path: root/Software/Visual_Studio/Tango.Editors/ElementsEditor.xaml.cs

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Media.Imaging;
using Tango.Core.Commands;
using Tango.Editors;

namespace Tango.Editors
{
    /// <summary>
    /// Represents a <see cref="IElementEditor"/> collection container and editor. The editor supports Undo, Redo, Cut, Copy and Paste operations.
    /// </summary>
    /// <seealso cref="Tango.Editors.HybridControl" />
    /// <seealso cref="Tango.Editors.IConfigurable" />
    /// <seealso cref="Tango.Editors.ISupportEditingOperations" />
    /// <seealso cref="Tango.Editors.ISupportUndoRedoOperations" />
    public partial class ElementsEditor : HybridControl, IConfigurable, ISupportEditingOperations, ISupportUndoRedoOperations
    {
        private List<IElementEditor> _copiedElements;
        private bool _isSelectionMouseDown; //Determines whether the mouse is down for selection by the selection rectangle.
        private Point _selectionMouseDownPoint; //Holds the originating point to perform the selection.
        private bool _selectionPerformed; //Determines whether the selection rectangle has moved at least 1 pixel.

        #region Events

        /// <summary>
        /// Occurs when attempting to create a new element using the selection rectangle and holding the shift key.
        /// </summary>
        public event EventHandler<ElementCreationEventArgs> ElementCreation;

        /// <summary>
        /// Occurs before removing selected elements using the DELETE key.
        /// </summary>
        public event EventHandler<ElementsEventArgs> RemovingElements;

        /// <summary>
        /// Occurs when elements selection has changed;.
        /// </summary>
        public event EventHandler<ElementsEventArgs> SelectionChanged;

        /// <summary>
        /// Occurs after pasting the currently copied elements. The collection of elements represents the new cloned elements.
        /// </summary>
        public event EventHandler<ElementsEventArgs> AfterPaste;

        /// <summary>
        /// Occurs when one or many elements were added.
        /// </summary>
        public event EventHandler<ElementsEventArgs> ElementsAdded;

        /// <summary>
        /// Occurs when one or many elements were removed.
        /// </summary>
        public event EventHandler<ElementsEventArgs> ElementsRemoved;

        public event EventHandler<IElementEditor> ElementDoubleClicked;

        #endregion

        #region Constructors

        /// <summary>
        /// Initializes a new instance of the <see cref="ElementsEditor"/> class.
        /// </summary>
        public ElementsEditor()
        {
            //Initialize Collections
            //Elements = new ObservableCollection<IElementEditor>();
            SelectedElements = new ObservableCollection<IElementEditor>();

            InitializeComponent();

            //Initialize Default Undo/Redo States Provider.
            UndoRedoStatesProvider = new ElementsEditorUndoRedoStatesProvider(this);

            //Register Events.
            Loaded += ElementsEditor_Loaded;

            //Initialize Commands
            CopyCommand = new RelayCommand(Copy, (x) => GetSelectedElements().Count > 0);
            PasteCommand = new RelayCommand(Paste, (x) => _copiedElements != null && _copiedElements.Count > 0);
            UndoCommand = new RelayCommand(Undo, (x) => UndoRedoStatesProvider.CanUndo);
            RedoCommand = new RelayCommand(Redo, (x) => UndoRedoStatesProvider.CanRedo);
            DeleteCommand = new RelayCommand(() => { RemoveSelectedElements(true); }, (x) => GetSelectedElements().Count > 0);
            CutCommand = new RelayCommand(Cut, (x) => GetSelectedElements().Count > 0);
            ZoomCommand = new RelayCommand<String>((str) => { Zoom(Convert.ToDouble(str)); });
            ResetZoomCommand = new RelayCommand(() => { ScaleFactor = 1; });
            SelectAllCommand = new RelayCommand(SelectAll);
            BringToFrontCommand = new RelayCommand(BringToFront, (x) => GetSelectedElements().Count > 0);
            SendToBackCommand = new RelayCommand(SendToBack, (x) => GetSelectedElements().Count > 0);
        }

        #endregion

        #region Properties

        public BitmapSource PreviewImage
        {
            get { return (BitmapSource)GetValue(PreviewImageProperty); }
            set { SetValue(PreviewImageProperty, value); }
        }
        public static readonly DependencyProperty PreviewImageProperty =
            DependencyProperty.Register("PreviewImage", typeof(BitmapSource), typeof(ElementsEditor), new PropertyMetadata(null));

        /// <summary>
        /// Gets or sets a value indicating whether to enable undo and redo operations using the keyboard.
        /// </summary>
        public bool EnableKeyboardUndoRedoOperations
        {
            get { return (bool)GetValue(EnableKeyboardUndoRedoOperationsProperty); }
            set { SetValue(EnableKeyboardUndoRedoOperationsProperty, value); }
        }
        public static readonly DependencyProperty EnableKeyboardUndoRedoOperationsProperty =
            DependencyProperty.Register("EnableKeyboardUndoRedoOperations", typeof(bool), typeof(ElementsEditor), new PropertyMetadata(true));

        /// <summary>
        /// Gets or sets a value indicating whether to enable editing operations using the keyboard.
        /// </summary>
        public bool EnableKeyboardEditingOperations
        {
            get { return (bool)GetValue(EnableKeyboardEditingOperationsProperty); }
            set { SetValue(EnableKeyboardEditingOperationsProperty, value); }
        }
        public static readonly DependencyProperty EnableKeyboardEditingOperationsProperty =
            DependencyProperty.Register("EnableKeyboardEditingOperations", typeof(bool), typeof(ElementsEditor), new PropertyMetadata(true));

        /// <summary>
        /// Gets or sets the width of the editor.
        /// </summary>
        public double EditorWidth
        {
            get { return (double)GetValue(EditorWidthProperty); }
            set { SetValue(EditorWidthProperty, value); }
        }
        public static readonly DependencyProperty EditorWidthProperty =
            DependencyProperty.Register("EditorWidth", typeof(double), typeof(ElementsEditor), new PropertyMetadata(1280.0));

        /// <summary>
        /// Gets or sets the height of the editor.
        /// </summary>
        public double EditorHeight
        {
            get { return (double)GetValue(EditorHeightProperty); }
            set { SetValue(EditorHeightProperty, value); }
        }
        public static readonly DependencyProperty EditorHeightProperty =
            DependencyProperty.Register("EditorHeight", typeof(double), typeof(ElementsEditor), new PropertyMetadata(720.0));

        /// <summary>
        /// Gets or sets the editor scale factor.
        /// </summary>
        public double ScaleFactor
        {
            get { return (double)GetValue(ScaleFactorProperty); }
            set { SetValue(ScaleFactorProperty, value); }
        }
        public static readonly DependencyProperty ScaleFactorProperty =
            DependencyProperty.Register("ScaleFactor", typeof(double), typeof(ElementsEditor), new PropertyMetadata(1.0, null, (d, e) => { return (d as ElementsEditor).OnCoerceScaleFactor(e); }));

        /// <summary>
        /// Gets or sets the collection of <see cref="IElementEditor"/>.
        /// </summary>
        public ObservableCollection<IElementEditor> Elements
        {
            get { return (ObservableCollection<IElementEditor>)GetValue(ElementsProperty); }
            set { SetValue(ElementsProperty, value); }
        }
        public static readonly DependencyProperty ElementsProperty =
            DependencyProperty.Register("Elements", typeof(ObservableCollection<IElementEditor>), typeof(ElementsEditor), new PropertyMetadata(null, (d, e) => { (d as ElementsEditor).OnElementsChanged(); }));

        /// <summary>
        /// Gets or sets the selected element.
        /// </summary>
        public IElementEditor SelectedElement
        {
            get { return (IElementEditor)GetValue(SelectedElementProperty); }
            set { SetValue(SelectedElementProperty, value); }
        }
        public static readonly DependencyProperty SelectedElementProperty =
            DependencyProperty.Register("SelectedElement", typeof(IElementEditor), typeof(ElementsEditor), new PropertyMetadata(null, (d, e) => { (d as ElementsEditor).OnSelectedElementChanged(); }));

        /// <summary>
        /// Gets or sets the selected elements.
        /// </summary>
        public ObservableCollection<IElementEditor> SelectedElements
        {
            get { return (ObservableCollection<IElementEditor>)GetValue(SelectedElementsProperty); }
            set { SetValue(SelectedElementsProperty, value); }
        }
        public static readonly DependencyProperty SelectedElementsProperty =
            DependencyProperty.Register("SelectedElements", typeof(ObservableCollection<IElementEditor>), typeof(ElementsEditor), new PropertyMetadata(null));

        /// <summary>
        /// Gets or sets the height of the ruler.
        /// </summary>
        public double RulerHeight
        {
            get { return (double)GetValue(RulerHeightProperty); }
            set { SetValue(RulerHeightProperty, value); }
        }
        public static readonly DependencyProperty RulerHeightProperty =
            DependencyProperty.Register("RulerHeight", typeof(double), typeof(ElementsEditor), new PropertyMetadata(22.0));

        /// <summary>
        /// Gets or sets the undo redo states provider.
        /// </summary>
        public IUndoRedoStatesProvider UndoRedoStatesProvider
        {
            get { return (IUndoRedoStatesProvider)GetValue(UndoRedoStatesProviderProperty); }
            set { SetValue(UndoRedoStatesProviderProperty, value); }
        }
        public static readonly DependencyProperty UndoRedoStatesProviderProperty =
            DependencyProperty.Register("UndoRedoStatesProvider", typeof(IUndoRedoStatesProvider), typeof(ElementsEditor), new PropertyMetadata(null));

        /// <summary>
        /// Gets or sets a value indicating whether to bring the selected element to the front z index.
        /// </summary>
        public bool BringToFrontOnSelect
        {
            get { return (bool)GetValue(BringToFrontOnSelectProperty); }
            set { SetValue(BringToFrontOnSelectProperty, value); }
        }
        public static readonly DependencyProperty BringToFrontOnSelectProperty =
            DependencyProperty.Register("BringToFrontOnSelect", typeof(bool), typeof(ElementsEditor), new PropertyMetadata(true));

        /// <summary>
        /// Gets or sets the editor mode.
        /// </summary>
        public ElementsEditorMode EditorMode
        {
            get { return (ElementsEditorMode)GetValue(EditorModeProperty); }
            set { SetValue(EditorModeProperty, value); }
        }
        public static readonly DependencyProperty EditorModeProperty =
            DependencyProperty.Register("EditorMode", typeof(ElementsEditorMode), typeof(ElementsEditor), new PropertyMetadata(ElementsEditorMode.Default));


        /// <summary>
        /// Gets or sets a value indicating whether to enable the creation of new elements using the mouse and Shift key.
        /// </summary>
        public bool EnableElementCreation
        {
            get { return (bool)GetValue(EnableElementCreationProperty); }
            set { SetValue(EnableElementCreationProperty, value); }
        }
        public static readonly DependencyProperty EnableElementCreationProperty =
            DependencyProperty.Register("EnableElementCreation", typeof(bool), typeof(ElementsEditor), new PropertyMetadata(true));

        /// <summary>
        /// Gets or sets an optional attached elements editor for editors mirroring mode.
        /// </summary>
        public ElementsEditor AttachedEditor
        {
            get { return (ElementsEditor)GetValue(AttachedEditorProperty); }
            set { SetValue(AttachedEditorProperty, value); }
        }
        public static readonly DependencyProperty AttachedEditorProperty =
            DependencyProperty.Register("AttachedEditor", typeof(ElementsEditor), typeof(ElementsEditor), new PropertyMetadata(null, (d, e) => (d as ElementsEditor).OnAttachedEditorChanged()));


        /// <summary>
        /// Gets or sets the preview visual source opacity.
        /// </summary>
        public double PreviewVisualSourceOpacity
        {
            get { return (double)GetValue(PreviewVisualSourceOpacityProperty); }
            set { SetValue(PreviewVisualSourceOpacityProperty, value); }
        }
        public static readonly DependencyProperty PreviewVisualSourceOpacityProperty =
            DependencyProperty.Register("PreviewVisualSourceOpacity", typeof(double), typeof(ElementsEditor), new PropertyMetadata(1.0));

        /// <summary>
        /// Gets or sets a value indicating whether this instance is editable.
        /// </summary>
        public bool IsEditable
        {
            get { return (bool)GetValue(IsEditableProperty); }
            set { SetValue(IsEditableProperty, value); }
        }
        public static readonly DependencyProperty IsEditableProperty =
            DependencyProperty.Register("IsEditable", typeof(bool), typeof(ElementsEditor), new PropertyMetadata(true));


        #endregion

        #region Attached Properties

        #region IsSelected

        /// <summary>
        /// Determines whether the element is currently selected.
        /// </summary>
        public static readonly DependencyProperty IsSelectedProperty =
            DependencyProperty.RegisterAttached("IsSelected",
            typeof(bool), typeof(ElementsEditor),
            new FrameworkPropertyMetadata(false));

        /// <summary>
        /// Sets the IsSelected attached property.
        /// </summary>
        /// <param name="element">The element.</param>
        /// <param name="value">if set to <c>true</c> selected.</param>
        public static void SetIsSelected(IElementEditor element, bool value)
        {
            (element as DependencyObject).SetValue(IsSelectedProperty, value);
        }

        /// <summary>
        /// Gets the is IsSelected attached property.
        /// </summary>
        /// <param name="element">The element.</param>
        /// <returns></returns>
        public static bool GetIsSelected(IElementEditor element)
        {
            return (bool)(element as DependencyObject).GetValue(IsSelectedProperty);
        }

        #endregion

        #endregion

        #region Theme Properties

        /// <summary>
        /// Gets or sets the ruler background.
        /// </summary>
        public Brush RulerBackground
        {
            get { return (Brush)GetValue(RulerBackgroundProperty); }
            set { SetValue(RulerBackgroundProperty, value); }
        }
        public static readonly DependencyProperty RulerBackgroundProperty =
            DependencyProperty.Register("RulerBackground", typeof(Brush), typeof(ElementsEditor), new FrameworkPropertyMetadata(null, FrameworkPropertyMetadataOptions.AffectsRender));

        /// <summary>
        /// Gets or sets the editor background.
        /// </summary>
        public Brush EditorBackground
        {
            get { return (Brush)GetValue(EditorBackgroundProperty); }
            set { SetValue(EditorBackgroundProperty, value); }
        }
        public static readonly DependencyProperty EditorBackgroundProperty =
            DependencyProperty.Register("EditorBackground", typeof(Brush), typeof(ElementsEditor), new FrameworkPropertyMetadata(null, FrameworkPropertyMetadataOptions.AffectsRender));

        /// <summary>
        /// Gets or sets the selection fill brush.
        /// </summary>
        public Brush SelectionFillBrush
        {
            get { return (Brush)GetValue(SelectionFillBrushProperty); }
            set { SetValue(SelectionFillBrushProperty, value); }
        }
        public static readonly DependencyProperty SelectionFillBrushProperty =
            DependencyProperty.Register("SelectionFillBrush", typeof(Brush), typeof(ElementsEditor), new FrameworkPropertyMetadata(null, FrameworkPropertyMetadataOptions.AffectsRender));

        /// <summary>
        /// Gets or sets the selection stroke brush.
        /// </summary>
        public Brush SelectionStrokeBrush
        {
            get { return (Brush)GetValue(SelectionStrokeBrushProperty); }
            set { SetValue(SelectionStrokeBrushProperty, value); }
        }
        public static readonly DependencyProperty SelectionStrokeBrushProperty =
            DependencyProperty.Register("SelectionStrokeBrush", typeof(Brush), typeof(ElementsEditor), new FrameworkPropertyMetadata(null, FrameworkPropertyMetadataOptions.AffectsRender));

        #endregion

        #region Virtual Methods

        /// <summary>
        /// Invoked when the attached editor has changed.
        /// </summary>
        protected virtual void OnAttachedEditorChanged()
        {
            if (AttachedEditor != null)
            {
                UndoRedoStatesProvider = new AttachedElementsEditorsUndoRedoStatesProvider(this, AttachedEditor);
                AttachedEditor.UndoRedoStatesProvider = UndoRedoStatesProvider;
            }
        }

        /// <summary>
        /// Raises the <see cref="E:ElementsAdded" /> event.
        /// </summary>
        /// <param name="e">The <see cref="ElementsEventArgs"/> instance containing the event data.</param>
        protected virtual void OnElementsAdded(ElementsEventArgs e)
        {
            if (ElementsAdded != null) ElementsAdded(this, e);
        }

        /// <summary>
        /// Raises the <see cref="E:ElementsRemoved" /> event.
        /// </summary>
        /// <param name="e">The <see cref="ElementsEventArgs"/> instance containing the event data.</param>
        protected virtual void OnElementsRemoved(ElementsEventArgs e)
        {
            if (ElementsRemoved != null) ElementsRemoved(this, e);
        }

        /// <summary>
        /// Called when the reset scale factor button was clicked.
        /// </summary>
        /// <param name="sender">The sender.</param>
        /// <param name="e">The <see cref="MouseButtonEventArgs"/> instance containing the event data.</param>
        protected virtual void OnResetScaleFactor(object sender, MouseButtonEventArgs e)
        {
            ScaleFactor = 1;
        }

        /// <summary>
        /// Called when the selected element has changed.
        /// </summary>
        protected virtual void OnSelectedElementChanged()
        {
            if (SelectedElement != null)
            {
                if (BringToFrontOnSelect)
                {
                    if (Elements.Count > 0)
                    {
                        Canvas.SetZIndex(SelectedElement as UIElement, Elements.Max(x => Canvas.GetZIndex(x as UIElement) + 1));
                    }
                }

                SetElementSelection(SelectedElement, true);

                if (AttachedEditor != null && AttachedEditor.SelectedElement != SelectedElement.AttachedEditor)
                {
                    AttachedEditor.SelectedElement = SelectedElement.AttachedEditor;
                }
            }
            else
            {
                if (AttachedEditor != null)
                {
                    AttachedEditor.SelectedElement = null;
                }
            }

            if (!IsCtrlDown())
            {
                foreach (var element in Elements.Where(x => x != SelectedElement))
                {
                    SetElementSelection(element, false);
                }
            }

            OnSelectionChanged();
            InvalidateRelayCommands();
        }

        /// <summary>
        /// Raises the <see cref="SelectionChanged"/> event.
        /// </summary>
        protected void OnSelectionChanged()
        {
            if (SelectionChanged != null) SelectionChanged(this, new ElementsEventArgs(GetSelectedElements()));
        }

        /// <summary>
        /// Called when the elements collection has changed.
        /// </summary>
        protected virtual void OnElementsChanged()
        {
            if (Elements != null)
            {
                RegisterElementsEvents();
                Elements.CollectionChanged -= Elements_CollectionChanged;
                Elements.CollectionChanged += Elements_CollectionChanged;

                SetCanvasElements();
            }

            InvalidateRelayCommands();
        }

        /// <summary>
        /// Called when the hosting canvas has captured a mouse down event.
        /// </summary>
        /// <param name="sender">The sender.</param>
        /// <param name="e">The <see cref="MouseButtonEventArgs"/> instance containing the event data.</param>
        protected virtual void OnCanvasMouseDown(object sender, MouseButtonEventArgs e)
        {
            DeselectElements();

            _selectionMouseDownPoint = e.GetPosition(selectionCanvas);
            _selectionPerformed = false;
            _isSelectionMouseDown = true;
            selectionRec.Width = 0;
            selectionRec.Height = 0;
            selectionCanvas.Visibility = System.Windows.Visibility.Visible;
        }

        /// <summary>
        /// Handles the canvas mouse up event.
        /// </summary>
        /// <param name="sender">The sender.</param>
        /// <param name="e">The <see cref="MouseButtonEventArgs"/> instance containing the event data.</param>
        protected virtual void OnCanvasMouseUp(object sender, MouseButtonEventArgs e)
        {
            if (_selectionPerformed)
            {
                _selectionPerformed = false;
                selectionCanvas.Visibility = System.Windows.Visibility.Hidden;
                e.Handled = true;

                if (IsShiftDown() && EnableElementCreation)
                {
                    OnElementCreation();
                }
            }

            _isSelectionMouseDown = false;
        }

        /// <summary>
        /// Raises the <see cref="ElementCreation"/> event.
        /// </summary>
        protected virtual void OnElementCreation()
        {
            PrepareUndoState();
            var args = new ElementCreationEventArgs(Canvas.GetLeft(selectionRec), Canvas.GetTop(selectionRec), selectionRec.Width, selectionRec.Height);
            if (ElementCreation != null) ElementCreation(this, args);
            if (args.AppendUndoState)
            {
                CommitUndoState();
            }
        }

        /// <summary>
        /// Handles the canvas mouse move event.
        /// </summary>
        /// <param name="sender">The sender.</param>
        /// <param name="e">The <see cref="MouseEventArgs"/> instance containing the event data.</param>
        protected virtual void OnCanvasMouseMove(object sender, MouseEventArgs e)
        {
            if (_isSelectionMouseDown)
            {
                Point currentMousePoint = e.GetPosition(selectionCanvas);

                _selectionPerformed = currentMousePoint.X != _selectionMouseDownPoint.X || currentMousePoint.Y != _selectionMouseDownPoint.Y;

                Canvas.SetLeft(selectionRec, _selectionMouseDownPoint.X);
                Canvas.SetTop(selectionRec, _selectionMouseDownPoint.Y);

                if (currentMousePoint.X - _selectionMouseDownPoint.X > 1)
                {
                    selectionRec.Width = currentMousePoint.X - _selectionMouseDownPoint.X;
                }

                if (currentMousePoint.Y - _selectionMouseDownPoint.Y > 1)
                {
                    selectionRec.Height = currentMousePoint.Y - _selectionMouseDownPoint.Y;
                }

                if (currentMousePoint.X < _selectionMouseDownPoint.X)
                {
                    Canvas.SetLeft(selectionRec, currentMousePoint.X);
                    selectionRec.Width = _selectionMouseDownPoint.X - currentMousePoint.X;
                }

                if (currentMousePoint.Y < _selectionMouseDownPoint.Y)
                {
                    Canvas.SetTop(selectionRec, currentMousePoint.Y);
                    selectionRec.Height = _selectionMouseDownPoint.Y - currentMousePoint.Y;
                }

                if (!IsShiftDown())
                {
                    //Select intersecting objects
                    Rect selectRect = new Rect(Canvas.GetLeft(selectionRec), Canvas.GetTop(selectionRec), selectionRec.Width, selectionRec.Height);

                    var allElements = GetAllElements();

                    foreach (var element in allElements)
                    {
                        SetElementSelection(element, GetElementBounds(element).IntersectsWith(selectRect));
                    }

                    var selectedElements = GetSelectedElements();

                    if (selectedElements.Count == 1)
                    {
                        SelectedElement = selectedElements.FirstOrDefault();
                    }
                }
            }
        }

        /// <summary>
        /// Called when coercing the scale factor.
        /// </summary>
        /// <param name="value">The value.</param>
        /// <returns></returns>
        protected virtual object OnCoerceScaleFactor(object value)
        {
            if ((double)value < 0.1)
            {
                return 0.1;
            }
            else
            {
                return value;
            }
        }

        /// <summary>
        /// Called when zooming with mouse wheel.
        /// </summary>
        /// <param name="sender">The sender.</param>
        /// <param name="e">The <see cref="MouseWheelEventArgs"/> instance containing the event data.</param>
        protected virtual void OnMouseWheelZooming(object sender, MouseWheelEventArgs e)
        {
            if (e.Delta > 0) //Ticks up
            {
                ScaleFactor += 0.1;
            }
            else //Ticks Down
            {
                ScaleFactor -= 0.1;
            }

            Point pointAbsolute = Mouse.GetPosition(gridCanvas);
            Point pointRelative = Mouse.GetPosition(scrollViewer);

            scrollViewer.ScrollToHorizontalOffset((pointAbsolute.X * ScaleFactor) - pointRelative.X);
            scrollViewer.ScrollToVerticalOffset((pointAbsolute.Y * ScaleFactor) - pointRelative.Y);
        }
        #endregion

        #region Event Handlers

        /// <summary>
        /// Handles the Loaded event of the ElementsEditor control.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="e">The <see cref="RoutedEventArgs"/> instance containing the event data.</param>
        private void ElementsEditor_Loaded(object sender, RoutedEventArgs e)
        {
            SetCanvasElements();
        }

        /// <summary>
        /// Handles the CollectionChanged event of the Elements control.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="e">The <see cref="System.Collections.Specialized.NotifyCollectionChangedEventArgs"/> instance containing the event data.</param>
        private void Elements_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
        {
            RegisterElementsEvents();
            SetCanvasElements();

            if (e.NewItems != null && e.NewItems.Count > 0)
            {
                OnElementsAdded(new ElementsEventArgs(e.NewItems.Cast<IElementEditor>().ToList()));
            }

            if (e.OldItems != null && e.OldItems.Count > 0)
            {
                OnElementsRemoved(new ElementsEventArgs(e.OldItems.Cast<IElementEditor>().ToList()));
            }
        }

        /// <summary>
        /// Handles the SelectionChanged event of the Element control.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="e">The <see cref="EventArgs"/> instance containing the event data.</param>
        /// <exception cref="System.NotImplementedException"></exception>
        private void Element_SelectionChanged(object sender, EventArgs e)
        {
            IElementEditor element = sender as IElementEditor;
            SelectedElement = element;
        }

        /// <summary>
        /// Handles the Moving event of the Element control.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="e">The <see cref="System.Windows.Controls.Primitives.DragDeltaEventArgs"/> instance containing the event data.</param>
        /// <exception cref="System.NotImplementedException"></exception>
        private void Element_Moving(object sender, System.Windows.Controls.Primitives.DragDeltaEventArgs e)
        {
            if (IsCtrlDown())
            {
                GetSelectedElements().Where(x => x != sender).ToList().ForEach(x => x.PushMove(e));
            }
        }

        /// <summary>
        /// Handles the AfterBoundsChange event of the Element control.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="e">The <see cref="EventArgs"/> instance containing the event data.</param>
        private void Element_AfterBoundsChange(object sender, EventArgs e)
        {
            CommitUndoState();
        }

        /// <summary>
        /// Handles the BeforeBoundsChange event of the Element control.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="e">The <see cref="EventArgs"/> instance containing the event data.</param>
        private void Element_BeforeBoundsChange(object sender, EventArgs e)
        {
            PrepareUndoState();
        }

        /// <summary>
        /// Handles the PreviewMouseDown event of the Element control.
        /// </summary>
        /// <param name="sender">The source of the event.</param>
        /// <param name="e">The <see cref="MouseButtonEventArgs"/> instance containing the event data.</param>
        private void Element_PreviewMouseDown(object sender, MouseButtonEventArgs e)
        {
            if (e.ChangedButton == MouseButton.Left && !Keyboard.IsKeyDown(Key.LeftShift))
            {
                SelectedElement = sender as IElementEditor;
            }
        }

        #endregion

        #region Private Methods

        private void SetCanvasElements()
        {
            if (!this.IsInDesignMode())
            {
                if (canvas != null && Elements != null)
                {
                    foreach (UIElement element in Elements)
                        if (!canvas.Children.Contains(element))
                            canvas.Children.Add(element);

                    List<UIElement> removeList = new List<UIElement>();
                    foreach (UIElement element in canvas.Children)
                        if (!Elements.Contains(element as IElementEditor))
                            removeList.Add(element);

                    foreach (UIElement element in removeList)
                        canvas.Children.Remove(element);
                }
            }
        }

        /// <summary>
        /// Determines whether the control key is down.
        /// </summary>
        private bool IsCtrlDown()
        {
            return Keyboard.IsKeyDown(Key.LeftCtrl);
        }

        /// <summary>
        /// Determines whether the shift control is down.
        /// </summary>
        private bool IsShiftDown()
        {
            return Keyboard.IsKeyDown(Key.LeftShift);
        }

        /// <summary>
        /// Registers the elements events.
        /// </summary>
        private void RegisterElementsEvents()
        {
            foreach (var element in Elements)
            {
                element.Moving -= Element_Moving;
                element.Moving += Element_Moving;
                element.BeforeBoundsChange -= Element_BeforeBoundsChange;
                element.BeforeBoundsChange += Element_BeforeBoundsChange;
                element.AfterBoundsChange -= Element_AfterBoundsChange;
                element.AfterBoundsChange += Element_AfterBoundsChange;

                if (element is FrameworkElement)
                {
                    (element as FrameworkElement).PreviewMouseDown -= Element_PreviewMouseDown;
                    (element as FrameworkElement).PreviewMouseDown += Element_PreviewMouseDown;
                    (element as FrameworkElement).PreviewMouseDown -= ElementsEditor_PreviewMouseDown;
                    (element as FrameworkElement).PreviewMouseDown += ElementsEditor_PreviewMouseDown;
                }
            }
        }

        private void ElementsEditor_PreviewMouseDown(object sender, MouseButtonEventArgs e)
        {
            if (e.ClickCount == 2)
            {
                ElementDoubleClicked?.Invoke(this, sender as IElementEditor);
            }
        }

        /// <summary>
        /// Prepares the state of the undo.
        /// </summary>
        private void PrepareUndoState()
        {
            UndoRedoStatesProvider.PrepareUndoState();
        }

        /// <summary>
        /// Commits the state of the undo.
        /// </summary>
        private void CommitUndoState()
        {
            UndoRedoStatesProvider.CommitUndoState();
        }

        /// <summary>
        /// Executes the undo/redo state.
        /// </summary>
        /// <param name="state">The state.</param>
        private void ExecuteUndoRedoState(List<AnimationSetup> state)
        {
            foreach (var setup in state)
            {
                setup.Animation.Completed += (x, y) =>
                {
                    var aniValue = setup.DependencyObject.GetValue(setup.DependencyProperty);
                    (setup.DependencyObject as IAnimatable).BeginAnimation(setup.DependencyProperty, null);
                    setup.DependencyObject.SetCurrentValue(setup.DependencyProperty, aniValue);
                };

                (setup.DependencyObject as IAnimatable).BeginAnimation(setup.DependencyProperty, setup.Animation);
            }
        }

        /// <summary>
        /// Creates an undo/redo state.
        /// </summary>
        /// <returns></returns>
        private List<AnimationSetup> CreateUndoRedoState()
        {
            List<AnimationSetup> all = new List<AnimationSetup>();

            foreach (var element in Elements)
            {
                var setups = element.GetAnimationSetups(TimeSpan.FromSeconds(0), AnimationSetupMode.Discrete);
                all.AddRange(setups);
            }

            return all;
        }

        /// <summary>
        /// Gets the element bounds.
        /// </summary>
        /// <param name="element">The element.</param>
        /// <returns></returns>
        private Rect GetElementBounds(IElementEditor element)
        {
            var visual = element as FrameworkElement;

            if (visual != null)
            {
                var position = visual.TranslatePoint(new Point(0, 0), selectionCanvas);
                return new Rect(position.X, position.Y, visual.ActualWidth, visual.ActualHeight);
            }
            else
            {
                return new Rect();
            }
        }

        /// <summary>
        /// Gets the visual child.
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="parent">The parent.</param>
        /// <returns></returns>
        private static T GetVisualChild<T>(DependencyObject parent) where T : Visual
        {
            T child = default(T);

            int numVisuals = VisualTreeHelper.GetChildrenCount(parent);
            for (int i = 0; i < numVisuals; i++)
            {
                Visual v = (Visual)VisualTreeHelper.GetChild(parent, i);
                child = v as T;
                if (child == null)
                {
                    child = GetVisualChild<T>(v);
                }
                if (child != null)
                {
                    break;
                }
            }
            return child;
        }
        #endregion

        #region Public Methods

        /// <summary>
        /// De-selects all elements.
        /// </summary>
        public void DeselectElements()
        {
            Elements.ToList().ForEach(x => SetElementSelection(x, false));
            SelectedElement = null;
            OnSelectionChanged();
            InvalidateRelayCommands();
        }

        /// <summary>
        /// Selects all elements.
        /// </summary>
        public void SelectAll()
        {
            Elements.ToList().ForEach(x => SetElementSelection(x, true));
            OnSelectionChanged();
            InvalidateRelayCommands();
        }

        /// <summary>
        /// Increase or decrease the <see cref="ScaleFactor"/> by the specified factor.
        /// </summary>
        /// <param name="factor">The factor (e.g 0.2 or -0.5).</param>
        public void Zoom(double factor)
        {
            ScaleFactor += factor;
        }

        /// <summary>
        /// Gets the selected elements.
        /// </summary>
        public List<IElementEditor> GetSelectedElements()
        {
            return GetAllElements().Where(x => GetIsSelected(x)).ToList();
        }

        /// <summary>
        /// Gets all elements.
        /// </summary>
        /// <returns></returns>
        public List<IElementEditor> GetAllElements()
        {
            return Elements.ToList();
        }

        /// <summary>
        /// Removes the selected elements.
        /// </summary>
        public void RemoveSelectedElements(bool raiseRemoveEvent = false)
        {
            ElementsEventArgs args = new ElementsEventArgs();

            if (raiseRemoveEvent)
            {
                args.Elements = GetSelectedElements();
                if (RemovingElements != null) RemovingElements(this, args);
            }

            if (!raiseRemoveEvent || !args.Cancel)
            {
                PrepareUndoState();
                var selectedElements = GetSelectedElements();
                selectedElements.ForEach(x => RemoveElement(x));

                if (AttachedEditor != null)
                {
                    foreach (var element in selectedElements)
                    {
                        if (element.AttachedEditor != null)
                        {
                            AttachedEditor.RemoveElement(element.AttachedEditor);
                        }
                    }
                }

                CommitUndoState();
                OnSelectionChanged();
                InvalidateRelayCommands();
            }
        }

        /// <summary>
        /// Removes the element.
        /// </summary>
        /// <param name="element">The element.</param>
        public void RemoveElement(IElementEditor element)
        {
            SetElementSelection(element, false);
            Elements.Remove(element);
            if (SelectedElement == element) SelectedElement = null;
            OnSelectionChanged();
            InvalidateRelayCommands();
        }

        /// <summary>
        /// Gets the element by the hosted element.
        /// </summary>
        /// <param name="hostedElement">The hosted element.</param>
        public IElementEditor GetElementByHostedElement(object hostedElement)
        {
            return Elements.SingleOrDefault(x => x.HostedElement == hostedElement);
        }

        /// <summary>
        /// Undoes the current state of the elements collection.
        /// </summary>
        public void Undo()
        {
            UndoRedoStatesProvider.Undo();
            InvalidateRelayCommands();
        }

        /// <summary>
        /// Redoes the current state of the elements collection.
        /// </summary>
        public void Redo()
        {
            UndoRedoStatesProvider.Redo();
            InvalidateRelayCommands();
        }

        /// <summary>
        /// Performs copy operation on the selected elements.
        /// </summary>
        public void Copy()
        {
            Copy(false);
        }

        private void Copy(bool fromAttached)
        {
            _copiedElements = GetSelectedElements();
            InvalidateRelayCommands();

            if (AttachedEditor != null && !fromAttached)
            {
                AttachedEditor.Copy(true);
            }
        }

        /// <summary>
        /// Performs a Cut operation over the selected elements.
        /// </summary>
        public void Cut()
        {
            Copy();
            RemoveSelectedElements();
            InvalidateRelayCommands();
        }

        /// <summary>
        /// Pastes the last copied elements.
        /// </summary>
        public void Paste()
        {
            Paste(false, Mouse.GetPosition(gridCanvas), null);
        }

        private void Paste(bool fromAttached, Point point, List<IElementEditor> fromAttachedElements)
        {
            if (_copiedElements != null)
            {
                PrepareUndoState();

                List<IElementEditor> elementsToAdd = new List<IElementEditor>();

                var clonedElements = _copiedElements.Select(x => x.Clone()).ToList();

                if (clonedElements.Count == 0) return;

                var mostLeft = clonedElements.OrderBy(x => x.Left).First().Left;
                var mostTop = clonedElements.OrderBy(x => x.Top).First().Top;

                int count = 0;

                foreach (var element in clonedElements)
                {
                    element.Left += point.X - mostLeft;
                    element.Top += point.Y - mostTop;
                    elementsToAdd.Add(element);

                    if (fromAttachedElements != null && fromAttachedElements.Count > 0)
                    {
                        fromAttachedElements[count].AttachedEditor = element;
                        element.AttachedEditor = fromAttachedElements[count++];
                    }
                }

                if (AttachedEditor != null && !fromAttached)
                {
                    AttachedEditor.Paste(true, point, clonedElements);
                }

                if (!fromAttached)
                {
                    if (AfterPaste != null) AfterPaste(this, new ElementsEventArgs(clonedElements));
                }

                foreach (var element in elementsToAdd)
                {
                    Elements.Add(element);
                }

                CommitUndoState();
            }

            InvalidateRelayCommands();
        }

        /// <summary>
        /// Brings the new element Z-index in front of the old element.
        /// </summary>
        /// <param name="oldElement">The old element.</param>
        /// <param name="newElement">The new element.</param>
        public void BringInFront(IElementEditor oldElement, IElementEditor newElement)
        {
            Canvas.SetZIndex(newElement as UIElement, Canvas.GetZIndex(oldElement as UIElement) + 1);
        }

        /// <summary>
        /// Brings the specified element to the Z-index front.
        /// </summary>
        /// <param name="element">The element.</param>
        public void BringToFront(IElementEditor element)
        {
            element.ZIndex = Elements.Max(x => Canvas.GetZIndex(x as UIElement) + 1);
        }

        /// <summary>
        /// Brings all the selected items to the front.
        /// </summary>
        public void BringToFront()
        {
            foreach (var element in GetSelectedElements())
            {
                BringToFront(element);
            }
        }

        /// <summary>
        /// Sends all the selected items to the back.
        /// </summary>
        public void SendToBack()
        {
            foreach (var element in GetSelectedElements())
            {
                SendToBack(element);
            }
        }

        /// <summary>
        /// Sets the element Z-index.
        /// </summary>
        /// <param name="element">The element.</param>
        /// <param name="index">The index.</param>
        public void SetZIndex(IElementEditor element, int index)
        {
            Canvas.SetZIndex(element as UIElement, index);
        }

        /// <summary>
        /// Gets the element Z-index.
        /// </summary>
        /// <param name="element">The element.</param>
        /// <returns></returns>
        public int GetZIndex(IElementEditor element)
        {
            return Canvas.GetZIndex(element as UIElement);
        }

        /// <summary>
        /// Sends the specified element to the Z-index back.
        /// </summary>
        /// <param name="element">The element.</param>
        public void SendToBack(IElementEditor element)
        {
            element.ZIndex = Elements.Min(x => Canvas.GetZIndex(x as UIElement) - 1);
        }

        #endregion

        #region Keyboard

        /// <summary>
        /// Invoked when an unhandled <see cref="E:System.Windows.Input.Keyboard.PreviewKeyDown" /> attached event reaches an element in its route that is derived from this class. Implement this method to add class handling for this event.
        /// </summary>
        /// <param name="e">The <see cref="T:System.Windows.Input.KeyEventArgs" /> that contains the event data.</param>
        protected override void OnPreviewKeyDown(KeyEventArgs e)
        {
            base.OnPreviewKeyDown(e);

            if (!IsEditable) return;

            if (e.Key == Key.Right)
            {
                GetSelectedElements().ForEach(x => x.PushMove(new DragDeltaEventArgs(1, 0)));
            }
            else if (e.Key == Key.Left)
            {
                GetSelectedElements().ForEach(x => x.PushMove(new DragDeltaEventArgs(-1, 0)));
            }
            else if (e.Key == Key.Up)
            {
                GetSelectedElements().ForEach(x => x.PushMove(new DragDeltaEventArgs(0, -1)));
            }
            else if (e.Key == Key.Down)
            {
                GetSelectedElements().ForEach(x => x.PushMove(new DragDeltaEventArgs(0, 1)));
            }
            else if (e.Key == Key.Z && IsCtrlDown() && EnableKeyboardUndoRedoOperations)
            {
                Undo();
            }
            else if (e.Key == Key.Y && IsCtrlDown() && EnableKeyboardUndoRedoOperations)
            {
                Redo();
            }
            else if (e.Key == Key.Delete)
            {
                RemoveSelectedElements(true);
            }
            else if (e.Key == Key.C && IsCtrlDown() && EnableKeyboardEditingOperations)
            {
                Copy();
            }
            else if (e.Key == Key.V && IsCtrlDown() && EnableKeyboardEditingOperations)
            {
                Paste();
            }
            else if (e.Key == Key.X && IsCtrlDown() && EnableKeyboardEditingOperations)
            {
                Cut();
            }
            else if (e.Key == Key.A && IsCtrlDown())
            {
                SelectAll();
            }
            else if (e.Key == Key.F && IsCtrlDown())
            {
                BringToFront();
            }
            else if (e.Key == Key.B && IsCtrlDown())
            {
                SendToBack();
            }
        }

        #endregion

        #region Override Methods

        /// <summary>
        /// Invoked when an unhandled <see cref="E:System.Windows.Input.Mouse.MouseEnter" /> attached event is raised on this element. Implement this method to add class handling for this event.
        /// </summary>
        /// <param name="e">The <see cref="T:System.Windows.Input.MouseEventArgs" /> that contains the event data.</param>
        protected override void OnMouseEnter(MouseEventArgs e)
        {
            base.OnMouseEnter(e);
            //scrollViewer.Focus();
        }

        #endregion

        #region Commands

        /// <summary>
        /// Gets or sets the copy command.
        /// </summary>
        public RelayCommand CopyCommand
        {
            get { return (RelayCommand)GetValue(CopyCommandProperty); }
            set { SetValue(CopyCommandProperty, value); }
        }
        public static readonly DependencyProperty CopyCommandProperty =
            DependencyProperty.Register("CopyCommand", typeof(RelayCommand), typeof(ElementsEditor), new PropertyMetadata(null));

        /// <summary>
        /// Gets or sets the paste command.
        /// </summary>
        public RelayCommand PasteCommand
        {
            get { return (RelayCommand)GetValue(PasteCommandProperty); }
            set { SetValue(PasteCommandProperty, value); }
        }
        public static readonly DependencyProperty PasteCommandProperty =
            DependencyProperty.Register("PasteCommand", typeof(RelayCommand), typeof(ElementsEditor), new PropertyMetadata(null));

        /// <summary>
        /// Gets or sets the undo command.
        /// </summary>
        public RelayCommand UndoCommand
        {
            get { return (RelayCommand)GetValue(UndoCommandProperty); }
            set { SetValue(UndoCommandProperty, value); }
        }
        public static readonly DependencyProperty UndoCommandProperty =
            DependencyProperty.Register("UndoCommand", typeof(RelayCommand), typeof(ElementsEditor), new PropertyMetadata(null));

        /// <summary>
        /// Gets or sets the redo command.
        /// </summary>
        public RelayCommand RedoCommand
        {
            get { return (RelayCommand)GetValue(RedoCommandProperty); }
            set { SetValue(RedoCommandProperty, value); }
        }
        public static readonly DependencyProperty RedoCommandProperty =
            DependencyProperty.Register("RedoCommand", typeof(RelayCommand), typeof(ElementsEditor), new PropertyMetadata(null));

        /// <summary>
        /// Gets or sets the delete command.
        /// </summary>
        public RelayCommand DeleteCommand
        {
            get { return (RelayCommand)GetValue(DeleteCommandProperty); }
            set { SetValue(DeleteCommandProperty, value); }
        }
        public static readonly DependencyProperty DeleteCommandProperty =
            DependencyProperty.Register("DeleteCommand", typeof(RelayCommand), typeof(ElementsEditor), new PropertyMetadata(null));

        /// <summary>
        /// Gets or sets the cut command.
        /// </summary>
        public RelayCommand CutCommand
        {
            get { return (RelayCommand)GetValue(CutCommandProperty); }
            set { SetValue(CutCommandProperty, value); }
        }
        public static readonly DependencyProperty CutCommandProperty =
            DependencyProperty.Register("CutCommand", typeof(RelayCommand), typeof(ElementsEditor), new PropertyMetadata(null));

        /// <summary>
        /// Gets or sets the select all command.
        /// </summary>
        public RelayCommand SelectAllCommand
        {
            get { return (RelayCommand)GetValue(SelectAllCommandProperty); }
            set { SetValue(SelectAllCommandProperty, value); }
        }
        public static readonly DependencyProperty SelectAllCommandProperty =
            DependencyProperty.Register("SelectAllCommand", typeof(RelayCommand), typeof(ElementsEditor), new PropertyMetadata(null));

        /// <summary>
        /// Gets or sets the zoom command.
        /// </summary>
        public RelayCommand<String> ZoomCommand
        {
            get { return (RelayCommand<String>)GetValue(ZoomCommandProperty); }
            set { SetValue(ZoomCommandProperty, value); }
        }
        public static readonly DependencyProperty ZoomCommandProperty =
            DependencyProperty.Register("ZoomCommand", typeof(RelayCommand<String>), typeof(ElementsEditor), new PropertyMetadata(null));

        /// <summary>
        /// Gets or sets the reset zoom command.
        /// </summary>
        public RelayCommand ResetZoomCommand
        {
            get { return (RelayCommand)GetValue(ResetZoomCommandProperty); }
            set { SetValue(ResetZoomCommandProperty, value); }
        }
        public static readonly DependencyProperty ResetZoomCommandProperty =
            DependencyProperty.Register("ResetZoomCommand", typeof(RelayCommand), typeof(ElementsEditor), new PropertyMetadata(null));

        /// <summary>
        /// Invokes bring to front on the selected item.
        /// </summary>
        public RelayCommand BringToFrontCommand
        {
            get { return (RelayCommand)GetValue(BringToFrontCommandProperty); }
            set { SetValue(BringToFrontCommandProperty, value); }
        }
        public static readonly DependencyProperty BringToFrontCommandProperty =
            DependencyProperty.Register("BringToFrontCommand", typeof(RelayCommand), typeof(ElementsEditor), new PropertyMetadata(null));

        /// <summary>
        /// Invokes send to back on the selected item.
        /// </summary>
        public RelayCommand SendToBackCommand
        {
            get { return (RelayCommand)GetValue(SendToBackCommandProperty); }
            set { SetValue(SendToBackCommandProperty, value); }
        }
        public static readonly DependencyProperty SendToBackCommandProperty =
            DependencyProperty.Register("SendToBackCommand", typeof(RelayCommand), typeof(ElementsEditor), new PropertyMetadata(null));

        #endregion

        #region IConfigurable Members

        /// <summary>
        /// Gets a configuration object representing the configurable properties. This configuration can be serialized to a stream or file, and later be loaded and applied to the configurable object.
        /// </summary>
        /// <returns></returns>
        public virtual IConfiguration GetConfiguration()
        {
            return GetConfiguration();
        }

        /// <summary>
        /// Gets the configuration.
        /// </summary>
        /// <param name="configurationName">Name of the configuration.</param>
        /// <returns></returns>
        public virtual ElementsEditorConfiguration GetConfiguration(String configurationName)
        {
            ElementsEditorConfiguration config = new ElementsEditorConfiguration();
            config.Name = configurationName;
            config.Date = DateTime.Now;
            config.ElementsConfigurations = new ObservableCollection<ElementEditorConfiguration>(Elements.Select(x => x.GetConfiguration() as ElementEditorConfiguration).ToList());
            return config;
        }

        /// <summary>
        /// Applies the specified configuration with an optional animation if supported by the configurable type.
        /// </summary>
        /// <param name="configuration">The configuration.</param>
        /// <param name="animation">The animation.</param>
        /// <exception cref="InvalidConfigurationException"></exception>
        public virtual void SetConfiguration(IConfiguration configuration, ConfigurationAnimation animation)
        {
            if (!(configuration is ElementsEditorConfiguration))
            {
                throw new InvalidConfigurationException();
            }

            UndoRedoStatesProvider.Reset();

            var config = configuration as ElementsEditorConfiguration;

            foreach (var elementConfig in config.ElementsConfigurations)
            {
                var existingElement = Elements.SingleOrDefault(x => x.ID == elementConfig.ID);
                if (existingElement != null)
                {
                    existingElement.SetConfiguration(elementConfig, animation);
                }
                else
                {
                    var newElement = elementConfig.CreateConfigurable<IElementEditor>();
                    Elements.Add(newElement);
                }
            }

            var elementsToRemove = Elements.Where(x => !config.ElementsConfigurations.ToList().Exists(y => y.ID == x.ID)).ToList();
            elementsToRemove.ForEach(x => RemoveElement(x));

            InvalidateRelayCommands();
        }

        #endregion

        private void SetElementSelection(IElementEditor element, bool selected)
        {
            SetIsSelected(element, selected);

            if (element.AttachedEditor != null && GetIsSelected(element.AttachedEditor) != selected)
            {
                ElementsEditor.SetIsSelected(element.AttachedEditor, selected);
            }
        }
    }
}