public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
try
{
Vertex v = value as Vertex;
UIElement e = ViewModelVertexEdge.findVertexPresenter(v);
if (e == null)
{
return(Binding.DoNothing);
}
return(e);
}
catch (InvalidCastException)
{
return(Binding.DoNothing);
}
}
public MainWindow()
{
InitializeComponent();
viewModel = new ViewModelVertexEdge();
DataContext = viewModel;
ViewModelVertexEdge.graphControl = monitor;
FollowupWindow = new Dijkstra_s_Algorithm_Followup_Window();
FollowupWindow.viewModel = viewModel;
FollowupWindow.DataContext = viewModel;
UIElement cvs = monitor as UIElement;
// These lambda functions are for draging Vertex nodes around.
moveStart = (varMoved, args) =>
{
var element = varMoved as UIElement;
dragStart = args.GetPosition(element);
element.CaptureMouse();
};
moveEnd = (varMoved, args) =>
{
var element = varMoved as UIElement;
dragStart = null;
element.ReleaseMouseCapture();
};
moving = (varMoved, args) =>
{
if (dragStart != null && args.LeftButton == MouseButtonState.Pressed)
{
var element = (UIElement)varMoved;
var p2 = args.GetPosition(cvs);
if (p2.X - dragStart.Value.X > 0)
{
Canvas.SetLeft(element, p2.X - dragStart.Value.X);
}
else
{
Canvas.SetLeft(element, 0);
}
if (p2.Y - dragStart.Value.Y > 0)
{
Canvas.SetTop(element, p2.Y - dragStart.Value.Y);
}
else
{
Canvas.SetTop(element, 0);
}
}
};
// This function is for selecting elements on the screen.
selectPresenter = (varMoved, args) =>
{
var presenter = varMoved as ContentPresenter;
switch (viewModel.CurrentStatus)
{
case SelectStatus.SelectAnElement:
if (presenter.Content is Vertex)
{
CancelSelectionAndResetStatus();
viewModel.SelectVertex(presenter.Content as Vertex);
args.Handled = true;
}
if (presenter.Content is EdgeViewModelClass)
{
CancelSelectionAndResetStatus();
viewModel.SelectEdge((presenter.Content as EdgeViewModelClass).edge);
args.Handled = true;
}
break;
case SelectStatus.EdgeBuilding:
if (presenter.Content is Vertex && presenter.Content != viewModel.CurrentVertexSelected)
{
Edge e = AddEdge(viewModel.CurrentVertexSelected, presenter.Content as Vertex);
CancelSelectionAndResetStatus();
if (e != null)
{
viewModel.SelectEdge(e);
}
args.Handled = true;
}
else
{
CancelSelectionAndResetStatus();
}
break;
case SelectStatus.SelectAStartingVertex:
if (presenter.Content is Vertex)
{
CancelSelectionAndResetStatus();
viewModel.SelectStartVertex(presenter.Content as Vertex);
args.Handled = true;
}
else
{
CancelSelectionAndResetStatus();
}
break;
case SelectStatus.SelectAnEndVertex:
if (presenter.Content is Vertex)
{
CancelSelectionAndResetStatus();
viewModel.SelectEndVertex(presenter.Content as Vertex);
args.Handled = true;
}
else
{
CancelSelectionAndResetStatus();
}
break;
default:
CancelSelectionAndResetStatus();
break;
}
};
}