/View/SystemDiagramView.xaml.cs

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Data;

using System.Windows.Documents;

using System.Windows.Input;

using System.Windows.Media;

using System.Windows.Media.Imaging;

using System.Windows.Navigation;

using System.Windows.Shapes;

using System.Collections.ObjectModel;

using QuickArch.ViewModel;



namespace QuickArch.View

{

    /// <summary>

    /// Interaction logic for ComponentDiagramView.xaml

    /// </summary>

    public partial class SystemDiagramView : UserControl

    {

        AdornerLayer aLayer;



        bool _isDown, _isDragging;

        bool selected = false;

        bool _isAddNewLink, _isLinkStarted = false;

        TemporaryConnectorViewModel _tempLink;

        SystemBasicView _linkedSystem;



        UIElement selectedElement = null;

        LineGeometry _link;



        Point _startPoint, _originalPoint;

        private Canvas myCanvas;

        private ObservableCollection<ComponentViewModel> _components;

        SystemViewModel _context;



        public SystemDiagramView()

        {

            InitializeComponent();

            _components = new ObservableCollection<ComponentViewModel>();

        }



        private void myCanvas_Loaded(object sender, RoutedEventArgs e)

        {

            myCanvas = sender as Canvas;

            myCanvas.PreviewMouseLeftButtonDown += new MouseButtonEventHandler(myCanvas_PreviewMouseLeftButtonDown);

            myCanvas.PreviewMouseLeftButtonUp += new MouseButtonEventHandler(DragFinishedMouseHandler);

            myCanvas.PreviewMouseMove += new MouseEventHandler(myCanvas_PreviewMouseMove);

        }



        private void Diagram_Created(object sender, RoutedEventArgs e)

        {

            this.MouseLeftButtonDown += new MouseButtonEventHandler(Diagram_MouseLeftButtonDown);

            this.MouseLeftButtonUp += new MouseButtonEventHandler(DragFinishedMouseHandler);

            this.MouseMove += new MouseEventHandler(Diagram_MouseMove);

            this.MouseLeave += new MouseEventHandler(Diagram_MouseLeave);

            _context = DataContext as SystemViewModel;

        }



        // Handler for drag stopping on leaving the window

        void Diagram_MouseLeave(object sender, MouseEventArgs e)

        {

            StopDragging();

            e.Handled = true;

        }



        // Handler for drag stopping on user choise

        void DragFinishedMouseHandler(object sender, MouseButtonEventArgs e)

        {

            if(e.Source.GetType() == typeof(SystemBasicView))

            {

                if (_tempLink != null)

                {

                    SystemBasicView targetSystem = e.Source as SystemBasicView;

                    SystemViewModel s = (targetSystem.DataContext) as SystemViewModel;

                    _tempLink.End = s;

                    _tempLink.EndPosition = e.GetPosition(this);

                    Mouse.OverrideCursor = null;

                    _isAddNewLink = false;

                    _isLinkStarted = false;

                    _context.ComponentVMs.Add(_tempLink);

                    _tempLink = null;

                    e.Handled = true;

                }

            }

            StopDragging();

            e.Handled = true;

        }



        // Method for stopping dragging

        private void StopDragging()

        {

            if (_isDown)

            {

                _isDown = false;

                _isDragging = false;

            }

        }



        // Hanler for providing drag operation with selected element

        void Diagram_MouseMove(object sender, MouseEventArgs e)

        {

            if (_isDown)

            {

                if ((_isDragging == false) &&

                    ((Math.Abs(e.GetPosition(myCanvas).X - _startPoint.X) > SystemParameters.MinimumHorizontalDragDistance) ||

                    (Math.Abs(e.GetPosition(myCanvas).Y - _startPoint.Y) > SystemParameters.MinimumVerticalDragDistance)))

                    _isDragging = true;



                if (_isDragging)

                {

                    Point position = Mouse.GetPosition(myCanvas);

                    var newX = position.X - (_startPoint.X - _originalPoint.X);

                    var newY = position.Y - (_startPoint.Y - _originalPoint.Y);

                    selectedElement.RenderTransform = new TranslateTransform(newX, newY);

                }

            }

        }



        // Handler for clearing element selection, adorner removal

        void Diagram_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)

        {

            if (selected)

            {

                selected = false;

                if (selectedElement != null)

                {

                    aLayer.Remove(aLayer.GetAdorners(selectedElement)[0]);

                    selectedElement = null;

                }

            }

        }



        // Handler for element selection on the canvas providing resizing adorner

        void myCanvas_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)

        {

            // Remove selection on clicking anywhere the window

            if (selected)

            {

                selected = false;

                if (selectedElement != null && aLayer.GetAdorners(selectedElement) != null)

                {

                    // Remove the adorner from the selected element

                    aLayer.Remove(aLayer.GetAdorners(selectedElement)[0]);

                    selectedElement = null;

                }

            }

            //If adding a new link

            if (e.Source.GetType() == typeof(SystemBasicView))

            {

                if (e.Source.GetType() == typeof(SystemBasicView) && _isAddNewLink)

                {

                    if (!_isLinkStarted)

                    {

                        if (_link == null || _link.EndPoint != _link.StartPoint)

                        {

                            _isLinkStarted = true;

                            _linkedSystem = e.Source as SystemBasicView;

                            SystemViewModel svm = (_linkedSystem.DataContext) as SystemViewModel;

                            _tempLink = new TemporaryConnectorViewModel(svm);

                            _tempLink.StartPostion = _linkedSystem.Position;

                            e.Handled = true;

                        }

                    }

                }

                // If a componentView is selected, add adorner layer to it

                else

                {

                    _isDown = true;

                    _startPoint = e.GetPosition(myCanvas);



                    selectedElement = e.Source as UIElement;

                    _originalPoint = selectedElement.TranslatePoint(new Point(0, 0), myCanvas);



                    aLayer = AdornerLayer.GetAdornerLayer(selectedElement);

                    aLayer.Add(new ResizingAdorner(selectedElement, myCanvas));



                    selected = true;

                    e.Handled = true;

                }

            }

        }

        void myCanvas_PreviewMouseMove(object sender, MouseEventArgs e)

        {

            if (_isAddNewLink && _isLinkStarted)

                e.Handled = true;

        }

        void myCanvas_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)

        {



        }



        public void NewLinkButton_Click(object sender, RoutedEventArgs e)

        {

            _isAddNewLink = true;

            Mouse.OverrideCursor = Cursors.Cross;

        }



        private void Components_Updated(object sender, DataTransferEventArgs e)

        {

            ComponentViewModel s = sender as ComponentViewModel;

            if (s != null)

            {

                _components.Add(s);

            }

        }



        private void ContextMenu_Opened(object sender, RoutedEventArgs e)

        {

            ContextMenu menu = sender as ContextMenu;

            menu.DataContext = DataContext;

        }

    }



    #region DataTemplateSelectorClass

    public class ItemsControlTemplateSelector : DataTemplateSelector

    {

        private DataTemplate _componentTemplate = null;

        public DataTemplate ComponentTemplate

        {

            get { return _componentTemplate; }

            set { _componentTemplate = value; }

        }



        private DataTemplate _tempConnectorTemplate = null;

        public DataTemplate TempConnectorTemplate

        {

            get { return _tempConnectorTemplate; }

            set { _tempConnectorTemplate = value; }

        }



        public override DataTemplate SelectTemplate(object item,

            DependencyObject container)

        {

            if (item is ComponentViewModel)

            {

                if (item is SystemViewModel)

                    return _componentTemplate;

                if (item is TemporaryConnectorViewModel)

                    return _tempConnectorTemplate;

                if (item is ConnectorViewModel)

                    return _tempConnectorTemplate;

            }

            return base.SelectTemplate(item, container);

        }

    }

    #endregion

}