/// <summary>
/// Event raised, to query for feedback, while the user is dragging a connection.
/// </summary>
private void networkControl_QueryConnectionFeedback(object sender, QueryConnectionFeedbackEventArgs e)
{
var draggedOutConnector = (ConnectorViewModel)e.ConnectorDraggedOut;
var draggedOverConnector = (ConnectorViewModel)e.DraggedOverConnector;
object feedbackIndicator = null;
bool connectionOk = true;
this.ViewModel.QueryConnnectionFeedback(draggedOutConnector, draggedOverConnector, out feedbackIndicator, out connectionOk);
//
// Return the feedback object to NetworkView.
// The object combined with the data-template for it will be used to create a 'feedback icon' to
// display (in an adorner) to the user.
//
e.FeedbackIndicator = feedbackIndicator;
//
// Let NetworkView know if the connection is ok or not ok.
//
e.ConnectionOk = connectionOk;
}
/// <summary>
/// Event raised while the user is dragging a connector.
/// </summary>
private void ConnectorItem_Dragging(object source, ConnectorItemDraggingEventArgs e)
{
e.Handled = true;
Trace.Assert((ConnectorItem)e.OriginalSource == this.draggedOutConnectorItem);
Point mousePoint = Mouse.GetPosition(this);
//
// Raise an event so that application code can compute intermediate connection points.
//
var connectionDraggingEventArgs =
new ConnectionDraggingEventArgs(ConnectionDraggingEvent, this,
this.draggedOutNodeDataContext, this.draggingConnectionDataContext,
this.draggedOutConnectorDataContext);
RaiseEvent(connectionDraggingEventArgs);
//
// Figure out if the connection has been dragged over a connector.
//
ConnectorItem connectorDraggedOver = null;
object connectorDataContextDraggedOver = null;
bool dragOverSuccess = DetermineConnectorItemDraggedOver(mousePoint, out connectorDraggedOver, out connectorDataContextDraggedOver);
if (connectorDraggedOver != null)
{
//
// Raise an event so that application code can specify if the connector
// that was dragged over is valid or not.
//
var queryFeedbackEventArgs =
new QueryConnectionFeedbackEventArgs(QueryConnectionFeedbackEvent, this, this.draggedOutNodeDataContext, this.draggingConnectionDataContext,
this.draggedOutConnectorDataContext, connectorDataContextDraggedOver);
RaiseEvent(queryFeedbackEventArgs);
if (queryFeedbackEventArgs.FeedbackIndicator != null)
{
//
// A feedback indicator was specified by the event handler.
// This is used to indicate whether the connection is good or bad!
//
AddFeedbackAdorner(connectorDraggedOver, queryFeedbackEventArgs.FeedbackIndicator);
}
else
{
//
// No feedback indicator specified by the event handler.
// Clear any existing feedback indicator.
//
ClearFeedbackAdorner();
}
}
else
{
//
// Didn't drag over any valid connector.
// Clear any existing feedback indicator.
//
ClearFeedbackAdorner();
}
}
