group and subgroup adding/editing, services added

TimetableDesigner.Core/Class.cs

@@ -11,10 +11,23 @@ namespace TimetableDesigner.Core
         #region PROPERTIES
 
         public string Name { get; set; }
-        public string Description { get; set; }
-        public Teacher Teacher { get; set; }
-        public Subgroup Subgroup { get; set; }
-        public Classroom Classroom { get; set; }
+        public Teacher? Teacher { get; set; }
+        public IGroup? Group { get; set; }
+        public Classroom? Classroom { get; set; }
+
+        #endregion
+
+
+
+        #region CONSTRUCTORS
+
+        public Class()
+        {
+            Name = string.Empty;
+            Teacher = null;
+            Group = null;
+            Classroom = null;
+        }
 
         #endregion
     }

TimetableDesigner.Core/Group.cs

@@ -6,15 +6,27 @@ using System.Threading.Tasks;
 
 namespace TimetableDesigner.Core
 {
-    public class Group
+    public class Group : IGroup
     {
         #region PROPERTIES
 
         public string Name { get; set; }
         public string Description { get; set; }
-        public Subgroup MainSubgroup { get; set; }
         public ICollection<Subgroup> AssignedSubgroups { get; set; }
 
         #endregion
+
+
+
+        #region CONSTRUCTORS
+
+        public Group()
+        {
+            Name = string.Empty;
+            Description = string.Empty;
+            AssignedSubgroups = new HashSet<Subgroup>();
+        }
+
+        #endregion
     }
 }

TimetableDesigner.Core/IGroup.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace TimetableDesigner.Core
+{
+    public interface IGroup
+    {
+        #region PROPERTIES
+
+        string Name { get; }
+
+        #endregion
+    }
+}

TimetableDesigner.Core/Project.cs

@@ -33,8 +33,10 @@ namespace TimetableDesigner.Core
             Author = string.Empty;
             Description = string.Empty;
             TimetableTemplate = new TimetableTemplate();
-            Classrooms = new List<Classroom>();
-            Teachers = new List<Teacher>();
+            Classrooms = new HashSet<Classroom>();
+            Teachers = new HashSet<Teacher>();
+            Groups = new HashSet<Group>();
+            Subgroups = new HashSet<Subgroup>();
         }
 
         #endregion

TimetableDesigner.Core/Subgroup.cs

@@ -6,12 +6,22 @@ using System.Threading.Tasks;
 
 namespace TimetableDesigner.Core
 {
-    public class Subgroup
+    public class Subgroup : IGroup
     {
         #region PROPERTIES
 
         public string Name { get; set; }
-        public string Description { get; set; }
+
+        #endregion
+
+
+
+        #region CONSTRUCTORS
+
+        public Subgroup()
+        {
+            Name = string.Empty;
+        }
 
         #endregion
     }

TimetableDesigner.Core/TimetableSpan.cs

@@ -33,29 +33,29 @@ namespace TimetableDesigner.Core
 
         #region PUBLIC METHODS
 
-        internal TimetableSpansCollision CheckCollision(TimetableSpan slot)
+        internal TimetableSpanCollision CheckCollision(TimetableSpan slot)
         {
             if (slot.To <= this.From)
             {
-                return TimetableSpansCollision.CheckedSlotBefore;
+                return TimetableSpanCollision.CheckedSlotBefore;
             }
             else if (this.To <= slot.From) 
             {
-                return TimetableSpansCollision.CheckedSlotAfter;
+                return TimetableSpanCollision.CheckedSlotAfter;
             }
             else
             {
                 if (this.From < slot.From && slot.To < this.To)
                 {
-                    return TimetableSpansCollision.CheckedSlotIn;
+                    return TimetableSpanCollision.CheckedSlotIn;
                 }
                 else if (this.From < slot.From && slot.From < this.To && this.To < slot.To)
                 {
-                    return TimetableSpansCollision.CheckedSlotFromIn;
+                    return TimetableSpanCollision.CheckedSlotFromIn;
                 }
                 else if (slot.From < this.From && this.From < slot.To && slot.To < this.To)
                 {
-                    return TimetableSpansCollision.CheckedSlotToIn;
+                    return TimetableSpanCollision.CheckedSlotToIn;
                 }
                 else
                 {

TimetableDesigner.Core/TimetableSpanCollection.cs

@@ -49,8 +49,8 @@ namespace TimetableDesigner.Core
                 {
                     switch (item.CheckCollision(_list.ElementAt(i)))
                     {
-                        case TimetableSpansCollision.CheckedSlotBefore: i++; break;
-                        case TimetableSpansCollision.CheckedSlotAfter: done ^= true; break;
+                        case TimetableSpanCollision.CheckedSlotBefore: i++; break;
+                        case TimetableSpanCollision.CheckedSlotAfter: done ^= true; break;
                         default: throw new ArgumentException("Slot collide with another slot");
                     }
                 }

TimetableDesigner.Core/TimetableSpanCollision.cs

@@ -6,7 +6,7 @@ using System.Threading.Tasks;
 
 namespace TimetableDesigner.Core
 {
-    internal enum TimetableSpansCollision
+    internal enum TimetableSpanCollision
     {
         CheckedSlotBefore,
         CheckedSlotAfter,