Add methods to update UniqueStudentInfoList

src/main/java/seedu/address/logic/Logic.java

@@ -12,6 +12,7 @@
 import seedu.address.model.group.Group;
 import seedu.address.model.group.Lesson;
 import seedu.address.model.group.Student;
+import seedu.address.model.group.StudentInfo;
 import seedu.address.model.person.Person;
 
 /**
@@ -69,15 +70,20 @@ public interface Logic {
     ObservableList<Group> getFilteredGroupList();
 
     /**
-     * Returns an unmodifiable view of the filtered list of Students from a group.
+     * Returns an unmodifiable view of the filtered list of students from a group.
      */
     ObservableList<Student> getStudentList();
 
     /**
-     * Returns an unmodifiable view of the list of lesson from a group.
+     * Returns an unmodifiable view of the filtered list of lesson from a group.
      */
     ObservableList<Lesson> getLessonList();
 
+    /**
+     * Returns an unmodifiable view of the filtered list of students info from a group-lesson.
+     */
+    ObservableList<StudentInfo> getFilteredStudentInfoList();
+
     /**
      * Returns the user prefs' serenity file path.
      */

src/main/java/seedu/address/logic/LogicManager.java

@@ -18,6 +18,7 @@
 import seedu.address.model.group.Group;
 import seedu.address.model.group.Lesson;
 import seedu.address.model.group.Student;
+import seedu.address.model.group.StudentInfo;
 import seedu.address.model.person.Person;
 import seedu.address.storage.Storage;
 
@@ -85,6 +86,8 @@ public void setGuiSettings(GuiSettings guiSettings) {
         model.setGuiSettings(guiSettings);
     }
 
+    // ========== Serenity ==========
+
     @Override
     public ReadOnlySerenity getSerenity() {
         return model.getSerenity();
@@ -105,6 +108,11 @@ public ObservableList<Lesson> getLessonList() {
         return model.getLessonList();
     }
 
+    @Override
+    public ObservableList<StudentInfo> getFilteredStudentInfoList() {
+        return model.getStudentInfoList();
+    }
+
     @Override
     public Path getSerenityFilePath() {
         return model.getSerenityFilePath();

src/main/java/seedu/address/logic/commands/ViewLsnCommand.java

@@ -36,13 +36,13 @@ private String getMessage(Model model) {
                 ? Messages.MESSAGE_LESSON_EMPTY
                 : String.format(Messages.MESSAGE_LESSON_LISTED_OVERVIEW,
                 model.getFilteredGroupList().get(0).getName(),
-                model.getLessonList());
+                model.getFilteredLessonList().get(0).getName());
     }
 
     @Override
     public CommandResult execute(Model model) {
         requireNonNull(model);
-        model.updateFilteredGroupList(grpPredicate);
+        model.updateFilteredLessonList(lsnPredicate);
         return new CommandResult(this.getMessage(model));
     }
 

src/main/java/seedu/address/model/Model.java

@@ -8,6 +8,7 @@
 import seedu.address.model.group.Group;
 import seedu.address.model.group.Lesson;
 import seedu.address.model.group.Student;
+import seedu.address.model.group.StudentInfo;
 import seedu.address.model.person.Person;
 
 /**
@@ -95,6 +96,8 @@ public interface Model {
      */
     void updateFilteredPersonList(Predicate<Person> predicate);
 
+    // ========== Serenity ==========
+
     /**
      * Returns the user prefs' serenity file path.
      */
@@ -137,18 +140,46 @@ public interface Model {
      */
     void updateStudentList();
 
-
     /**
      * Updates the lesson list to filter when changing to another group of interest.
      */
-    public void updateLessonList();
+    void updateLessonList();
+
+    /**
+     * Updates the filter of the filtered group list to filter by the given {@code predicate}.
+     *
+     * @throws NullPointerException if {@code predicate} is null.
+     */
+    void updateFilteredLessonList(Predicate<Lesson> predicate);
+
+    /**
+     * Updates the student info list to filter when changing to another lesson of interest.
+     */
+    void updateStudentInfoList();
 
     /**
-     * Returns an unmodifiable view of the filtered group list
+     * Returns an unmodifiable view of the filtered group list.
      */
     ObservableList<Group> getFilteredGroupList();
 
+    /**
+     * Returns an unmodifiable view of the student list.
+     */
     ObservableList<Student> getStudentList();
 
+    /**
+     * Returns an unmodifiable view of the lesson list.
+     */
     ObservableList<Lesson> getLessonList();
+
+    /**
+     * Returns an unmodifiable view of the filtered lesson list.
+     */
+    ObservableList<Lesson> getFilteredLessonList();
+
+    /**
+     * Returns an unmodifiable view of the student info list
+     */
+    ObservableList<StudentInfo> getStudentInfoList();
+
 }

src/main/java/seedu/address/model/ModelManager.java

@@ -11,11 +11,7 @@
 import javafx.collections.transformation.FilteredList;
 import seedu.address.commons.core.GuiSettings;
 import seedu.address.commons.core.LogsCenter;
-import seedu.address.model.group.Group;
-import seedu.address.model.group.Lesson;
-import seedu.address.model.group.Student;
-import seedu.address.model.group.UniqueLessonList;
-import seedu.address.model.group.UniqueStudentList;
+import seedu.address.model.group.*;
 import seedu.address.model.person.Person;
 
 /**
@@ -26,13 +22,15 @@ public class ModelManager implements Model {
     private static final Logger logger = LogsCenter.getLogger(ModelManager.class);
 
     private final AddressBook addressBook;
-    private final Serenity serenity;
     private final UserPrefs userPrefs;
-
     private final FilteredList<Person> filteredPersons;
+
+    private final Serenity serenity;
     private final FilteredList<Group> filteredGroups;
     private final ArrayObservableList<Student> students;
     private final ArrayObservableList<Lesson> lessons;
+    private final FilteredList<Lesson> filteredLessons;
+    private final ArrayObservableList<StudentInfo> studentsInfo;
 
     /**
      * Initializes a ModelManager with the given addressBook, userPrefs and serenity.
@@ -47,13 +45,15 @@ public ModelManager(ReadOnlyAddressBook addressBook, ReadOnlyUserPrefs userPrefs
                 + " and serenity " + serenity);
 
         this.addressBook = new AddressBook(addressBook);
-        this.serenity = new Serenity(serenity);
         this.userPrefs = new UserPrefs(userPrefs);
 
+        this.serenity = new Serenity(serenity);
         filteredPersons = new FilteredList<>(this.addressBook.getPersonList());
         filteredGroups = new FilteredList<>(this.serenity.getGroupList());
         students = new ArrayObservableList<>(new UniqueStudentList().asUnmodifiableObservableList());
-        lessons = new ArrayObservableList<>(new UniqueLessonList().asUnmodifiableObservableList());
+        lessons =  new ArrayObservableList<>(new UniqueLessonList().asUnmodifiableObservableList());
+        filteredLessons = new FilteredList<>(new UniqueLessonList().asUnmodifiableObservableList());
+        studentsInfo = new ArrayObservableList<>(new UniqueStudentInfoList().asUnmodifiableObservableList());
     }
 
     /**
@@ -66,20 +66,22 @@ public ModelManager(ReadOnlyAddressBook addressBook, ReadOnlyUserPrefs userPrefs
         logger.fine("Initializing with address book: " + addressBook + " and user prefs " + userPrefs);
 
         this.addressBook = new AddressBook(addressBook);
-        this.serenity = new Serenity();
         this.userPrefs = new UserPrefs(userPrefs);
 
+        this.serenity = new Serenity();
         filteredPersons = new FilteredList<>(this.addressBook.getPersonList());
         filteredGroups = new FilteredList<>(this.serenity.getGroupList());
         students = new ArrayObservableList<>(new UniqueStudentList().asUnmodifiableObservableList());
-        lessons = new ArrayObservableList<>(new UniqueLessonList().asUnmodifiableObservableList());
+        lessons =  new ArrayObservableList<>(new UniqueLessonList().asUnmodifiableObservableList());
+        filteredLessons = new FilteredList<>(new UniqueLessonList().asUnmodifiableObservableList());
+        studentsInfo = new ArrayObservableList<>(new UniqueStudentInfoList().asUnmodifiableObservableList());
     }
 
     public ModelManager() {
         this(new AddressBook(), new UserPrefs(), new Serenity());
     }
 
-    //=========== UserPrefs ==================================================================================
+    // =========== UserPrefs ==================================================================================
 
     @Override
     public void setUserPrefs(ReadOnlyUserPrefs userPrefs) {
@@ -103,7 +105,7 @@ public void setGuiSettings(GuiSettings guiSettings) {
         userPrefs.setGuiSettings(guiSettings);
     }
 
-    //=========== AddressBook ================================================================================
+    // =========== AddressBook ================================================================================
 
     @Override
     public Path getAddressBookFilePath() {
@@ -149,7 +151,7 @@ public void setPerson(Person target, Person editedPerson) {
         addressBook.setPerson(target, editedPerson);
     }
 
-    //=========== Serenity ================================================================================
+    // =========== Serenity ================================================================================
 
     @Override
     public Path getSerenityFilePath() {
@@ -206,6 +208,20 @@ public void updateLessonList() {
         }
     }
 
+    @Override
+    public void updateFilteredLessonList(Predicate<Lesson> predicate) {
+        requireAllNonNull(predicate);
+        this.filteredLessons.setPredicate(predicate);
+        updateStudentInfoList();
+    }
+
+    @Override
+    public void updateStudentInfoList() {
+        if (!filteredGroups.isEmpty() || !lessons.isEmpty()) {
+            this.studentsInfo.setAll(this.lessons.get(0).getStudentsInfoAsUnmodifiableObservableList());
+        }
+    }
+
     @Override
     public ObservableList<Group> getFilteredGroupList() {
         return filteredGroups;
@@ -221,6 +237,16 @@ public ObservableList<Lesson> getLessonList() {
         return lessons;
     }
 
+    @Override
+    public ObservableList<Lesson> getFilteredLessonList() {
+        return lessons;
+    }
+
+    @Override
+    public ObservableList<StudentInfo> getStudentInfoList() {
+        return studentsInfo;
+    }
+
     //=========== Filtered Person List Accessors =============================================================
 
     /**

src/main/java/seedu/address/model/group/Lesson.java

@@ -1,5 +1,7 @@
 package seedu.address.model.group;
 
+import javafx.collections.ObservableList;
+
 import static seedu.address.commons.util.AppUtil.checkArgument;
 import static seedu.address.commons.util.CollectionUtil.requireAllNonNull;
 
@@ -14,6 +16,7 @@ public class Lesson {
 
     public static final String NAME_CONSTRAINT = "Class name cannot be empty";
     public static final String STUDENTS_INFO_CONSTRAINT = "Students information cannot be empty";
+
     private final String name;
     private final UniqueStudentInfoList studentsInfo;
 
@@ -34,17 +37,20 @@ boolean isValidName(String name) {
         return name.length() > 0;
     }
 
-    public UniqueStudentInfoList getStudentsInfo() {
-        return studentsInfo;
+    public String getName() {
+        return name;
     }
 
     boolean isValidStudentInfo(UniqueStudentInfoList studentsInfo) {
         return studentsInfo.size() > 0;
     }
 
+    public UniqueStudentInfoList getStudentsInfo() {
+        return studentsInfo;
+    }
 
-    public String getName() {
-        return name;
+    public ObservableList<StudentInfo> getStudentsInfoAsUnmodifiableObservableList() {
+        return studentsInfo.asUnmodifiableObservableList();
     }
 
     @Override