protected void DetachFromAllShapes(GraphicElement el)
{
el.DisconnectShapeFromConnector(GripType.Start);
el.DisconnectShapeFromConnector(GripType.End);
el.RemoveConnection(GripType.Start);
el.RemoveConnection(GripType.End);
}
public override bool Snap(GripType type, ref Point delta)
{
// Snapping permitted only when one and only one element is selected.
if (selectedElements.Count != 1)
{
return(false);
}
bool snapped = false;
GraphicElement selectedElement = selectedElements[0];
// Look for connection points on nearby elements.
// If a connection point is nearby, and the delta is moving toward that connection point, then snap to that connection point.
// So, it seems odd that we're using the connection points of the line, rather than the anchors.
// However, this is actually simpler, and a line's connection points should at least include the endpoint anchors.
IEnumerable <ConnectionPoint> connectionPoints = selectedElement.GetConnectionPoints().Where(p => type == GripType.None || p.Type == type);
List <SnapInfo> nearElements = GetNearbyElements(connectionPoints);
ShowConnectionPoints(nearElements.Select(e => e.NearElement), true);
ShowConnectionPoints(currentlyNear.Where(e => !nearElements.Any(e2 => e.NearElement == e2.NearElement)).Select(e => e.NearElement), false);
currentlyNear = nearElements;
foreach (SnapInfo si in nearElements)
{
ConnectionPoint nearConnectionPoint = si.NearElement.GetConnectionPoints().FirstOrDefault(cp => cp.Point.IsNear(si.LineConnectionPoint.Point, SNAP_CONNECTION_POINT_RANGE));
if (nearConnectionPoint != null)
{
Point sourceConnectionPoint = si.LineConnectionPoint.Point;
int neardx = nearConnectionPoint.Point.X - sourceConnectionPoint.X; // calculate to match possible delta sign
int neardy = nearConnectionPoint.Point.Y - sourceConnectionPoint.Y;
int neardxsign = neardx.Sign();
int neardysign = neardy.Sign();
int deltaxsign = delta.X.Sign();
int deltaysign = delta.Y.Sign();
// Are we attached already or moving toward the shape's connection point?
if ((neardxsign == 0 || deltaxsign == 0 || neardxsign == deltaxsign) &&
(neardysign == 0 || deltaysign == 0 || neardysign == deltaysign))
{
// If attached, are we moving away from the connection point to detach it?
if (neardxsign == 0 && neardxsign == 0 && (delta.X.Abs() >= SNAP_DETACH_VELOCITY || delta.Y.Abs() >= SNAP_DETACH_VELOCITY))
{
selectedElement.DisconnectShapeFromConnector(type);
selectedElement.RemoveConnection(type);
}
else
{
// Not already connected?
// if (!si.NearElement.Connections.Any(c => c.ToElement == selectedElement))
if (neardxsign != 0 || neardysign != 0)
{
si.NearElement.Connections.Add(new Connection()
{
ToElement = selectedElement, ToConnectionPoint = si.LineConnectionPoint, ElementConnectionPoint = nearConnectionPoint
});
selectedElement.SetConnection(si.LineConnectionPoint.Type, si.NearElement);
}
delta = new Point(neardx, neardy);
snapped = true;
break;
}
}
}
}
return(snapped);
}
protected void Disconnect(GraphicElement el, GripType gripType)
{
el.DisconnectShapeFromConnector(gripType);
el.RemoveConnection(gripType);
}
public void Detach()
{
connector.DisconnectShapeFromConnector(gripType);
connector.RemoveConnection(gripType);
}
