kmpdfkit_demo/Demo/Examples/Compdfkit_Tools/Common/Helper/CommonHelper.cs

using ComPDFKit.PDFAnnotation;
using ComPDFKit.PDFDocument;
using Microsoft.Win32;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.IO;
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;

namespace Compdfkit_Tools.Helper
{
    public static class CommonHelper
    {
        /// <summary>
        /// Returns the file size based on the specified file path, with the smallest unit being bytes (B).
        /// </summary>
        /// <param name="filePath">The path to the file.</param>
        /// <returns>
        /// The calculated file size, with units in bytes (B), kilobytes (KB), megabytes (MB), or gigabytes (GB).
        /// </returns>
        public static string GetFileSize(string filePath)
        {
            FileInfo fileInfo = null;
            try
            {
                fileInfo = new FileInfo(filePath);
            }
            catch
            {
                return "0B";
            }
            if (fileInfo != null && fileInfo.Exists)
            {
                double fileSize = fileInfo.Length;
                if (fileSize > 1024)
                {
                    fileSize = Math.Round(fileSize / 1024, 2);
                    if (fileSize > 1024)
                    {
                        fileSize = Math.Round(fileSize / 1024, 2);
                        if (fileSize > 1024)
                        {
                            fileSize = Math.Round(fileSize / 1024, 2);
                            return fileSize + " GB";
                        }
                        else
                        {
                            return fileSize + " MB";
                        }
                    }
                    else
                    {
                        return fileSize + " KB";
                    }
                }
                else
                {
                    return fileSize + " B";
                }
            }
            return "0B";
        }
         
        public static string GetFilePathOrEmpty()
        {
            string selectedFilePath = string.Empty;
            OpenFileDialog openFileDialog = new OpenFileDialog();
            openFileDialog.Filter = "PDF files (*.pdf)|*.pdf";

            if (openFileDialog.ShowDialog() == true)
            {
                selectedFilePath = openFileDialog.FileName;
            }
            return selectedFilePath;
        }
         
        public static bool GetPagesInRange(ref List<int> pageList, string pageRange, int count, char[] enumerationSeparator, char[] rangeSeparator, bool inittag = false)
        {
            string[] rangeSplit = pageRange.Split(enumerationSeparator); 

            pageList.Clear();

            foreach (string range in rangeSplit)
            {
                int starttag = 1;
                if (inittag)
                {
                    starttag = 0;
                }
                if (range.Contains("-")) 
                {
                    try
                    {
                        string[] limits = range.Split(rangeSeparator); 
                        if (limits.Length >= 2 && !string.IsNullOrWhiteSpace(limits[0]) && !string.IsNullOrWhiteSpace(limits[1]))
                        {
                            int start = int.Parse(limits[0]);
                            int end = int.Parse(limits[1]);

                            if ((start < starttag) || (end > count) || (start > end))
                            { 
                                return false;
                            }

                            for (int i = start; i <= end; ++i)
                            {
                                if (pageList.Contains(i))
                                { 
                                    return false;
                                }

                                pageList.Add(i - 1);
                            }
                            continue;
                        }
                    }
                    catch (Exception ex)
                    { 
                        return false;
                    }
                }
                int pageNr;
                try
                { 
                    pageNr = int.Parse(range); 
                }
                catch (Exception) 
                {
                    return false;
                }
                if (pageNr < starttag || pageNr > count)
                {
                    return false; 
                }
                if (pageList.Contains(pageNr))
                {
                    return false; 
                }
                pageList.Add(pageNr - 1);
            }
            return true;
        }

        internal static class PageEditHelper
        { 
            public static T FindVisualParent<T>(DependencyObject obj) where T : class
            {
                while (obj != null)
                {
                    if (obj is T)
                        return obj as T;

                    obj = VisualTreeHelper.GetParent(obj);
                }
                return null;
            }

            public static childItem FindVisualChild<childItem>(DependencyObject obj)
                 where childItem : DependencyObject
            {
                for (int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++)
                {
                    DependencyObject child = VisualTreeHelper.GetChild(obj, i);
                    if (child != null && child is childItem)
                        return (childItem)child;
                    else
                    {
                        childItem childOfChild = FindVisualChild<childItem>(child);
                        if (childOfChild != null)
                            return childOfChild;
                    }
                }
                return null;
            }
        }

        public static class ViewportHelper
        {
            public static CPDFDocument CopyDoc;

            public static bool IsInViewport(ScrollViewer sv, Control item)
            {
                if (item == null) return false;
                ItemsControl itemsControl = null;
                if (item is ListBoxItem)
                    itemsControl = ItemsControl.ItemsControlFromItemContainer(item) as ListBox;
                else
                    throw new NotSupportedException(item.GetType().Name);
                ScrollContentPresenter scrollContentPresenter = (ScrollContentPresenter)sv.Template.FindName("PART_ScrollContentPresenter", sv);
                MethodInfo isInViewportMethod = sv.GetType().GetMethod("IsInViewport", BindingFlags.NonPublic | BindingFlags.Instance);
                return (bool)isInViewportMethod.Invoke(sv, new object[] { scrollContentPresenter, item });
            }

            public static T FindVisualParent<T>(DependencyObject obj) where T : class
            {
                while (obj != null)
                {
                    if (obj is T)
                        return obj as T;

                    obj = VisualTreeHelper.GetParent(obj);
                }
                return null;
            }

            public static childItem FindVisualChild<childItem>(DependencyObject obj)
                   where childItem : DependencyObject
            {
                for (int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++)
                {
                    DependencyObject child = VisualTreeHelper.GetChild(obj, i);
                    if (child != null && child is childItem)
                        return (childItem)child;
                    else
                    {
                        childItem childOfChild = FindVisualChild<childItem>(child);
                        if (childOfChild != null)
                            return childOfChild;
                    }
                }
                return null;
            }
        }

        public class ArrowHelper
        { 
            public bool HasStartArrow
            {
                get
                {
                    if (StartSharp != C_LINE_TYPE.LINETYPE_UNKNOWN && StartSharp != C_LINE_TYPE.LINETYPE_NONE)
                    {
                        return true;
                    }
                    return false;
                }
            } 

            public bool IsStartClosed
            {
                get
                {
                    if (StartSharp == C_LINE_TYPE.LINETYPE_CLOSEDARROW || StartSharp == C_LINE_TYPE.LINETYPE_RCLOSEDARROW || StartSharp == C_LINE_TYPE.LINETYPE_DIAMOND)
                    {
                        return true;
                    }
                    return false;
                }
            } 

            public bool HasEndArrow
            {
                get
                {
                    if (EndSharp != C_LINE_TYPE.LINETYPE_UNKNOWN && EndSharp != C_LINE_TYPE.LINETYPE_NONE)
                    {
                        return true;
                    }
                    return false;
                }
            } 

            public bool IsEndClosed
            {
                get
                {
                    if (EndSharp == C_LINE_TYPE.LINETYPE_CLOSEDARROW || EndSharp == C_LINE_TYPE.LINETYPE_RCLOSEDARROW || EndSharp == C_LINE_TYPE.LINETYPE_DIAMOND)
                    {
                        return true;
                    }
                    return false;
                }
            } 

            public uint ArrowAngle { get; set; } 
            public uint ArrowLength { get; set; } 
            public Point? LineStart { get; set; } 
            public Point? LineEnd { get; set; } 
            public PathGeometry Body { get; set; } 
            public C_LINE_TYPE StartSharp { get; set; } 
            public C_LINE_TYPE EndSharp { get; set; } 
            public ArrowHelper()
            {
                Body = new PathGeometry();
                ArrowLength = 12;
                ArrowAngle = 60;
            }
            protected PathFigure CreateLineBody()
            {
                if (LineStart != null && LineEnd != null)
                {
                    PathFigure lineFigure = new PathFigure(); 
                    lineFigure.StartPoint = (Point)LineStart;
                    LineSegment linePath = new LineSegment();
                    linePath.Point = (Point)LineEnd; 
                    lineFigure.Segments.Add(linePath);
                    return lineFigure;
                }
                return null;
            }
            protected PathFigure CreateStartArrow()
            {
                switch (StartSharp)
                {
                    case C_LINE_TYPE.LINETYPE_NONE:
                    case C_LINE_TYPE.LINETYPE_UNKNOWN:
                        break;
                    case C_LINE_TYPE.LINETYPE_ARROW:
                    case C_LINE_TYPE.LINETYPE_CLOSEDARROW:
                        return CreateStartOpenArrow();
                    case C_LINE_TYPE.LINETYPE_ROPENARROW:
                    case C_LINE_TYPE.LINETYPE_RCLOSEDARROW:
                        return CreateStartReverseArrow();
                    case C_LINE_TYPE.LINETYPE_BUTT:
                        return CreateStartButtArrow();
                    case C_LINE_TYPE.LINETYPE_DIAMOND:
                        return CreateStartDiamondArrow();
                    case C_LINE_TYPE.LINETYPE_CIRCLE:
                        return CreateStartRoundArrow();
                    case C_LINE_TYPE.LINETYPE_SQUARE:
                        return CreateStartSquareArrow();
                    case C_LINE_TYPE.LINETYPE_SLASH:
                        return CreateStartSlashArrow();
                    default:
                        break;
                }
                return null;
            }
            protected virtual PathFigure CreateEndArrow()
            {
                switch (EndSharp)
                {
                    case C_LINE_TYPE.LINETYPE_NONE:
                    case C_LINE_TYPE.LINETYPE_UNKNOWN:
                        break;
                    case C_LINE_TYPE.LINETYPE_ARROW:
                    case C_LINE_TYPE.LINETYPE_CLOSEDARROW:
                        return CreateEndOpenArrow();
                    case C_LINE_TYPE.LINETYPE_ROPENARROW:
                    case C_LINE_TYPE.LINETYPE_RCLOSEDARROW:
                        return CreateEndReverseArrow();
                    case C_LINE_TYPE.LINETYPE_BUTT:
                        return CreateEndButtArrow();
                    case C_LINE_TYPE.LINETYPE_DIAMOND:
                        return CreateEndDiamondArrow();
                    case C_LINE_TYPE.LINETYPE_CIRCLE:
                        return CreateEndRoundArrow();
                    case C_LINE_TYPE.LINETYPE_SQUARE:
                        return CreateEndSquareArrow();
                    case C_LINE_TYPE.LINETYPE_SLASH:
                        return CreateEndSlashArrow();
                    default:
                        break;
                }
                return null;
            } 

            public PathGeometry BuildArrowBody()
            {
                Body.Figures.Clear();
                PathFigure lineBody = CreateLineBody();
                if (lineBody != null)
                {
                    Body.Figures.Add(lineBody);
                    PathFigure arrowFigure = CreateStartArrow();
                    if (arrowFigure != null)
                    {
                        Body.Figures.Add(arrowFigure);
                    }
                    arrowFigure = CreateEndArrow();
                    if (arrowFigure != null)
                    {
                        Body.Figures.Add(arrowFigure);
                    }
                }
                return Body;
            }
             
            private PathFigure CreateStartOpenArrow()
            {
                if (ArrowLength == 0 || !HasStartArrow || LineStart == null || LineEnd == null || ArrowAngle == 0)
                {
                    return null;
                }
                PathFigure arrowFigure = new PathFigure();
                PolyLineSegment arrowSegment = new PolyLineSegment();
                Vector lineVector = (Point)LineEnd - (Point)LineStart;
                lineVector.Normalize();
                lineVector *= ArrowLength;
                Matrix rotateMatrix = new Matrix();
                rotateMatrix.Rotate(ArrowAngle / 2);
                arrowFigure.StartPoint = (Point)LineStart + (lineVector * rotateMatrix);
                arrowSegment.Points.Add((Point)LineStart);
                rotateMatrix.Rotate(-ArrowAngle);
                arrowSegment.Points.Add((Point)LineStart + (lineVector * rotateMatrix));
                arrowFigure.Segments.Add(arrowSegment);
                arrowFigure.IsClosed = IsStartClosed;
                arrowFigure.IsFilled = IsStartClosed;
                return arrowFigure;
            } 

            private PathFigure CreateEndOpenArrow()
            {
                if (ArrowLength == 0 || !HasEndArrow || LineStart == null || LineEnd == null || ArrowAngle == 0)
                {
                    return null;
                }
                PathFigure arrowFigure = new PathFigure();
                PolyLineSegment arrowSegment = new PolyLineSegment();
                Vector lineVector = (Point)LineStart - (Point)LineEnd;
                lineVector.Normalize();
                lineVector *= ArrowLength;
                Matrix rotateMatrix = new Matrix();
                rotateMatrix.Rotate(ArrowAngle / 2);
                arrowFigure.StartPoint = (Point)LineEnd + (lineVector * rotateMatrix);
                arrowSegment.Points.Add((Point)LineEnd);
                rotateMatrix.Rotate(-ArrowAngle);
                arrowSegment.Points.Add((Point)LineEnd + (lineVector * rotateMatrix));
                arrowFigure.Segments.Add(arrowSegment);
                arrowFigure.IsClosed = IsEndClosed;
                arrowFigure.IsFilled = IsEndClosed;
                return arrowFigure;
            } 

            private PathFigure CreateStartReverseArrow()
            {
                if (ArrowLength == 0 || !HasStartArrow || LineStart == null || LineEnd == null || ArrowAngle == 0)
                {
                    return null;
                }
                PathFigure arrowFigure = new PathFigure();
                PolyLineSegment arrowSegment = new PolyLineSegment();
                Vector lineVector = (Point)LineStart - (Point)LineEnd;
                lineVector.Normalize();
                lineVector *= ArrowLength;
                Matrix rotateMatrix = new Matrix();
                rotateMatrix.Rotate(ArrowAngle / 2);
                arrowFigure.StartPoint = (Point)LineStart + (lineVector * rotateMatrix);
                arrowSegment.Points.Add((Point)LineStart);
                rotateMatrix.Rotate(-ArrowAngle);
                arrowSegment.Points.Add((Point)LineStart + (lineVector * rotateMatrix));
                arrowFigure.Segments.Add(arrowSegment);
                arrowFigure.IsClosed = IsStartClosed;
                arrowFigure.IsFilled = IsStartClosed;
                return arrowFigure;
            } 

            private PathFigure CreateEndReverseArrow()
            {
                if (ArrowLength == 0 || !HasEndArrow || LineStart == null || LineEnd == null || ArrowAngle == 0)
                {
                    return null;
                }
                PathFigure arrowFigure = new PathFigure();
                PolyLineSegment arrowSegment = new PolyLineSegment();
                Vector lineVector = (Point)LineEnd - (Point)LineStart;
                lineVector.Normalize();
                lineVector *= ArrowLength;
                Matrix rotateMatrix = new Matrix();
                rotateMatrix.Rotate(ArrowAngle / 2);
                arrowFigure.StartPoint = (Point)LineEnd + (lineVector * rotateMatrix);
                arrowSegment.Points.Add((Point)LineEnd);
                rotateMatrix.Rotate(-ArrowAngle);
                arrowSegment.Points.Add((Point)LineEnd + (lineVector * rotateMatrix));
                arrowFigure.Segments.Add(arrowSegment);
                arrowFigure.IsClosed = IsEndClosed;
                arrowFigure.IsFilled = IsEndClosed;
                return arrowFigure;
            }
             
            private PathFigure CreateStartButtArrow()
            {
                if (ArrowLength == 0 || !HasStartArrow || LineStart == null || LineEnd == null)
                {
                    return null;
                }
                PathFigure arrowFigure = new PathFigure();
                LineSegment buttSegment = new LineSegment();
                Vector lineVector = (Point)LineStart - (Point)LineEnd;
                lineVector.Normalize();
                lineVector *= ArrowLength;
                Matrix rotateMatrix = new Matrix();
                rotateMatrix.Rotate(90);
                arrowFigure.StartPoint = (Point)LineStart + (lineVector * rotateMatrix);
                rotateMatrix.Rotate(-180);
                buttSegment.Point = ((Point)LineStart + (lineVector * rotateMatrix));
                arrowFigure.Segments.Add(buttSegment);
                return arrowFigure;
            } 

            private PathFigure CreateEndButtArrow()
            {
                if (ArrowLength == 0 || !HasEndArrow || LineStart == null || LineEnd == null)
                {
                    return null;
                }
                PathFigure arrowFigure = new PathFigure();
                LineSegment buttSegment = new LineSegment();
                Vector lineVector = (Point)LineEnd - (Point)LineStart;
                lineVector.Normalize();
                lineVector *= ArrowLength;
                Matrix rotateMatrix = new Matrix();
                rotateMatrix.Rotate(90);
                arrowFigure.StartPoint = (Point)LineEnd + (lineVector * rotateMatrix);
                rotateMatrix.Rotate(-180);
                buttSegment.Point = ((Point)LineEnd + (lineVector * rotateMatrix));
                arrowFigure.Segments.Add(buttSegment);

                return arrowFigure;
            } 

            private PathFigure CreateStartDiamondArrow()
            {
                if (ArrowLength == 0 || !HasStartArrow || LineStart == null || LineEnd == null)
                {
                    return null;
                }
                PathFigure arrowFigure = new PathFigure();
                PolyLineSegment arrowSegment = new PolyLineSegment();
                Vector lineVector = (Point)LineStart - (Point)LineEnd;
                lineVector.Normalize();
                lineVector *= ArrowLength;
                Matrix rotateMatrix = new Matrix();
                rotateMatrix.Rotate(45);

                Point cornerTop = (Point)LineStart + (lineVector * rotateMatrix);

                Vector turnVector = cornerTop - (Point)LineStart;
                turnVector.Normalize();
                turnVector *= ArrowLength;
                Matrix turnMatrix = new Matrix();
                turnMatrix.Rotate(-90);
                Point awayPoint = cornerTop + (turnVector * turnMatrix);

                rotateMatrix = new Matrix();
                rotateMatrix.Rotate(-45);
                Point cornerDown = (Point)LineStart + (lineVector * rotateMatrix);

                arrowFigure.StartPoint = (Point)LineStart;
                arrowSegment.Points.Add(cornerTop);
                arrowSegment.Points.Add(awayPoint);
                arrowSegment.Points.Add(cornerDown);
                arrowSegment.Points.Add((Point)LineStart);

                arrowFigure.Segments.Add(arrowSegment);
                arrowFigure.IsClosed = IsStartClosed;
                arrowFigure.IsFilled = IsStartClosed;
                return arrowFigure;
            } 

            private PathFigure CreateEndDiamondArrow()
            {

                if (ArrowLength == 0 || !HasEndArrow || LineStart == null || LineEnd == null)
                {
                    return null;
                }
                PathFigure arrowFigure = new PathFigure();
                PolyLineSegment arrowSegment = new PolyLineSegment();
                Vector lineVector = (Point)LineEnd - (Point)LineStart;
                lineVector.Normalize();
                lineVector *= ArrowLength;
                Matrix rotateMatrix = new Matrix();
                rotateMatrix.Rotate(45);

                Point cornerTop = (Point)LineEnd + (lineVector * rotateMatrix);

                Vector turnVector = cornerTop - (Point)LineEnd;
                turnVector.Normalize();
                turnVector *= ArrowLength;
                Matrix turnMatrix = new Matrix();
                turnMatrix.Rotate(-90);
                Point awayPoint = cornerTop + (turnVector * turnMatrix);

                rotateMatrix = new Matrix();
                rotateMatrix.Rotate(-45);
                Point cornerDown = (Point)LineEnd + (lineVector * rotateMatrix);

                arrowFigure.StartPoint = (Point)LineEnd;
                arrowSegment.Points.Add(cornerTop);
                arrowSegment.Points.Add(awayPoint);
                arrowSegment.Points.Add(cornerDown);
                arrowSegment.Points.Add((Point)LineEnd);

                arrowFigure.Segments.Add(arrowSegment);
                arrowFigure.IsClosed = IsEndClosed;
                arrowFigure.IsFilled = IsEndClosed;
                return arrowFigure;
            } 

            private PathFigure CreateStartRoundArrow()
            {
                if (ArrowLength == 0 || !HasStartArrow || LineStart == null || LineEnd == null)
                {
                    return null;
                }
                PathFigure arrowFigure = new PathFigure();
                Vector lineVector = (Point)LineEnd - (Point)LineStart;
                lineVector.Normalize();
                lineVector *= ArrowLength;

                Matrix rotateMatrix = new Matrix();
                rotateMatrix.Rotate(180);
                arrowFigure.StartPoint = (Point)LineStart + (lineVector * rotateMatrix);
                ArcSegment circleSegment = new ArcSegment();
                circleSegment.Point = (Point)LineStart;
                circleSegment.Size = new Size(ArrowLength / 2, ArrowLength / 2);
                arrowFigure.Segments.Add(circleSegment);
                circleSegment = new ArcSegment();
                circleSegment.Point = (Point)arrowFigure.StartPoint;
                circleSegment.Size = new Size(ArrowLength / 2, ArrowLength / 2);

                arrowFigure.Segments.Add(circleSegment);

                return arrowFigure;
            } 

            private PathFigure CreateEndRoundArrow()
            {
                if (ArrowLength == 0 || !HasEndArrow || LineStart == null || LineEnd == null)
                {
                    return null;
                }
                PathFigure arrowFigure = new PathFigure();
                Vector lineVector = (Point)LineStart - (Point)LineEnd;
                lineVector.Normalize();
                lineVector *= ArrowLength;

                Matrix rotateMatrix = new Matrix();
                rotateMatrix.Rotate(180);
                arrowFigure.StartPoint = (Point)LineEnd + (lineVector * rotateMatrix);
                ArcSegment circleSegment = new ArcSegment();
                circleSegment.Point = (Point)LineEnd;
                circleSegment.Size = new Size(ArrowLength / 2, ArrowLength / 2);
                arrowFigure.Segments.Add(circleSegment);
                circleSegment = new ArcSegment();
                circleSegment.Point = (Point)arrowFigure.StartPoint;
                circleSegment.Size = new Size(ArrowLength / 2, ArrowLength / 2);

                arrowFigure.Segments.Add(circleSegment);

                return arrowFigure;
            } 

            private PathFigure CreateStartSquareArrow()
            {
                if (ArrowLength == 0 || !HasStartArrow || LineStart == null || LineEnd == null)
                {
                    return null;
                }
                PathFigure arrowFigure = new PathFigure();
                PolyLineSegment squreSegment = new PolyLineSegment();

                Vector lineVector = (Point)LineEnd - (Point)LineStart;
                lineVector.Normalize();
                lineVector *= (ArrowLength / 2);
                Matrix rotateMatrix = new Matrix();
                rotateMatrix.Rotate(90);
                arrowFigure.StartPoint = (Point)LineStart + (lineVector * rotateMatrix);
                rotateMatrix.Rotate(-180);
                Point pointCorner = (Point)LineStart + (lineVector * rotateMatrix);
                squreSegment.Points.Add(pointCorner);

                Vector moveVector = arrowFigure.StartPoint - pointCorner;
                moveVector.Normalize();
                moveVector *= (ArrowLength);
                rotateMatrix = new Matrix();
                rotateMatrix.Rotate(90);

                squreSegment.Points.Add(pointCorner + (moveVector * rotateMatrix));
                squreSegment.Points.Add(arrowFigure.StartPoint + (moveVector * rotateMatrix));
                squreSegment.Points.Add(arrowFigure.StartPoint);
                squreSegment.Points.Add((Point)LineStart);
                arrowFigure.Segments.Add(squreSegment);

                return arrowFigure;
            } 

            private PathFigure CreateEndSquareArrow()
            {

                if (ArrowLength == 0 || !HasEndArrow || LineStart == null || LineEnd == null)
                {
                    return null;
                }
                PathFigure arrowFigure = new PathFigure();
                PolyLineSegment squreSegment = new PolyLineSegment();

                Vector lineVector = (Point)LineStart - (Point)LineEnd;
                lineVector.Normalize();
                lineVector *= (ArrowLength / 2);
                Matrix rotateMatrix = new Matrix();
                rotateMatrix.Rotate(90);
                arrowFigure.StartPoint = (Point)LineEnd + (lineVector * rotateMatrix);
                rotateMatrix.Rotate(-180);
                Point pointCorner = (Point)LineEnd + (lineVector * rotateMatrix);
                squreSegment.Points.Add(pointCorner);

                Vector moveVector = arrowFigure.StartPoint - pointCorner;
                moveVector.Normalize();
                moveVector *= (ArrowLength);
                rotateMatrix = new Matrix();
                rotateMatrix.Rotate(90);

                squreSegment.Points.Add(pointCorner + (moveVector * rotateMatrix));
                squreSegment.Points.Add(arrowFigure.StartPoint + (moveVector * rotateMatrix));
                squreSegment.Points.Add(arrowFigure.StartPoint);
                squreSegment.Points.Add((Point)LineEnd);
                arrowFigure.Segments.Add(squreSegment);

                return arrowFigure;
            } 

            private PathFigure CreateStartSlashArrow()
            {
                if (ArrowLength == 0 || !HasStartArrow || LineStart == null || LineEnd == null)
                {
                    return null;
                }
                PathFigure arrowFigure = new PathFigure();
                LineSegment buttSegment = new LineSegment();
                Vector lineVector = (Point)LineStart - (Point)LineEnd;
                lineVector.Normalize();
                lineVector *= ArrowLength;
                Matrix rotateMatrix = new Matrix();
                rotateMatrix.Rotate(45);
                arrowFigure.StartPoint = (Point)LineStart + (lineVector * rotateMatrix);
                rotateMatrix.Rotate(-180);
                buttSegment.Point = ((Point)LineStart + (lineVector * rotateMatrix));
                arrowFigure.Segments.Add(buttSegment);
                return arrowFigure;
            } 

            private PathFigure CreateEndSlashArrow()
            {
                if (ArrowLength == 0 || !HasEndArrow || LineStart == null || LineEnd == null)
                {
                    return null;
                }
                PathFigure arrowFigure = new PathFigure();
                LineSegment buttSegment = new LineSegment();
                Vector lineVector = (Point)LineEnd - (Point)LineStart;
                lineVector.Normalize();
                lineVector *= ArrowLength;
                Matrix rotateMatrix = new Matrix();
                rotateMatrix.Rotate(45);
                arrowFigure.StartPoint = (Point)LineEnd + (lineVector * rotateMatrix);
                rotateMatrix.Rotate(-180);
                buttSegment.Point = ((Point)LineEnd + (lineVector * rotateMatrix));
                arrowFigure.Segments.Add(buttSegment);

                return arrowFigure;
            }
        }
    }

    public class PanelState
    {
        private static PanelState instance;

        public enum RightPanelState
        {
            None,
            PropertyPanel,
            ViewSettings
        }

        private bool _isLeftPanelExpand;
        public bool IsLeftPanelExpand
        {
            get { return _isLeftPanelExpand; }
            set
            {
                if (_isLeftPanelExpand != value)
                {
                    _isLeftPanelExpand = value;
                    OnPropertyChanged();
                }
            }
        }

        private RightPanelState _rightPanel;
        public RightPanelState RightPanel
        {
            get { return _rightPanel; }
            set
            {
                if (_rightPanel != value)
                {
                    _rightPanel = value;
                    OnPropertyChanged();
                }
            }
        }

        private PanelState() { }

        public static PanelState GetInstance()
        {
            if (instance == null)
            {
                instance = new PanelState();
            }
            return instance;
        }

        public event PropertyChangedEventHandler PropertyChanged;
        protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }

    public class SaveHelper
    {
        private static SaveHelper instance;
        private bool _canSave;
        public bool CanSave
        {
            get { return _canSave; }
            set
            {
                if (_canSave != value)
                {
                    _canSave = value;
                    OnPropertyChanged();
                }
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;
        protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}