🏗️✨ Implement VM and make Stub

resources/fxml/MainWindow.fxml

@@ -2,14 +2,19 @@
 
 <?import javafx.scene.control.*?>
 <?import javafx.scene.layout.*?>
+<?import java.lang.Integer?>
 <BorderPane xmlns="http://javafx.com/javafx" xmlns:fx="http://javafx.com/fxml">
+    <fx:define>
+        <Integer fx:id="minus1" fx:value="-1"/>
+    </fx:define>
     <center>
         <ListView fx:id="promLV"/>
     </center>
     <bottom>
         <HBox>
             <Button text="add student" onAction="#clickAddStudent"/>
-            <Button text="remove student" onAction="#clickRemoveStudent"/>
+            <Button text="remove student" onAction="#clickRemoveStudent"
+                    disable="${promLV.selectionModel.selectedIndex == minus1}"/>
             <Button text="QUIT" onAction="#clickQuit"/>
         </HBox>
     </bottom>

src/data/Stub.java

@@ -1,6 +1,7 @@
 package data;
 
 import viewmodel.PromotionVM;
+import viewmodel.StudentVM;
 
 public class Stub implements Loadable {
 
@@ -8,7 +9,10 @@ public class Stub implements Loadable {
     public PromotionVM load(){
         PromotionVM VM = new PromotionVM();
 
-        //... add studentVMs
+        VM.addStudentVM(new StudentVM("ONE", "Alan"));
+        VM.addStudentVM(new StudentVM("TWO", "Allan"));
+        VM.addStudentVM(new StudentVM("THREE", "Alllan"));
+        VM.addStudentVM(new StudentVM("FOUR", "Allllan"));
 
         return VM;
     }

src/model/Promotion.java

@@ -1,14 +1,62 @@
 package model;
 
+import java.beans.PropertyChangeListener;
+import java.beans.PropertyChangeSupport;
 import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 
 public class Promotion implements Serializable {
+    public static final String PROP_PROMOTION_ADD_STUDENT = "model.Promotion.addStudent";
+    public static final String PROP_PROMOTION_RMV_STUDENT = "model.Promotion.removeStudent";
+
     private final List<Student> students = new ArrayList<>();
 
     public List<Student> getStudents() {
         return Collections.unmodifiableList(students);
     }
+
+    public void addStudent(Student toAdd) {
+        if (toAdd != null) {
+            int i = 0;
+
+            students.add(i, toAdd);
+            // fire
+            getSupport().fireIndexedPropertyChange(
+                    PROP_PROMOTION_ADD_STUDENT,
+                    i,
+                    students.size() > i + 1 ? students.get(i + 1) : null,
+                    toAdd
+            );
+        }
+    }
+
+    public void removeStudent(Student toRemove) {
+        if (toRemove != null) {
+            int i = students.indexOf(toRemove);
+
+            students.remove(i);
+            // fire
+            getSupport().fireIndexedPropertyChange(
+                    PROP_PROMOTION_RMV_STUDENT,
+                    i,
+                    toRemove,
+                    students.size() > i ? students.get(i) : null
+            );
+        }
+    }
+
+    PropertyChangeSupport support = null;
+
+    public PropertyChangeSupport getSupport() {
+        if (support == null) {
+            support = new PropertyChangeSupport(this);
+        }
+        return support;
+    }
+
+    public void addListener(PropertyChangeListener listener) {
+        getSupport().addPropertyChangeListener(listener);
+    }
 }

src/model/Student.java

@@ -1,31 +1,59 @@
 package model;
 
+import java.beans.PropertyChangeListener;
+import java.beans.PropertyChangeSupport;
 import java.io.Serializable;
 
 public class Student implements Serializable {
 
+    public static final String PROP_STUDENT_LASTNAME = "model.Student.lastname";
+    public static final String PROP_STUDENT_FIRSTNAME = "model.Student.firstname";
+
     private String lastname;
 
-    private String firstName;
+    private String firstname;
 
     public Student(String lastname, String firstName) {
         this.lastname = !lastname.isEmpty() ? lastname : "DOE";
-        this.firstName = !firstName.isEmpty() ? firstName : "John";
+        this.firstname = !firstName.isEmpty() ? firstName : "John";
     }
 
     public String getLastname() {
         return lastname;
     }
 
-    public String getFirstName() {
-        return firstName;
-    }
-
-    public void setFirstName(String firstName) {
-        this.firstName = firstName;
+    public String getFirstname() {
+        return firstname;
     }
 
     public void setLastname(String lastname) {
+        if(lastname != null) {
+            String oldV = getLastname();
             this.lastname = lastname;
+            // fire
+            getSupport().firePropertyChange(PROP_STUDENT_LASTNAME, oldV, getLastname());
+        }
+    }
+
+    public void setFirstname(String firstname) {
+        if(firstname != null) {
+            String oldV = getFirstname();
+            this.firstname = firstname;
+            // fire
+            getSupport().firePropertyChange(PROP_STUDENT_FIRSTNAME, oldV, getFirstname());
+        }
+    }
+
+    private PropertyChangeSupport support = null;
+
+    public PropertyChangeSupport getSupport() {
+        if (support == null) {
+            support = new PropertyChangeSupport(this);
+        }
+        return support;
+    }
+
+    public void addListener(PropertyChangeListener listener) {
+        getSupport().addPropertyChangeListener(listener);
     }
 }

src/view/MainWindow.java

@@ -16,12 +16,12 @@ public class MainWindow {
 
     @FXML
     private void clickAddStudent() {
-        VM.addStudent();
+        VM.addStudentVM();
     }
 
     @FXML
     private void clickRemoveStudent() {
-        VM.removeStudent(promLV.getSelectionModel().getSelectedItem());
+        VM.removeStudentVM(promLV.getSelectionModel().getSelectedItem());
     }
 
     @FXML
@@ -37,6 +37,21 @@ public class MainWindow {
 
     @FXML
     private void initialize() {
+        promLV.itemsProperty().bind(VM.studentsVMProperty());
+        initPromLV();
+        promLV.setCellFactory(__ -> new StudentVMCell());
+    }
 
+    private void initPromLV() {
+        promLV.getSelectionModel().selectedItemProperty().addListener((__, oldV, newV) -> {
+            if (oldV != null) {
+                lastnameTF.textProperty().unbindBidirectional(oldV.lastnameProperty());
+                firstnameTF.textProperty().unbindBidirectional(oldV.firstnameProperty());
+            }
+            if (newV != null) {
+                lastnameTF.textProperty().bindBidirectional(newV.lastnameProperty());
+                firstnameTF.textProperty().bindBidirectional(newV.firstnameProperty());
+            }
+        });
     }
 }

src/view/StudentVMCell.java

@@ -0,0 +1,29 @@
+package view;
+
+import javafx.scene.control.Label;
+import javafx.scene.control.ListCell;
+import javafx.scene.layout.BorderPane;
+import viewmodel.StudentVM;
+
+public class StudentVMCell extends ListCell<StudentVM> {
+    @Override
+    protected void updateItem(StudentVM item, boolean empty) {
+        super.updateItem(item, empty);
+        if (!empty) {
+
+            Label lastnameLbl = new Label();
+            Label firstnameLbl = new Label();
+            lastnameLbl.textProperty().bind(item.lastnameProperty());
+            firstnameLbl.textProperty().bind(item.firstnameProperty());
+
+            BorderPane pane = new BorderPane();
+            pane.setLeft(lastnameLbl);
+            pane.setCenter(firstnameLbl);
+
+            setGraphic(pane);
+        }
+        else {
+            setGraphic(null);
+        }
+    }
+}

src/viewmodel/PromotionVM.java

@@ -1,28 +1,70 @@
 package viewmodel;
 
+import javafx.beans.property.ListProperty;
+import javafx.beans.property.ReadOnlyListProperty;
+import javafx.beans.property.SimpleListProperty;
+import javafx.collections.FXCollections;
+import javafx.collections.ObservableList;
 import model.Promotion;
 
-public class PromotionVM {
+import java.beans.IndexedPropertyChangeEvent;
+import java.beans.PropertyChangeEvent;
+import java.beans.PropertyChangeListener;
 
-    private Promotion model;
+public class PromotionVM implements PropertyChangeListener {
+
+    private final Promotion model;
+
+    public Promotion getModel() {
+        return model;
+    }
 
     public PromotionVM(Object o) {
+        Promotion model;
+        if (o instanceof Promotion) {
+            model = (Promotion) o;
+        }
+        else {
+            model = new Promotion();
+        }
+        this.model = model;
+
+        // load
+        model.getStudents().forEach(s -> studentsVMObs.add(new StudentVM(s)));
 
+        // subscribe
+        model.addListener(this);
+
+        // promise to update
+        // ... in methods
     }
 
     public PromotionVM() {
-
+        this(null);
     }
 
-    public Promotion getModel() {
-        return model;
+    public void addStudentVM(StudentVM toAdd) {
+        model.addStudent(toAdd.getModel());
     }
 
-    public void addStudent(StudentVM toAdd) {
+    public void addStudentVM() {addStudentVM(new StudentVM());}
+
+    public void removeStudentVM(StudentVM toRemove) {
+        model.removeStudent(toRemove.getModel());
     }
 
-    public void addStudent() { addStudent(new StudentVM()); }
+    private final ObservableList<StudentVM> studentsVMObs = FXCollections.observableArrayList();
+    private final ListProperty<StudentVM> studentsVM = new SimpleListProperty<>(studentsVMObs);
+    public ObservableList<StudentVM> getStudentsVM() {return FXCollections.unmodifiableObservableList(studentsVM.get());}
+    public ReadOnlyListProperty<StudentVM> studentsVMProperty() {return studentsVM;}
 
-    public void removeStudent(StudentVM toRemove) {
+    @Override
+    public void propertyChange(PropertyChangeEvent evt) {
+        if (evt.getPropertyName().equals(Promotion.PROP_PROMOTION_ADD_STUDENT)) {
+            studentsVMObs.add(((IndexedPropertyChangeEvent) evt).getIndex(), new StudentVM(evt.getNewValue()));
+        }
+        if (evt.getPropertyName().equals(Promotion.PROP_PROMOTION_RMV_STUDENT)) {
+            studentsVMObs.remove(((IndexedPropertyChangeEvent) evt).getIndex());
+        }
     }
 }

src/viewmodel/StudentVM.java

@@ -1,4 +1,76 @@
 package viewmodel;
 
-public class StudentVM {
+import javafx.beans.property.SimpleStringProperty;
+import javafx.beans.property.StringProperty;
+import model.Student;
+
+import java.beans.PropertyChangeEvent;
+import java.beans.PropertyChangeListener;
+
+public class StudentVM implements PropertyChangeListener {
+    private final Student model;
+
+    public Student getModel() {
+        return model;
+    }
+
+    private final StringProperty lastname = new SimpleStringProperty();
+    public String getLastname() {return lastname.get();}
+    public StringProperty lastnameProperty() {return lastname;}
+    public void setLastname(String lastname) {this.lastname.set(lastname);}
+
+    private final StringProperty firstname = new SimpleStringProperty();
+    public String getFirstname() {return firstname.get();}
+    public StringProperty firstnameProperty() {return firstname;}
+    public void setFirstname(String firstname) {this.firstname.set(firstname);}
+
+    public StudentVM(Object o) {
+        Student model;
+        if (o instanceof Student) {
+            model = (Student) o;
+        }
+        else {
+            model = new Student("", "");
+        }
+
+        this.model = model;
+
+        // load into self
+        setFirstname(model.getFirstname());
+        setLastname(model.getLastname());
+
+        // subscribe
+        model.addListener(this);
+
+        // promise to update
+        firstnameProperty().addListener((__, ___, newV) -> model.setFirstname(newV));
+        lastnameProperty().addListener((__, ___, newV) -> model.setLastname(newV));
+    }
+
+    public StudentVM(String lastname, String firstname) {
+        this(new Student(lastname, firstname));
+    }
+
+    public StudentVM(Student model) {
+        this((Object) model);
+    }
+
+    public StudentVM() {
+        this(null);
+    }
+
+    @Override
+    public void propertyChange(PropertyChangeEvent evt) {
+        if (evt.getPropertyName().equals(Student.PROP_STUDENT_LASTNAME)) {
+            setLastname(isNotEmptyOrToDashes((String) evt.getNewValue()));
+        }
+        if (evt.getPropertyName().equals(Student.PROP_STUDENT_FIRSTNAME)) {
+            setFirstname(isNotEmptyOrToDashes((String) evt.getNewValue()));
+        }
+    }
+
+    private String isNotEmptyOrToDashes(String stringEvt) {
+        return stringEvt.isEmpty() ? "---" : stringEvt;
+    }
+
 }