using System;
using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;
namespace DiagramDesigner
{
// Note: I couldn't find a useful open source library that does
// orthogonal routing so started to write something on my own.
// Categorize this as a quick and dirty short term solution.
// I will keep on searching.
// Helper class to provide an orthogonal connection path
internal class PathFinder
{
private const int margin = 20;
internal static List<Point> GetConnectionLine(ConnectorInfo source, ConnectorInfo sink, bool showLastLine)
{
List<Point> linePoints = new List<Point>();
Rect rectSource = GetRectWithMargin(source, margin);
Rect rectSink = GetRectWithMargin(sink, margin);
Point startPoint = GetOffsetPoint(source, rectSource);
Point endPoint = GetOffsetPoint(sink, rectSink);
linePoints.Add(startPoint);
Point currentPoint = startPoint;
if (!rectSink.Contains(currentPoint) && !rectSource.Contains(endPoint))
{
while (true)
{
#region source node
if (IsPointVisible(currentPoint, endPoint, new Rect[] { rectSource, rectSink }))
{
linePoints.Add(endPoint);
currentPoint = endPoint;
break;
}
Point neighbour = GetNearestVisibleNeighborSink(currentPoint, endPoint, sink, rectSource, rectSink);
if (!double.IsNaN(neighbour.X))
{
linePoints.Add(neighbour);
linePoints.Add(endPoint);
currentPoint = endPoint;
break;
}
if (currentPoint == startPoint)
{
bool flag;
Point n = GetNearestNeighborSource(source, endPoint, rectSource, rectSink, out flag);
linePoints.Add(n);
currentPoint = n;
if (!IsRectVisible(currentPoint, rectSink, new Rect[] { rectSource }))
{
Point n1, n2;
GetOppositeCorners(source.Orientation, rectSource, out n1, out n2);
if (flag)
{
linePoints.Add(n1);
currentPoint = n1;
}
else
{
linePoints.Add(n2);
currentPoint = n2;
}
if (!IsRectVisible(currentPoint, rectSink, new Rect[] { rectSource }))
{
if (flag)
{
linePoints.Add(n2);
currentPoint = n2;
}
else
{
linePoints.Add(n1);
currentPoint = n1;
}
}
}
}
#endregion
#region sink node
else // from here on we jump to the sink node
{
Point n1, n2; // neighbour corner
Point s1, s2; // opposite corner
GetNeighborCorners(sink.Orientation, rectSink, out s1, out s2);
GetOppositeCorners(sink.Orientation, rectSink, out n1, out n2);
bool n1Visible = IsPointVisible(currentPoint, n1, new Rect[] { rectSource, rectSink });
bool n2Visible = IsPointVisible(currentPoint, n2, new Rect[] { rectSource, rectSink });
if (n1Visible && n2Visible)
{
if (rectSource.Contains(n1))
{
linePoints.Add(n2);
if (rectSource.Contains(s2))
{
linePoints.Add(n1);
linePoints.Add(s1);
}
else
linePoints.Add(s2);
linePoints.Add(endPoint);
currentPoint = endPoint;
break;
}
if (rectSource.Contains(n2))
{
linePoints.Add(n1);
if (rectSource.Contains(s1))
{
linePoints.Add(n2);
linePoints.Add(s2);
}
else
linePoints.Add(s1);
linePoints.Add(endPoint);
currentPoint = endPoint;
break;
}
if ((Distance(n1, endPoint) <= Distance(n2, endPoint)))
{
linePoints.Add(n1);
if (rectSource.Contains(s1))
{
linePoints.Add(n2);
linePoints.Add(s2);
}
else
linePoints.Add(s1);
linePoints.Add(endPoint);
currentPoint = endPoint;
break;
}
else
{
linePoints.Add(n2);
if (rectSource.Contains(s2))
{
linePoints.Add(n1);
linePoints.Add(s1);
}
else
linePoints.Add(s2);
linePoints.Add(endPoint);
currentPoint = endPoint;
break;
}
}
else if (n1Visible)
{
linePoints.Add(n1);
if (rectSource.Contains(s1))
{
linePoints.Add(n2);
linePoints.Add(s2);
}
else
linePoints.Add(s1);
linePoints.Add(endPoint);
currentPoint = endPoint;
break;
}
else
{
linePoints.Add(n2);
if (rectSource.Contains(s2))
{
linePoints.Add(n1);
linePoints.Add(s1);
}
else
linePoints.Add(s2);
linePoints.Add(endPoint);
currentPoint = endPoint;
break;
}
}
#endregion
}
}
else
{
linePoints.Add(endPoint);
}
linePoints = OptimizeLinePoints(linePoints, new Rect[] { rectSource, rectSink }, source.Orientation, sink.Orientation);
CheckPathEnd(source, sink, showLastLine, linePoints);
return linePoints;
}
internal static List<Point> GetConnectionLine(ConnectorInfo source, Point sinkPoint, ConnectorOrientation preferredOrientation)
{
List<Point> linePoints = new List<Point>();
Rect rectSource = GetRectWithMargin(source, 10);
Point startPoint = GetOffsetPoint(source, rectSource);
Point endPoint = sinkPoint;
linePoints.Add(startPoint);
Point currentPoint = startPoint;
if (!rectSource.Contains(endPoint))
{
while (true)
{
if (IsPointVisible(currentPoint, endPoint, new Rect[] { rectSource }))
{
linePoints.Add(endPoint);
break;
}
bool sideFlag;
Point n = GetNearestNeighborSource(source, endPoint, rectSource, out sideFlag);
linePoints.Add(n);
currentPoint = n;
if (IsPointVisible(currentPoint, endPoint, new Rect[] { rectSource }))
{
linePoints.Add(endPoint);
break;
}
else
{
Point n1, n2;
GetOppositeCorners(source.Orientation, rectSource, out n1, out n2);
if (sideFlag)
linePoints.Add(n1);
else
linePoints.Add(n2);
linePoints.Add(endPoint);
break;
}
}
}
else
{
linePoints.Add(endPoint);
}
if (preferredOrientation != ConnectorOrientation.None)
linePoints = OptimizeLinePoints(linePoints, new Rect[] { rectSource }, source.Orientation, preferredOrientation);
else
linePoints = OptimizeLinePoints(linePoints, new Rect[] { rectSource }, source.Orientation, GetOpositeOrientation(source.Orientation));
return linePoints;
}
private static List<Point> OptimizeLinePoints(List<Point> linePoints, Rect[] rectangles, ConnectorOrientation sourceOrientation, ConnectorOrientation sinkOrientation)
{
List<Point> points = new List<Point>();
int cut = 0;
for (int i = 0; i < linePoints.Count; i++)
{
if (i >= cut)
{
for (int k = linePoints.Count - 1; k > i; k--)
{
if (IsPointVisible(linePoints[i], linePoints[k], rectangles))
{
cut = k;
break;
}
}
points.Add(linePoints[i]);
}
}
#region Line
for (int j = 0; j < points.Count - 1; j++)
{
if (points[j].X != points[j + 1].X && points[j].Y != points[j + 1].Y)
{
ConnectorOrientation orientationFrom;
ConnectorOrientation orientationTo;
// orientation from point
if (j == 0)
orientationFrom = sourceOrientation;
else
orientationFrom = GetOrientation(points[j], points[j - 1]);
// orientation to pint
if (j == points.Count - 2)
orientationTo = sinkOrientation;
else
orientationTo = GetOrientation(points[j + 1], points[j + 2]);
if ((orientationFrom == ConnectorOrientation.Left || orientationFrom == ConnectorOrientation.Right) &&
(orientationTo == ConnectorOrientation.Left || orientationTo == ConnectorOrientation.Right))
{
double centerX = Math.Min(points[j].X, points[j + 1].X) + Math.Abs(points[j].X - points[j + 1].X) / 2;
points.Insert(j + 1, new Point(centerX, points[j].Y));
points.Insert(j + 2, new Point(centerX, points[j + 2].Y));
if (points.Count - 1 > j + 3)
points.RemoveAt(j + 3);
return points;
}
if ((orientationFrom == ConnectorOrientation.Top || orientationFrom == ConnectorOrientation.Bottom) &&
(orientationTo == ConnectorOrientation.Top || orientationTo == ConnectorOrientation.Bottom))
{
double centerY = Math.Min(points[j].Y, points[j + 1].Y) + Math.Abs(points[j].Y - points[j + 1].Y) / 2;
points.Insert(j + 1, new Point(points[j].X, centerY));
points.Insert(j + 2, new Point(points[j + 2].X, centerY));
if (points.Count - 1 > j + 3)
points.RemoveAt(j + 3);
return points;
}
if ((orientationFrom == ConnectorOrientation.Left || orientationFrom == ConnectorOrientation.Right) &&
(orientationTo == ConnectorOrientation.Top || orientationTo == ConnectorOrientation.Bottom))
{
points.Insert(j + 1, new Point(points[j + 1].X, points[j].Y));
return points;
}
if ((orientationFrom == ConnectorOrientation.Top || orientationFrom == ConnectorOrientation.Bottom) &&
(orientationTo == ConnectorOrientation.Left || orientationTo == ConnectorOrientation.Right))
{
points.Insert(j + 1, new Point(points[j].X, points[j + 1].Y));
return points;
}
}
}
#endregion
return points;
}
private static ConnectorOrientation GetOrientation(Point p1, Point p2)
{
if (p1.X == p2.X)
{
if (p1.Y >= p2.Y)
return ConnectorOrientation.Bottom;
else
return ConnectorOrientation.Top;
}
else if (p1.Y == p2.Y)
{
if (p1.X >= p2.X)
return ConnectorOrientation.Right;
else
return ConnectorOrientation.Left;
}
throw new Exception("Failed to retrieve orientation");
}
private static Orientation GetOrientation(ConnectorOrientation sourceOrientation)
{
switch (sourceOrientation)
{
case ConnectorOrientation.Left:
return Orientation.Horizontal;
case ConnectorOrientation.Top:
return Orientation.Vertical;
case ConnectorOrientation.Right:
return Orientation.Horizontal;
case ConnectorOrientation.Bottom:
return Orientation.Vertical;
default:
throw new Exception("Unknown ConnectorOrientation");
}
}
private static Point GetNearestNeighborSource(ConnectorInfo source, Point endPoint, Rect rectSource, Rect rectSink, out bool flag)
{
Point n1, n2; // neighbors
GetNeighborCorners(source.Orientation, rectSource, out n1, out n2);
if (rectSink.Contains(n1))
{
flag = false;
return n2;
}
if (rectSink.Contains(n2))
{
flag = true;
return n1;
}
if ((Distance(n1, endPoint) <= Distance(n2, endPoint)))
{
flag = true;
return n1;
}
else
{
flag = false;
return n2;
}
}
private static Point GetNearestNeighborSource(ConnectorInfo source, Point endPoint, Rect rectSource, out bool flag)
{
Point n1, n2; // neighbors
GetNeighborCorners(source.Orientation, rectSource, out n1, out n2);
if ((Distance(n1, endPoint) <= Distance(n2, endPoint)))
{
flag = true;
return n1;
}
else
{
flag = false;
return n2;
}
}
private static Point GetNearestVisibleNeighborSink(Point currentPoint, Point endPoint, ConnectorInfo sink, Rect rectSource, Rect rectSink)
{
Point s1, s2; // neighbors on sink side
GetNeighborCorners(sink.Orientation, rectSink, out s1, out s2);
bool flag1 = IsPointVisible(currentPoint, s1, new Rect[] { rectSource, rectSink });
bool flag2 = IsPointVisible(currentPoint, s2, new Rect[] { rectSource, rectSink });
if (flag1) // s1 visible
{
if (flag2) // s1 and s2 visible
{
if (rectSink.Contains(s1))
return s2;
if (rectSink.Contains(s2))
return s1;
if ((Distance(s1, endPoint) <= Distance(s2, endPoint)))
return s1;
else
return s2;
}
else
{
return s1;
}
}
else // s1 not visible
{
if (flag2) // only s2 visible
{
return s2;
}
else // s1 and s2 not visible
{
return new Point(double.NaN, double.NaN);
}
}
}
private static bool IsPointVisible(Point fromPoint, Point targetPoint, Rect[] rectangles)
{
foreach (Rect rect in rectangles)
{
if (RectangleIntersectsLine(rect, fromPoint, targetPoint))
return false;
}
return true;
}
private static bool IsRectVisible(Point fromPoint, Rect targetRect, Rect[] rectangles)
{
if (IsPointVisible(fromPoint, targetRect.TopLeft, rectangles))
return true;
if (IsPointVisible(fromPoint, targetRect.TopRight, rectangles))
return true;
if (IsPointVisible(fromPoint, targetRect.BottomLeft, rectangles))
return true;
if (IsPointVisible(fromPoint, targetRect.BottomRight, rectangles))
return true;
return false;
}
private static bool RectangleIntersectsLine(Rect rect, Point startPoint, Point endPoint)
{
rect.Inflate(-1, -1);
return rect.IntersectsWith(new Rect(startPoint, endPoint));
}
private static void GetOppositeCorners(ConnectorOrientation orientation, Rect rect, out Point n1, out Point n2)
{
switch (orientation)
{
case ConnectorOrientation.Left:
n1 = rect.TopRight; n2 = rect.BottomRight;
break;
case ConnectorOrientation.Top:
n1 = rect.BottomLeft; n2 = rect.BottomRight;
break;
case ConnectorOrientation.Right:
n1 = rect.TopLeft; n2 = rect.BottomLeft;
break;
case ConnectorOrientation.Bottom:
n1 = rect.TopLeft; n2 = rect.TopRight;
break;
default:
throw new Exception("No opposite corners found!");
}
}
private static void GetNeighborCorners(ConnectorOrientation orientation, Rect rect, out Point n1, out Point n2)
{
switch (orientation)
{
case ConnectorOrientation.Left:
n1 = rect.TopLeft; n2 = rect.BottomLeft;
break;
case ConnectorOrientation.Top:
n1 = rect.TopLeft; n2 = rect.TopRight;
break;
case ConnectorOrientation.Right:
n1 = rect.TopRight; n2 = rect.BottomRight;
break;
case ConnectorOrientation.Bottom:
n1 = rect.BottomLeft; n2 = rect.BottomRight;
break;
default:
throw new Exception("No neighour corners found!");
}
}
private static double Distance(Point p1, Point p2)
{
return Point.Subtract(p1, p2).Length;
}
private static Rect GetRectWithMargin(ConnectorInfo connectorThumb, double margin)
{
Rect rect = new Rect(connectorThumb.DesignerItemLeft,
connectorThumb.DesignerItemTop,
connectorThumb.DesignerItemSize.Width,
connectorThumb.DesignerItemSize.Height);
rect.Inflate(margin, margin);
return rect;
}
private static Point GetOffsetPoint(ConnectorInfo connector, Rect rect)
{
Point offsetPoint = new Point();
switch (connector.Orientation)
{
case ConnectorOrientation.Left:
offsetPoint = new Point(rect.Left, connector.Position.Y);
break;
case ConnectorOrientation.Top:
offsetPoint = new Point(connector.Position.X, rect.Top);
break;
case ConnectorOrientation.Right:
offsetPoint = new Point(rect.Right, connector.Position.Y);
break;
case ConnectorOrientation.Bottom:
offsetPoint = new Point(connector.Position.X, rect.Bottom);
break;
default:
break;
}
return offsetPoint;
}
private static void CheckPathEnd(ConnectorInfo source, ConnectorInfo sink, bool showLastLine, List<Point> linePoints)
{
if (showLastLine)
{
Point startPoint = new Point(0, 0);
Point endPoint = new Point(0, 0);
double marginPath = 15;
switch (source.Orientation)
{
case ConnectorOrientation.Left:
startPoint = new Point(source.Position.X - marginPath, source.Position.Y);
break;
case ConnectorOrientation.Top:
startPoint = new Point(source.Position.X, source.Position.Y - marginPath);
break;
case ConnectorOrientation.Right:
startPoint = new Point(source.Position.X + marginPath, source.Position.Y);
break;
case ConnectorOrientation.Bottom:
startPoint = new Point(source.Position.X, source.Position.Y + marginPath);
break;
default:
break;
}
switch (sink.Orientation)
{
case ConnectorOrientation.Left:
endPoint = new Point(sink.Position.X - marginPath, sink.Position.Y);
break;
case ConnectorOrientation.Top:
endPoint = new Point(sink.Position.X, sink.Position.Y - marginPath);
break;
case ConnectorOrientation.Right:
endPoint = new Point(sink.Position.X + marginPath, sink.Position.Y);
break;
case ConnectorOrientation.Bottom:
endPoint = new Point(sink.Position.X, sink.Position.Y + marginPath);
break;
default:
break;
}
linePoints.Insert(0, startPoint);
linePoints.Add(endPoint);
}
else
{
linePoints.Insert(0, source.Position);
linePoints.Add(sink.Position);
}
}
private static ConnectorOrientation GetOpositeOrientation(ConnectorOrientation connectorOrientation)
{
switch (connectorOrientation)
{
case ConnectorOrientation.Left:
return ConnectorOrientation.Right;
case ConnectorOrientation.Top:
return ConnectorOrientation.Bottom;
case ConnectorOrientation.Right:
return ConnectorOrientation.Left;
case ConnectorOrientation.Bottom:
return ConnectorOrientation.Top;
default:
return ConnectorOrientation.Top;
}
}
}
}
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