port from perforce

intromat/NodeNetwork/Utilities/WPF/WPFUtils.cs

@@ -0,0 +1,74 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Data;
+using System.Windows.Media;
+
+namespace NodeNetwork.Views.Controls
+{
+    public static class WPFUtils
+    {
+        public static T FindParent<T>(DependencyObject childObject) where T : DependencyObject
+        {
+            DependencyObject curObj = childObject;
+            do
+            {
+                curObj = VisualTreeHelper.GetParent(curObj);
+                if (curObj == null) return default(T);
+            } while (!(curObj is T));
+            return (T)curObj;
+        }
+
+        public static DependencyObject GetVisualAncestorNLevelsUp(DependencyObject childObject, int levels)
+        {
+            DependencyObject curObj = childObject;
+            for (int i = 0; i < levels; i++)
+            {
+                curObj = VisualTreeHelper.GetParent(curObj);
+                if (curObj == null) return null;
+            }
+            return curObj;
+        }
+
+        public static IEnumerable<Point> GetIntersectionPoints(Geometry g1, Geometry g2)
+        {
+            Geometry og1 = g1.GetWidenedPathGeometry(new Pen(Brushes.Black, 1.0));
+            Geometry og2 = g2.GetWidenedPathGeometry(new Pen(Brushes.Black, 1.0));
+
+            CombinedGeometry cg = new CombinedGeometry(GeometryCombineMode.Intersect, og1, og2);
+
+            PathGeometry pg = cg.GetFlattenedPathGeometry();
+            foreach (PathFigure figure in pg.Figures)
+            {
+                Rect fig = new PathGeometry(new[] { figure }).Bounds;
+                yield return new Point(fig.Left + fig.Width / 2.0, fig.Top + fig.Height / 2.0);
+            }
+        }
+
+        public static IEnumerable<T> FindDescendantsOfType<T>(DependencyObject root, bool skipChildrenOnHit) where T : DependencyObject
+        {
+            int childCount = VisualTreeHelper.GetChildrenCount(root);
+            for (int i = 0; i < childCount; i++)
+            {
+                var obj = VisualTreeHelper.GetChild(root, i);
+                if (obj is T t)
+                {
+                    yield return t;
+
+                    if (skipChildrenOnHit)
+                    {
+                        continue;
+                    }
+                }
+
+                foreach (var subChild in FindDescendantsOfType<T>(obj, skipChildrenOnHit))
+                {
+                    yield return subChild;
+                }
+            }
+        }
+    }
+}