ES-975464 - Resolve the ReadMe file length issue in this sample repository

README.md

@@ -1,2 +1,202 @@
-# How to drag and drop rows in wpf and uwp between listview and treegrid?
-This example illustrates how to drag and drop rows in wpf and uwp between listview and treegrid.
+# How to Drag and Drop Rows in WPF / UWP between ListView and TreeGrid?
+
+This example illustrates how to drag and drop rows between [WPF TreeGrid](https://www.syncfusion.com/wpf-controls/treegrid) / [UWP TreeGrid](https://www.syncfusion.com/uwp-ui-controls/treegrid) (SfTreeGrid) and listview.
+
+You can drag the item from ListView and drop into TreeGrid by overriding the [GetDropPosition](https://help.syncfusion.com/cr/uwp/Syncfusion.UI.Xaml.TreeGrid.TreeGridRowDragDropController.html#Syncfusion_UI_Xaml_TreeGrid_TreeGridRowDragDropController_GetDropPosition_Windows_UI_Xaml_DragEventArgs_Syncfusion_UI_Xaml_ScrollAxis_RowColumnIndex_), [ProcessOnDragOver](https://help.syncfusion.com/cr/uwp/Syncfusion.UI.Xaml.TreeGrid.TreeGridRowDragDropController.html#Syncfusion_UI_Xaml_TreeGrid_TreeGridRowDragDropController_ProcessOnDragOver_Windows_UI_Xaml_DragEventArgs_Syncfusion_UI_Xaml_ScrollAxis_RowColumnIndex_), and [ProcessOnDrop](https://help.syncfusion.com/cr/uwp/Syncfusion.UI.Xaml.TreeGrid.TreeGridRowDragDropController.html#Syncfusion_UI_Xaml_TreeGrid_TreeGridRowDragDropController_ProcessOnDrop_Windows_UI_Xaml_DragEventArgs_Syncfusion_UI_Xaml_ScrollAxis_RowColumnIndex_) methods in the [TreeGridRowDragDropController](https://help.syncfusion.com/cr/uwp/Syncfusion.UI.Xaml.TreeGrid.TreeGridRowDragDropController.html) class.
+
+In ListView, use the **DragItemsStarting** event and add dragged item. 
+
+``` csharp
+listView.CanDragItems = true;          
+listView.DragItemsStarting += ListView_DragItemsStarting;
+listView.DragItemsCompleted += ListView_DragItemsCompleted;
+
+private void ListView_DragItemsStarting(object sender, DragItemsStartingEventArgs e)
+{
+    e.Data.Properties.Add("DraggedItem", listView.SelectedItem);
+    e.Data.SetText(StandardDataFormats.Text);
+}
+
+private void ListView_DragItemsCompleted(ListViewBase sender, DragItemsCompletedEventArgs args)
+{
+    foreach (var item in args.Items)
+    {
+        (listView.ItemsSource as ObservableCollection<PersonInfo>).Remove(item as PersonInfo);
+    }
+}
+```
+
+``` csharp
+public class TreeGridRowDragDropControllerExt : TreeGridRowDragDropController
+{
+
+    public TreeGridRowDragDropControllerExt(SfTreeGrid treeGrid) : base(treeGrid)
+    {
+    }
+
+    protected override void ProcessOnDrop(DragEventArgs args, RowColumnIndex rowColumnIndex)
+    {
+        this.TreeGrid.AutoScroller.AutoScrolling = AutoScrollOrientation.None;
+        var dropPosition = GetDropPosition(args, rowColumnIndex);
+
+        if (dropPosition != DropPosition.None && rowColumnIndex.RowIndex != -1)
+        {
+            var draggedItem = GetDraggedItem(args);
+
+            if (this.TreeGrid.View is TreeGridNestedView)
+            {
+                var treeNode = this.TreeGrid.GetNodeAtRowIndex(rowColumnIndex.RowIndex);
+
+                if (treeNode == null)
+                    return;
+                var data = treeNode.Item;
+                TreeGrid.SelectionController.SuspendUpdates();
+                var itemIndex = -1;
+
+                TreeNode parentNode = null;
+
+                if (dropPosition == DropPosition.DropBelow || dropPosition == DropPosition.DropAbove)
+                    parentNode = treeNode.ParentNode;
+                else if (dropPosition == DropPosition.DropAsChild)
+                {
+                    if (!treeNode.IsExpanded)
+                        TreeGrid.ExpandNode(treeNode);
+                    parentNode = treeNode;
+                }
+                IList sourceCollection = null;
+
+                if (dropPosition == DropPosition.DropBelow || dropPosition == DropPosition.DropAbove)
+                {
+
+                    if (treeNode.ParentNode != null)
+                    {
+                        var collection = TreeGrid.View.GetPropertyAccessProvider().GetValue(treeNode.ParentNode.Item, TreeGrid.ChildPropertyName) as IEnumerable;
+                        sourceCollection = GetSourceListCollection(collection);
+                    }
+                    else
+                    {
+                        sourceCollection = GetSourceListCollection(TreeGrid.View.SourceCollection);
+                    }
+
+                    itemIndex = sourceCollection.IndexOf(data);
+
+                    if (dropPosition == DropPosition.DropBelow)
+                    {
+                        itemIndex += 1;
+                    }
+                }
+                else if (dropPosition == DropPosition.DropAsChild)
+                {
+                    var collection = TreeGrid.View.GetPropertyAccessProvider().GetValue(data, TreeGrid.ChildPropertyName) as IEnumerable;
+                    sourceCollection = GetSourceListCollection(collection);
+
+                    if (sourceCollection == null)
+                    {
+                        var list = data.GetType().GetProperty(TreeGrid.ChildPropertyName).PropertyType.CreateNew() as IList;
+
+                        if (list != null)
+                        {
+                            TreeGrid.View.GetPropertyAccessProvider().SetValue(treeNode.Item, TreeGrid.ChildPropertyName, list);
+                            sourceCollection = list;
+                        }
+                    }
+                    itemIndex = sourceCollection.Count;
+                }
+                sourceCollection.Insert(itemIndex, draggedItem);
+                TreeGrid.SelectionController.ResumeUpdates();
+                (TreeGrid.SelectionController as TreeGridRowSelectionController).RefreshSelection();
+            }
+        }
+        CloseDragIndicators();
+    }
+
+    protected override DropPosition GetDropPosition(DragEventArgs args, RowColumnIndex rowColumnIndex)
+    {
+        bool canDrop = true;
+        var p = args.GetPosition(this.TreeGrid);
+        var treeNode = this.TreeGrid.GetNodeAtRowIndex(rowColumnIndex.RowIndex);
+        ScrollAxisRegion columnRegion = ScrollAxisRegion.Body;
+        var treeGridPanel = TreeGrid.GetTreePanel();
+
+        if (treeGridPanel.FrozenColumns > 0)
+            columnRegion = ScrollAxisRegion.Header;
+        var rowRect = treeGridPanel.RangeToRect(ScrollAxisRegion.Body, columnRegion, rowColumnIndex, true, false);
+        var node = treeNode;
+
+        if (!canDrop)
+            return DropPosition.None;
+        else if (p.Y > rowRect.Y + 15 && p.Y < rowRect.Y + 35)
+        {
+            return DropPosition.DropAsChild;
+        }
+        else if (p.Y < rowRect.Y + 15)
+        {
+            return DropPosition.DropAbove;
+        }
+        else if (p.Y > rowRect.Y + 35)
+        {
+            return DropPosition.DropBelow;
+        }
+        else
+            return DropPosition.Default;
+    }
+
+    protected override void ProcessOnDragOver(DragEventArgs args, RowColumnIndex rowColumnIndex)
+    {
+        autoExpandNode = null;
+        var node = this.TreeGrid.GetNodeAtRowIndex(rowColumnIndex.RowIndex);
+        var draggedItem = GetDraggedItem(args);
+        var dropPosition = GetDropPosition(args, rowColumnIndex);
+
+        if (draggedItem == null)
+            return;
+
+        if (dropPosition == DropPosition.None || dropPosition == DropPosition.Default)
+        {
+            CloseDragIndicators();
+            args.AcceptedOperation = DataPackageOperation.None;
+            args.DragUIOverride.Caption = "Can't drop here";
+            return;
+        }
+        else if (dropPosition == DropPosition.DropAbove)
+        {
+            args.DragUIOverride.Caption = "Drop above";
+        }
+        else if (dropPosition == DropPosition.DropAsChild)
+        {
+            args.DragUIOverride.Caption = "Drop as child";
+        }
+        else
+        {
+            args.DragUIOverride.Caption = "Drop below";
+        }
+        args.AcceptedOperation = DataPackageOperation.Move;
+        ShowDragIndicators(dropPosition, rowColumnIndex);
+        args.Handled = true;
+    }
+
+    private object GetDraggedItem(DragEventArgs dragEventArgs)
+    {
+        if (dragEventArgs.DataView.Properties.ContainsKey("DraggedItem"))
+            return dragEventArgs.DataView.Properties["DraggedItem"];
+        else
+            return null;
+    }
+
+    internal IList GetSourceListCollection(IEnumerable collection = null)
+    {
+        IList list = null;
+
+        if (collection == null)
+            collection = TreeGrid.View.SourceCollection;
+
+        if ((collection as IList) != null)
+        {
+            list = collection as IList;
+        }
+        return list;
+    }
+}
+```
+
+After dropping in TreeGrid, the dragged item is added to TreeGrid based on the dropped position.