From 87459dab50bd48f7e4175e973f87176839049080 Mon Sep 17 00:00:00 2001
From: Nick Stolbov <nick.stolbov@informatik.hs-fulda.de>
Date: Thu, 13 Jan 2022 15:00:22 +0100
Subject: [PATCH] Added back function to MenuManager.

---
 src/main/java/Application/MenuManager.java    |  7 +++++
 .../java/Application/MenuManagerTest.java     | 30 +++++++++++++++++--
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/src/main/java/Application/MenuManager.java b/src/main/java/Application/MenuManager.java
index 31979c8..383e5f8 100644
--- a/src/main/java/Application/MenuManager.java
+++ b/src/main/java/Application/MenuManager.java
@@ -14,6 +14,13 @@ public class MenuManager {
         this.currentMenu = currentMenu.getMenu(i);
     }
 
+    public void back() throws Exception {
+        if(!this.inRootMenu())
+            this.currentMenu = this.currentMenu.getPreviousMenu();
+        else
+            throw new Exception("Menu is a root menu, a previous menu doesn't exist");
+    }
+
     public Menu getCurrentMenu(){
         return this.currentMenu;
     }
diff --git a/src/test/java/Application/MenuManagerTest.java b/src/test/java/Application/MenuManagerTest.java
index 87bd8e3..d6031de 100644
--- a/src/test/java/Application/MenuManagerTest.java
+++ b/src/test/java/Application/MenuManagerTest.java
@@ -1,6 +1,7 @@
 package Application;
 
 import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
@@ -28,7 +29,7 @@ class MenuManagerTest {
     }
 
     @Test
-    void testSelectFunction(){
+    void testSelectFunction() {
         assertEquals(mm.getCurrentMenu(), rootMenu);
         mm.select(0);
         assertEquals(mm.getCurrentMenu(), rootMenu.getMenu(0));
@@ -37,9 +38,34 @@ class MenuManagerTest {
     }
 
     @Test
-    void testIsRootMenuFunction(){
+    void testIsRootMenuFunction() {
         assertTrue(mm.inRootMenu());
         mm.select(0);
         assertFalse(mm.inRootMenu());
     }
+
+    @Test
+    void testBackFunction() {
+        try {
+            mm.back();
+            Assertions.fail("Test failed: shouldn't be able to go back in rootMenu");
+        } catch (Exception e) {
+            //Should throw Exception because currently in rootMenu
+        }
+        mm.select(0);
+        try {
+            mm.back();
+            assertEquals(mm.getCurrentMenu(), rootMenu);
+        } catch (Exception e) {
+            Assertions.fail("Test failed: " + e.getMessage());
+        }
+        mm.select(0);
+        mm.select(0);
+        try {
+            mm.back();
+            assertEquals(mm.getCurrentMenu(), rootMenu.getMenu(0));
+        } catch (Exception e) {
+            Assertions.fail("Test failed: " + e.getMessage());
+        }
+    }
 }
\ No newline at end of file