Imports System.ComponentModel
Imports System.Reflection
Imports System.Windows.Forms.VisualStyles

Namespace UI
    Public Enum AutoCheckMode
        None
        SingleClick
        DoubleClick
    End Enum

    Public Class ListViewEx
        Inherits ListView

        Private LastDragOverPos As Point
        Private LastDrawPos As Integer
        Private _blockItemChanged As Boolean = False

        Private _backAlternateColor As Color
        Private _backHighlightColor As Color
        Private _backSelectedColor As Color
        Private _foreHighlightColor As Color
        Private _foreSelectedColor As Color
        Private _separatorColor As Color
        Private _symbolImageColor As Color

        Event ControlsUpdated()

        Public Property BackAlternateColor As Color
            Get
                Return _backAlternateColor
            End Get
            Set(value As Color)
                _backAlternateColor = value
                Invalidate()
            End Set
        End Property

        Private Function ShouldSerializeBackAlternateColor() As Boolean
            Return BackAlternateColor <> Color.Empty
        End Function

        Public Property BackHighlightColor As Color
            Get
                Return _backHighlightColor
            End Get
            Set(value As Color)
                _backHighlightColor = value
                Invalidate()
            End Set
        End Property

        Private Function ShouldSerializeBackHighlightColor() As Boolean
            Return BackHighlightColor <> Color.Empty
        End Function

        Public Property BackSelectedColor As Color
            Get
                Return _backSelectedColor
            End Get
            Set(value As Color)
                _backSelectedColor = value
                Invalidate()
            End Set
        End Property

        Private Function ShouldSerializeBackSelectedColor() As Boolean
            Return BackSelectedColor <> Color.Empty
        End Function

        Public Property ForeHighlightColor As Color
            Get
                Return _foreHighlightColor
            End Get
            Set(value As Color)
                _foreHighlightColor = value
                Invalidate()
            End Set
        End Property

        Private Function ShouldSerializeForeHighlightColor() As Boolean
            Return ForeHighlightColor <> Color.Empty
        End Function

        Public Property ForeSelectedColor As Color
            Get
                Return _foreSelectedColor
            End Get
            Set(value As Color)
                _foreSelectedColor = value
                Invalidate()
            End Set
        End Property

        Private Function ShouldSerializeForeSelectedColor() As Boolean
            Return ForeSelectedColor <> Color.Empty
        End Function

        Public Property SymbolImageColor As Color
            Get
                Return _symbolImageColor
            End Get
            Set(value As Color)
                _symbolImageColor = value
                Invalidate()
            End Set
        End Property

        Private Function ShouldSerializeSymbolImageColor() As Boolean
            Return SymbolImageColor <> Color.Empty
        End Function

        Public Property SeparatorColor As Color
            Get
                Return _separatorColor
            End Get
            Set(value As Color)
                _separatorColor = value
                Invalidate()
            End Set
        End Property

        Private Function ShouldSerializeSeparatorColor() As Boolean
            Return SeparatorColor <> Color.Empty
        End Function

        Event ItemsChanged(indices As Integer())
        Event ItemRemoved(item As ListViewItem)
        Event UpdateContextMenu()

        <DefaultValue(GetType(ButtonEx), Nothing)>
        Property UpButton As ButtonEx

        <DefaultValue(GetType(ButtonEx), Nothing)>
        Property DownButton As ButtonEx

        <DefaultValue(GetType(ButtonEx), Nothing)>
        Property RemoveButton As ButtonEx

        <DefaultValue(GetType(ButtonEx()), Nothing)>
        Property SingleSelectionButtons As Button()

        <DefaultValue(GetType(ButtonEx()), Nothing)>
        Property MultiSelectionButtons As Button()

        <DefaultValue(CStr(Nothing))>
        Property ItemCheckProperty As String

        <DefaultValue(False)>
        Property ShowContextMenuOnLeftClick As Boolean

        <DefaultValue(False)>
        Property RightClickOnlyForMenu As Boolean

        <DefaultValue(GetType(AutoCheckMode), "DoubleClick")>
        Property AutoCheckMode As AutoCheckMode = AutoCheckMode.DoubleClick

        Sub New()
            DoubleBuffered = True
            OwnerDraw = True
            Font = FontManager.GetDefaultFont()

            ApplyTheme()

            AddHandler ThemeManager.CurrentThemeChanged, AddressOf OnThemeChanged
        End Sub

        Protected Overrides Sub Dispose(disposing As Boolean)
            RemoveHandler ThemeManager.CurrentThemeChanged, AddressOf OnThemeChanged
            MyBase.Dispose(disposing)
        End Sub

        Sub OnThemeChanged(theme As Theme)
            ApplyTheme(theme)
        End Sub

        Sub ApplyTheme()
            ApplyTheme(ThemeManager.CurrentTheme)
        End Sub

        Sub ApplyTheme(theme As Theme)
            If DesignHelp.IsDesignMode Then
                Exit Sub
            End If

            BackColor = theme.General.Controls.ListView.BackColor
            BackAlternateColor = theme.General.Controls.ListView.BackAlternateColor
            BackHighlightColor = theme.General.Controls.ListView.BackHighlightColor
            BackSelectedColor = theme.General.Controls.ListView.BackSelectedColor
            ForeColor = theme.General.Controls.ListView.ForeColor
            ForeHighlightColor = theme.General.Controls.ListView.ForeHighlightColor
            ForeSelectedColor = theme.General.Controls.ListView.ForeSelectedColor
            SeparatorColor = theme.General.Controls.ListView.SeparatorColor
            SymbolImageColor = theme.General.Controls.ListView.SymbolImageColor
            BorderStyle = BorderStyle.Fixed3D
        End Sub

        Protected Overrides Sub OnDrawItem(e As DrawListViewItemEventArgs)
            e.DrawDefault = False
            Dim flags = GetTextAlignment(0)
            Dim fc = e.Item.ForeColor
            Dim rect = e.Item.Bounds

            If e.Item.Selected Then
                Using brush As New SolidBrush(BackSelectedColor)
                    e.Graphics.FillRectangle(brush, e.Bounds)
                End Using
                fc = ForeSelectedColor
            Else
                e.Item.BackColor = If(e.ItemIndex Mod 2 = 1, BackAlternateColor, BackColor)
                e.DrawBackground()
            End If

            Dim separatorRect = New Rectangle(e.Item.Bounds.Right - 2, e.Item.Bounds.Top, 2, Height)
            Using brush As New SolidBrush(SeparatorColor)
                e.Graphics.FillRectangle(brush, separatorRect)
            End Using

            If CheckBoxes Then
                Dim checkedState = If(e.Item.Checked, CheckBoxState.CheckedNormal, CheckBoxState.UncheckedNormal)
                Dim glyphSize = CheckBoxRendererEx.GetGlyphSize(e.Graphics, checkedState)
                Dim hPos = (e.Bounds.Height - glyphSize.Height) \ 2
                Dim vPos = hPos + e.Bounds.Y
                Dim location = New Point(hPos, vPos)
                Dim textOffset = CInt(glyphSize.Width * 1.25)
                rect.X += textOffset
                rect.Width -= textOffset

                CheckBoxRendererEx.DrawCheckBox(e.Graphics, location, checkedState)
            End If

            TextRenderer.DrawText(e.Graphics, e.Item.Text, e.Item.Font, rect, fc, flags)
        End Sub

        Protected Overrides Sub OnDrawSubItem(e As DrawListViewSubItemEventArgs)
            Dim flags = GetTextAlignment(e.ColumnIndex)
            Dim fc = If(e.Item.Selected, ForeSelectedColor, ForeColor)

            If Not CheckBoxes OrElse e.ColumnIndex <> 0 Then
                TextRenderer.DrawText(e.Graphics, e.SubItem.Text, e.SubItem.Font, e.Bounds, fc, flags)
            End If

            Dim separatorRect = New Rectangle(e.SubItem.Bounds.Left - 2, e.SubItem.Bounds.Top, 2, Height)
            Using brush As New SolidBrush(SeparatorColor)
                e.Graphics.FillRectangle(brush, separatorRect)
            End Using
        End Sub

        Protected Overrides Sub OnCreateControl()
            MyBase.OnCreateControl()
        End Sub

        Sub OnItemsChanged(ParamArray indices As Integer())
            RaiseEvent ItemsChanged(indices)
        End Sub

        Function GetTextAlignment(columnIndex As Integer) As TextFormatFlags
            Dim flags As TextFormatFlags = If(View = View.Tile, If(columnIndex = 0, TextFormatFlags.Default, TextFormatFlags.Bottom), TextFormatFlags.VerticalCenter)
            flags = flags Or TextFormatFlags.NoPrefix

            If View = View.Details Then
                flags = flags Or TextFormatFlags.LeftAndRightPadding
            End If

            If columnIndex < Columns.Count AndAlso Not Columns(columnIndex).TextAlign = HorizontalAlignment.Left Then
                flags = flags Or CType(CInt(Columns(columnIndex).TextAlign ^ 3), TextFormatFlags)
            End If

            Return flags
        End Function

        Sub SelectFirst()
            If Items.Count > 0 Then
                Items(0).Selected = True
            End If

            UpdateControls()
        End Sub

        Function SelectedItem(Of T)() As T
            If SelectedItems.Count > 0 Then
                Return DirectCast(SelectedItems(0).Tag, T)
            End If
        End Function

        Function SelectedItem() As Object
            If SelectedItems.Count > 0 Then
                Return SelectedItems(0).Tag
            End If
        End Function

        Function AddItem(item As Object) As ListViewItem
            Dim listItem = Items.Add("")
            listItem.Tag = item
            RefreshItem(listItem.Index)
            If Not _blockItemChanged Then OnItemsChanged()
            Return listItem
        End Function

        Sub AddItems(items As IEnumerable)
            _blockItemChanged = True
            For Each item In items
                AddItem(item)
            Next
            _blockItemChanged = False
        End Sub

        Sub RefreshItem(index As Integer)
            If ItemCheckProperty <> "" Then
                Items(index).Checked = CBool(Items(index).Tag.GetType.GetProperty(ItemCheckProperty).GetValue(Items(index).Tag))
            End If

            Items(index).Text = Items(index).Tag.ToString
        End Sub

        Sub RefreshSelection()
            For Each item As ListViewItem In SelectedItems
                RefreshItem(item.Index)
            Next
        End Sub

        Sub EnableListBoxMode()
            View = View.Details
            FullRowSelect = True
            Columns.Add("")
            HeaderStyle = ColumnHeaderStyle.None
            AddHandler Layout, Sub() Columns(0).Width = Width - 4 - SystemInformation.VerticalScrollBarWidth
            AddHandler HandleCreated, Sub() Columns(0).Width = Width - 4
        End Sub

        Sub UpdateControls()
            If Not UpButton Is Nothing Then
                UpButton.Enabled = CanMoveUp()
            End If

            If Not DownButton Is Nothing Then
                DownButton.Enabled = CanMoveDown()
            End If

            If Not RemoveButton Is Nothing Then
                RemoveButton.Enabled = Not SelectedItem() Is Nothing
            End If

            If Not SingleSelectionButtons Is Nothing Then
                For Each button In SingleSelectionButtons
                    button.Enabled = SelectedItems.Count = 1
                Next
            End If

            If Not MultiSelectionButtons Is Nothing Then
                For Each button In MultiSelectionButtons
                    button.Enabled = SelectedItems.Count > 0
                Next
            End If

            RaiseEvent ControlsUpdated()
        End Sub

        Function CanMoveUp() As Boolean
            Return SelectedIndices.Count > 0 AndAlso SelectedIndices(0) > 0
        End Function

        Function CanMoveDown() As Boolean
            Return SelectedIndices.Count > 0 AndAlso SelectedIndices(SelectedIndices.Count - 1) < Items.Count - 1
        End Function

        Sub MoveSelectionTop()
            If CanMoveUp() Then
                BeginUpdate()
                Dim selected = SelectedItems.OfType(Of ListViewItem).ToList

                For Each i In selected
                    Items.Remove(i)
                Next

                For x = 0 To selected.Count - 1
                    Items.Insert(x, selected(x))
                Next

                EndUpdate()
            End If
        End Sub

        Sub MoveSelectionBottom()
            If CanMoveDown() Then
                BeginUpdate()
                Dim selected = SelectedItems.OfType(Of ListViewItem).ToArray

                For Each item In selected
                    Items.Remove(item)
                Next

                Items.AddRange(selected)
                EndUpdate()
            End If
        End Sub

        Sub MoveSelectionUp()
            If CanMoveUp() Then
                Dim indexAbove = SelectedIndices(0) - 1
                If indexAbove < 0 Then Exit Sub

                Dim movedIndices = SelectedIndices.Cast(Of Integer).Union({indexAbove}).ToArray()
                Dim itemAbove = Items(indexAbove)
                Dim indexInsert = SelectedIndices(SelectedIndices.Count - 1)

                BeginUpdate()
                Items.RemoveAt(indexAbove)
                Items.Insert(indexInsert, itemAbove)
                UpdateControls()
                OnItemsChanged(movedIndices)
                EnsureVisible(indexAbove)
                EndUpdate()
            End If
        End Sub

        Sub MoveSelectionDown()
            If CanMoveDown() Then
                Dim indexBelow = SelectedIndices(SelectedIndices.Count - 1) + 1
                If indexBelow >= Items.Count Then Exit Sub

                Dim movedIndices = SelectedIndices.Cast(Of Integer).Union({indexBelow}).ToArray()
                Dim itemBelow = Items(indexBelow)
                Dim indexInsert = SelectedIndices(0)

                BeginUpdate()
                Items.RemoveAt(indexBelow)
                Items.Insert(indexInsert, itemBelow)
                UpdateControls()
                OnItemsChanged(movedIndices)
                EnsureVisible(indexBelow)
                EndUpdate()
            End If
        End Sub

        Sub RemoveSelection()
            If SelectedItems.Count > 0 Then
                Const maxToDisplay As Integer = 15
                Dim names = SelectedItems.OfType(Of ListViewItem).Take(maxToDisplay).Select(Function(x) x.Text).Join(BR, True)

                If names = "" Then
                    Try
                        names = SelectedItems.OfType(Of ListViewItem).Take(maxToDisplay).Select(Function(x) CStr(x.Tag)).Join(BR, True)
                    Catch
                    End Try
                End If

                If SelectedItems.Count > maxToDisplay AndAlso names.Length > 4 Then
                    names = names + BR + "... and more ..."
                End If

                If MsgQuestion("Remove Selection?", names) <> DialogResult.OK Then
                    Exit Sub
                End If

                BeginUpdate()

                If Not MultiSelect Then
                    Dim index = SelectedIndices(0)

                    If Items.Count - 1 > index Then
                        Items(index + 1).Selected = True
                    Else
                        If index > 0 Then
                            Items(index - 1).Selected = True
                        End If
                    End If

                    Dim removedItem = Items(index)
                    Items.RemoveAt(index)
                    RaiseEvent ItemRemoved(removedItem)
                Else
                    Dim iFirst = SelectedIndices(0)
                    Dim indices(SelectedIndices.Count - 1) As Integer
                    SelectedIndices.CopyTo(indices, 0)

                    For i = indices.Length - 1 To 0 Step -1
                        Dim removedItem = Items(indices(i))
                        Items.RemoveAt(indices(i))
                        RaiseEvent ItemRemoved(removedItem)
                    Next

                    If Items.Count > 0 Then
                        Dim index = If(iFirst > Items.Count - 1, Items.Count - 1, iFirst)
                        Items(index).Selected = True
                        EnsureVisible(index)
                    End If
                End If

                EndUpdate()
                UpdateControls()
                OnItemsChanged()
            End If
        End Sub

        Sub SortItems()
            BeginUpdate()
            Dim sortedItems = Items.OfType(Of ListViewItem).OrderBy(Function(item) item.Text).ToArray
            Items.Clear()
            Items.AddRange(sortedItems)
            EndUpdate()
            UpdateControls()
            OnItemsChanged()
        End Sub

        Protected Overrides Sub OnSelectedIndexChanged(e As EventArgs)
            UpdateControls()
            MyBase.OnSelectedIndexChanged(e)
        End Sub

        Sub HideFocusRectange()
            Const UIS_SET = 1, UISF_HIDEFOCUS = &H1, WM_CHANGEUISTATE = &H127
            Native.SendMessage(Handle, WM_CHANGEUISTATE, MAKEWPARAM(UIS_SET, UISF_HIDEFOCUS), 0)
        End Sub

        Function MAKEWPARAM(low As Integer, high As Integer) As Integer
            Return (low And &HFFFF) Or (high << 16)
        End Function

        Protected Overrides Sub WndProc(ByRef m As Message)
            Select Case m.Msg
                Case &H203 'WM_LBUTTONDBLCLK
                    If CheckBoxes AndAlso AutoCheckMode <> AutoCheckMode.DoubleClick Then
                        OnDoubleClick(Nothing)
                        Exit Sub
                    End If
                Case &H201 'WM_LBUTTONDOWN
                    If CheckBoxes AndAlso AutoCheckMode = AutoCheckMode.SingleClick Then
                        Dim pos = ClientMousePos
                        Dim item = GetItemAt(pos.X, pos.Y)

                        If Not item Is Nothing Then
                            Dim itemBounds = item.GetBounds(ItemBoundsPortion.Entire)

                            If pos.X > itemBounds.Left + itemBounds.Height Then
                                item.Checked = Not item.Checked
                            End If
                        End If
                    End If
                Case &H204 'WM_RBUTTONDOWN
                    If RightClickOnlyForMenu Then
                        m.Result = New IntPtr(1)
                        ShowMenu()
                        Exit Sub
                    End If
            End Select

            Try
                MyBase.WndProc(m)
            Catch ex As DivideByZeroException
                If m.Msg = &H20A Then 'WM_MOUSEWHEEL
                Else
                    Throw ex
                End If
            End Try
        End Sub

        Protected Overrides Sub OnMouseUp(e As MouseEventArgs)
            If e.Button = MouseButtons.Right Then
                RaiseEvent UpdateContextMenu()
            End If

            If ShowContextMenuOnLeftClick AndAlso e.Button = MouseButtons.Left Then
                RaiseEvent UpdateContextMenu()
                ContextMenuStrip.Show(Me, e.Location)
            End If

            MyBase.OnMouseUp(e)
        End Sub

        Sub ShowMenu()
            RaiseEvent UpdateContextMenu()
            ContextMenuStrip.Show(Me, PointToClient(MousePosition))
        End Sub

        Function GetBounds(mousePos As Point) As Rectangle
            Dim x, y, w, h, columnLeft, checkLength As Integer

            For Each header As ColumnHeader In Columns
                If header.Index = 0 AndAlso CheckBoxes Then
                    checkLength = 20
                Else
                    checkLength = 0
                End If

                If mousePos.X >= columnLeft + checkLength AndAlso
                    mousePos.X <= columnLeft + header.Width Then

                    x = columnLeft + checkLength
                    w = header.Width - checkLength
                    Exit For
                End If

                columnLeft += header.Width
            Next

            For Each item As ListViewItem In Items
                Dim bounds = item.GetBounds(ItemBoundsPortion.Entire)

                If mousePos.Y >= bounds.Top AndAlso mousePos.Y <= bounds.Bottom Then
                    y = bounds.Top
                    h = bounds.Height
                End If
            Next

            If w = 0 OrElse h = 0 Then
                Return Rectangle.Empty
            Else
                Return New Rectangle(x, y, w, h)
            End If
        End Function

        Function GetPos(mousePos As Point) As Point
            Dim x, y, checkLength, columnLeft As Integer

            For Each header As ColumnHeader In Columns
                If header.Index = 0 AndAlso CheckBoxes Then
                    checkLength = 20
                Else
                    checkLength = 0
                End If

                If mousePos.X >= columnLeft + checkLength AndAlso
                    mousePos.X <= columnLeft + header.Width Then

                    x = header.Index
                End If

                columnLeft += header.Width
            Next

            For Each item As ListViewItem In Items
                Dim bounds = item.GetBounds(ItemBoundsPortion.Entire)

                If mousePos.Y >= bounds.Top AndAlso mousePos.Y <= bounds.Bottom Then
                    y = item.Index
                End If
            Next

            Return New Point(x, y)
        End Function

        Protected Overrides Sub OnDragEnter(e As DragEventArgs)
            If e.Data.GetDataPresent(DataFormats.FileDrop) Then
                e.Effect = DragDropEffects.Copy
                MyBase.OnDragEnter(e)
                Exit Sub
            End If

            e.Effect = DragDropEffects.Move
            MyBase.OnDragEnter(e)
        End Sub

        Protected Overrides Sub OnItemDrag(e As ItemDragEventArgs)
            If SelectedItems.Count > 1 Then
                Exit Sub
            End If

            DoDragDrop(e.Item, DragDropEffects.Move)
            MyBase.OnItemDrag(e)
        End Sub

        Function GetMousePos() As Point
            Return PointToClient(Control.MousePosition)
        End Function

        Protected Overrides Sub OnDragOver(e As DragEventArgs)
            If e.Data.GetDataPresent(DataFormats.FileDrop) Then
                MyBase.OnDragOver(e)
                Exit Sub
            End If

            If Control.MousePosition <> LastDragOverPos Then
                Dim mousePos = GetMousePos()
                Dim bounds = GetBounds(mousePos)

                If Not e.Data.GetDataPresent(GetType(ListViewItem)) Then
                    e.Effect = DragDropEffects.None
                ElseIf Not bounds = Rectangle.Empty Then
                    e.Effect = DragDropEffects.Move
                    Dim y As Integer

                    If Math.Abs(mousePos.Y - bounds.Top) <
                        Math.Abs(mousePos.Y - bounds.Bottom) Then

                        y = bounds.Top
                    Else
                        y = bounds.Bottom
                    End If

                    If y <> LastDrawPos Then
                        LastDrawPos = y
                        Refresh()

                        Using gx As Graphics = CreateGraphics()
                            gx.DrawLine(Pens.Black, 0, y, Width, y)
                        End Using
                    End If
                Else
                    LastDrawPos = -1
                    e.Effect = DragDropEffects.None
                    Refresh()
                End If
            End If

            LastDragOverPos = Control.MousePosition
            MyBase.OnDragOver(e)
        End Sub

        Protected Overrides Sub OnDragDrop(e As DragEventArgs)
            If e.Data.GetDataPresent(DataFormats.FileDrop) Then
                Dim form = FindForm()

                If form.AllowDrop Then
                    form.GetType.GetMethod("OnDragDrop",
                        BindingFlags.Instance Or BindingFlags.NonPublic).Invoke(form, {e})
                End If

                Exit Sub
            End If

            Dim item = DirectCast(e.Data.GetData(GetType(ListViewItem)), ListViewItem)
            Dim mousePos = GetMousePos()
            Dim p = GetPos(mousePos)
            Dim r = GetBounds(mousePos)
            Dim index As Integer

            If Math.Abs(mousePos.Y - r.Top) < Math.Abs(mousePos.Y - r.Bottom) Then

                index = p.Y
            Else
                index = p.Y + 1
            End If

            If index > item.Index Then
                index -= 1
            End If

            item.Remove()
            Items.Insert(index, item)
            MyBase.OnDragDrop(e)
        End Sub

        Protected Overrides Sub OnHandleCreated(e As EventArgs)
            MyBase.OnHandleCreated(e)
            Native.SetWindowTheme(Handle, "explorer", Nothing)

            If Not UpButton Is Nothing Then UpButton.ClickAction = AddressOf MoveSelectionUp
            If Not DownButton Is Nothing Then DownButton.ClickAction = AddressOf MoveSelectionDown
            If Not RemoveButton Is Nothing Then RemoveButton.ClickAction = AddressOf RemoveSelection

            If ItemCheckProperty <> "" Then
                AddHandler ItemCheck, Sub(sender As Object, e2 As ItemCheckEventArgs)
                                          Items(e2.Index).Tag.GetType.GetProperty(ItemCheckProperty).SetValue(Items(e2.Index).Tag, e2.NewValue = CheckState.Checked)
                                          OnItemsChanged()
                                      End Sub
            End If
        End Sub

        Protected Overrides Sub OnColumnClick(e As ColumnClickEventArgs)
            MyBase.OnColumnClick(e)

            Dim sorter = TryCast(ListViewItemSorter, ColumnSorter)

            If Not sorter Is Nothing Then
                If sorter.LastColumn = e.Column Then
                    If Sorting = SortOrder.Ascending Then
                        Sorting = SortOrder.Descending
                    Else
                        Sorting = SortOrder.Ascending
                    End If
                Else
                    Sorting = SortOrder.Descending
                End If

                sorter.ColumnIndex = e.Column
                Sort()
            End If
        End Sub

        Class ColumnSorter
            Implements IComparer

            Property LastColumn As Integer
            Property ColumnIndex As Integer

            Function Compare(o1 As Object, o2 As Object) As Integer Implements IComparer.Compare
                Dim item1 = DirectCast(o2, ListViewItem)
                Dim item2 = DirectCast(o1, ListViewItem)

                Dim s1 = DirectCast(item1.SubItems(ColumnIndex).Tag, IComparable)
                Dim s2 = DirectCast(item2.SubItems(ColumnIndex).Tag, IComparable)

                If s1 Is Nothing Then
                    s1 = DirectCast(item1.Tag, IComparable)
                    s2 = DirectCast(item2.Tag, IComparable)
                End If

                Dim r As Integer

                If item1.ListView.Sorting = SortOrder.Ascending Then
                    r = s1.CompareTo(s2)
                Else
                    r = s2.CompareTo(s1)
                End If

                LastColumn = ColumnIndex

                Return r
            End Function
        End Class

        Shadows Sub AutoResizeColumns(lastAtListViewWidth As Boolean)
            If Columns.Count = 0 Then
                Exit Sub
            End If

            BeginUpdate()

            Dim offset = CInt(FontHeight / 5)

            For Each header As ColumnHeader In Columns
                Select Case header.Text
                    Case "Hidden"
                        header.Width = 0
                        Continue For
                    Case ""
                        Columns(0).Width = CInt(Font.Height * 1.25)
                        Continue For
                End Select

                header.AutoResize(ColumnHeaderAutoResizeStyle.HeaderSize)

                Dim headerWidth = header.Width
                header.AutoResize(ColumnHeaderAutoResizeStyle.ColumnContent)
                header.Width += offset

                If header.Width < headerWidth Then
                    header.Width = headerWidth
                End If
            Next

            If lastAtListViewWidth Then
                Dim widthAll = Aggregate i In Columns.OfType(Of ColumnHeader)() Into Sum(i.Width)
                Columns(Columns.Count - 1).Width -= widthAll - ClientSize.Width
            End If

            EndUpdate()
        End Sub
    End Class
End Namespace