private void OnPreviewLeftMouseDown(object sender, MouseButtonEventArgs e)
{
Point mouseScreenPoint = e.GetPosition(mapControl).ToMapsui();
var draggingFeature = GetFeaturesAtScreenPoint(mouseScreenPoint).OfType <DraggingFeature>().FirstOrDefault();
if (draggingFeature == null && insertionPreviewFeature != null)
{
int insertedIndex = insertionPreviewFeature.Index;
Point insertedVertex = insertionPreviewFeature.Vertex;
draggingFeature = InsertVertex(insertedIndex, insertedVertex);
draggingLayer.TryRemove(insertionPreviewFeature);
insertionPreviewFeature = null;
}
if (draggingFeature != null)
{
// Preventing map panning
e.Handled = true;
this.draggingFeature = draggingFeature;
Point mouseWorldPoint = ScreenPointToGlobal(mouseScreenPoint);
draggingOffset = mouseWorldPoint - draggingFeature.Vertex;
return;
}
}
protected override void EndImpl()
{
UnsubscribeMouseEvents();
draggingLayer.Clear();
draggingLayer.Refresh();
insertionPreviewFeature = null;
editedObject = null;
}
private void OnPreviewMouseMove(object sender, MouseEventArgs e)
{
if (draggingFeature != null)
{
Point mousePoint = ScreenPointToGlobal(e.GetPosition(mapControl).ToMapsui());
draggingFeature.Vertex = mousePoint - draggingOffset;
draggingLayer.Refresh();
targetLayer.Refresh();
}
else
{
Point mouseScreenPoint = e.GetPosition(mapControl).ToMapsui();
if (GetFeaturesAtScreenPoint(mouseScreenPoint).OfType <DraggingFeature>().Any())
{
TryRemoveInsertionPreviewFeature();
return;
}
Point mouseWorldPoint = ScreenPointToGlobal(mouseScreenPoint);
Point previewPoint;
int index;
GetInsertionPreviewPoint(mouseScreenPoint, mouseWorldPoint, out previewPoint, out index);
if (previewPoint != null)
{
UpdateInsertionPreviewFeature(previewPoint, index);
}
else
{
TryRemoveInsertionPreviewFeature();
}
}
///////// Helper local funcs
void TryRemoveInsertionPreviewFeature()
{
if (insertionPreviewFeature != null)
{
draggingLayer.TryRemove(insertionPreviewFeature);
insertionPreviewFeature = null;
draggingLayer.Refresh();
}
}
void UpdateInsertionPreviewFeature(Point previewPoint, int index)
{
if (insertionPreviewFeature == null)
{
insertionPreviewFeature = new InsertionPreviewFeature(editedObject, previewPoint, index);
draggingLayer.Add(insertionPreviewFeature);
}
insertionPreviewFeature.Update(previewPoint, index);
draggingLayer.Refresh();
}
void GetInsertionPreviewPoint(Point mouseScreenPoint, Point mouseWorldPoint, out Point previewPoint, out int index)
{
IList <Point> vertices = editedObject.Vertices;
previewPoint = null;
index = -1;
double minDistance = double.PositiveInfinity;
int prevI, i;
if (editedObject.AreVerticesLooped)
{
prevI = vertices.Count - 1;
i = 0;
}
else
{
// The branch above allows to insert points between end and start vertices.
// If the shape is not like a ring, we should be able to to this
prevI = 0;
i = 1;
}
for (; i < vertices.Count; i++)
{
Point closestPoint = GetClosestPoint(mouseWorldPoint, vertices[prevI], vertices[i]);
Point screenPerpBase = GlobalPointToScreen(closestPoint);
double screenDistance = screenPerpBase.Distance(mouseScreenPoint);
if (screenDistance < VertexInsertionDistance && screenDistance < minDistance)
{
minDistance = screenDistance;
previewPoint = closestPoint;
index = i;
}
prevI = i;
}
}
///////// End helper local funcs
}