Public Class RowNodes
    Implements IList, ICollection, IEnumerable

    Private ReadOnly _owner As RowNode

    Private nodes As List(Of RowNode)

    Friend Sub New(node As RowNode)
        _owner = node
        nodes = New List(Of RowNode)
    End Sub


    Default Public Property Item(index As Integer) As Object Implements IList.Item
        Get
            Return nodes.Item(index)
        End Get
        Set(value As Object)
            nodes(index) = CType(value, RowNode)
        End Set
    End Property



    Public ReadOnly Property IsReadOnly As Boolean Implements IList.IsReadOnly
        Get
            Return False
        End Get
    End Property

    Public ReadOnly Property IsFixedSize As Boolean Implements IList.IsFixedSize
        Get
            Return False
        End Get
    End Property

    Public ReadOnly Property Count As Integer Implements ICollection.Count
        Get
            Return nodes.Count
        End Get
    End Property

    Public ReadOnly Property SyncRoot As Object Implements ICollection.SyncRoot
        Get
            Return False
        End Get
    End Property

    Public ReadOnly Property IsSynchronized As Boolean Implements ICollection.IsSynchronized
        Get
            Return False
        End Get
    End Property


    ''' <summary>
    ''' 更新节点的上一节点指向
    ''' </summary>
    ''' <param name="node">需要更新的节点</param>
    Private Sub AddNodeUpdatePrevNode(node As RowNode)
        If node.Index > 0 Then
            node.PrevNode = node.ParentNode.Nodes(node.Index - 1)

            '更新上一节点的下一节点指向
            node.PrevNode.NextNode = node
        Else
            node.PrevNode = Nothing
        End If
    End Sub

    ''' <summary>
    ''' 更新节点的下一节点指向
    ''' </summary>
    ''' <param name="node">需要更新的节点</param>
    Private Sub AddNodeUpdateNextNode(node As RowNode)
        If node.Index < node.ParentNode.Nodes.Count - 1 Then
            node.NextNode = node.ParentNode.Nodes(node.Index + 1)

            '更新下一节点的上一节点指向
            node.NextNode.PrevNode = node
        Else
            node.NextNode = Nothing
        End If
    End Sub

    ''' <summary>
    ''' 新增节点后,更新父节点的所有子节点计数
    ''' </summary>
    ''' <param name="node">新增的节点</param>
    Private Sub AddNodeUpdateAllChildCount(node As RowNode)
        Dim pNode As RowNode = node.ParentNode

        While pNode IsNot Nothing
            pNode.AllChildCount += (node.AllChildCount + 1)

            pNode = pNode.ParentNode
        End While
    End Sub


    ''' <summary>
    ''' 删除节点后,更新父节点的所有子节点计数
    ''' </summary>
    ''' <param name="node">被删除的节点</param>
    ''' <param name="include">包含当前节点</param>
    Private Sub DelNodeUpdateAllChildCount(node As RowNode, Optional include As Boolean = True)

        Dim removeCount As Integer

        If include Then
            removeCount = node.AllChildCount + 1
        Else
            removeCount = node.AllChildCount
        End If

        Dim pNode As RowNode = node.ParentNode
        While pNode IsNot Nothing
            pNode.AllChildCount -= removeCount

            pNode = pNode.ParentNode
        End While

    End Sub


    ''' <summary>
    ''' 插入节点后,更新节点下方节点的索引
    ''' </summary>
    ''' <param name="node">需要更新下方节点索引的节点</param>
    Private Sub AddNodeUpdateRowIndex(node As RowNode)
        While node.NextNode IsNot Nothing
            node.NextNode.Index = node.Index + 1
            node = node.NextNode
        End While
    End Sub

    ''' <summary>
    ''' 删除节点后,更新节点下方节点的索引
    ''' </summary>
    ''' <param name="node"></param>
    Private Sub DelNodeUpdateRowIndex(node As RowNode)
        If node.NextNode Is Nothing Then Return
        node.NextNode.Index = node.Index
        node = node.NextNode

        While node.NextNode IsNot Nothing
            node.NextNode.Index = node.Index + 1
            node = node.NextNode
        End While
    End Sub


    ''' <summary>
    ''' 获取新添加的节点的链状目录索引
    ''' </summary>
    ''' <param name="node"></param>
    ''' <returns></returns>
    Private Function GetRowListIndex(node As RowNode) As Integer
        Dim rowListIndex As Integer
        If node.Index = 0 Then
            rowListIndex = node.ParentNode.RowListIndex + 1
        Else
            rowListIndex = node.PrevNode.RowListIndex + node.PrevNode.AllChildCount + 1
        End If
        Return rowListIndex
    End Function

    ''' <summary>
    ''' 更新节点的所有子节点的链式结合的指向
    ''' </summary>
    ''' <param name="pNode"></param>
    ''' <param name="node"></param>
    Private Sub AddNodeUpdateRowList(pNode As RowNode, node As RowNode)
        node.RowList = pNode.RowList
        node.RowListIndex = GetRowListIndex(node)
        node.RowList.Insert(node.RowListIndex, node)

        For Each cNode As RowNode In node.Nodes
            AddNodeUpdateRowList(node, cNode)
        Next
    End Sub

    ''' <summary>
    ''' 删除节点后，更新链状列表
    ''' </summary>
    ''' <param name="node"></param>
    ''' <param name="include">包含当前节点</param>
    Private Sub DelNodeUpdateRowList(node As RowNode, Optional include As Boolean = True)
        Dim index As Integer

        If include Then
            index = node.RowListIndex
            node.RowList.RemoveAt(index)
        Else
            index = node.RowListIndex + 1
        End If

        Dim removeCount As Integer = node.AllChildCount
        While removeCount > 0
            node.RowList.RemoveAt(index)
            removeCount -= 1
        End While

    End Sub

    ''' <summary>
    ''' 插入节点后,更新链状目录中受影响节点的索引
    ''' </summary>
    ''' <param name="node"></param>
    Private Sub AddNodeUpdateRowListIndex(node As RowNode)
        Dim startIndex As Integer = node.RowListIndex + node.AllChildCount + 1

        For index As Integer = startIndex To node.RowList.Count - 1
            node.RowList(index).RowListIndex = index
        Next
    End Sub

    ''' <summary>
    ''' 删除节点后,更新链状目录中受影响节点的索引
    ''' </summary>
    ''' <param name="node">删除的节点</param>
    ''' <param name="include">是否保存该节点</param>
    Private Sub DelNodeUpdateRowListIndex(node As RowNode, Optional include As Boolean = True)
        Dim startIndex As Integer = node.RowListIndex
        If include = False Then startIndex += 1
        For i As Integer = startIndex To node.RowList.Count - 1
            _owner.RowList(i).RowListIndex = i
        Next
    End Sub


    Public Function Add(value As Object) As Integer Implements IList.Add
        Dim node As RowNode
        Try
            node = CType(value, RowNode)
        Catch ex As Exception
            Return -1
        End Try

        nodes.Add(node)
        node.HeadNode = _owner.HeadNode
        node.ParentNode = _owner
        node.Lever = _owner.Lever + 1
        node.Index = nodes.Count - 1
        node.RowList = _owner.RowList
        node.Visible = _owner.Visible And _owner.Expanded

        '更新节点可见属性
        node.UpdateVisible()

        '更新节点参与编译
        node.UpdateCompile()

        '更新节点可见节点数
        ' If _owner.Expanded Then _owner.UpdateVisibleCount(1 + node.VisibleNodesCount)
        If node.Visible Then _owner.UpdateVisibleCount(1 + node.VisibleNodesCount)

        '更新父节点总子节点计数
        AddNodeUpdateAllChildCount(node)

        '更新上一节点指向
        AddNodeUpdatePrevNode(node)

        '更新下一节点指向
        node.NextNode = Nothing

        '将节点及其子节点插入到链状目录中,并更新链状目指向
        AddNodeUpdateRowList(_owner, node)

        '更新下方节点链状索引
        AddNodeUpdateRowListIndex(node)

        Return nodes.Count
    End Function


    Public Sub Insert(index As Integer, value As Object) Implements IList.Insert
        Dim node As RowNode = CType(value, RowNode)
        nodes.Insert(index, node)
        node.HeadNode = _owner.HeadNode
        node.ParentNode = _owner
        node.Lever = _owner.Lever + 1
        node.Index = index
        node.RowList = _owner.RowList
        node.Visible = _owner.Visible And _owner.Expanded
        'node.Compile = _owner.Compile AndAlso node.Action

        '更新节点可见属性
        node.UpdateVisible()

        '更新节点参与编译
        node.UpdateCompile()

        '更新节点可见节点数
        'If _owner.Expanded Then _owner.UpdateVisibleCount(1 + node.VisibleNodesCount)
        If node.Visible Then _owner.UpdateVisibleCount(1 + node.VisibleNodesCount)

        '更新父节点总子节点计数
        AddNodeUpdateAllChildCount(node)

        '更新上一节点指向
        AddNodeUpdatePrevNode(node)

        '更新下一节点指向
        AddNodeUpdateNextNode(node)

        '更新下方节点树状索引
        AddNodeUpdateRowIndex(node)

        '将节点及其子节点插入到链状目录中,并更新链状目指向
        AddNodeUpdateRowList(_owner, node)

        '更新下方节点链状索引
        AddNodeUpdateRowListIndex(node)
    End Sub

    ''' <summary>
    ''' 移除指定节点
    ''' </summary>
    ''' <param name="value"></param>
    Public Sub Remove(value As Object) Implements IList.Remove
        Dim node As RowNode = CType(value, RowNode)
        nodes.Remove(node)

        _owner.UpdateVisibleCount(0 - (1 + node.VisibleNodesCount))

        '更新父节点总子节点计数
        DelNodeUpdateAllChildCount(node)

        '更新上一节点的下一节点指向
        If node.PrevNode IsNot Nothing Then
            node.PrevNode.NextNode = node.NextNode
        End If

        '更新下一节点的上一节点指向
        If node.NextNode IsNot Nothing Then
            node.NextNode.PrevNode = node.PrevNode
        End If

        '更新下方节点树状索引
        DelNodeUpdateRowIndex(node)



        '链状目录移除被删除的节点
        DelNodeUpdateRowList(node)

        '更新链状目录中的节点索引
        DelNodeUpdateRowListIndex(node)
    End Sub

    Public Sub RemoveAt(index As Integer) Implements IList.RemoveAt
        Dim node As RowNode = nodes(index)
        nodes.RemoveAt(index)

        _owner.UpdateVisibleCount(0 - (1 + node.VisibleNodesCount))

        '更新父节点总子节点计数
        DelNodeUpdateAllChildCount(node)

        '更新上一节点的下一节点指向
        If node.PrevNode IsNot Nothing Then
            node.PrevNode.NextNode = node.NextNode
        End If

        '更新下一节点的上一节点指向
        If node.NextNode IsNot Nothing Then
            node.NextNode.PrevNode = node.PrevNode
        End If

        '更新下方节点树状索引
        DelNodeUpdateRowIndex(node)



        '链状目录移除被删除的节点
        DelNodeUpdateRowList(node)

        '更新链状目录中的节点索引
        DelNodeUpdateRowListIndex(node)
    End Sub

    ''' <summary>
    ''' 清空节点
    ''' </summary>
    Public Sub Clear() Implements IList.Clear
        _owner.UpdateVisibleCount(0 - _owner.VisibleNodesCount)

        '清空树状目录子节点
        nodes.Clear()

        '更新父节点总子节点计数
        DelNodeUpdateAllChildCount(_owner, False)

        '链状目录移除被删除的节点
        DelNodeUpdateRowList(_owner, False)

        '更新链状目录中的节点索引
        DelNodeUpdateRowListIndex(_owner, False)

        '更新总子节点计数
        _owner.AllChildCount = 0
    End Sub
    Public Sub CopyTo(array As Array, index As Integer) Implements ICollection.CopyTo
        nodes.CopyTo(CType(array, RowNode()), index)
    End Sub

    Public Function Contains(value As Object) As Boolean Implements IList.Contains
        Return nodes.Contains(CType(value, RowNode))
    End Function

    Public Function IndexOf(value As Object) As Integer Implements IList.IndexOf
        Return nodes.IndexOf(CType(value, RowNode))
    End Function

    Public Function GetEnumerator() As IEnumerator Implements IEnumerable.GetEnumerator
        Return nodes.GetEnumerator
    End Function
End Class