migrate to wpf

DragHandler.cs

@@ -0,0 +1,73 @@
+// Copyright(c) 2019 pypy. All rights reserved.
+//
+// This work is licensed under the terms of the MIT license.
+// For a copy, see <https://opensource.org/licenses/MIT>.
+
+using System;
+using System.Collections.Generic;
+using System.Drawing;
+using CefSharp;
+using CefSharp.Enums;
+
+namespace VRCX
+{
+    public class DragHandler : IDragHandler
+    {
+        public event Action<Region> RegionsChanged;
+
+        public void Dispose()
+        {
+            RegionsChanged = null;
+        }
+
+        bool IDragHandler.OnDragEnter(IWebBrowser chromiumWebBrowser, IBrowser browser, IDragData dragData, DragOperationsMask mask)
+        {
+            return false;
+        }
+
+        void IDragHandler.OnDraggableRegionsChanged(IWebBrowser chromiumWebBrowser, IBrowser browser, IFrame frame, IList<DraggableRegion> regions)
+        {
+            //By default popup browers are native windows in WPF so we cannot handle their drag using this method
+            if (browser.IsPopup == false)
+            {
+                //NOTE: I haven't tested with dynamically adding removing regions so this may need some tweaking
+                Region draggableRegion = null;
+
+                if (regions.Count > 0)
+                {
+                    //Take the individual Region and construct a complex Region that represents them all.
+                    foreach (var region in regions)
+                    {
+                        var rect = new Rectangle(region.X, region.Y, region.Width, region.Height);
+
+                        if (draggableRegion == null)
+                        {
+                            draggableRegion = new Region(rect);
+                        }
+                        else
+                        {
+                            if (region.Draggable)
+                            {
+                                draggableRegion.Union(rect);
+                            }
+                            else
+                            {
+                                //In the scenario where we have an outer region, that is draggable and it has
+                                // an inner region that's not, we must exclude the non draggable.
+                                // Not all scenarios are covered in this example.
+                                draggableRegion.Exclude(rect);
+                            }
+                        }
+                    }
+                }
+
+                var handler = RegionsChanged;
+
+                if (handler != null)
+                {
+                    handler(draggableRegion);
+                }
+            }
+        }
+    }
+}