Implement copying of elements.

Tests/ViewModels/SettingsViewModelTest.cs

@@ -156,7 +156,33 @@ namespace Tests.ViewModels
         [Test]
         public void CopyElement()
         {
-            throw new NotImplementedException();
+            string testString = "this text should be duplicated";
+            _settingsVM.AddElementViewModel(
+                new ControlElementViewModel(new SelectEachDay(new Items(testString))));
+            int oldCount = _settingsVM.Elements.Count;
+            _settingsVM.Elements.First().IsSelected = true;
+            Assert.IsTrue(_settingsVM.CopyElementCommand.CanExecute(null),
+                "CopyElementCommand should be enabled.");
+            _settingsVM.CopyElementCommand.Execute(null);
+            Assert.AreEqual(oldCount + 1, _settingsVM.Elements.Count);
+
+            // Access the first element
+            ControlElementViewModel controlVM = _settingsVM.Elements.First() as ControlElementViewModel;
+            FormatElementViewModel formatVM = controlVM.Elements.First() as FormatElementViewModel;
+            Items items = formatVM.RevealModelObject() as Items;
+            Assert.IsNotNull(items,
+                "Child ViewModel of first ControlElementViewModel does not wrap Items object.");
+            Assert.AreEqual(testString, items.Content,
+                "First control element's child element has incorrect Content string.");
+
+            // Access the second element
+            controlVM = _settingsVM.Elements.Last() as ControlElementViewModel;
+            formatVM = controlVM.Elements.First() as FormatElementViewModel;
+            items = formatVM.RevealModelObject() as Items;
+            Assert.IsNotNull(items,
+                "Child ViewModel of last ControlElementViewModel does not wrap Items object.");
+            Assert.AreEqual(testString, items.Content,
+                "First control element's child element has incorrect Content string.");
         }
     }
 }

zaaReloaded2/ViewModels/ControlElementViewModel.cs

@@ -81,5 +81,18 @@ namespace zaaReloaded2.ViewModels
         }
 
         #endregion
+
+        public override object Clone()
+        {
+            ControlElementViewModel clone = new ControlElementViewModel();
+            clone.Element = Element;
+            clone.Elements = new ObservableCollection<ElementViewModel>(
+                Elements.Select(evm => evm.Clone() as ElementViewModel));
+            foreach (FormatElementViewModel evm in clone.Elements)
+            {
+                evm.Parent = clone;
+            }
+            return clone;
+        }
     }
 }

zaaReloaded2/ViewModels/ElementViewModel.cs

@@ -26,7 +26,7 @@ using System.Collections.ObjectModel;
 
 namespace zaaReloaded2.ViewModels
 {
-    public abstract class ElementViewModel : ViewModelBase
+    public abstract class ElementViewModel : ViewModelBase, ICloneable
     {
         #region Properties
 
@@ -69,5 +69,11 @@ namespace zaaReloaded2.ViewModels
         }
 
         #endregion
+
+        #region Implementation of ICloneable
+        
+        public abstract object Clone();
+
+        #endregion
     }
 }

zaaReloaded2/ViewModels/FormatElementViewModel.cs

@@ -58,5 +58,13 @@ namespace zaaReloaded2.ViewModels
         }
 
         #endregion
+
+        public override object Clone()
+        {
+            FormatElementViewModel clone = new FormatElementViewModel();
+            clone.Parent = Parent;
+            clone.Element = Element;
+            return clone;
+        }
     }
 }

zaaReloaded2/ViewModels/SettingsViewModel.cs

@@ -314,8 +314,7 @@ namespace zaaReloaded2.ViewModels
         {
             if (CanDeleteElement())
             {
-                if (LastSelectedElement is ControlElementViewModel ||
-                    ((FormatElementViewModel)LastSelectedElement).Parent == null)
+                if (IsTopLevelElement())
                 {
                     // First level of the hierarchy
                     Elements.Remove(LastSelectedElement);
@@ -335,7 +334,21 @@ namespace zaaReloaded2.ViewModels
 
         bool CanDeleteElement() { return LastSelectedElement != null && LastSelectedElement.IsSelected; }
 
-        void DoCopyElement() { }
+        void DoCopyElement()
+        {
+            if (CanCopyElement())
+            {
+                if (IsTopLevelElement())
+                {
+                    AddElementViewModel(LastSelectedElement.Clone() as ElementViewModel);
+                }
+                else
+                {
+                    FormatElementViewModel formatVM = LastSelectedElement as FormatElementViewModel;
+                    formatVM.Parent.AddChildElement(formatVM.Clone() as FormatElementViewModel);
+                }
+            }
+        }
 
         bool CanCopyElement() { return LastSelectedElement != null && LastSelectedElement.IsSelected; }
 
@@ -355,6 +368,16 @@ namespace zaaReloaded2.ViewModels
             }
         }
 
+        /// <summary>
+        /// Returns true if the selected ElementViewModel is at the top
+        /// level of the hierarchy.
+        /// </summary>
+        bool IsTopLevelElement()
+        {
+            return (LastSelectedElement is ControlElementViewModel ||
+                ((FormatElementViewModel)LastSelectedElement).Parent == null);
+        }
+
         #endregion
 
         #region Implementation of ViewModelBase