protected override void DropOnto(System.Windows.Point pt)
{
// handle dropped "Instrument"s by adding them to the Link's LabelNode (a Group)
// and by remembering the position of the label relative to a segment of the Link.Route
var newlabs = this.Diagram.SelectedParts.OfType <Node>().Where(n => Labelable(n)).ToList();
if (newlabs.Count() > 0)
{
// see if the user is dropping onto a Link
Link overlink = this.Diagram.Panel.FindElementAt <Link>(pt, Part.FindAncestor <Link>, p => ConsiderDragOver(pt, p), SearchLayers.Links);
if (overlink != null)
{
PipeData linkdata = overlink.Data as PipeData;
MyModel model = this.Diagram.Model as MyModel;
if (linkdata != null && model != null)
{
// get link's existing label group
ItemData labelgroup = model.GetLabelNodeForLink(linkdata);
if (labelgroup == null) // create it if it doesn't have one already
{
labelgroup = new InstrumentData()
{
Key = "LG", IsSubGraph = true
};
model.AddNode(labelgroup); // will provide unique Key for new group
model.SetLinkLabelKey(linkdata, labelgroup.Key);
}
// add each dropped label to link's label group
foreach (Node lab in newlabs)
{
ItemData labdata = lab.Data as ItemData;
if (labdata != null)
{
model.SetGroupNodeKey(labdata, labelgroup.Key);
}
}
}
}
// find closest segment for each label node and remember it and its offset
foreach (Node lab in newlabs)
{
InstrumentData labdata = lab.Data as InstrumentData;
if (labdata == null)
{
continue;
}
Group labcoll = lab.ContainingSubGraph;
if (labcoll == null)
{
continue;
}
Link link = labcoll.LabeledLink;
if (link != null)
{
Point labc = new Point(lab.Bounds.X + lab.Bounds.Width / 2, lab.Bounds.Y + lab.Bounds.Height / 2);
var pts = link.Route.Points;
if (pts.Count < 2)
{
continue;
}
int idx = link.Route.FindClosestSegment(labc);
if (idx >= pts.Count - 1)
{
idx = pts.Count - 2;
}
labdata.Index = idx;
Point a = pts[idx];
Point b = pts[idx + 1];
if (Math.Abs(a.Y - b.Y) < 0.1)
{
if (a.X < b.X)
{
labdata.Fraction = (labc.X <= a.X ? 0 : (labc.X >= b.X ? 1 : (labc.X - a.X) / (b.X - a.X)));
labdata.Location = new Point(0, labc.Y - a.Y);
}
else
{
labdata.Fraction = (labc.X >= a.X ? 0 : (labc.X <= b.X ? 1 : (labc.X - a.X) / (b.X - a.X)));
labdata.Location = new Point(0, a.Y - labc.Y);
}
}
else
{
if (a.Y < b.Y)
{
labdata.Fraction = (labc.Y <= a.Y ? 0 : (labc.Y >= b.Y ? 1 : (labc.Y - a.Y) / (b.Y - a.Y)));
labdata.Location = new Point(0, a.X - labc.X);
}
else
{
labdata.Fraction = (labc.Y >= a.Y ? 0 : (labc.Y <= b.Y ? 1 : (labc.Y - a.Y) / (b.Y - a.Y)));
labdata.Location = new Point(0, labc.X - a.X);
}
}
}
}
}
else
{
// rotate dropped "Valve"s
newlabs = this.Diagram.SelectedParts.OfType <Node>().Where(n => Spliceable(n)).ToList();
if (newlabs.Count() > 0)
{
// see if the user is dropping onto a Link
Link overlink = this.Diagram.Panel.FindElementAt <Link>(pt, Part.FindAncestor <Link>, p => ConsiderDragOver(pt, p), SearchLayers.Links);
MyModel model = this.Diagram.Model as MyModel;
if (overlink != null && model != null)
{
// get the data representing a Pipe
PipeData oldlinkdata = overlink.Data as PipeData;
// get the Group holding Instruments for the Pipe, if any
ItemData labelgroup = model.GetLabelNodeForLink(oldlinkdata);
var pts = overlink.Route.Points;
if (pts.Count >= 2)
{
// maybe rotate the Valve nodes
foreach (Node lab in newlabs)
{
Point labc = new Point(lab.Bounds.X + lab.Bounds.Width / 2, lab.Bounds.Y + lab.Bounds.Height / 2);
int idx = overlink.Route.FindClosestSegment(labc);
if (idx >= pts.Count - 1)
{
idx = pts.Count - 2;
}
Point a = pts[idx];
Point b = pts[idx + 1];
// if the valve were bi-directional, this needs to be smarter?
int angle = 0;
if (Math.Abs(a.Y - b.Y) < 0.1) // horizontal
{
angle = (a.X < b.X ? 0 : 180);
}
else
{
angle = (a.Y < b.Y ? 90 : 270);
}
lab.RotationAngle = angle;
// the StackPanel.Orientation governs the relative position of the TextBlock;
// it is bound to the Node.RotationAngle using a ValveOrientationConverter
}
}
base.DropOnto(pt); // this will splice the Valve(s) into the Link
if (oldlinkdata != null)
{
// find one of the new Pipes
PipeData newlinkdata = model.GetFromLinksForNode(newlabs.First().Data as ItemData).First();
// this is the label group holding all of the Instruments of the original Link
if (labelgroup != null)
{
// attach the old group of Instruments to the new Pipe
model.AddNode(labelgroup);
model.SetLinkLabelKey(newlinkdata, labelgroup.Key);
}
}
}
}
else // handle regular nodes
{
base.DropOnto(pt);
}
}
}