using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Windows.Forms;

namespace Dongke.IBOSS.Basics.FlowSetting
{
    /// <summary>
    /// 流程项目绘制管理器
    /// </summary>
    internal class ItemManager
    {
        #region 成员变量

        /// <summary>
        /// 流程项目自增ID
        /// </summary>
        private int _newItemID = 0;
        /// <summary>
        /// 管理器编码
        /// </summary>
        private string _managerCode = Guid.NewGuid().ToString();
        /// <summary>
        /// 画板
        /// </summary>
        private CanvasBox _canvasBox = null;
        /// <summary>
        /// 流程设计器
        /// </summary>
        private FlowBox _flowBox = null;
        /// <summary>
        /// 画布控件
        /// </summary>
        private Control _canvasControl = null;
        /// <summary>
        /// 流程编辑模式
        /// </summary>
        private FlowBoxMode _flowBoxMode = FlowBoxMode.Edit;

        #region 项目集合
        // todo 自定义 list 管理 外部不能add，remove只能get，可以通过，itemid，onlycode，itemindex(显示顺序)取得。
        /// <summary>
        /// 全部流程项目
        /// </summary>
        private List<FlowItem> _items = new List<FlowItem>();
        /// <summary>
        /// 选中的流程项目
        /// </summary>
        private List<FlowItem> _selectedItems = new List<FlowItem>();
        ///// <summary>
        ///// 删除的流程项目
        ///// </summary>
        //private List<FlowItem> _deletedItems = new List<FlowItem>();
        ///// <summary>
        ///// 选中的流程节点
        ///// </summary>
        //private List<FlowNode> _selectedNodes = new List<FlowNode>();
        /// <summary>
        /// 全部流程节点
        /// </summary>
        private List<FlowNode> _allNodes = new List<FlowNode>();
        /// <summary>
        /// 删除的流程项目
        /// </summary>
        private List<FlowNode> _deletedNodes = new List<FlowNode>();
        #endregion 项目集合

        #region 新建项目
        /// <summary>
        /// 鼠标操作，指定位置，新建Item
        /// </summary>
        private FlowItem _drawingItem = null;
        /// <summary>
        /// 鼠标操作，指定位置，新建节点
        /// </summary>
        private FlowNode _drawingNode = null;
        /// <summary>
        /// 鼠标操作，指定位置，新建线段
        /// </summary>
        private FlowLine _drawingLine = null;
        #endregion 新建项目

        #region 鼠标操作
        /// <summary>
        /// 鼠标动作
        /// </summary>
        private MouseOperatingType _mouseOperatingType = MouseOperatingType.None;
        /// <summary>
        /// 鼠标框选范围
        /// </summary>
        private Rectangle _mouseSelectRect = Rectangle.Empty;
        /// <summary>
        /// 鼠标按下的点
        /// </summary>
        private Point _mouseDownPoint = Point.Empty;
        /// <summary>
        /// 鼠标移动的点
        /// </summary>
        private Point _mouseMovePoint = Point.Empty;
        /// <summary>
        /// 鼠标抬起的点
        /// </summary>
        private Point _mouseUpPoint = Point.Empty;
        /// <summary>
        /// 鼠标是否按下
        /// </summary>
        private bool _isMouseDown = false;
        /// <summary>
        /// 鼠标是否移动
        /// </summary>
        private bool _isMouseMove = false;
        /// <summary>
        /// 鼠标是否抬起
        /// </summary>
        private bool _isMouseUp = false;
        /// <summary>
        /// 进行改变大小操作的节点
        /// </summary>
        private FlowNode _nodeSizeChanging = null;
        /// <summary>
        /// 进行改变大小操作的线段
        /// </summary>
        private FlowLine _linePointChanging = null;
        /// <summary>
        /// 正在显示锚点的节点
        /// </summary>
        private FlowNode _nodeAnchorShowing = null;
        #endregion 鼠标操作

        #region 绘制项目
        // TODO 使用后销毁？？
        /// <summary>
        /// 画节点笔
        /// </summary>
        private Pen _penDrawNode = new Pen(Consts.NODE_BORDERCOLOR_DEFAULT);
        /// <summary>
        /// 画线段笔
        /// </summary>
        private Pen _penDrawLine = new Pen(Consts.LINE_COLOR_DEFAULT, Consts.LINE_WIDTH_DEFAULT);
        /// <summary>
        /// 写字笔
        /// </summary>
        private Pen _penDrawString = new Pen(Consts.FONT_COLOR_DEFAULT);
        #endregion 绘制项目

        #endregion 成员变量

        #region 构造函数

        /// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="flowBox">流程设计器</param>
        /// <param name="canvasBox">画板</param>
        internal ItemManager(FlowBox flowBox, CanvasBox canvasBox)
        {
            this._flowBox = flowBox;
            this._canvasBox = canvasBox;
            this._canvasControl = canvasBox.CanvasControl;
            this._flowBoxMode = flowBox.BoxMode;

            // 线段连接线 以圆点开始，箭头结束
            AdjustableArrowCap myArrow = new AdjustableArrowCap(4, 4);
            CustomLineCap customArrow = myArrow;
            this._penDrawLine.CustomEndCap = myArrow;
            //this._penDrawLine.StartCap = LineCap.RoundAnchor;

            this.SetDefaultCursor();
        }

        #endregion 构造函数

        #region 属性

        /// <summary>
        /// 获取全部流程项目
        /// </summary>
        public List<FlowItem> Items
        {
            get
            {
                return this._items;
            }
        }

        /// <summary>
        /// 获取选择的流程项目
        /// </summary>
        public List<FlowItem> SelectedItems
        {
            get
            {
                return this._selectedItems;
            }
        }

        /// <summary>
        /// 获取删除的节点
        /// </summary>
        public List<FlowNode> DeletedNodes
        {
            get
            {
                return this._deletedNodes;
            }
        }

        /// <summary>
        /// 获取全部的节点（包括删除的）
        /// </summary>
        public List<FlowNode> AllNodes
        {
            get
            {
                return this._allNodes;
            }
        }

        /// <summary>
        /// 获取或设置管理器编码
        /// </summary>
        internal string ManagerCode
        {
            get
            {
                return this._managerCode;
            }
            set
            {
                this._managerCode = value;
            }
        }

        /// <summary>
        /// 获取或设置流程编辑模式
        /// </summary>
        internal FlowBoxMode BoxMode
        {
            get
            {
                return this._flowBoxMode;
            }
            set
            {
                this._flowBoxMode = value;
            }
        }

        /// <summary>
        /// 获取或设置新的itemID
        /// </summary>
        internal int NewItemID
        {
            get
            {
                return ++this._newItemID;
            }
        }

        /// <summary>
        /// 获取或设置画板的鼠标样式
        /// </summary>
        private Cursor CanvasCursor
        {
            get
            {
                return this._canvasControl.Cursor;
            }
            set
            {
                this._canvasControl.Cursor = value;
            }
        }

        #endregion 属性

        #region 公有方法

        #region 新建项目

        /// <summary>
        /// 停止新建节点（鼠标操作）
        /// </summary>
        public void StopDrawingItem()
        {
            this._drawingItem = null;
            this._drawingNode = null;
            this._drawingLine = null;
            this.SetDefaultCursor();
        }

        /// <summary>
        /// 新建节点（鼠标操作，指定位置）
        /// </summary>
        public FlowNode DrawingNode()
        {
            this._drawingNode = new FlowNode(this);
            this._drawingLine = null;
            this._drawingItem = this._drawingNode;
            this.SetDrawingNodeCursor();
            return this._drawingNode;
        }

        /// <summary>
        /// 新建线段（鼠标操作，指定位置）
        /// </summary>
        public FlowLine DrawingLine()
        {
            this._drawingNode = null;
            this._drawingLine = new FlowLine(this);
            this._drawingItem = this._drawingLine;
            this.SetDrawingLineCursor();
            return this._drawingLine;
        }

        /// <summary>
        /// 新建节点（默认位置）
        /// </summary>
        /// <returns>节点</returns>
        public FlowNode NewNode()
        {
            this._drawingItem = null;
            this._drawingNode = null;
            this._drawingLine = null;
            return this.NewNodeInternal(null);
        }

        /// <summary>
        /// 新建节点（指定位置）
        /// </summary>
        /// <param name="location">节点位置</param>
        public FlowNode NewNode(Point location)
        {
            this._drawingItem = null;
            this._drawingNode = null;
            this._drawingLine = null;
            return this.NewNodeInternal(location);
        }

        /// <summary>
        /// 新建线段（默认位置）
        /// </summary>
        /// <returns>线段</returns>
        public FlowLine NewLine()
        {
            this._drawingItem = null;
            this._drawingNode = null;
            this._drawingLine = null;
            return this.NewLineInternal(null, null);
        }

        /// <summary>
        /// 新建线段（指定位置）
        /// </summary>
        /// <param name="pointBegin">起始点</param>
        /// <param name="pointEnd">结束点</param>
        /// <returns>线段</returns>
        public FlowLine NewLine(Point pointBegin, Point pointEnd)
        {
            this._drawingItem = null;
            this._drawingNode = null;
            this._drawingLine = null;
            return this.NewLineInternal(pointBegin, pointEnd);
        }

        #endregion 新建项目

        #region 刷项目

        ///// <summary>
        ///// 刷新未激活Item的图片
        ///// </summary>
        //public void RefreshStaticItems()
        //{
        //    // 清除画布
        //    Graphics graphics = this._canvasBox.Canvas;
        //    graphics.Clear(Color.Transparent);
        //    // 绘制未激活的Item
        //    this.DrawStaticItems(graphics);
        //    // 设定未激活的Item为图片
        //    this._canvasBox.SetItemsImage(this._canvasBox.CanvasImage);
        //}

        ///// <summary>
        ///// 刷新激活Item的图片
        ///// </summary>
        //public void RefreshActiveItems()
        //{
        //    // 清除画布
        //    Graphics graphics = this._canvasBox.Canvas;
        //    graphics.Clear(Color.Transparent);
        //    // 绘制激活的Item
        //    this.DrawActiveItems(graphics);
        //    // 设定未激活的Item为图片
        //    this._canvasBox.SetItemsImage(this._canvasBox.CanvasImage);
        //}

        ///// <summary>
        ///// 刷新激活Item
        ///// </summary>
        ///// <param name="graphics"></param>
        //public void RefreshActiveItems(Graphics graphics)
        //{
        //    // todo 在paint绘制事件中绘制激活的item，未激活item作为背景
        //    // 绘制激活的Item
        //    this.DrawActiveItems(graphics);
        //}

        /// <summary>
        /// 刷新Item的图片
        /// </summary>
        public void RefreshItems()
        {
            // 清除画布
            Graphics graphics = this._canvasBox.Canvas;
            graphics.Clear(Color.Transparent);
            // 绘制激活的Item
            this.DrawItems(graphics);
            // 设定未激活的Item为图片
            this._canvasBox.SetItemsImage(this._canvasBox.CanvasImage);
            GC.Collect();
        }

        #endregion 刷新项目

        #region 操作项目

        /// <summary>
        /// 全部不选择
        /// </summary>
        public void ClearSelection()
        {
            foreach (FlowItem item in this._selectedItems)
            {
                item.MouseOperating = false;
                item.Selected = false;
            }
            this._selectedItems.Clear();
        }

        /// <summary>
        /// 全部选择
        /// </summary>
        public void SelectAllItems()
        {
            foreach (FlowItem item in this._items)
            {
                if (!item.Selected)
                {
                    this._selectedItems.Add(item);
                    item.Selected = true;
                }
            }
        }

        /// <summary>
        /// 删除全部项目
        /// </summary>
        public void DeleteAllItems()
        {
            foreach (FlowItem item in this._items)
            {
                item.MouseOperating = false;
                item.Selected = false;

                if (item is FlowNode)
                {
                    FlowNode node = item as FlowNode;
                    node.ShowAnchor = false;
                    node.InLines.Clear();
                    node.OutLines.Clear();
                    node.TopLines.Clear();
                    node.LeftLines.Clear();
                    node.RightLines.Clear();
                    node.BottomLines.Clear();
                    node.PreNodes.Clear();
                    node.NextNodes.Clear();
                    if (node.NodeState == FlowNodeState.Added ||
                        node.NodeState == FlowNodeState.Detached)
                    {
                        node.NodeState = FlowNodeState.Detached;
                    }
                    else
                    {
                        node.NodeState = FlowNodeState.Deleted;
                    }

                    this._deletedNodes.Add(item as FlowNode);
                    continue;
                }

                if (item is FlowLine)
                {
                    FlowLine line = item as FlowLine;

                    line.AnchorBegin = AnchorKind.None;
                    line.AnchorEnd = AnchorKind.None;
                    line.NodeBegin = null;
                    line.NodeEnd = null;
                    line.NodeCodeBegin = null;
                    line.NodeCodeEnd = null;

                    continue;
                }
            }

            this._selectedItems.Clear();
            this._items.Clear();
        }

        /// <summary>
        /// 删除选择项目
        /// </summary>
        public void DeleteSelectedItems()
        {
            foreach (FlowItem item in this._selectedItems)
            {
                item.MouseOperating = false;
                item.Selected = false;

                if (item is FlowNode)
                {
                    FlowNode node = item as FlowNode;
                    node.ShowAnchor = false;

                    foreach (FlowLine line in node.InLines)
                    {
                        //if (!line.Selected)
                        {
                            line.NodeEnd = null;
                            line.AnchorEnd = AnchorKind.None;
                        }
                    }
                    foreach (FlowLine line in node.OutLines)
                    {
                        //if (!line.Selected)
                        {
                            line.NodeBegin = null;
                            line.AnchorBegin = AnchorKind.None;
                        }
                    }
                    node.InLines.Clear();
                    node.OutLines.Clear();
                    node.TopLines.Clear();
                    node.LeftLines.Clear();
                    node.RightLines.Clear();
                    node.BottomLines.Clear();
                    node.PreNodes.Clear();
                    node.NextNodes.Clear();
                    if (node.NodeState == FlowNodeState.Added ||
                        node.NodeState == FlowNodeState.Detached)
                    {
                        node.NodeState = FlowNodeState.Detached;
                    }
                    else
                    {
                        node.NodeState = FlowNodeState.Deleted;
                    }

                    this._items.Remove(node);
                    this._deletedNodes.Add(item as FlowNode);
                    continue;
                }

                if (item is FlowLine)
                {
                    FlowLine line = item as FlowLine;

                    if (line.NodeBegin != null && !line.NodeBegin.Selected)
                    {
                        line.NodeBegin.OutLines.Remove(line);
                        switch (line.AnchorBegin)
                        {
                            case AnchorKind.Top:
                                line.NodeBegin.TopLines.Remove(line);
                                break;
                            case AnchorKind.Left:
                                line.NodeBegin.LeftLines.Remove(line);
                                break;
                            case AnchorKind.Right:
                                line.NodeBegin.RightLines.Remove(line);
                                break;
                            case AnchorKind.Bottom:
                                line.NodeBegin.BottomLines.Remove(line);
                                break;
                            default:
                                break;
                        }
                    }
                    if (line.NodeEnd != null && !line.NodeEnd.Selected)
                    {
                        line.NodeEnd.InLines.Remove(line);
                        switch (line.AnchorEnd)
                        {
                            case AnchorKind.Top:
                                line.NodeEnd.TopLines.Remove(line);
                                break;
                            case AnchorKind.Left:
                                line.NodeEnd.LeftLines.Remove(line);
                                break;
                            case AnchorKind.Right:
                                line.NodeEnd.RightLines.Remove(line);
                                break;
                            case AnchorKind.Bottom:
                                line.NodeEnd.BottomLines.Remove(line);
                                break;
                            default:
                                break;
                        }
                    }

                    line.AnchorBegin = AnchorKind.None;
                    line.AnchorEnd = AnchorKind.None;
                    line.NodeBegin = null;
                    line.NodeEnd = null;

                    this._items.Remove(line);
                    continue;
                }
            }

            this._selectedItems.Clear();
        }

        /// <summary>
        /// 对齐选定的节点
        /// </summary>
        /// <param name="arrangeType">对齐方式</param>
        public void ArrangeNodes(ArrangeType arrangeType)
        {
            switch (arrangeType)
            {
                case ArrangeType.Left:
                    ArrangeNodesLeft();
                    break;
                case ArrangeType.Right:
                    ArrangeNodesRight();
                    break;
                case ArrangeType.HorizontalCenter:
                    ArrangeNodesHorizontalCenter();
                    break;
                case ArrangeType.Top:
                    ArrangeNodesTop();
                    break;
                case ArrangeType.Bottom:
                    ArrangeNodesBottom();
                    break;
                case ArrangeType.VerticalCenter:
                    ArrangeNodesVerticalCenter();
                    break;
                default:
                    break;
            }
        }

        /// <summary>
        /// 顶部对齐所有选中的节点
        /// </summary>
        public void ArrangeNodesTop()
        {
            int minTop = this._canvasControl.Height;
            foreach (FlowItem item in this._selectedItems)
            {
                FlowNode node = item as FlowNode;
                if (node != null)
                {
                    minTop = Math.Min(node.Top, minTop);
                }
            }

            foreach (FlowItem item in this._selectedItems)
            {
                FlowNode node = item as FlowNode;
                if (node != null)
                {
                    node.Top = minTop;
                }
            }
        }

        /// <summary>
        /// 底部对齐所有选中的节点
        /// </summary>
        public void ArrangeNodesBottom()
        {

        }

        /// <summary>
        /// 左侧对齐所有选中的节点
        /// </summary>
        public void ArrangeNodesLeft()
        {

        }

        /// <summary>
        /// 右侧对齐所有选中的节点
        /// </summary>
        public void ArrangeNodesRight()
        {

        }

        /// <summary>
        /// 垂直方向中心对齐所有选中的节点
        /// </summary>
        public void ArrangeNodesVerticalCenter()
        {

        }

        /// <summary>
        /// 水平方向中心对齐所有选中的节点
        /// </summary>
        public void ArrangeNodesHorizontalCenter()
        {

        }

        #endregion 操作项目

        #endregion 公有方法

        #region 内部方法

        /// <summary>
        /// 获取新ItemID（用于流程保存）
        /// </summary>
        /// <returns>ItemID</returns>
        internal int GetNewItemID()
        {
            return this._newItemID;
        }

        /// <summary>
        /// 设置新ItemID（用于流程读取）
        /// </summary>
        /// <param name="itemID">ItemID</param>
        internal void SetNewItemID(int itemID)
        {
            this._newItemID = itemID;
        }

        #region 刷新项目

        /// <summary>
        /// 刷新鼠标框选范围
        /// </summary>
        internal void RefreshMouseSelectRect(Graphics graphics)
        {
            if (this._mouseOperatingType == MouseOperatingType.RectSelect)
            {
                ControlPaint.DrawFocusRectangle(graphics, this._mouseSelectRect,
                    this._canvasControl.BackColor, Color.Transparent);
            }
        }

        #endregion 刷新项目

        #region 鼠标操作

        /// <summary>
        /// 处理鼠标按下事件
        /// </summary>
        /// <param name="e"></param>
        internal void MouseDown(MouseEventArgs e)
        {
            if (e.Button != MouseButtons.Left)
            {
                this._drawingItem = null;
                this._drawingNode = null;
                this._drawingLine = null;
                this.SetDefaultCursor();
                return;
            }

            this._mouseDownPoint = e.Location;
            this._mouseMovePoint = e.Location;
            this._isMouseDown = true;
            this._isMouseMove = false;
            this._isMouseUp = false;

            if (this._mouseOperatingType != MouseOperatingType.Move)
            {
                this.CanvasCursor = Cursors.Cross;
            }

            // 鼠标绘制item
            if (this._drawingItem != null)
            {
                //// 节点
                //if (this._drawingItem is FlowNode)
                //{
                //    FlowNode node = this._drawingItem as FlowNode;
                //    node.Location = e.Location;
                //    node.Size = Size.Empty;
                //    return;
                //}

                //// 线段
                //if (this._drawingItem is FlowLine)
                //{
                //    FlowLine line = this._drawingItem as FlowLine;
                //    line.PointBegin = e.Location;
                //    line.PointEnd = e.Location;
                //    return;
                //}

                return;
            }

            // 改变节点大小
            if (this._mouseOperatingType == MouseOperatingType.NodeTopAndLeft ||
                this._mouseOperatingType == MouseOperatingType.NodeTopAndRight ||
                this._mouseOperatingType == MouseOperatingType.NodeBottomAndLeft ||
                this._mouseOperatingType == MouseOperatingType.NodeBottomAndRight ||
                this._mouseOperatingType == MouseOperatingType.NodeTop ||
                this._mouseOperatingType == MouseOperatingType.NodeBottom ||
                this._mouseOperatingType == MouseOperatingType.NodeLeft ||
                this._mouseOperatingType == MouseOperatingType.NodeRight)
            {
                // 选择的节点随着改变 begin
                //foreach (FlowItem selectedItem in this._selectedItems)
                //{
                //    if (selectedItem is FlowNode)
                //    {
                //        FlowNode node = selectedItem as FlowNode;
                //        node.MouseDownRect = node.Bounds;
                //    }
                //}
                // 选择的节点随着改变 end

                // 只改变当前节点 begin
                this.ClearSelection();
                if (this._nodeSizeChanging != null)
                {
                    this._nodeSizeChanging.Selected = true;
                    this._selectedItems.Add(this._nodeSizeChanging);
                    this._nodeSizeChanging.MouseDownRect = this._nodeSizeChanging.Bounds;
                }

                this.RefreshItems();
                // 只改变当前节点 end
                return;
            }

            // 改变线段端点位置
            if (this._mouseOperatingType == MouseOperatingType.LineBegin ||
                this._mouseOperatingType == MouseOperatingType.LineEnd)
            {
                if (this._flowBoxMode != FlowBoxMode.Edit)
                {
                    return;
                }

                // 取消其他item选择状态 begin
                this.ClearSelection();
                if (this._linePointChanging != null)
                {
                    this._linePointChanging.Selected = true;
                    this._selectedItems.Add(this._linePointChanging);
                }

                this.RefreshItems();
                // 取消其他item选择状态 end
                return;
            }

            // 正在进行其他操作
            if (this._mouseOperatingType != MouseOperatingType.None)
            {
                return;
            }

            // 选择item
            FlowItem item = this.SelectItemByPoint(e.Location);
            if (item != null)
            {
                // 点选
                if (!item.Selected)
                {
                    this.ClearSelection();
                    item.Selected = true;
                    this._selectedItems.Add(item);
                }
                this.SetMoveCursor();
                this.RefreshItems();
                return;
            }
            else
            {
                // 框选
                this._mouseSelectRect = new Rectangle(e.Location, Size.Empty);
                this.SetRectSelectCursor();
                // 框选开始就清空选择 begin
                //this.ClearSelectItem();
                //this.RefreshItems();
                // 框选开始就清空选择 end
                return;
            }
        }

        /// <summary>
        /// 处理鼠标移动事件
        /// </summary>
        /// <param name="e"></param>
        internal void MouseMove(MouseEventArgs e)
        {
            if (e.Button == MouseButtons.None && this._drawingItem == null)
            {
                this.SetMouseCursorByMove(e.Location);
                return;
            }

            if (e.Button != MouseButtons.Left)
            {
                return;
            }

            Point mouseBeginPoint = this._mouseMovePoint;
            this._mouseMovePoint = e.Location;
            this._isMouseMove = true;

            bool hasRefreshItems = false;

            #region 鼠标绘制item
            if (this._drawingItem != null)
            {
                // 节点
                if (this._mouseOperatingType == MouseOperatingType.DrawingNode)
                {
                    //FlowNode node = this._drawingItem as FlowNode;
                    this._drawingNode.Location = mouseBeginPoint;
                    this._drawingNode.Size = Size.Empty;
                    this._drawingNode.Selected = true;
                    this._drawingNode.NodeState = FlowNodeState.Added;

                    this.ClearSelection();
                    this._items.Add(this._drawingNode);
                    this._allNodes.Add(this._drawingNode);
                    this._selectedItems.Add(this._drawingNode);

                    this._drawingNode.MouseDownRect = this._drawingNode.Bounds;
                    this._nodeSizeChanging = this._drawingNode;
                    this._drawingItem = null;
                }

                // 线段
                if (this._mouseOperatingType == MouseOperatingType.DrawingLine)
                {
                    //FlowLine line = this._drawingItem as FlowLine;
                    this._drawingLine.PointBegin = mouseBeginPoint;
                    this._drawingLine.PointEnd = e.Location;
                    this._drawingLine.Selected = true;

                    this.ClearSelection();
                    this._items.Add(this._drawingLine);
                    this._selectedItems.Add(this._drawingLine);

                    this._linePointChanging = this._drawingLine;
                    this._drawingItem = null;
                }
            }
            #endregion 鼠标绘制item

            #region 激活item
            if (this._isMouseDown)
            {
                hasRefreshItems = true;
                foreach (FlowItem item in this._selectedItems)
                {
                    item.MouseOperating = true;
                }
                this._isMouseDown = false;
                // todo 在paint绘制事件中绘制激活的item，未激活item作为背景
                //this.RefreshStaticItems();
            }

            //// 取消激活item
            //if (this._isMouseUp)
            //{
            //    hasRefreshItems = true;
            //    foreach (FlowItem item in this._selectedItems)
            //    {
            //        item.MouseOperating = false;
            //    }
            //    this._isMouseUp = false;
            //    // todo 在paint绘制事件中绘制激活的item，未激活item作为背景
            //    //this.RefreshStaticItems();
            //}
            #endregion 激活item

            #region 框选
            if (this._mouseOperatingType == MouseOperatingType.RectSelect)
            {
                this._mouseSelectRect = this.GetNewRect(this._mouseSelectRect, this._mouseDownPoint, e.Location);
                this._canvasControl.Invalidate();
                return;
            }
            #endregion 框选

            #region 移动
            if (this._mouseOperatingType == MouseOperatingType.Move)
            {
                int xMove = e.X - mouseBeginPoint.X;
                int yMove = e.Y - mouseBeginPoint.Y;
                this.MoveSelectedItems(xMove, yMove);
                this.RefreshItems();
                return;
            }
            #endregion 移动

            #region 左上角
            if (this._mouseOperatingType == MouseOperatingType.NodeTopAndLeft)
            {
                if (this._nodeSizeChanging == null)
                {
                    return;
                }
                Point point = this.GetRectTopAndLeft(this._nodeSizeChanging.MouseDownRect);
                int xRect = e.X - point.X;
                int yRect = e.Y - point.Y;
                foreach (FlowItem item in this._selectedItems)
                {
                    if (item is FlowNode)
                    {
                        FlowNode node = item as FlowNode;
                        Point fixedPoint = this.GetRectBottomAndRight(node.MouseDownRect);
                        node.Bounds = new Rectangle(fixedPoint, new Size(xRect - node.MouseDownRect.Width, yRect - node.MouseDownRect.Height));

                        // 移动连接线
                        foreach (FlowLine line in node.InLines)
                        {
                            line.PointEnd = node.GetAnchor(line.AnchorEnd);
                        }

                        // 移动连接线
                        foreach (FlowLine line in node.OutLines)
                        {
                            line.PointBegin = node.GetAnchor(line.AnchorBegin);
                        }
                    }
                }

                this.RefreshItems();
                return;
            }
            #endregion 左上角

            #region 右上角
            if (this._mouseOperatingType == MouseOperatingType.NodeTopAndRight)
            {
                if (this._nodeSizeChanging == null)
                {
                    return;
                }
                Point point = this.GetRectTopAndRight(this._nodeSizeChanging.MouseDownRect);
                int xRect = e.X - point.X;
                int yRect = e.Y - point.Y;
                foreach (FlowItem item in this._selectedItems)
                {
                    if (item is FlowNode)
                    {
                        FlowNode node = item as FlowNode;
                        Point fixedPoint = this.GetRectBottomAndLeft(node.MouseDownRect);
                        node.Bounds = new Rectangle(fixedPoint, new Size(xRect + node.MouseDownRect.Width, yRect - node.MouseDownRect.Height));

                        // 移动连接线
                        foreach (FlowLine line in node.InLines)
                        {
                            line.PointEnd = node.GetAnchor(line.AnchorEnd);
                        }

                        // 移动连接线
                        foreach (FlowLine line in node.OutLines)
                        {
                            line.PointBegin = node.GetAnchor(line.AnchorBegin);
                        }
                    }
                }

                this.RefreshItems();
                return;
            }
            #endregion 右上角

            #region 左下角
            if (this._mouseOperatingType == MouseOperatingType.NodeBottomAndLeft)
            {
                if (this._nodeSizeChanging == null)
                {
                    return;
                }
                Point point = this.GetRectBottomAndLeft(this._nodeSizeChanging.MouseDownRect);
                int xRect = e.X - point.X;
                int yRect = e.Y - point.Y;
                foreach (FlowItem item in this._selectedItems)
                {
                    if (item is FlowNode)
                    {
                        FlowNode node = item as FlowNode;
                        Point fixedPoint = this.GetRectTopAndRight(node.MouseDownRect);
                        node.Bounds = new Rectangle(fixedPoint, new Size(xRect - node.MouseDownRect.Width, yRect + node.MouseDownRect.Height));

                        // 移动连接线
                        foreach (FlowLine line in node.InLines)
                        {
                            line.PointEnd = node.GetAnchor(line.AnchorEnd);
                        }

                        // 移动连接线
                        foreach (FlowLine line in node.OutLines)
                        {
                            line.PointBegin = node.GetAnchor(line.AnchorBegin);
                        }
                    }
                }

                this.RefreshItems();
                return;
            }
            #endregion 左下角

            #region 右下角
            if (this._mouseOperatingType == MouseOperatingType.NodeBottomAndRight ||
                this._mouseOperatingType == MouseOperatingType.DrawingNode)
            {
                if (this._nodeSizeChanging == null)
                {
                    return;
                }
                Point point = this.GetRectBottomAndRight(this._nodeSizeChanging.MouseDownRect);
                int xRect = e.X - point.X;
                int yRect = e.Y - point.Y;
                foreach (FlowItem item in this._selectedItems)
                {
                    if (item is FlowNode)
                    {
                        FlowNode node = item as FlowNode;
                        Point fixedPoint = this.GetRectTopAndLeft(node.MouseDownRect);
                        node.Bounds = new Rectangle(fixedPoint, new Size(xRect + node.MouseDownRect.Width, yRect + node.MouseDownRect.Height));

                        // 移动连接线
                        foreach (FlowLine line in node.InLines)
                        {
                            line.PointEnd = node.GetAnchor(line.AnchorEnd);
                        }

                        // 移动连接线
                        foreach (FlowLine line in node.OutLines)
                        {
                            line.PointBegin = node.GetAnchor(line.AnchorBegin);
                        }
                    }
                }

                this.RefreshItems();
                return;
            }
            #endregion 右下角

            #region 上中
            if (this._mouseOperatingType == MouseOperatingType.NodeTop)
            {
                if (this._nodeSizeChanging == null)
                {
                    return;
                }
                Point point = this.GetRectTop(this._nodeSizeChanging.MouseDownRect);
                int xRect = 0;
                int yRect = e.Y - point.Y;
                foreach (FlowItem item in this._selectedItems)
                {
                    if (item is FlowNode)
                    {
                        FlowNode node = item as FlowNode;
                        Point fixedPoint = this.GetRectBottomAndLeft(node.MouseDownRect);
                        node.Bounds = new Rectangle(fixedPoint, new Size(xRect + node.MouseDownRect.Width, yRect - node.MouseDownRect.Height));

                        // 移动连接线
                        foreach (FlowLine line in node.InLines)
                        {
                            line.PointEnd = node.GetAnchor(line.AnchorEnd);
                        }

                        // 移动连接线
                        foreach (FlowLine line in node.OutLines)
                        {
                            line.PointBegin = node.GetAnchor(line.AnchorBegin);
                        }
                    }
                }

                this.RefreshItems();
                return;
            }
            #endregion 上中

            #region 下中
            if (this._mouseOperatingType == MouseOperatingType.NodeBottom)
            {
                if (this._nodeSizeChanging == null)
                {
                    return;
                }
                Point point = this.GetRectBottom(this._nodeSizeChanging.MouseDownRect);
                int xRect = 0;
                int yRect = e.Y - point.Y;
                foreach (FlowItem item in this._selectedItems)
                {
                    if (item is FlowNode)
                    {
                        FlowNode node = item as FlowNode;
                        Point fixedPoint = this.GetRectTopAndLeft(node.MouseDownRect);
                        node.Bounds = new Rectangle(fixedPoint, new Size(xRect + node.MouseDownRect.Width, yRect + node.MouseDownRect.Height));

                        // 移动连接线
                        foreach (FlowLine line in node.InLines)
                        {
                            line.PointEnd = node.GetAnchor(line.AnchorEnd);
                        }

                        // 移动连接线
                        foreach (FlowLine line in node.OutLines)
                        {
                            line.PointBegin = node.GetAnchor(line.AnchorBegin);
                        }
                    }
                }

                this.RefreshItems();
                return;
            }
            #endregion 下中

            #region 左中
            if (this._mouseOperatingType == MouseOperatingType.NodeLeft)
            {
                if (this._nodeSizeChanging == null)
                {
                    return;
                }
                Point point = this.GetRectLeft(this._nodeSizeChanging.MouseDownRect);
                int xRect = e.X - point.X;
                int yRect = 0;
                foreach (FlowItem item in this._selectedItems)
                {
                    if (item is FlowNode)
                    {
                        FlowNode node = item as FlowNode;
                        Point fixedPoint = this.GetRectTopAndRight(node.MouseDownRect);
                        node.Bounds = new Rectangle(fixedPoint, new Size(xRect - node.MouseDownRect.Width, yRect + node.MouseDownRect.Height));

                        // 移动连接线
                        foreach (FlowLine line in node.InLines)
                        {
                            line.PointEnd = node.GetAnchor(line.AnchorEnd);
                        }

                        // 移动连接线
                        foreach (FlowLine line in node.OutLines)
                        {
                            line.PointBegin = node.GetAnchor(line.AnchorBegin);
                        }
                    }
                }

                this.RefreshItems();
                return;
            }
            #endregion 左中

            #region 右中
            if (this._mouseOperatingType == MouseOperatingType.NodeRight)
            {
                if (this._nodeSizeChanging == null)
                {
                    return;
                }
                Point point = this.GetRectRight(this._nodeSizeChanging.MouseDownRect);
                int xRect = e.X - point.X;
                int yRect = 0;
                foreach (FlowItem item in this._selectedItems)
                {
                    if (item is FlowNode)
                    {
                        FlowNode node = item as FlowNode;
                        Point fixedPoint = this.GetRectTopAndLeft(node.MouseDownRect);
                        node.Bounds = new Rectangle(fixedPoint, new Size(xRect + node.MouseDownRect.Width, yRect + node.MouseDownRect.Height));

                        // 移动连接线
                        foreach (FlowLine line in node.InLines)
                        {
                            line.PointEnd = node.GetAnchor(line.AnchorEnd);
                        }

                        // 移动连接线
                        foreach (FlowLine line in node.OutLines)
                        {
                            line.PointBegin = node.GetAnchor(line.AnchorBegin);
                        }
                    }
                }

                this.RefreshItems();
                return;
            }
            #endregion 右中

            #region 线段开始点
            if (this._mouseOperatingType == MouseOperatingType.LineBegin)
            {
                if (this._linePointChanging == null)
                {
                    return;
                }

                FlowLine line = this._linePointChanging;
                line.PointBegin = e.Location;

                // 断开连接
                if (line.NodeBegin != null)
                {
                    this.DisconnectL2NPointBegin(line);
                }

                // 查询可连接的锚点
                FlowNode rectNode = this.GetL2N(e.Location);
                this._nodeAnchorShowing = rectNode;

                // 连接
                if (rectNode != null)
                {
                    rectNode.ShowAnchor = true;
                    Rectangle[] rects = rectNode.GetAnchorRects();
                    for (int i = 0; i < rects.Length; i++)
                    {
                        Rectangle rect = rects[i];
                        rect.Inflate(Consts.L2N_PRECISION_EDGE, Consts.L2N_PRECISION_EDGE);
                        if (rect.Contains(e.Location))
                        {
                            AnchorKind anchorKind = (AnchorKind)i;
                            this.ConnectL2NPointBegin(line, rectNode, anchorKind);
                        }
                    }
                }

                this.RefreshItems();
                return;
            }
            #endregion 线段开始点

            #region 线段结束点
            if (this._mouseOperatingType == MouseOperatingType.LineEnd ||
                this._mouseOperatingType == MouseOperatingType.DrawingLine)
            {
                if (this._linePointChanging == null)
                {
                    return;
                }

                FlowLine line = this._linePointChanging;
                line.PointEnd = e.Location;

                // 断开连接
                if (line.NodeEnd != null)
                {
                    this.DisconnectL2NPointEnd(line);
                }

                // 查询可连接的锚点
                FlowNode rectNode = this.GetL2N(e.Location);
                this._nodeAnchorShowing = rectNode;

                // 连接
                if (rectNode != null)
                {
                    rectNode.ShowAnchor = true;
                    Rectangle[] rects = rectNode.GetAnchorRects();
                    for (int i = 0; i < rects.Length; i++)
                    {
                        Rectangle rect = rects[i];
                        rect.Inflate(Consts.L2N_PRECISION_EDGE, Consts.L2N_PRECISION_EDGE);
                        if (rect.Contains(e.Location))
                        {
                            AnchorKind anchorKind = (AnchorKind)i;
                            this.ConnectL2NPointEnd(line, rectNode, anchorKind);
                        }
                    }
                }

                this.RefreshItems();
                return;
            }
            #endregion 线段结束点

            // todo 在paint绘制事件中绘制激活的item，未激活item作为背景
            //this._canvasControl.Invalidate();

            if (hasRefreshItems)
            {
                this.RefreshItems();
            }
        }

        /// <summary>
        /// 处理鼠标抬起事件
        /// </summary>
        /// <param name="e"></param>
        internal void MouseUp(MouseEventArgs e)
        {
            if (e.Button != MouseButtons.Left)
            {
                this._drawingItem = null;
                this._drawingNode = null;
                this._drawingLine = null;
                return;
            }

            this._mouseUpPoint = e.Location;
            this._isMouseDown = false;
            this._isMouseUp = true;
            bool hasRefreshItems = false;

            #region 取消激活item
            if (this._isMouseMove)
            {
                hasRefreshItems = true;
                foreach (FlowItem item in this._selectedItems)
                {
                    item.MouseOperating = false;
                }
                this._isMouseMove = false;
                if (this._nodeAnchorShowing != null)
                {
                    this._nodeAnchorShowing.ShowAnchor = false;
                    this._nodeAnchorShowing = null;
                }

                this._nodeSizeChanging = null;
                this._linePointChanging = null;

                // todo 在paint绘制事件中绘制激活的item，未激活item作为背景
                //this.RefreshStaticItems();
            }
            #endregion 取消激活item

            #region 鼠标绘制item
            if (this._drawingItem != null)
            {
                if (this._mouseOperatingType == MouseOperatingType.DrawingNode)
                {
                    this.NewNodeInternal(e.Location);
                }

                if (this._mouseOperatingType == MouseOperatingType.DrawingLine)
                {
                    Point pBegin = e.Location;
                    Point pEnd = pBegin;
                    pEnd.Offset(Consts.LINE_POINT_END_DEFAULT);
                    this.NewLineInternal(pBegin, pEnd);
                }

                this._drawingItem = null;
                this._drawingNode = null;
                this._drawingLine = null;
                this.RefreshItems();
                return;
            }
            else
            {
                // 用新加线段连接节点
                if (this._mouseOperatingType == MouseOperatingType.DrawingLine)
                {
                    Point pBegin = this._drawingLine.PointBegin;
                    Point pEnd = this._drawingLine.PointEnd;
                    FlowNode nodeBegin = this.SelectNodeByPoint(pBegin);
                    FlowNode nodeEnd = this._drawingLine.NodeEnd;
                    if (nodeEnd == null)
                    {
                        nodeEnd = this.SelectNodeByPoint(pEnd);
                    }

                    if ((nodeBegin == null && nodeEnd != null) ||
                        (nodeBegin != null && nodeEnd == null) ||
                        (nodeBegin != null && nodeEnd != null && nodeBegin.ItemCode != nodeEnd.ItemCode))
                    {
                        if (nodeBegin != null)
                        {
                            Point np1 = this.GetRectTopAndLeft(nodeBegin.Bounds);
                            Point np2 = this.GetRectTopAndRight(nodeBegin.Bounds);
                            Point np3 = this.GetRectBottomAndLeft(nodeBegin.Bounds);
                            Point np4 = this.GetRectBottomAndRight(nodeBegin.Bounds);

                            if (this.IsSegmentIntersect(pBegin, pEnd, np1, np2))
                            {
                                this.ConnectL2NPointBegin(this._drawingLine, nodeBegin, AnchorKind.Top);
                            }
                            else if (this.IsSegmentIntersect(pBegin, pEnd, np3, np4))
                            {
                                this.ConnectL2NPointBegin(this._drawingLine, nodeBegin, AnchorKind.Bottom);
                            }
                            else if (this.IsSegmentIntersect(pBegin, pEnd, np1, np3))
                            {
                                this.ConnectL2NPointBegin(this._drawingLine, nodeBegin, AnchorKind.Left);
                            }
                            else if (this.IsSegmentIntersect(pBegin, pEnd, np2, np4))
                            {
                                this.ConnectL2NPointBegin(this._drawingLine, nodeBegin, AnchorKind.Right);
                            }
                        }

                        if (this._drawingLine.AnchorEnd == AnchorKind.None && nodeEnd != null)
                        {
                            Point np1 = this.GetRectTopAndLeft(nodeEnd.Bounds);
                            Point np2 = this.GetRectTopAndRight(nodeEnd.Bounds);
                            Point np3 = this.GetRectBottomAndLeft(nodeEnd.Bounds);
                            Point np4 = this.GetRectBottomAndRight(nodeEnd.Bounds);

                            if (this.IsSegmentIntersect(pBegin, pEnd, np1, np2))
                            {
                                this.ConnectL2NPointEnd(this._drawingLine, nodeEnd, AnchorKind.Top);
                            }
                            else if (this.IsSegmentIntersect(pBegin, pEnd, np3, np4))
                            {
                                this.ConnectL2NPointEnd(this._drawingLine, nodeEnd, AnchorKind.Bottom);
                            }
                            else if (this.IsSegmentIntersect(pBegin, pEnd, np1, np3))
                            {
                                this.ConnectL2NPointEnd(this._drawingLine, nodeEnd, AnchorKind.Left);
                            }
                            else if (this.IsSegmentIntersect(pBegin, pEnd, np2, np4))
                            {
                                this.ConnectL2NPointEnd(this._drawingLine, nodeEnd, AnchorKind.Right);
                            }
                        }
                    }

                    this._drawingItem = null;
                    this._drawingNode = null;
                    this._drawingLine = null;

                    this.RefreshItems();
                    return;
                }

                this._drawingNode = null;
                this._drawingLine = null;
            }
            #endregion 鼠标绘制item

            #region 框选
            if (this._mouseOperatingType == MouseOperatingType.RectSelect)
            {
                this.SelectItemByRect(this._mouseSelectRect);
                this._mouseSelectRect = Rectangle.Empty;
                this.RefreshItems();
                //this._canvasControl.Invalidate();
                return;
            }
            #endregion 框选

            //this.SetDefaultCursor();
            if (hasRefreshItems)
            {
                this.RefreshItems();
            }
        }

        /// <summary>
        /// 鼠标双击
        /// </summary>
        /// <param name="e"></param>
        /// <returns></returns>
        internal FlowNode MouseDoubleClick(MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                if (this._selectedItems.Count == 1)
                {
                    FlowItem item = this._selectedItems[0];
                    if (item is FlowNode)
                    {
                        return item as FlowNode;
                    }
                }
            }

            return null;
        }

        /// <summary>
        /// 移动选择的项目
        /// </summary>
        /// <param name="xMove">X轴的移动量</param>
        /// <param name="yMove">Y轴的移动量</param>
        internal void MoveSelectedItems(int xMove, int yMove)
        {
            foreach (FlowItem item in this._selectedItems)
            {
                if (item is FlowNode)
                {
                    FlowNode node = item as FlowNode;
                    node.Left += xMove;
                    node.Top += yMove;

                    // 移动连接线
                    foreach (FlowLine line in node.InLines)
                    {
                        if (!line.Selected)
                        {
                            line.PointEnd = node.GetAnchor(line.AnchorEnd);
                        }
                    }

                    // 移动连接线
                    foreach (FlowLine line in node.OutLines)
                    {
                        if (!line.Selected)
                        {
                            line.PointBegin = node.GetAnchor(line.AnchorBegin);
                        }
                    }

                    continue;
                }

                if (item is FlowLine)
                {
                    FlowLine line = item as FlowLine;
                    Point p = line.PointBegin;
                    p.X += xMove;
                    p.Y += yMove;
                    line.PointBegin = p;
                    p = line.PointEnd;
                    p.X += xMove;
                    p.Y += yMove;
                    line.PointEnd = p;

                    // 断开连接
                    if (line.NodeBegin != null && !line.NodeBegin.Selected)
                    {
                        this.DisconnectL2NPointBegin(line);
                    }

                    if (line.NodeEnd != null && !line.NodeEnd.Selected)
                    {
                        this.DisconnectL2NPointEnd(line);
                    }

                    continue;
                }
            }
        }

        #endregion 鼠标操作

        #endregion 内部方法

        #region 私有方法

        #region 新建项目

        /// <summary>
        /// 新建节点
        /// </summary>
        /// <param name="location">节点位置</param>
        /// <returns>节点</returns>
        private FlowNode NewNodeInternal(Point? location)
        {
            //FlowNode node = this._drawingItem as FlowNode;
            FlowNode newNode = (this._drawingNode == null) ? new FlowNode(this) : this._drawingNode;
            newNode.Selected = true;
            if (location.HasValue)
            {
                newNode.Location = location.Value;
            }
            if (newNode.Bounds.IsEmpty)
            {
                newNode.Bounds = Consts.NODE_BOUNDS_DEFAULT;
            }
            if (newNode.Size.IsEmpty)
            {
                newNode.Size = Consts.NODE_BOUNDS_DEFAULT.Size;
            }
            newNode.NodeState = FlowNodeState.Added;
            this.ClearSelection();
            this._items.Add(newNode);
            this._allNodes.Add(newNode);
            this._selectedItems.Add(newNode);

            this._drawingItem = null;
            this._drawingNode = null;
            this._drawingLine = null;
            this.SetDefaultCursor();

            return newNode;
        }

        /// <summary>
        /// 新建线段
        /// </summary>
        /// <param name="pointBegin">起始点</param>
        /// <param name="pointEnd">结算点</param>
        /// <returns>线段</returns>
        private FlowLine NewLineInternal(Point? pointBegin, Point? pointEnd)
        {
            //FlowLine line = this._drawingItem as FlowLine;
            FlowLine newLine = (this._drawingLine == null) ? new FlowLine(this) : this._drawingLine;
            newLine.Selected = true;
            if (pointBegin.HasValue)
            {
                newLine.PointBegin = pointBegin.Value;
                newLine.PointEnd = pointEnd.Value;
            }
            else
            {
                newLine.PointBegin = Consts.LINE_POINT_Begin_DEFAULT;
                newLine.PointEnd = Consts.LINE_POINT_END_DEFAULT;
            }

            this.ClearSelection();
            this._items.Add(newLine);
            this._selectedItems.Add(newLine);

            this._drawingItem = null;
            this._drawingNode = null;
            this._drawingLine = null;
            this.SetDefaultCursor();

            return newLine;
        }

        #endregion 新建项目

        #region 绘制项目

        /// <summary>
        /// 绘制Item
        /// </summary>
        /// <param name="graphics">Graphics</param>
        private void DrawItems(Graphics graphics)
        {
            foreach (FlowItem item in this._items)
            {
                this.DrawItem(graphics, item);
            }

            foreach (FlowItem item in this._items)
            {
                this.DrawSelectedItem(graphics, item);
            }
        }

        ///// <summary>
        ///// 绘制未激活的Item
        ///// </summary>
        ///// <param name="graphics">Graphics</param>
        //private void DrawStaticItems(Graphics graphics)
        //{
        //    foreach (FlowItem item in this._items)
        //    {
        //        // 不绘制激活的item
        //        if (item.MouseOperating)
        //        {
        //            continue;
        //        }

        //        this.DrawItem(graphics, item);
        //    }
        //}

        ///// <summary>
        ///// 绘制激活的Item
        ///// </summary>
        ///// <param name="graphics">Graphics</param>
        //private void DrawActiveItems(Graphics graphics)
        //{
        //    foreach (FlowItem item in this._items)
        //    {
        //        // 绘制激活的item
        //        if (!item.MouseOperating)
        //        {
        //            continue;
        //        }

        //        this.DrawItem(graphics, item);
        //    }
        //}

        /// <summary>
        /// 绘制图片
        /// </summary>
        /// <param name="graphics"></param>
        /// <param name="image"></param>
        /// <param name="rect"></param>
        private void DrawImage(Graphics graphics, Image image, Rectangle rect)
        {
            graphics.DrawImage(image, rect);
        }

        /// <summary>
        /// 绘制Item
        /// </summary>
        /// <param name="graphics">Graphics</param>
        /// <param name="item">item</param>
        private void DrawItem(Graphics graphics, FlowItem item)
        {
            if (item is FlowNode)
            {
                FlowNode node = item as FlowNode;
                this.DrawNode(graphics, node);
                return;
            }

            if (item is FlowLine)
            {
                FlowLine line = item as FlowLine;
                this.DrawLine(graphics, line);
                return;
            }
        }

        /// <summary>
        /// 绘制选中状态Item的附属
        /// </summary>
        /// <param name="graphics">Graphics</param>
        /// <param name="item">item</param>
        private void DrawSelectedItem(Graphics graphics, FlowItem item)
        {
            if (item is FlowNode)
            {
                FlowNode node = item as FlowNode;
                this.DrawSelectedNode(graphics, node);
                return;
            }

            if (item is FlowLine)
            {
                FlowLine line = item as FlowLine;
                this.DrawSelectedLine(graphics, line);
                return;
            }
        }

        /// <summary>
        /// 绘制节点
        /// </summary>
        /// <param name="graphics">Graphics</param>
        /// <param name="node">节点</param>
        private void DrawNode(Graphics graphics, FlowNode node)
        {
            // 填充颜色
            if (node.FillColor.HasValue && node.FillColor != Color.Transparent)
            {
                this._penDrawNode.Color = node.FillColor.Value;
                graphics.FillRectangle(this._penDrawNode.Brush, node.Bounds);
            }
            // 画图
            if (node.NodeImage != null)
            {
                this.DrawImage(graphics, node.NodeImage, node.Bounds);
            }
            // 画边框
            if (node.BorderWidth > 0 && node.BorderColor != Color.Transparent)
            {
                this._penDrawNode.Color = node.BorderColor;
                this._penDrawNode.Width = node.BorderWidth;
                graphics.DrawRectangle(this._penDrawNode, node.Bounds);
            }
            // 显示名称
            if (node.ShowName)
            {
                Point p5 = this.GetRectBottom(node.Bounds);
                SizeF size = graphics.MeasureString(node.Name, node.Font);
                this._penDrawString.Color = node.FontColor;
                graphics.DrawString(node.Name, node.Font, this._penDrawString.Brush, p5.X - size.Width / 2, p5.Y + Consts.NODE_STRING_MARGIN);
            }

            // this.DrawSelectedNode(graphics, node);
        }

        /// <summary>
        /// 绘制选中节点的附属
        /// </summary>
        /// <param name="graphics">Graphics</param>
        /// <param name="node">节点</param>
        private void DrawSelectedNode(Graphics graphics, FlowNode node)
        {
            Rectangle[] rects = node.GetSelectedStyle();
            // 画激活状态
            if (node.MouseOperating)
            {
                for (int i = 0; i < rects.Length; i++)
                {
                    bool isAnchor = false;
                    switch ((NodePointKind)i)
                    {
                        case NodePointKind.Top:
                            if (node.TopLines != null && node.TopLines.Count > 0)
                            {
                                isAnchor = true;
                            }
                            break;
                        case NodePointKind.Bottom:
                            if (node.BottomLines != null && node.BottomLines.Count > 0)
                            {
                                isAnchor = true;
                            }
                            break;
                        case NodePointKind.Left:
                            if (node.LeftLines != null && node.LeftLines.Count > 0)
                            {
                                isAnchor = true;
                            }
                            break;
                        case NodePointKind.Right:
                            if (node.RightLines != null && node.RightLines.Count > 0)
                            {
                                isAnchor = true;
                            }
                            break;
                        default:
                            break;
                    }

                    this.DrawSelected(graphics, rects[i], isAnchor, true);
                }
            }
            // 画选择状态
            else if (node.Selected)
            {
                for (int i = 0; i < rects.Length; i++)
                {
                    bool isAnchor = false;
                    switch ((NodePointKind)i)
                    {
                        case NodePointKind.Top:
                            if (node.TopLines != null && node.TopLines.Count > 0)
                            {
                                isAnchor = true;
                            }
                            break;
                        case NodePointKind.Bottom:
                            if (node.BottomLines != null && node.BottomLines.Count > 0)
                            {
                                isAnchor = true;
                            }
                            break;
                        case NodePointKind.Left:
                            if (node.LeftLines != null && node.LeftLines.Count > 0)
                            {
                                isAnchor = true;
                            }
                            break;
                        case NodePointKind.Right:
                            if (node.RightLines != null && node.RightLines.Count > 0)
                            {
                                isAnchor = true;
                            }
                            break;
                        default:
                            break;
                    }

                    this.DrawSelected(graphics, rects[i], isAnchor, false);
                }
            }

            if (node.ShowAnchor)
            {
                Rectangle[] anchorRects = node.GetAnchorRects();
                foreach (Rectangle rect in anchorRects)
                {
                    this.DrawSelected(graphics, rect, true, true);
                }
            }
        }

        /// <summary>
        /// 绘制线段
        /// </summary>
        /// <param name="graphics">Graphics</param>
        /// <param name="line">线段</param>
        private void DrawLine(Graphics graphics, FlowLine line)
        {
            this._penDrawLine.Color = line.LineColor;
            this._penDrawLine.Width = line.LineWidth;
            // 画线段
            graphics.DrawLine(this._penDrawLine, line.PointBegin, line.PointEnd);
            // 显示名称
            if (line.ShowName)
            {
                Point mp = this.GetLineMidpoint(line.PointBegin, line.PointEnd);
                SizeF size = graphics.MeasureString(line.Name, line.Font);
                this._penDrawString.Color = line.FontColor;
                graphics.DrawString(line.Name, line.Font, this._penDrawString.Brush, mp.X - size.Width / 2, mp.Y - size.Height / 2);
            }

            // this.DrawSelectedLine(graphics, node);
        }

        /// <summary>
        /// 绘制选中线段的附属
        /// </summary>
        /// <param name="graphics">Graphics</param>
        /// <param name="line">线段</param>
        private void DrawSelectedLine(Graphics graphics, FlowLine line)
        {
            Rectangle[] rects = line.GetSelectedStyle();
            // 画激活状态
            if (line.MouseOperating)
            {
                if (line.NodeBegin != null)
                {
                    if (!line.NodeBegin.Selected)
                    {
                        this.DrawSelected(graphics, rects[0], true, true);
                    }
                }
                else
                {
                    this.DrawSelected(graphics, rects[0], false, true);
                }

                if (line.NodeEnd != null)
                {
                    if (!line.NodeEnd.Selected)
                    {
                        this.DrawSelected(graphics, rects[1], true, true);
                    }
                }
                else
                {
                    this.DrawSelected(graphics, rects[1], false, true);
                }
            }
            // 画选择状态
            else if (line.Selected)
            {
                if (line.NodeBegin != null)
                {
                    if (!line.NodeBegin.Selected)
                    {
                        this.DrawSelected(graphics, rects[0], true, false);
                    }
                }
                else
                {
                    this.DrawSelected(graphics, rects[0], false, false);
                }

                if (line.NodeEnd != null)
                {
                    if (!line.NodeEnd.Selected)
                    {
                        this.DrawSelected(graphics, rects[1], true, false);
                    }
                }
                else
                {
                    this.DrawSelected(graphics, rects[1], false, false);
                }
            }
        }

        /// <summary>
        /// 绘制折线
        /// </summary>
        /// <param name="graphics"></param>
        /// <param name="line"></param>
        private void DrawPolyline(Graphics graphics, FlowPolyline line)
        {
        }

        /// <summary>
        /// 绘制选择Item的附属
        /// </summary>
        /// <param name="graphics"></param>
        /// <param name="rect"></param>
        /// <param name="isAnchor"></param>
        /// <param name="operating"></param>
        private void DrawSelected(Graphics graphics, Rectangle rect, bool isAnchor, bool operating)
        {
            if (operating)
            {
                if (isAnchor)
                {
                    graphics.FillEllipse(Consts.SELECT_POINT_BRUSH_LINE_TO_NODE, rect);
                    graphics.DrawEllipse(Consts.SELECT_POINT_PEN, rect);
                }
                else
                {
                    graphics.FillEllipse(Consts.SELECT_POINT_BRUSH, rect);
                    graphics.DrawEllipse(Consts.SELECT_POINT_PEN, rect);
                }
            }
            else
            {
                if (isAnchor)
                {
                    graphics.FillRectangle(Consts.SELECT_POINT_BRUSH_LINE_TO_NODE, rect);
                    graphics.DrawRectangle(Consts.SELECT_POINT_PEN, rect);
                }
                else
                {
                    graphics.FillRectangle(Consts.SELECT_POINT_BRUSH, rect);
                    graphics.DrawRectangle(Consts.SELECT_POINT_PEN, rect);
                }
            }
        }

        #endregion 绘制项目

        #region 鼠标样式

        /// <summary>
        /// 设置鼠标样式
        /// </summary>
        /// <param name="type"></param>
        private void SetCursor(MouseOperatingType type)
        {
            this._mouseOperatingType = type;
            switch (type)
            {
                case MouseOperatingType.None:
                    this.CanvasCursor = Cursors.Default;
                    break;
                case MouseOperatingType.RectSelect:
                    this.CanvasCursor = Cursors.Cross;
                    break;
                case  MouseOperatingType.Move:
                    this.CanvasCursor = Cursors.SizeAll;
                    break;
                case MouseOperatingType.NodeTopAndLeft:
                case MouseOperatingType.NodeBottomAndRight:
                    this.CanvasCursor = Cursors.SizeNWSE;
                    break;
                case MouseOperatingType.NodeTopAndRight:
                case MouseOperatingType.NodeBottomAndLeft:
                    this.CanvasCursor = Cursors.SizeNESW;
                    break;
                case MouseOperatingType.NodeTop:
                case MouseOperatingType.NodeBottom:
                    this.CanvasCursor = Cursors.SizeNS;
                    break;
                case MouseOperatingType.NodeLeft:
                case MouseOperatingType.NodeRight:
                    this.CanvasCursor = Cursors.SizeWE;
                    break;
                case MouseOperatingType.LineBegin:
                case MouseOperatingType.LineEnd:
                    this.CanvasCursor = Cursors.Hand;
                    break;
                case MouseOperatingType.DrawingNode:
                    this.CanvasCursor = ItemCursor.NodeCursor;
                    break;
                case MouseOperatingType.DrawingLine:
                    this.CanvasCursor = ItemCursor.LineCursor;
                    break;
                default:
                    this.CanvasCursor = Cursors.Default;
                    break;
            }
        }

        /// <summary>
        /// 设置手动画节点时鼠标样式
        /// </summary>
        private void SetDrawingNodeCursor()
        {
            this.SetCursor(MouseOperatingType.DrawingNode);
        }

        /// <summary>
        /// 设置手动画节点时鼠标样式
        /// </summary>
        private void SetDrawingLineCursor()
        {
            this.SetCursor(MouseOperatingType.DrawingLine);
        }

        /// <summary>
        /// 设置框选时鼠标样式
        /// </summary>
        private void SetRectSelectCursor()
        {
            this.SetCursor(MouseOperatingType.RectSelect);
        }

        /// <summary>
        /// 设置默认鼠标样式
        /// </summary>
        private void SetDefaultCursor()
        {
            this.SetCursor(MouseOperatingType.None);
        }

        /// <summary>
        /// 设置移动时鼠标样式
        /// </summary>
        private void SetMoveCursor()
        {
            this.SetCursor(MouseOperatingType.Move);
        }

        /// <summary>
        /// 设置改变节点大小时鼠标样式
        /// </summary>
        /// <param name="kind">节点端点</param>
        private void SetNodeResizeCursor(NodePointKind kind)
        {
            MouseOperatingType type = MouseOperatingType.None;
            switch (kind)
            {
                case NodePointKind.TopAndLeft:
                    type = MouseOperatingType.NodeTopAndLeft;
                    break;
                case NodePointKind.TopAndRight:
                    type = MouseOperatingType.NodeTopAndRight;
                    break;
                case NodePointKind.BottomAndLeft:
                    type = MouseOperatingType.NodeBottomAndLeft;
                    break;
                case NodePointKind.BottomAndRight:
                    type = MouseOperatingType.NodeBottomAndRight;
                    break;
                case NodePointKind.Top:
                    type = MouseOperatingType.NodeTop;
                    break;
                case NodePointKind.Bottom:
                    type = MouseOperatingType.NodeBottom;
                    break;
                case NodePointKind.Left:
                    type = MouseOperatingType.NodeLeft;
                    break;
                case NodePointKind.Right:
                    type = MouseOperatingType.NodeRight;
                    break;
                default:
                    type = MouseOperatingType.None;
                    break;
            }

            this.SetCursor(type);
        }

        /// <summary>
        /// 设置改变线段端点时鼠标样式
        /// </summary>
        /// <param name="kind">线段端点</param>
        private void SetLineResizeCursor(LinePointKind kind)
        {
            MouseOperatingType type = MouseOperatingType.None;
            switch (kind)
            {
                case LinePointKind.Begin:
                    type = MouseOperatingType.LineBegin;
                    break;
                case LinePointKind.End:
                    type = MouseOperatingType.LineEnd;
                    break;
                default:
                    type = MouseOperatingType.None;
                    break;
            }

            this.SetCursor(type);
        }

        /// <summary>
        /// 鼠标移动时，根据鼠标位置设置鼠标样式
        /// </summary>
        /// <param name="point">鼠标位置</param>
        private void SetMouseCursorByMove(Point point)
        {
            this._nodeSizeChanging = null;
            this._linePointChanging = null;

            // item附属判断
            for (int i = this._items.Count - 1; i >= 0; i--)
            {
                FlowItem item = this._items[i];

                if (!item.Selected)
                {
                    continue;
                }

                Rectangle[] rects = item.GetSelectedStyle();

                if (item is FlowNode)
                {
                    FlowNode node = item as FlowNode;
                    for (int index = 0; index < rects.Length; index++)
                    {
                        if (rects[index].Contains(point))
                        {
                            NodePointKind kind = (NodePointKind)index;
                            // 优先操作连接节点的线段
                            switch (kind)
                            {
                                case NodePointKind.Top:
                                    if (!this.CanOperateNode(node.TopLines))
                                    {
                                        continue;
                                    }
                                    break;
                                case NodePointKind.Bottom:
                                    if (!this.CanOperateNode(node.BottomLines))
                                    {
                                        continue;
                                    }
                                    break;
                                case NodePointKind.Left:
                                    if (!this.CanOperateNode(node.LeftLines))
                                    {
                                        continue;
                                    }
                                    break;
                                case NodePointKind.Right:
                                    if (!this.CanOperateNode(node.RightLines))
                                    {
                                        continue;
                                    }
                                    break;
                                default:
                                    break;
                            }
                            this.SetNodeResizeCursor(kind);
                            this._nodeSizeChanging = node;
                            return;
                        }
                    }
                }

                if (this._flowBoxMode != FlowBoxMode.Edit)
                {
                    continue;
                }

                if (item is FlowLine)
                {
                    for (int index = 0; index < rects.Length; index++)
                    {
                        if (rects[index].Contains(point))
                        {
                            LinePointKind kind = (LinePointKind)index;
                            this.SetLineResizeCursor(kind);
                            this._linePointChanging = item as FlowLine;
                            return;
                        }
                    }
                }
            }

            // item内部判断
            for (int i = this._items.Count - 1; i >= 0; i--)
            {
                FlowItem item = this._items[i];

                if (!item.Selected)
                {
                    continue;
                }

                if (item is FlowNode)
                {
                    if (this.IsPointOnNode(point, item as FlowNode))
                    {
                        this.SetMoveCursor();
                        return;
                    }
                }

                if (this._flowBoxMode != FlowBoxMode.Edit)
                {
                    continue;
                }

                if (item is FlowLine)
                {
                    if (this.IsPointOnLine(point, item as FlowLine))
                    {
                        this.SetMoveCursor();
                        return;
                    }
                }
            }

            this._nodeSizeChanging = null;
            this._linePointChanging = null;
            this.SetDefaultCursor();
        }

        #endregion 鼠标样式

        #region 流程控制

        /// <summary>
        /// 连接PointBegin到节点
        /// </summary>
        /// <param name="line">线段</param>
        /// <param name="node">节点</param>
        /// <param name="anchorKind">锚点</param>
        private void ConnectL2NPointBegin(FlowLine line, FlowNode node, AnchorKind anchorKind)
        {
            line.AnchorBegin = anchorKind;
            // 连接节点
            line.PointBegin = node.GetAnchor(anchorKind);
            line.NodeBegin = node;
            node.OutLines.Add(line);
            switch (anchorKind)
            {
                case AnchorKind.Top:
                    node.TopLines.Add(line);
                    break;
                case AnchorKind.Bottom:
                    node.BottomLines.Add(line);
                    break;
                case AnchorKind.Left:
                    node.LeftLines.Add(line);
                    break;
                case AnchorKind.Right:
                    node.RightLines.Add(line);
                    break;
                default:
                    break;
            }
        }

        /// <summary>
        /// 连接PointEnd到节点
        /// </summary>
        /// <param name="line">线段</param>
        /// <param name="node">节点</param>
        /// <param name="anchorKind">锚点</param>
        private void ConnectL2NPointEnd(FlowLine line, FlowNode node, AnchorKind anchorKind)
        {
            line.AnchorEnd = anchorKind;
            // 连接节点
            line.PointEnd = node.GetAnchor(anchorKind);
            line.NodeEnd = node;
            node.InLines.Add(line);
            switch (anchorKind)
            {
                case AnchorKind.Top:
                    node.TopLines.Add(line);
                    break;
                case AnchorKind.Bottom:
                    node.BottomLines.Add(line);
                    break;
                case AnchorKind.Left:
                    node.LeftLines.Add(line);
                    break;
                case AnchorKind.Right:
                    node.RightLines.Add(line);
                    break;
                default:
                    break;
            }
        }

        /// <summary>
        /// 断开PointBegin的连接
        /// </summary>
        /// <param name="line">线段</param>
        private void DisconnectL2NPointBegin(FlowLine line)
        {
            switch (line.AnchorBegin)
            {
                case AnchorKind.Top:
                    line.NodeBegin.TopLines.Remove(line);
                    break;
                case AnchorKind.Bottom:
                    line.NodeBegin.BottomLines.Remove(line);
                    break;
                case AnchorKind.Left:
                    line.NodeBegin.LeftLines.Remove(line);
                    break;
                case AnchorKind.Right:
                    line.NodeBegin.RightLines.Remove(line);
                    break;
                default:
                    break;
            }
            line.NodeBegin.OutLines.Remove(line);
            line.NodeBegin = null;
            line.AnchorBegin = AnchorKind.None;
        }

        /// <summary>
        /// 断开PointEnd的连接
        /// </summary>
        /// <param name="line">线段</param>
        private void DisconnectL2NPointEnd(FlowLine line)
        {
            switch (line.AnchorEnd)
            {
                case AnchorKind.Top:
                    line.NodeEnd.TopLines.Remove(line);
                    break;
                case AnchorKind.Bottom:
                    line.NodeEnd.BottomLines.Remove(line);
                    break;
                case AnchorKind.Left:
                    line.NodeEnd.LeftLines.Remove(line);
                    break;
                case AnchorKind.Right:
                    line.NodeEnd.RightLines.Remove(line);
                    break;
                default:
                    break;
            }
            line.NodeEnd.InLines.Remove(line);
            line.NodeEnd = null;
            line.AnchorEnd = AnchorKind.None;
        }

        /// <summary>
        /// 获得可连接的节点
        /// </summary>
        /// <param name="point">鼠标位置</param>
        /// <returns>可连接的节点</returns>
        private FlowNode GetL2N(Point point)
        {
            FlowNode inNode = null;
            FlowNode edgeNode = null;
            for (int i = this._items.Count - 1; i >= 0; i--)
            {
                FlowNode node = this._items[i] as FlowNode;
                if (node == null)
                {
                    continue;
                }
                node.ShowAnchor = false;

                // 在节点范围内
                if (node.Bounds.Contains(point))
                {
                    inNode = node;
                }

                // 在节点边缘
                Rectangle rect = node.Bounds;
                rect.Inflate(Consts.L2N_PRECISION_EDGE, Consts.L2N_PRECISION_EDGE);
                if (rect.Contains(point))
                {
                    edgeNode = node;
                }
            }

            if (inNode != null)
            {
                inNode.ShowAnchor = true;
                return inNode;
            }

            if (edgeNode != null)
            {
                edgeNode.ShowAnchor = true;
                return edgeNode;
            }

            return null;
        }

        #endregion 流程控制

        #region 鼠标操作

        /// <summary>
        /// 框选Item
        /// </summary>
        /// <param name="rect">框选范围</param>
        private void SelectItemByRect(Rectangle rect)
        {
            this.ClearSelection();
            foreach (FlowItem item in this._items)
            {
                if (item is FlowNode)
                {
                    FlowNode node = item as FlowNode;
                    if (rect.IntersectsWith(node.Bounds))
                    {
                        node.Selected = true;
                        this._selectedItems.Add(node);
                    }
                    else
                    {
                        node.Selected = false;
                    }

                    continue;
                }

                if (this._flowBoxMode != FlowBoxMode.Edit)
                {
                    continue;
                }

                if (item is FlowLine)
                {
                    FlowLine line = item as FlowLine;
                    if (rect.Contains(line.PointBegin) || rect.Contains(line.PointEnd))
                    {
                        line.Selected = true;
                        this._selectedItems.Add(line);
                    }
                    else
                    {
                        line.Selected = false;
                    }

                    continue;
                }
            }
        }

        /// <summary>
        /// 点选Item
        /// </summary>
        /// <param name="point">鼠标点</param>
        /// <returns>选中的item</returns>
        private FlowItem SelectItemByPoint(Point point)
        {
            for (int i = this._items.Count - 1; i >= 0; i--)
            {
                FlowItem item = this._items[i];
                if (item is FlowNode)
                {
                    if (this.IsPointOnNode(point, item as FlowNode))
                    {
                        return item;
                    }
                }

                if (this._flowBoxMode != FlowBoxMode.Edit)
                {
                    continue;
                }

                if (item is FlowLine)
                {
                    if (this.IsPointOnLine(point, item as FlowLine))
                    {
                        return item;
                    }
                }

                //if (item is FlowPolyline)
                //{
                //    if (this.IsPointOnPolyLine(point, item as FlowPolyline))
                //    {
                //        return item;
                //    }
                //}
            }

            return null;
        }

        /// <summary>
        /// 点选节点
        /// </summary>
        /// <param name="point">鼠标点</param>
        /// <returns>选中的节点</returns>
        private FlowNode SelectNodeByPoint(Point point)
        {
            for (int i = this._items.Count - 1; i >= 0; i--)
            {
                FlowItem item = this._items[i];
                if (item is FlowNode)
                {
                    FlowNode node = item as FlowNode;
                    if (this.IsPointOnNode(point, node))
                    {
                        return node;
                    }
                }
            }

            return null;
        }

        /// <summary>
        /// 能否操作节点（鼠标在锚点）
        /// </summary>
        /// <param name="lines">连接的线段</param>
        /// <returns>能否操作节点</returns>
        private bool CanOperateNode(List<FlowLine> lines)
        {
            if (lines != null && lines.Count > 0)
            {
                foreach (FlowLine line in lines)
                {
                    if (line.Selected)
                    {
                        return false;
                    }
                }
            }

            return true;
        }

        #endregion 鼠标操作

        #region 工具

        /// <summary>
        /// 判断线段是否相交
        /// </summary>
        /// <param name="p1">线段1的开始点</param>
        /// <param name="p2">线段1的结束点</param>
        /// <param name="p3">线段2的开始点</param>
        /// <param name="p4">线段2的结束点</param>
        /// <returns>是否相交</returns>
        private bool IsSegmentIntersect(Point p1, Point p2, Point p3, Point p4)
        {
            double d1 = this.GetDirection(p3, p4, p1);
            double d2 = this.GetDirection(p3, p4, p2);
            double d3 = this.GetDirection(p1, p2, p3);
            double d4 = this.GetDirection(p1, p2, p4);

            if (d1 * d2 < 0 && d3 * d4 < 0)
            {
                return true;
            }
            else if (d1 == 0 && this.IsOnSegment(p3, p4, p1))
            {
                return true;
            }
            else if (d2 == 0 && this.IsOnSegment(p3, p4, p2))
            {
                return true;
            }
            else if (d3 == 0 && this.IsOnSegment(p1, p2, p3))
            {
                return true;
            }
            else if (d4 == 0 && this.IsOnSegment(p1, p2, p4))
            {
                return true;
            }
            else
            {
                return false;
            }
        }

        /// <summary>
        /// 获取点1到点2和点3的向量的叉乘
        /// </summary>
        /// <param name="p1">点1</param>
        /// <param name="p2">点2</param>
        /// <param name="p3">点3</param>
        /// <returns></returns>
        private int GetDirection(Point p1, Point p2, Point p3)
        {
            Point v1 = new Point(p3.X - p1.X, p3.Y - p1.Y);
            Point v2 = new Point(p2.X - p1.X, p2.Y - p1.Y);
            return v1.X * v2.Y - v1.Y * v2.X;
        }

        /// <summary>
        /// 点3在线上时，判断点3在线段上，还是在线段的延长线上
        /// </summary>
        /// <param name="p1">线段的开始点</param>
        /// <param name="p2">线段的结束点</param>
        /// <param name="p3">点3</param>
        /// <returns></returns>
        private bool IsOnSegment(Point p1, Point p2, Point p3)
        {
            int x_min, x_max, y_min, y_max;
            if (p1.X < p2.X)
            {
                x_min = p1.X;
                x_max = p2.X;
            }
            else
            {
                x_min = p2.X;
                x_max = p1.X;
            }
            if (p1.Y < p2.Y)
            {
                y_min = p1.Y;
                y_max = p2.Y;
            }
            else
            {
                y_min = p2.Y;
                y_max = p1.Y;
            }

            if (p3.X < x_min || p3.X > x_max || p3.Y < y_min || p3.Y > y_max)
            {
                return false;
            }
            else
            {
                return true;
            }
        }

        /// <summary>
        /// 点是否在节点上
        /// </summary>
        /// <param name="point">点</param>
        /// <param name="node">节点</param>
        /// <returns>是否在节点上</returns>
        private bool IsPointOnNode(Point point, FlowNode node)
        {
            return node.Bounds.Contains(point);
        }

        /// <summary>
        /// 点是否在线段上
        /// </summary>
        /// <param name="point">点</param>
        /// <param name="line">线段</param>
        /// <returns>否在线段上</returns>
        private bool IsPointOnLine(Point point, FlowLine line)
        {
            double p2ls = this.GetP2LSDistance(point, line.PointBegin, line.PointEnd);
            //if (p2ls <= (line.LineWidth - 1) / 2 + Consts.P2L_PRECISION)
            if (p2ls <= (line.LineWidth) / 2 + Consts.P2L_PRECISION)
            {
                return true;
            }

            return false;
        }

        /// <summary>
        /// 获取点到线段的距离
        /// </summary>
        /// <param name="p">点</param>
        /// <param name="pBegin">线段的端点</param>
        /// <param name="pEnd">线段的端点</param>
        /// <returns>点到线段的距离</returns>
        private double GetP2LSDistance(Point p, Point pBegin, Point pEnd)
        {
            // 点在线段端点
            double pp1 = this.GetP2PDistance(p, pBegin);
            if (pp1 < Consts.DOUBLE_PRECISION)
            {
                return pp1;
            }
            double pp2 = this.GetP2PDistance(p, pEnd);
            if (pp2 < Consts.DOUBLE_PRECISION)
            {
                return pp2;
            }
            double p1p2 = this.GetP2PDistance(pBegin, pEnd);
            // 线段端点相同
            if (p1p2 < Consts.DOUBLE_PRECISION)
            {
                return pp1;
            }

            // 点在线段端点外
            double pp12 = pp1 * pp1;
            double pp22 = pp2 * pp2;
            double p1p22 = p1p2 * p1p2;
            if (pp12 >= pp22 + p1p22)
            {
                return pp22;
            }
            if (pp22 >= pp12 + p1p22)
            {
                return pp12;
            }

            // 点在线段端点内
            // 周长的一半
            double l = (pp1 + pp2 + p1p2) / 2;
            // 海伦公式求面积，也可以用矢量求
            double s = Math.Sqrt(l * (l - pp1) * (l - pp2) * (l - p1p2));
            return 2 * s / p1p2;
        }

        /// <summary>
        /// 获取两点间的距离
        /// </summary>
        /// <param name="point1"></param>
        /// <param name="point2"></param>
        /// <returns>两点间的距离</returns>
        private double GetP2PDistance(Point point1, Point point2)
        {
            return Math.Sqrt((point1.X - point2.X) * (point1.X - point2.X) + (point1.Y - point2.Y) * (point1.Y - point2.Y));
        }

        /// <summary>
        /// 获取鼠标操作后的新范围
        /// </summary>
        /// <param name="rect">源范围</param>
        /// <param name="fixedPoint">固定点</param>
        /// <param name="newPoint">移动点</param>
        /// <returns>新范围</returns>
        private Rectangle GetNewRect(Rectangle rect, Point fixedPoint, Point newPoint)
        {
            int xRect = newPoint.X - fixedPoint.X;
            int yRect = newPoint.Y - fixedPoint.Y;
            if (xRect < 0)
            {
                rect.X = newPoint.X;
                rect.Width = -xRect;
            }
            else
            {
                rect.X = fixedPoint.X;
                rect.Width = xRect;
            }
            if (yRect < 0)
            {
                rect.Y = newPoint.Y;
                rect.Height = -yRect;
            }
            else
            {
                rect.Y = fixedPoint.Y;
                rect.Height = yRect;
            }

            return rect;
        }

        /// <summary>
        /// 获取鼠标操作后的新范围
        /// </summary>
        /// <param name="rect">源范围</param>
        /// <param name="fixedPoint">固定点</param>
        /// <param name="xRect">x方向移动距离</param>
        /// <param name="yRect">y方向移动距离</param>
        /// <returns>新范围</returns>
        private Rectangle GetNewRect(Rectangle rect, Point fixedPoint, int xRect, int yRect)
        {
            if (xRect < 0)
            {
                rect.X = fixedPoint.X + xRect;
                rect.Width = -xRect;
            }
            else
            {
                rect.X = fixedPoint.X;
                rect.Width = xRect;
            }
            if (yRect < 0)
            {
                rect.Y = fixedPoint.Y + yRect;
                rect.Height = -yRect;
            }
            else
            {
                rect.Y = fixedPoint.Y;
                rect.Height = yRect;
            }

            return rect;
        }

        /// <summary>
        /// 获得矩形的左上角
        /// </summary>
        /// <param name="rect">矩形</param>
        /// <returns>左上角</returns>
        private Point GetRectTopAndLeft(Rectangle rect)
        {
            return rect.Location;
        }

        /// <summary>
        /// 获得矩形的右上角
        /// </summary>
        /// <param name="rect">矩形</param>
        /// <returns>右上角</returns>
        private Point GetRectTopAndRight(Rectangle rect)
        {
            return new Point(rect.Right, rect.Top);
        }

        /// <summary>
        /// 获得矩形的左下角
        /// </summary>
        /// <param name="rect">矩形</param>
        /// <returns>左下角</returns>
        private Point GetRectBottomAndLeft(Rectangle rect)
        {
            return new Point(rect.Left, rect.Bottom);
        }

        /// <summary>
        /// 获得矩形的右下角
        /// </summary>
        /// <param name="rect">矩形</param>
        /// <returns>右下角</returns>
        private Point GetRectBottomAndRight(Rectangle rect)
        {
            return new Point(rect.Right, rect.Bottom);
        }

        /// <summary>
        /// 获得矩形的上中点
        /// </summary>
        /// <param name="rect">矩形</param>
        /// <returns>上中点</returns>
        private Point GetRectTop(Rectangle rect)
        {
            return new Point(rect.Left + rect.Width / 2, rect.Top);
        }

        /// <summary>
        /// 获得矩形的下中点
        /// </summary>
        /// <param name="rect">矩形</param>
        /// <returns>下中点</returns>
        private Point GetRectBottom(Rectangle rect)
        {
            return new Point(rect.Left + rect.Width / 2, rect.Bottom);
        }

        /// <summary>
        /// 获得矩形的左中点
        /// </summary>
        /// <param name="rect">矩形</param>
        /// <returns>左中点</returns>
        private Point GetRectLeft(Rectangle rect)
        {
            return new Point(rect.Left, rect.Top + rect.Height / 2);
        }

        /// <summary>
        /// 获得矩形的右中点
        /// </summary>
        /// <param name="rect">矩形</param>
        /// <returns>右中点</returns>
        private Point GetRectRight(Rectangle rect)
        {
            return new Point(rect.Right, rect.Top + rect.Height / 2);
        }

        /// <summary>
        /// 获得线段的中点
        /// </summary>
        /// <param name="pointBegin">线段开始点</param>
        /// <param name="pointEnd">线段结束点</param>
        /// <returns>中点</returns>
        private Point GetLineMidpoint(Point pointBegin, Point pointEnd)
        {
            return new Point((pointBegin.X + pointEnd.X) / 2, (pointBegin.Y + pointEnd.Y) / 2);
        }

        #endregion 工具

        #endregion 私有方法
    }
}