }
@@ -108,7 +106,6 @@ public class MenubarController implements Initializable, Controller {
       File dir = FileOperations.openFolderWithDialog(stage);
 
       // TODO: Move Model modification inside event
-      Model.setProjectPath(dir.toPath());
       this.eventBus.post(new OpenProjectEvent(dir.toPath()));
     } catch (FileNotFoundException e) {
       DialogBoxes.showErrorMessage("Folder not found!");

src/main/java/app/events/FileSelectedEvent.java

@@ -2,6 +2,10 @@ package app.events;
 
 import java.nio.file.Path;
 
+import java.util.Optional;
+
+import app.model.Model;
+
 /**
  * Event signalizing that a file was selected in the filetree.
  * 
@@ -9,7 +13,7 @@ import java.nio.file.Path;
  */
 public class FileSelectedEvent extends Event {
 
-  private Path path;
+  private Optional<Path> path;
 
   /**
    * Event signalizing that a file was selected in the filetree.
@@ -17,14 +21,15 @@ public class FileSelectedEvent extends Event {
    * Not to be confused with {@link OpenFileEvent}
    * @param path The path of the selected file
    */
-  public FileSelectedEvent(Path path) {
+  public FileSelectedEvent(Optional<Path> path) {
     this.path = path;
+    Model.setActiveFilePath(path);
   }
 
   /**
    * @return The path of the selected file
    */
-  public Path getPath() {
+  public Optional<Path> getPath() {
     return this.path;
   }
 

src/main/java/app/events/OpenFileEvent.java

@@ -1,6 +1,9 @@
 package app.events;
 
 import java.nio.file.Path;
+import java.util.Optional;
+
+import app.model.Model;
 
 /**
  * Event signalizing that a file outside the current project is supposed to be opened in the editor.
@@ -9,21 +12,22 @@ import java.nio.file.Path;
  */
 public class OpenFileEvent extends Event {
 
-    private Path path;
+  private Optional<Path> path;
 
-    /**
-     * Event signalizing that a file outside the current project is supposed to be opened in the editor.
-     * @param path The path of the file to be opened
-     */
-    public OpenFileEvent(Path path) {
-        this.path = path;
-    }
+  /**
+   * Event signalizing that a file outside the current project is supposed to be opened in the editor.
+   * @param path The path of the file to be opened
+   */
+  public OpenFileEvent(Optional<Path> path) {
+    this.path = path;
+    Model.setActiveFilePath(path);
+  }
 
-    /**
-     * @return The path of the file to be opened
-     */
-    public Path getPath() {
-        return this.path;
-    }
+  /**
+   * @return The path of the file to be opened
+   */
+  public Optional<Path> getPath() {
+    return this.path;
+  }
 
 }

src/main/java/app/events/OpenProjectEvent.java

@@ -1,6 +1,9 @@
 package app.events;
 
 import java.nio.file.Path;
+import java.util.Optional;
+
+import app.model.Model;
 
 /**
  * Event signalizing that a folder is supposed to be opened in the filetree.
@@ -15,6 +18,7 @@ public class OpenProjectEvent extends Event {
      */
     public OpenProjectEvent(Path path) {
         this.path = path;
+        Model.setProjectPath(Optional.of(path));
     }
 
     /**

src/main/java/app/model/Model.java

@@ -1,6 +1,7 @@
 package app.model;
 
 import java.nio.file.Path;
+import java.util.Optional;
 
 import app.settings.SettingsProvider;
 import javafx.scene.Scene;
@@ -13,26 +14,26 @@ import javafx.scene.Scene;
  */
 public class Model {
   private static boolean fileIsSaved;
-  private static Path activeFilePath;
-  private static Path currentProjectPath;
+  private static Optional<Path> activeFilePath;
+  private static Optional<Path> currentProjectPath;
   private static ProgrammingLanguage currentProgrammingLanguage;
   private static String theme;
   private static Scene scene;
   private static SettingsProvider settings;
 
-  public static Path getActiveFilePath() {
+  public static Optional<Path> getActiveFilePath() {
     return activeFilePath;
   }
 
-  public static void setActiveFilePath(Path path) {
+  public static void setActiveFilePath(Optional<Path> path) {
     Model.activeFilePath = path;
   }
 
-  public static Path getProjectPath() {
+  public static Optional<Path> getProjectPath() {
     return currentProjectPath;
   }
 
-  public static void setProjectPath(Path path) {
+  public static void setProjectPath(Optional<Path> path) {
     Model.currentProjectPath = path;
   }
 

src/main/java/app/service/FileOperations.java

@@ -4,6 +4,7 @@ import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.PrintWriter;
 import java.nio.file.Path;
+import java.util.Optional;
 import java.util.Scanner;
 
 import app.model.Model;
@@ -64,8 +65,7 @@ public class FileOperations {
     FileChooser fc = new FileChooser();
     fc.setTitle("Save as");
 
-    if (Model.getProjectPath() != null)
-      fc.setInitialDirectory(Model.getProjectPath().toFile());
+    Model.getProjectPath().ifPresent(path -> fc.setInitialDirectory(path.toFile()));
 
     FileChooser.ExtensionFilter extJava = new FileChooser.ExtensionFilter("Java", "*.java");
     FileChooser.ExtensionFilter extMd = new FileChooser.ExtensionFilter("Markdown", "*.md");
@@ -77,7 +77,7 @@ public class FileOperations {
       return false;
 
     if (saveFile(chosenLocation.getAbsolutePath(), content)) {
-      Model.setActiveFilePath(chosenLocation.toPath());
+      Model.setActiveFilePath(Optional.of(chosenLocation.toPath()));
       return true;
     }
 

src/main/java/app/service/FiletreeOperations.java

@@ -130,7 +130,7 @@ public class FiletreeOperations {
   }
 
   public static Path getPathOfTreeItem(TreeItem<String> item) {
-      String root = Model.getProjectPath().getFileName().toString();
+      String root = Model.getProjectPath().orElseThrow().getFileName().toString();
       String path = "";
       while (!root.equals(item.getValue())) {
         path = File.separator + item.getValue() + path;