GridManager.vb

Imports System
Imports System.Collections.Generic
Imports System.Linq
Imports DevExpress.XtraGrid
Imports System.Data
Imports DevExpress.XtraTreeList.Nodes
Imports System.Windows.Forms
Imports DevExpress.XtraGrid.Views.Grid
Imports DevExpress.XtraGrid.Views.Grid.ViewInfo
Imports System.Drawing
Imports DevExpress.XtraTreeList

Namespace DragAndDropBetweenGridAndTreeList
    Friend Class GridManager
        Private ReadOnly _gridControl As GridControl
        Private _dragStartHitInfo As GridHitInfo
        Private _dragRowCursor As Cursor
        Private ReadOnly _imageHelper As DragGridImageHelper

        Public Sub New(ByVal grid As GridControl)
            _gridControl = grid
            SetUpGrid(grid)
            _imageHelper = New DragGridImageHelper(TryCast(grid.FocusedView, GridView))
        End Sub

        Public Sub SetUpGrid(ByVal grid As GridControl)
            grid.AllowDrop = True
            AddHandler grid.DragOver, AddressOf grid_DragOver
            AddHandler grid.DragDrop, AddressOf grid_DragDrop
            AddHandler grid.DragLeave, AddressOf grid_DragLeave
            AddHandler grid.Paint, AddressOf grid_Paint
            AddHandler grid.GiveFeedback, AddressOf grid_GiveFeedback
            Dim view As GridView = TryCast(grid.MainView, GridView)
            view.OptionsBehavior.Editable = False
            AddHandler view.MouseMove, AddressOf view_MouseMove
            AddHandler view.MouseDown, AddressOf view_MouseDown
        End Sub

        Private Sub view_MouseDown(ByVal sender As Object, ByVal e As MouseEventArgs)
            Dim view As GridView = TryCast(sender, GridView)
            _dragStartHitInfo = Nothing
            Dim hitInfo As GridHitInfo = view.CalcHitInfo(New Point(e.X, e.Y))
            If Control.ModifierKeys <> Keys.None Then
                Return
            End If
            If e.Button = MouseButtons.Left AndAlso hitInfo.RowHandle >= 0 Then
                _dragStartHitInfo = hitInfo
            End If
        End Sub

        Private Sub view_MouseMove(ByVal sender As Object, ByVal e As MouseEventArgs)
            Dim view As GridView = TryCast(sender, GridView)
            If e.Button = MouseButtons.Left AndAlso _dragStartHitInfo IsNot Nothing Then
                Dim dragSize As Size = SystemInformation.DragSize
                Dim dragRect As New Rectangle(New Point(_dragStartHitInfo.HitPoint.X - dragSize.Width \ 2, _dragStartHitInfo.HitPoint.Y - dragSize.Height \ 2), dragSize)
                If Not dragRect.Contains(New Point(e.X, e.Y)) Then
                    _dragRowCursor = _imageHelper.GetDragCursor(_dragStartHitInfo.RowHandle, e.Location)
                    Dim row As DataRow = view.GetDataRow(_dragStartHitInfo.RowHandle)
                    view.GridControl.DoDragDrop(row, DragDropEffects.Move)
                    _dragStartHitInfo = Nothing
                    DevExpress.Utils.DXMouseEventArgs.GetMouseArgs(e).Handled = True
                End If
            End If
        End Sub


        Private dropTargetRowHandle_Renamed As Integer = -1
        Private Property DropTargetRowHandle() As Integer
            Get
                Return dropTargetRowHandle_Renamed
            End Get
            Set(ByVal value As Integer)
                dropTargetRowHandle_Renamed = value
                _gridControl.Invalidate()
            End Set
        End Property

        Private Sub grid_DragDrop(ByVal sender As Object, ByVal e As DragEventArgs)
            Dim grid As GridControl = TryCast(sender, GridControl)
            Dim table As DataTable = TryCast(grid.DataSource, DataTable)
            Dim node As TreeListNode = TryCast(e.Data.GetData(GetType(TreeListNode)), TreeListNode)
            If node.RootNode Is node Then
                Return
            End If
            If node IsNot Nothing AndAlso table IsNot Nothing Then
                Dim itemArray As New List(Of Object)()
                For Each column As DataColumn In table.Columns
                    itemArray.Add(node.GetValue(column))
                Next column
                Dim tmp(itemArray.Count - 1) As Object
                itemArray.CopyTo(tmp)
                Dim row As DataRow = table.NewRow()
                row.ItemArray = tmp
                table.Rows.InsertAt(row, DropTargetRowHandle)
                Dim treeList As TreeList = node.TreeList
                treeList.DeleteNode(node)
            End If
            DropTargetRowHandle = -1
        End Sub

        Private Sub grid_DragOver(ByVal sender As Object, ByVal e As DragEventArgs)
            Dim grid As GridControl = DirectCast(sender, GridControl)
            Dim pt As New Point(e.X, e.Y)
            pt = grid.PointToClient(pt)
            Dim view As GridView = TryCast(grid.GetViewAt(pt), GridView)
            If view Is Nothing Then
                Return
            End If
            Dim hitInfo As GridHitInfo = view.CalcHitInfo(pt)
            If hitInfo.RowHandle = GridControl.InvalidRowHandle Then
                DropTargetRowHandle = view.DataRowCount
            Else
                DropTargetRowHandle = hitInfo.RowHandle
            End If
            Dim node As TreeListNode = TryCast(e.Data.GetData(GetType(TreeListNode)), TreeListNode)
            If DropTargetRowHandle >= 0 AndAlso e.Data.GetDataPresent(GetType(TreeListNode)) AndAlso node.RootNode IsNot node Then
                e.Effect = DragDropEffects.Move
            Else
                e.Effect = DragDropEffects.None
            End If
        End Sub

        Private Sub grid_DragLeave(ByVal sender As Object, ByVal e As EventArgs)
            DropTargetRowHandle = -1
        End Sub

        Private Sub grid_Paint(ByVal sender As Object, ByVal e As PaintEventArgs)
            If DropTargetRowHandle < 0 Then
                Return
            End If
            Dim grid As GridControl = DirectCast(sender, GridControl)
            Dim view As GridView = CType(grid.MainView, GridView)
            Dim isBottomLine As Boolean = DropTargetRowHandle = view.DataRowCount
            Dim viewInfo As GridViewInfo = TryCast(view.GetViewInfo(), GridViewInfo)
            Dim rowInfo As GridRowInfo = viewInfo.GetGridRowInfo(If(isBottomLine, DropTargetRowHandle - 1, DropTargetRowHandle))
            If rowInfo Is Nothing Then
                Return
            End If
            Dim p1, p2 As Point
            If isBottomLine Then
                p1 = New Point(rowInfo.Bounds.Left, rowInfo.Bounds.Bottom - 1)
                p2 = New Point(rowInfo.Bounds.Right, rowInfo.Bounds.Bottom - 1)
            Else
                p1 = New Point(rowInfo.Bounds.Left, rowInfo.Bounds.Top - 1)
                p2 = New Point(rowInfo.Bounds.Right, rowInfo.Bounds.Top - 1)
            End If
            e.Graphics.DrawLine(Pens.Blue, p1, p2)
        End Sub

        Private Sub grid_GiveFeedback(ByVal sender As Object, ByVal e As GiveFeedbackEventArgs)
            If _dragStartHitInfo IsNot Nothing Then
                e.UseDefaultCursors = False
                Cursor.Current = _dragRowCursor
            End If
        End Sub
    End Class
End Namespace