• Responding to global key combinations
• Getting a snapshot of the screen and finding an object in it
• Parsing a visual image for digits in a certain format
• The algorithm for solving the puzzle in a reasonable amount of time and memory (it was not trivial)

1. Start PixeloTools.GameSolver.exe
2. Open the browser to the Pixelo game
3. Start a puzzle
4. Press Ctrl-Shift-P

5 1 10, 3 3 7, 2 5 4, 2 5 2, 2 1 1 1, 1 1 1 1 1, 1 1 3 1 1, 1 1 1 1 1, 1 1 1, 1 1, 1 1, 2 2 2 4, 2 1 1 1 2 4, 2 1 2 1, 7 4, 2 2 1 2 2 2, 2 1 1 1 1 1 1, 2 1 1 4 2, 1 3 4 2 1, 1 1
8 1 1, 5 2 2 1, 2 1 3, 1 1, 1 7 4 1, 3 5 1, 3 1 1 3, 4 3 4, 3 1 1 3, 3 5 1, 1 7 4 1, 1 2, 1 1 1, 2 2 2, 2 1 1 2, 2 1 2 2, 3 2 1, 3 1 1, 4 1 2 2, 9 2 3

start "" PixeloTools.GameSolver.exe myFile.txt

• The name of the appender class has to be set to log4net.Appender.RollingFileAppender
• The name of the log files need to start with Application_ and end in .log
• The name of the log files need to contain the date in the correct format
• The logger needs to know that the files need to be created daily

<appender name="FileAppender" type="log4net.Appender.RollingFileAppender">
     <filter type="log4net.Filter.LevelRangeFilter">
         <acceptOnMatch value="true" />
         <levelMin value="DEBUG" />
     </filter>

  <file type="log4net.Util.PatternString" value="c:\logfiles\Application_.log" />
  <appendToFile value="true" />
  <rollingStyle value="Date" />
  <datePattern value="yyyyMMdd" />
  <preserveLogFileNameExtension value="true"/>
  <staticLogFileName value="false" />

  <lockingModel type="log4net.Appender.FileAppender+MinimalLock"/>
  <layout type="log4net.Layout.PatternLayout">
    <conversionPattern value="%date %-5level %logger - %message%newline"/>
  </layout>
</appender>

• Change the project version to 4.5.1 (or whatever the newest usable .NET framework version)
• go to the NuGet Package Manager Console in Visual Studio
• Run command Update-Package -reinstall Microsoft.AspNet.Mvc

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Siderite.DataStructures
{
    /// <summary>
    /// IList implementation that doesn't require a contiguous memory space (an array)
    /// </summary>
    /// <typeparam name="T"></typeparam>
    public class BucketList<T>:IList<T>
    {
        private int _bucketSize;
        private List<List<T>> _list;
        private int _count;

        /// <summary>
        /// Default constructor
        /// </summary>
        public BucketList():this(10000)
        {
            _list = new List<List<T>>();
        }

        /// <summary>
        /// Specify the bucket size (default 10000)
        /// </summary>
        /// <param name="bucketSize"></param>
        public BucketList(int bucketSize)
        {
            _bucketSize = bucketSize;
        }

        /// <summary>
        /// Create a bucket list from an IEnumerable
        /// </summary>
        /// <param name="enm"></param>
        public BucketList(IEnumerable<T> enm):this()
        {
            var list = (IList<T>)this;
            foreach (var itm in enm)
            {
                list.Add(itm);
            }
        }

        /// <summary>
        /// The item count
        /// </summary>
        public int Count
        {
            get
            {
                return ((IList<T>)this).Count;
            }
        }

        #region IList<T> implementation

        int IList<T>.IndexOf(T item)
        {
            var index = 0;
            for (var i = 0; i < _list.Count; i++)
            {
                var idx = _list[i].IndexOf(item);
                if (idx < 0)
                {
                    index += _list[i].Count;
                }
                else
                {
                    index += idx;
                    return index;
                }
            }
            return -1;
        }

        void IList<T>.Insert(int index, T item)
        {
            var idx = 0;
            for (var i = 0; i < _list.Count; i++)
            {
                var lst = _list[i];
                if (index < idx + lst.Count)
                {
                    lst.Insert(index - idx, item);
                    splitListIfTooLarge(i);
                    _count++;
                    return;
                }
                else
                {
                    idx += lst.Count;
                }
            }
            throw new IndexOutOfRangeException("index");
        }

        void IList<T>.RemoveAt(int index)
        {
            var idx = 0;
            for (var i = 0; i < _list.Count; i++)
            {
                var lst = _list[i];
                if (index < idx + lst.Count)
                {
                    lst.RemoveAt(index - idx);
                    removeListIfEmpty(i);
                    _count--;
                    return;
                }
                else
                {
                    idx += lst.Count;
                }
            }
            throw new IndexOutOfRangeException("index");
        }

        T IList<T>.this[int index]
        {
            get
            {
                var idx = 0;
                for (var i = 0; i < _list.Count; i++)
                {
                    var lst = _list[i];
                    if (index < idx + lst.Count)
                    {
                        return lst[index - idx];
                    }
                    else
                    {
                        idx += lst.Count;
                    }
                }
                throw new IndexOutOfRangeException("index");
            }
            set
            {
                var idx = 0;
                for (var i = 0; i < _list.Count; i++)
                {
                    var lst = _list[i];
                    if (index < idx + lst.Count)
                    {
                        lst[index - idx]=value;
                    }
                    else
                    {
                        idx += lst.Count;
                    }
                }
                throw new IndexOutOfRangeException("index");
            }
        }

        void ICollection<T>.Add(T item)
        {
            List<T> lst;
            int index;
            if (_list.Count == 0)
            {
                lst = new List<T>();
                _list.Add(lst);
                index=0;
            }
            else
            {
                index=_list.Count - 1;
                lst = _list[index];
            }
            lst.Add(item);
            splitListIfTooLarge(index);
            _count++;
        }

        void ICollection<T>.Clear()
        {
            _list.Clear();
            _count = 0;
        }

        bool ICollection<T>.Contains(T item)
        {
            return ((IList<T>)this).IndexOf(item) > -1;
        }

        void ICollection<T>.CopyTo(T[] array, int arrayIndex)
        {
            var index = arrayIndex;
            foreach (var lst in _list)
            {
                lst.CopyTo(array, index);
                index += lst.Count;
            }
        }

        int ICollection<T>.Count
        {
            get
            {
                return _count;
            }
        }

        bool ICollection<T>.IsReadOnly
        {
            get { return false; }
        }

        bool ICollection<T>.Remove(T item)
        {
            for (var i = 0; i < _list.Count; i++)
            {
                var lst = _list[i];
                if (lst.Remove(item))
                {
                    _count--;
                    removeListIfEmpty(i);
                    return true;
                }
            }
            return false;
        }

        IEnumerator<T> IEnumerable<T>.GetEnumerator()
        {
            foreach (var lst in _list)
            {
                foreach (var item in lst)
                {
                    yield return item;
                }
            }
        }

        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
        {
            return ((IList<T>)this).GetEnumerator();
        }

        #endregion

        private void splitListIfTooLarge(int listIndex)
        {
            var lst = _list[listIndex];
            if (lst.Count > _bucketSize)
            {
                var newList = lst.GetRange(0, _bucketSize);
                lst.RemoveRange(0, _bucketSize);
                _list.Insert(listIndex, newList);
            }
        }

        private void removeListIfEmpty(int listIndex)
        {
            var lst = _list[listIndex];
            if (lst.Count ==0)
            {
                _list.RemoveAt(listIndex);
            }
        }
    }
}

I have been working on a REST API lately and, while using Entity Framework or some other similar framework to abstract the database is certainly possible, I wanted to control every aspect of the implementation. I know, reinventing wheels, but this is how one learns. One of the most annoying bits was trying to translate some complex object from JSON to the (two dimensional) database relational tables. This post will explore my attempts and the solutions I have found.

My first attempt was straightforward: just send all types as DataTables, with some extra property to define identity and parent entity. This relies on the Microsoft Server SQL mechanism that allows sending of table variables to stored procedures. But this approach has several downsides. One of them is that in order to send a datatable to SQL you need... DataTables. As I have pointed out in several blog posts, the DataTable object is slow, and sometimes downright buggy. Even if I didn't care about performance that much, in order for SQL to receive the content of the DataTable one must create corresponding User Defined Types on the database side. Working with UDTs is very difficult for several reasons: you cannot alter a UDT (unless employing some SQL voodoo that changes system tables), you can only drop it and recreate it. This does not work if you use the UDT anywhere, so a lot of renaming needs to be done. Even if you automate the process, it's still very annoying. Then the UDT definition has to be an exact duplicate of the DataTable definition. Move some columns around and it fails. Debugging is also made difficult by the fact that the SQL profiler does not see the content of table variables when sending them to the server.

Long story short, I was looking for alternatives and I found XML. Now, you might think that this leads to a simple, and maybe even obvious, solution. But it's not that easy. Imagine that you send a list of objects in an XML. Each object is represented by an XML element and each property by a child element. In order to get the value of a property you need to do iterate through all the nodes, for each node find the properties, for each property find the one element that defines it, then get the attribute value or content of the property, all while making sure you select everything in a table. It's not that easy.

The solution I found, which simplifies the SQL code (and hopefully brings some well needed performance to the table) is to serialize the objects in a way that makes the selection simple enough. Here is an example: I have a Configuration object with an Id and a Name that also has a property called Servers, containing Server objects having an Id and a Url. Here is an example of XML serialization from the DataContractSerializer:

<?xml version="1.0" encoding="UTF-8"?>
<Configuration xmlns="http://schemas.datacontract.org/2004/07/SerializationTest" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
   <Id>1</Id>
   <Name>Test Config</Name>
   <Servers>
      <Server>
         <Id>1</Id>
         <Url>http://some.url</Url>
      </Server>
      <Server>
         <Id>2</Id>
         <Url>http://some.other.url</Url>
      </Server>
   </Servers>
</Configuration>

The SQL code to get the information from an XML variable with this content would look like this:

DECLARE @Xml XML='<?xml version="1.0" encoding="UTF-8"?>
<Configuration xmlns="http://schemas.datacontract.org/2004/07/SerializationTest" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
   <Id>1</Id>
   <Name>Test Config</Name>
   <Servers>
      <Server>
         <Id>1</Id>
         <Url>http://some.url</Url>
      </Server>
      <Server>
         <Id>2</Id>
         <Url>http://some.other.url</Url>
      </Server>
   </Servers>
</Configuration>'

;WITH XMLNAMESPACES(DEFAULT 'http://schemas.datacontract.org/2004/07/SerializationTest')
SELECT T.Item.value('(Id/text())[1]','INT')  as Id,
       T.Item.value('(Name/text())[1]','NVARCHAR(100)')  as Name
FROM @Xml.nodes('//Configuration') as T(Item)

;WITH XMLNAMESPACES(DEFAULT 'http://schemas.datacontract.org/2004/07/SerializationTest')
SELECT T.Item.value('(Id/text())[1]','INT')  as Id,
       T.Item.value('(Url/text())[1]','NVARCHAR(100)')  as Url
FROM @Xml.nodes('//Configuration/Servers/Server') as T(Item)

This works, but look at that code. In my case, the situation was worse, the object I was using was a wrapper which implemented IDictionary<string,object> and, even if it did implement ISerializable, both XmlSerializer and DataContractSerializer use the dictionary as their data and in the end I get ugly key elements and value elements that are even harder to get to and, I suppose, more inefficient to parse. Therefore I found the solution in IXmlSerializable, (yet) another serialization interface used exclusively by XML serializer classes. If every simple value would be saved as an attribute and every complex object in an element, then this could be the SQL code:

DECLARE @Xml XML='<?xml version="1.0" encoding="UTF-8"?>
<Configuration xmlns="http://schemas.datacontract.org/2004/07/SerializationTest" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
   <Config Id="1" Name="Test Config">
   <Servers>
      <List>
        <Server Id="1" Url="http://some.url" />
        <Server Id="2" Url="http://some.other.url" />
      </List>
   </Servers>
   </Config>
</Configuration>'

;WITH XMLNAMESPACES(DEFAULT 'http://schemas.datacontract.org/2004/07/SerializationTest')
SELECT T.Item.value('@Id','INT')  as Id,
       T.Item.value('@Name','NVARCHAR(100)')  as Name
FROM @Xml.nodes('//Configuration/Config') as T(Item)

;WITH XMLNAMESPACES(DEFAULT 'http://schemas.datacontract.org/2004/07/SerializationTest')
SELECT T.Item.value('@Id','INT')  as Id,
       T.Item.value('@Url','NVARCHAR(100)')  as Url
FROM @Xml.nodes('//Configuration/Config/Servers/List/Server') as T(Item)

Much easier to read and hopefully to parse.

I am not going to write here about the actual implementation of IXmlSerializable. There are plenty of tutorials on the Internet about that. It's not pretty, :) but not too difficult, either.

What was the purpose of this exercise? Now I can send a complex object to SQL in a single query, making inserts and updates simple and not requiring at a call for each instance of each type of complex object. Now, is it fast? I have no idea. Certainly if performance is needed, perhaps the UDT/DataTable approach is faster. However you will have to define a type for each type that you send as a DataTable to a stored procedure. An alternative can be a binary serializer and a CLR SQL function that translates it into tables. However, in my project I need to easily implement very custom API methods and to control every aspect, including tracing and profiling the various SQL calls. I believe the customized IXmlSerializable/XML in SQL approach is a reasonable one.

As always, I hope this helps someone.

/// <summary>
/// It caches the property setters and getters for the public properties of a type 
/// </summary>
public class TypeCache
{
    private static ConcurrentDictionary<Type, TypeCache> _typeCacheDict = new ConcurrentDictionary<Type, TypeCache>();

    public static TypeCache Get(Type type)
    {
        TypeCache cache;
        if (!_typeCacheDict.TryGetValue(type, out cache))
        {
            cache = new TypeCache(type);
            _typeCacheDict[type] = cache;
        }
        return cache;
    }

    private TypeCache(Type type)
    {
        Type = type;
        Setters = new ConcurrentDictionary<string, Action<object, object>>();
        Getters = new ConcurrentDictionary<string, Func<object, object>>();
        var props = type.GetProperties(BindingFlags.Public | BindingFlags.Instance);
        Properties = new ConcurrentDictionary<string, PropertyInfo>();
        foreach (var prop in props)
        {
            if (prop.CanRead)
            {
                var objGetter = prop.GetValueGetter();
                Getters[prop.Name] = objGetter.Compile();
            }
            if (prop.CanWrite)
            {
                var objSetter = prop.GetValueSetter();
                Setters[prop.Name] = objSetter.Compile();
            }
            Properties[prop.Name] = prop;
        }
    }

    public Type Type { get; private set; }
    public ConcurrentDictionary<string, Action<object, object>> Setters { get; private set; }
    public ConcurrentDictionary<string, Func<object, object>> Getters { get; private set; }
    public ConcurrentDictionary<string, PropertyInfo> Properties { get; private set; }
}

public static class TypeCacheExtensions
{
    /// <summary>
    /// Set the value of a property by name
    /// </summary>
    /// <param name="cache"></param>
    /// <param name="item"></param>
    /// <param name="key"></param>
    /// <param name="value"></param>
    public static void Set<T>(this TypeCache cache, object item, string key, T value)
    {
        if (cache == null || item == null) return;
        Action<object, object> setter;
        if (!cache.Setters.TryGetValue(key, out setter)) return;
        setter(item, (object)value);
    }

    /// <summary>
    /// Get the value of a property by name
    /// </summary>
    /// <param name="cache"></param>
    /// <param name="item"></param>
    /// <param name="key"></param>
    /// <returns></returns>
    public static T Get<T>(this TypeCache cache, object item, string key)
    {
        if (cache == null || item == null) return default(T);
        Func<object, object> getter;
        if (!cache.Getters.TryGetValue(key, out getter)) return default(T);
        return (T)getter(item);
    }

    /// <summary>
    /// Set the value for a property to default by name
    /// </summary>
    /// <param name="cache"></param>
    /// <param name="item"></param>
    /// <param name="key"></param>
    public static void Delete(this TypeCache cache, object item, string key)
    {
        if (cache == null || item == null) return;
        Action<object, object> setter;
        if (!cache.Setters.TryGetValue(key, out setter)) return;
        var value = cache.Properties[key].PropertyType.GetDefaultValue();
        setter(item, value);
    }

    /// <summary>
    /// Set the values for all the public properties of a class to their default
    /// </summary>
    /// <param name="cache"></param>
    /// <param name="item"></param>
    public static void Clear(this TypeCache cache, object item)
    {
        if (cache == null || item == null) return;
        Action<object, object> setter;
        foreach (var pair in cache.Properties)
        {
            if (!cache.Setters.TryGetValue(pair.Key, out setter)) continue;
            var value = pair.Value.PropertyType.GetDefaultValue();
            setter(item, value);
        }
    }
}

class Program
    {
        static void Main(string[] args)
        {
            var obj = new TestObject();
            var cache = TypeCache.Get(obj.GetType());
            Stopwatch sw = new Stopwatch();
            sw.Start();
            for (var i = 0; i < 100000; i++)
            {
                cache.Get<int>(obj, "TestProperty");
                cache.Set<int>(obj, "TestProperty",i);
            }
            sw.Stop();
            Console.WriteLine("Time: " + sw.Elapsed.TotalMilliseconds);
            Console.ReadKey();
        }
    }

    public static class ReflectionExtensions
    {
        public static Expression<Func<object, object>> GetValueGetter(this PropertyInfo propertyInfo)
        {
            var getter=propertyInfo.GetGetMethod();
            return (obj) => getter.Invoke(obj, new object[] { });
        }

        public static Expression<Action<object, object>> GetValueSetter(this PropertyInfo propertyInfo)
        {
            var setter = propertyInfo.GetSetMethod();
            return (obj,val) => setter.Invoke(obj, new[] { val });
        }

        public static object GetDefaultValue(this Type type)
        {
            return type.IsValueType ? Activator.CreateInstance(type) : null;
        }
    }

    public static class ReflectionExtensions
    {
        /// <summary>
        /// Get the expression of a value getter for a property. Compile the expression to execute or combine it with other expressions.
        /// </summary>
        /// <param name="propertyInfo"></param>
        /// <returns></returns>
        public static Expression<Func<object, object>> GetValueGetter(this PropertyInfo propertyInfo)
        {
            var instance = Expression.Parameter(typeof(object), "i");
            var convertObj = Expression.TypeAs(instance, propertyInfo.DeclaringType);
            var property = Expression.Property(convertObj, propertyInfo);
            var convert = Expression.Convert(property, typeof(object));
            return (Expression<Func<object, object>>)Expression.Lambda(convert, instance);
        }

        /// <summary>
        /// Get the expression of a value setter for a property. Compile the expression to execute or combine it with other expressions.
        /// </summary>
        /// <param name="propertyInfo"></param>
        /// <returns></returns>
        public static Expression<Action<object, object>> GetValueSetter(this PropertyInfo propertyInfo)
        {
            var instance = Expression.Parameter(typeof(object), "i");
            var argument = Expression.Parameter(typeof(object), "a");
            var convertObj = Expression.TypeAs(instance, propertyInfo.DeclaringType);
            var convert = Expression.Convert(argument, propertyInfo.PropertyType);
            var setterCall = Expression.Call(convertObj,propertyInfo.GetSetMethod(),convert);
            return (Expression<Action<object, object>>)Expression.Lambda(setterCall, instance, argument);
        }

        /// <summary>
        /// Get the default value of a type
        /// </summary>
        /// <param name="type"></param>
        /// <returns></returns>
        public static object GetDefaultValue(this Type type)
        {
            return type.IsValueType ? New.Instance(type) : null;
        }
    }

    /// <summary>
    /// Class used to get instances of a type
    /// </summary>
    public static class New
    {
        private static ConcurrentDictionary<Type, Func<object>> _dict = new ConcurrentDictionary<Type, Func<object>>();

        public static object Instance(Type type)
        {
            Func<object> func;
            if (!_dict.TryGetValue(type, out func))
            {
                func = Expression.Lambda<Func<object>>(Expression.New(type)).Compile();
                _dict[type] = func;
            }
            return func();
        }
    }

• the expression has one parameter, of type object
• we will attempt to safely convert it (as) into the declaring type (the object the property belongs to)
• we will access a property of an object of the declaring type
• which we then convert to object so that the resulting expression returns object not the specific type of the property
• transform it all into a lambda expression and return it

There are four steps to language detection using NTextCat:
• Reference NTextCat - the library is now available as a NuGet package as well
• Instantiate an identifier factory (usually RankedLanguageIdentifierFactory)
• Get an instance of a RankedLanguageIdentifier from the factory by loading a language XML file
• Call the Identify method on your text and get a list of languages in the order of the probability that the text in that language

public class LanguageProcessor
{
    private RankedLanguageIdentifier _identifier;

    public string IdentifyLanguage(string text)
    {
        if (_identifier == null)
        {
            var file = new FileInfo(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "LanguageModels/Core14.profile.xml"));
            if (!file.Exists)
            {
                throw new FileNotFoundException("Could not find LanguageModels/Core14.profile.xml to detect the language");
            }
            using (var readStream = File.OpenRead(file.FullName))
            {
                var factory = new RankedLanguageIdentifierFactory();
                _identifier = factory.Load(readStream);
            }
        }
        var languages = _identifier.Identify(text);
        var mostCertainLanguage = languages.FirstOrDefault();
        if (mostCertainLanguage != null)
        {
            return mostCertainLanguage.Item1.Iso639_3;
        }
        return null;
    }

}

using AnotherJiraRestClient;
using log4net.Appender;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace JiraLog4netAppender
{
    public class JiraAppender : AppenderSkeleton // most appender functionality is found in this abstract class
    {
        private List<string> _notifyUsers;

        // properties of the appender, configurable in the log4net.config file as children elements of the appender
        public string url { get; set; } // the url of the JIRA site
        public string user { get; set; } // the JIRA user
        public string password { get; set; } // the JIRA password
        public string project { get; set; } // the JIRA project
        public string notify // a comma separated list of JIRA users who will be notified of the issue's creation
        {
            get
            {
                return string.Join(", ", _notifyUsers);
            }
            set
            {
                _notifyUsers.Clear();
                if (!string.IsNullOrWhiteSpace(value))
                {
                    _notifyUsers.AddRange(value.Split(',').Select(s => s.Trim()).Where(s => !string.IsNullOrWhiteSpace(s)));
                }
            }
        }

        CancellationTokenSource _ts;
        StringWriter _sw;
        Task _task;
        private JiraClient _jc;
        private string _priorityId;
        private string _issueTypeId;

        private object _writerLock=new object();

        public JiraAppender()
        {
            _notifyUsers = new List<string>();
            _ts = new CancellationTokenSource(); // use this to cancel the Delay task
            _sw = new StringWriter();
        }

        protected override void Append(log4net.Core.LoggingEvent loggingEvent)
        {
            this.Layout.Format(_sw, loggingEvent); // use the appender layout to format the log lines (warning: for this you need to override RequiresLayout and return true)
            _ts.Cancel(); // cancel the task and create a new one. This means as long as the logger writes, the 5 second delay will be reset
            _ts = new CancellationTokenSource();
            _task = Task.Delay(5000, _ts.Token).ContinueWith(writeToJira, _ts.Token); // after 5 seconds (I guess you could make this configurable as well) create a JIRA issue
        }

        protected override bool RequiresLayout
        {
            get
            {
                return true;
            }
        }

        /// <summary>
        /// write to jira, either when 5 seconds of inactivity passed or the appender is closed.
        /// </summary>
        /// <param name="task"></param>
        private void writeToJira(Task task)
        {
            string s;
            lock (_writerLock) // maybe the method was already in progress when another one was called. We need to clear the StringWriter before we allow access to it again
            {
                s = _sw.ToString();
                var sb = _sw.GetStringBuilder();
                sb.Clear();
            }
            if (!string.IsNullOrWhiteSpace(s))
            {
                writeTextToJira(s);
            }
        }

        private void writeTextToJira(string text)
        {
            ensureClientAndValues();
            var summary = "Log: " + this.Name; // the issue summary
            var labels = new List<string> // some labels
            {
                this.Name, this.GetType().Name
            };
            var issue = new AnotherJiraRestClient.JiraModel.CreateIssue(project, summary, text, _issueTypeId, _priorityId, labels); // create the issue with type Issue and priority Trivial
            var basicIssue = _jc.CreateIssue(issue);
            _jc.Notify(basicIssue, _notifyUsers, "JiraAppender created an issue", null, null); // notify users of the issue's creation
        }

        /// <summary>
        /// Make sure we have a JiraClient and that we know the ids of the Issue type and the Trivial priority
        /// </summary>
        private void ensureClientAndValues()
        {
            if (_jc == null)
            {
                _jc = new JiraClient(new JiraAccount
                {
                    ServerUrl = url,
                    User = user,
                    Password = password
                });
            }
            if (_priorityId==null) {
                var priority = _jc.GetPriorities().FirstOrDefault(p => p.name == "Trivial");
                if (priority == null)
                {
                    throw new Exception("A priority with the name 'Trivial' was not found");
                }
                _priorityId = priority.id;
            }
            if (_issueTypeId == null)
            {
                var meta = _jc.GetProjectMeta(project);
                var issue = meta.issuetypes.FirstOrDefault(i => i.name == "Issue");
                if (issue == null)
                {
                    throw new Exception("An issue type with the name 'Issue' was not found");
                }
                _issueTypeId = issue.id;
            }
        }

        protected override void OnClose() //clean what you can and write to jira if there is anything to write
        {
            _ts.Cancel();
            writeToJira(null);
            _sw.Dispose();
            _ts.Dispose();
            _task = null;
            base.OnClose();
        }

    }
}

• add to JiraClient the following method:

  public void Notify(BasicIssue issue, IEnumerable<string> userList, string subject, string textBody, string htmlBody)
  {
      var request = new RestRequest()
      {
          Method = Method.POST,
          Resource = ResourceUrls.Notify(issue.id),
          RequestFormat = DataFormat.Json
      };
      request.AddBody(new NotifyData
      {
          subject = subject,
          textBody = textBody,
          htmlBody = htmlBody,
          to = new NotifyTo
          {
              users = userList.Select(u => new User
              {
                  active = false,
                  name = u
              }).ToList()
          }
      });
      var response = client.Execute(request);
      if (response.StatusCode != HttpStatusCode.NoContent)
      {
          throw new JiraApiException("Failed to notify users from issue with id=" + issue.id+"("+response.StatusCode+")");
      }
  }

• add to ResourceUrls the following method:

  public static string Notify(string issueId)
  {
      return Url(string.Format("issue/{0}/notify", issueId));
  }
  

• create the following classes in the JiraModel folder and namespace:

  public class NotifyData
  {
      public string subject { get; set; }
      public string textBody { get; set; }
      public string htmlBody { get; set; }
      public NotifyTo to { get; set; }
  }
  
  public class NotifyTo
  {
      public List<User> users { get; set; }
  }
  
  public class User
  {
      public string name { get; set; }
      public bool active { get; set; }
  }

<log4net>
   <appender name="JiraAppender" type="JiraLog4netAppender.JiraAppender, JiraLog4netAppender">
      <url value="https://my.server.url/jira"/>
      <user value="jirauser"/>
      <password value="jirapassword"/>
      <project value="jiraproject"/>
      <notify value="siderite,someotheruser" />
      <layout type="log4net.Layout.PatternLayout">
          <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
      </layout>
        <filter type="log4net.Filter.LevelRangeFilter">
          <levelMin value="WARN" />
          <levelMax value="FATAL" />
        </filter>
   </appender>
     <root>
     <level value="DEBUG" />
         <appender-ref ref="JiraAppender" />
   </root>
</log4net>

var longPathDirectoryType = typeof(System.IO.Directory).Assembly.GetTypes().First(t=>t.Name=="LongPathDirectory");
var createDirectoryMethodInfo = longPathDirectoryType.GetMethod("CreateDirectory", System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.NonPublic);
createDirectoryMethodInfo.Invoke(null, new object[] { path });

var fileStreamConstructorInfo = typeof(System.IO.FileStream).GetConstructor(System.Reflection.BindingFlags.NonPublic|System.Reflection.BindingFlags.Instance,null,
        new Type[] { 
        typeof(string) /*path*/, typeof(System.IO.FileMode) /*mode*/, typeof(System.IO.FileAccess) /*access*/, 
        typeof(System.IO.FileShare) /*share*/, typeof(int) /*bufferSize*/, typeof(System.IO.FileOptions) /*options*/, 
        typeof(string) /*msgPath*/, typeof(bool) /*bFromProxy*/, typeof(bool) /*useLongPath*/, typeof(bool) /*checkHost*/},null);
    var stream = (System.IO.Stream)fileStreamConstructorInfo.Invoke(new object[] {
        path, System.IO.FileMode.Create, System.IO.FileAccess.Write,
        System.IO.FileShare.None, 4096, System.IO.FileOptions.None,
        System.IO.Path.GetFileName(path), false, true, false
    });

• How does one find the neighbours of a cell? On Step 3 we also create a list of neighbors for each new cluster by looking for a cluster that is at coordinates immediately above, below, left or right. When we merge two clusters, we get a cluster that is a neighbour to all the neighbours of the merged clusters.
• How does one quickly get the cluster at a certain position? We create a dictionary that has the coordinates as the key. What about when we merge two clusters? Then the new cluster will be accessible by any of the original cluster keys (that implied that each cluster has a list of keys, as well)
• How does one find the smallest cell in the cluster list? After Step 3 we sort the cluster list by the number of items they contain and each time we perform a merge we find the first item larger than the merged result and we insert it in the list at that location, so that the list always remains sorted.
• How do we easily find the first item larger than an item? By employing a divide-et-impera method of splitting the list in two at each step and choosing to look into one bucket based on the item count of the cluster at the middle position

/// <summary>
/// Generic x,y positioned item class
/// </summary>
public class Item
{
    public double X { get; set; }
    public double Y { get; set; }
}

public class ClusteringDataProcessor
{
    /// <summary>
    /// the squared root of the initial cell number (100*100 = 10000)
    /// </summary>
    private const int initialClustersSquareSide = 100;
    /// <summary>
    /// the desired number of resulting clusters
    /// </summary>
    private const int numberOfFinalClusters = 1000;
    private static Random _rnd = new Random();

    /// <summary>
    /// In this implementation, the Cluster inherits from Item, so the result is a list of Item
    /// In the case of one Item Clusters, we actually return the original Item
    /// </summary>
    /// <param name="list"></param>
    /// <returns></returns>
    public List<Item> Process(List<Item> list)
    {
        if (list.Count <= numberOfFinalClusters) return list;
        // find bounds. If already known, this can be provided as parameters
        double minY = double.MaxValue;
        double minX = double.MaxValue;
        double maxY = double.MinValue;
        double maxX = double.MinValue;
        foreach (var item in list)
        {
            var y = item.Y;
            var x = item.X;
            minY = Math.Min(minY, y);
            maxY = Math.Max(maxY, y);
            minX = Math.Min(minX, x);
            maxX = Math.Max(maxX, x);
        }
        // the original list of clusters
        var clusterArr = new List<Cluster>();

        // the dictionary used to index clusters on their position
        var clusterDict = new Dictionary<string, Cluster>();

        // the unit for finding the cell position for the initial clusters
        var qX = (maxX - minX) / initialClustersSquareSide;
        var qY = (maxY - minY) / initialClustersSquareSide;

        foreach (var item in list)
        {
            // compute cell coordinates (integer and the values used as keys in the dictionary)
            var cx = Math.Min((int)((item.X - minX) / qX), initialClustersSquareSide - 1);
            var cy = Math.Min((int)((item.Y - minY) / qY), initialClustersSquareSide - 1);
            var key = getKey(cx, cy);
            Cluster cluster;
            // if the cluster for this position does not exist, create it
            if (!clusterDict.TryGetValue(key, out cluster))
            {
                cluster = new Cluster
                {
                    Keys = new List<string> { key },
                    X = minX + cx * qX + qX / 2,
                    Y = minY + cy * qY + qY / 2,
                    //Items = new List<Item>(),
                    Count = 0,
                    Neighbors = new List<string>()
                };
                // the neighbours of this cluster are the existing clusters that are below, above, left or right. If they exist, this cluster also is added to their neighbour list
                var nkeys = new[] { getKey(cx - 1, cy), getKey(cx + 1, cy), getKey(cx, cy - 1), getKey(cx, cy - 1) };
                for (var j = 0; j < 4; j++)
                {
                    Cluster nc;
                    if (clusterDict.TryGetValue(nkeys[j], out nc))
                    {
                        cluster.Neighbors.Add(nkeys[j]);
                        nc.Neighbors.Add(key);
                    }
                }
                clusterDict[key] = cluster;
                clusterArr.Add(cluster);
            }
            // add the item to the cluster (note that the commented lines hold the items in a list, while the current implementation only remember the number of items)
            //cluster.Items.Add(item);
            cluster.Item = item;
            cluster.Count++;
            // add the item position to the sums, so that we can compute the final position of the cluster at the Finalize stage without enumerating the items (or having to hold them in an Items list)
            cluster.SumX += item.X;
            cluster.SumY += item.Y;
        }
        // if the number of items is already smaller than the desired number of clusters, just return the clusters
        if (clusterArr.Count <= numberOfFinalClusters)
        {
            return clusterArr.Select(c => c.Finalize()).ToList();
        }

        // sort the cluster list so we can efficiently find the smallest cluster
        //clusterArr.Sort(new Comparison<Cluster>((c1, c2) => c1.Items.Count.CompareTo(c2.Items.Count)));
        LinkedList<Cluster> clusterLinkedList = new LinkedList<Cluster>(clusterArr.OrderBy(c => c.Count));

        // remember last merged cluster, as next merged clusters might have similar sizes
        var lastCount = int.MaxValue;
        LinkedListNode<Cluster> lastLinkedNode = null;

        // do this until we get to the desired number of clusters
        while (clusterLinkedList.Count > numberOfFinalClusters)
        {
            // we need to get the smallest (so first) cluster that has any neighbours
            var cluster1 = clusterLinkedList.First(c => c.Neighbors.Any());
            Cluster cluster2 = null;
            // then find the smallest neighbour
            var min = int.MaxValue;
            foreach (var nkey in cluster1.Neighbors)
            {
                var n = clusterDict[nkey];
                //var l = n.Items.Count;
                var l = n.Count;
                if (l < min)
                {
                    min = l;
                    cluster2 = n;
                }
            }
            // join the clusters
            var keys = cluster1.Keys.Union(cluster2.Keys).ToList();
            var cluster = new Cluster
            {
                Keys = keys,
                // approximate cluster position, not needed
                //X = (cluster1.X + cluster2.X) / 2,
                //Y = (cluster1.Y + cluster2.Y) / 2,

                // the result holds the count of both clusters
                //Items = cluster1.Items.Union(cluster2.Items).ToList(),
                Count = cluster1.Count + cluster2.Count,
                // the neighbors are in the union of their neighbours that does not contain themselves
                Neighbors = cluster1.Neighbors.Union(cluster2.Neighbors)
                    .Distinct()
                    .Except(keys)
                    .ToList(),
                // compute the sums for the final position
                SumX = cluster1.SumX + cluster2.SumX,
                SumY = cluster1.SumY + cluster2.SumY
            };
            foreach (var key in keys)
            {
                clusterDict[key] = cluster;
            }
            // efficiently remove clusters since LinkedList removals are fast
            clusterLinkedList.Remove(cluster1);
            clusterLinkedList.Remove(cluster2);

            // a little bit of magic to make the finding of the insertion point faster (LinkedLists go through the entire list to find an item)
            // if the last merged cluster is smaller or equal to the new merged cluster, then start searching from it.
            // this halves the insert time operation, but I am sure there are even better implementations, just didn't think it's so important
            LinkedListNode<Cluster> start;
            if (lastCount <= cluster.Count && lastLinkedNode.Value != cluster1 && lastLinkedNode.Value != cluster2)
            {
                start = lastLinkedNode;
            }
            else
            {
                start = clusterLinkedList.First;
            }
            var insertionPoint = nextOrDefault(clusterLinkedList, start, c => c.Count >= cluster.Count);
            // remember last merged cluster
            LinkedListNode<Cluster> link;
            if (insertionPoint == null)
            {
                link = clusterLinkedList.AddLast(cluster);
            }
            else
            {
                link = clusterLinkedList.AddBefore(insertionPoint, cluster);
            }
            lastLinkedNode = link;
            lastCount = cluster.Count;
        }
        return clusterLinkedList.Select(c => c.Finalize()).ToList();
    }

    private LinkedListNode<T> nextOrDefault<T>(LinkedList<T> list, LinkedListNode<T> start, Func<T, bool> condition)
    {
        while (start.Next != null)
        {
            if (condition(start.Value)) return start;
            start = start.Next;
        }
        return null;
    }

    private string getKey(int cx, int cy)
    {
        return cx + ":" + cy;
    }

    private class Cluster : Item
    {
        public Cluster()
        {
            SumX = 0;
            SumY = 0;
        }

        public double SumX { get; set; }
        public double SumY { get; set; }

        public List<string> Keys { get; set; }

        //public List<Item> Items { get; set; }
        public int Count { get; set; }
        public Item Item { get; set; }

        public List<string> Neighbors { get; set; }


        /// <summary>
        /// the function that finalizes the computation of the values or even decides to return the only item in the cluster
        /// </summary>
        /// <returns></returns>
        public Item Finalize()
        {
            //if (Items.Count == 1) return Items[0];
            if (Count == 1) return Item;
            /*Y = SumY / Items.Count;
            X = SumX / Items.Count;
            Count = Items.Count;*/
            Y = SumY / Count;
            X = SumX / Count;
            Count = Count;
            return this;
        }
    }
}

/// <summary>
    /// Generic x,y positioned item class
    /// </summary>
    public class Item
    {
        public double X { get; set; }
        public double Y { get; set; }
    }

    public class ClusteringDataProcessor
    {
        /// <summary>
        /// the squared root of the initial cell number (70*70 = 4900)
        /// </summary>
        private const int initialClustersSquareSide = 70;
        /// <summary>
        /// the desired number of resulting clusters
        /// </summary>
        private const int numberOfFinalClusters = 1000;
        private static Random _rnd = new Random();

        /// <summary>
        /// In this implementation, the Cluster inherits from Item, so the result is a list of Item
        /// In the case of one Item Clusters, we actually return the original Item
        /// </summary>
        /// <param name="list"></param>
        /// <returns></returns>
        public List<Item> Process(List<Item> list)
        {
            if (list.Count <= numberOfFinalClusters) return list;
            // find bounds. If already known, this can be provided as parameters
            double minY = double.MaxValue;
            double minX = double.MaxValue;
            double maxY = double.MinValue;
            double maxX = double.MinValue;
            foreach (var item in list)
            {
                var y = item.Y;
                var x = item.X;
                minY = Math.Min(minY, y);
                maxY = Math.Max(maxY, y);
                minX = Math.Min(minX, x);
                maxX = Math.Max(maxX, x);
            }
            // the list of clusters
            var clusterArr = new List<Cluster>();

            // the dictionary used to index clusters on their position
            var clusterDict = new Dictionary<string, Cluster>();

            // the unit for finding the cell position for the initial clusters
            var qX = (maxX - minX) / initialClustersSquareSide;
            var qY = (maxY - minY) / initialClustersSquareSide;

            foreach (var item in list)
            {
                // compute cell coordinates (integer and the values used as keys in the dictionary)
                var cx = Math.Min((int)((item.X - minX) / qX), initialClustersSquareSide - 1);
                var cy = Math.Min((int)((item.Y - minY) / qY), initialClustersSquareSide - 1);
                var key = getKey(cx, cy);
                Cluster cluster;
                // if the cluster for this position does not exist, create it
                if (!clusterDict.TryGetValue(key, out cluster))
                {
                    cluster = new Cluster
                    {
                        Keys = new List<string> { key },
                        X = minX + cx * qX + qX / 2,
                        Y = minY + cy * qY + qY / 2,
                        //Items = new List<Item>(),
                        Count = 0,
                        Neighbors = new List<string>()
                    };
                    // the neighbours of this cluster are the existing clusters that are below, above, left or right. If they exist, this cluster also is added to their neighbour list
                    var nkeys = new[] { getKey(cx - 1, cy), getKey(cx + 1, cy), getKey(cx, cy - 1), getKey(cx, cy - 1) };
                    for (var j = 0; j < 4; j++)
                    {
                        Cluster nc;
                        if (clusterDict.TryGetValue(nkeys[j],out nc))
                        {
                            cluster.Neighbors.Add(nkeys[j]);
                            nc.Neighbors.Add(key);
                        }
                    }
                    clusterDict[key] = cluster;
                    clusterArr.Add(cluster);
                }
                // add the item to the cluster (note that the commented lines hold the items in a list, while the current implementation only remember the number of items)
                //cluster.Items.Add(item);
                cluster.Item = item;
                cluster.Count++;
                // add the item position to the sums, so that we can compute the final position of the cluster at the Finalize stage without enumerating the items (or having to hold them in an Items list)
                cluster.SumX += item.X;
                cluster.SumY += item.Y;
            }
            // if the number of items is already smaller than the desired number of clusters, just return the clusters
            if (clusterArr.Count > numberOfFinalClusters)
            {
                // sort the cluster list so we can efficiently find the smallest cluster
                //clusterArr.Sort(new Comparison<Cluster>((c1, c2) => c1.Items.Count.CompareTo(c2.Items.Count)));
                clusterArr.Sort(new Comparison<Cluster>((c1, c2) => c1.Count.CompareTo(c2.Count)));
                // do this until we get to the desired number of clusters
                while (clusterArr.Count > numberOfFinalClusters)
                {
                    // we need to get the smallest (so first) cluster that has any neighbours
                    var cluster1Index = clusterArr.FindIndex(c => c.Neighbors.Any());
                    if (cluster1Index < 0) break;
                    var cluster1 = clusterArr[cluster1Index];
                    Cluster cluster2 = null;
                    // then find the smallest neighbour
                    var min = int.MaxValue;
                    foreach (var nkey in cluster1.Neighbors)
                    {
                        var n = clusterDict[nkey];
                        //var l = n.Items.Count;
                        var l = n.Count;
                        if (l < min)
                        {
                            min = l;
                            cluster2 = n;
                        }
                    }
                    // join the clusters
                    var keys = cluster1.Keys.Union(cluster2.Keys).ToList();
                    var cluster = new Cluster
                    {
                        Keys = keys,
                        // approximate cluster position, not needed
                        //X = (cluster1.X + cluster2.X) / 2,
                        //Y = (cluster1.Y + cluster2.Y) / 2,

                        // the result holds the count of both clusters
                        //Items = cluster1.Items.Union(cluster2.Items).ToList(),
                        Count = cluster1.Count + cluster2.Count,
                        // the neighbors are in the union of their neighbours that does not contain themselves
                        Neighbors = cluster1.Neighbors.Union(cluster2.Neighbors)
                            .Distinct()
                            .Except(keys)
                            .ToList(),
                        // compute the sums for the final position
                        SumX = cluster1.SumX + cluster2.SumX,
                        SumY = cluster1.SumY + cluster2.SumY
                    };
                    foreach (var key in keys)
                    {
                        clusterDict[key] = cluster;
                    }
                    // efficiently remove first cluster since we know its index
                    clusterArr.RemoveAt(cluster1Index);
                    // remove this cluster from the list (perhaps some sort of caching can speed this up, too)
                    clusterArr.Remove(cluster2);

                    // find the index of the cluster before which we want to insert our merged result
                    // the first comment is the naive implementation
                    // the current implementation is a divide-et-impera quick find in a sorted list

                    //var index = clusterArr.FindIndex(c => c.Items.Count > cluster.Items.Count);
                    //var index = findFastIndex(clusterArr, cluster.Items.Count, 0, clusterArr.Count);
                    var index = findFastIndex(clusterArr, cluster.Count, 0, clusterArr.Count);
                    if (index < 0)
                    {
                        // if not found, just add it at the end, it's bigger than all existing clusters
                        clusterArr.Add(cluster);
                    }
                    else
                    {
                        clusterArr.Insert(index, cluster);
                    }
                }
            }
            return clusterArr.Select(c=>c.Finalize()).ToList();
        }

        /// <summary>
        /// Quickly find the insertion index in an ordered list based on a count
        /// </summary>
        /// <param name="clusterArr"></param>
        /// <param name="count"></param>
        /// <param name="start"></param>
        /// <param name="length"></param>
        /// <returns></returns>
        private int findFastIndex(List<Cluster> clusterArr, int count, int start, int length)
        {
            if (length == 0) return start;
            if (start < 0 || start >= clusterArr.Count) return -1;
            //var currCount = clusterArr[start].Items.Count;
            var currCount = clusterArr[start].Count;
            if (currCount < count)
            {
                return findFastIndex(clusterArr, count, start + length / 2, length / 2);
            }
            if (currCount > count)
            {
                return findFastIndex(clusterArr, count, start - length / 2, length / 2);
            }
            return start;
        }

        private string getKey(int cx, int cy)
        {
            return cx + ":" + cy;
        }

        private class Cluster:Item
        {
            public Cluster()
            {
                SumX = 0;
                SumY = 0;
            }

            public double SumX { get; set; }
            public double SumY { get; set; }

            public List<string> Keys { get; set; }

            //public List<Item> Items { get; set; }
            public int Count { get; set; }
            public Item Item { get; set; }

            public List<string> Neighbors { get; set; }


            /// <summary>
            /// the function that finalizes the computation of the values or even decides to return the only item in the cluster
            /// </summary>
            /// <returns></returns>
            public Item Finalize()
            {
                //if (Items.Count == 1) return Items[0];
                if (Count == 1) return Item;
                /*Y = SumY / Items.Count;
                X = SumX / Items.Count;
                Count = Items.Count;*/
                Y = SumY / Count;
                X = SumX / Count;
                Count = Count;
                return this;
            }
        }

    }

<EventTrigger RoutedEvent="Binding.TargetUpdated">
    <EventTrigger.Actions>
        <BeginStoryboard>
            <Storyboard>
                <local:SafeDoubleAnimation Storyboard.TargetProperty="(Canvas.Left)" Duration="0:0:1" FillBehavior="Stop" />
                <local:SafeDoubleAnimation Storyboard.TargetProperty="(Canvas.Top)" Duration="0:0:1" FillBehavior="Stop" />
            </Storyboard>
        </BeginStoryboard>
    </EventTrigger.Actions>
</EventTrigger>

public class SafeDoubleAnimation:DoubleAnimation
{
    protected override double GetCurrentValueCore(double defaultOriginValue, double defaultDestinationValue, AnimationClock animationClock)
    {
        if (double.IsNaN(defaultOriginValue)) defaultOriginValue = 0;
        if (double.IsNaN(defaultDestinationValue)) defaultDestinationValue = defaultOriginValue;
        try
        {
            return base.GetCurrentValueCore(defaultOriginValue, defaultDestinationValue, animationClock);
        }
        catch
        {
            return 0;
        }
    }
}

public MyWindow()
{
    InitializeComponent();
    DataContextChanged += ItemGrid_DataContextChanged;
}

void ItemGrid_DataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
{
    var vm = e.NewValue as INotifyPropertyChanged;
    if (vm != null)
    {
        vm.PropertyChanged += (s, ev) =>
        {
            if (ev.PropertyName == "SpecialPropertyName")
            {
                animateChanges();
            }
        };
    }
}

private void animateChanges()
{
    var vm = (MyViewModel)DataContext;
    var zoom = vm.Zoom;
    var sb = new Storyboard();
    var converter=new CoordinateConverter(); // the same converter that I am using in the XAML databinding
    foreach (var child in lvKernelItems.Items)
    {
        var item=(KernelItem)child;
        var container = (UIElement)lvKernelItems.ItemContainerGenerator.ContainerFromItem(child); // ugly way of getting the UIElement associated to a data item
        var currentVal=Canvas.GetLeft(container);
        var nextVal=(double)converter.Convert(new object[] { item.X, lvKernelItems.ActualWidth, zoom },typeof(double),null,CultureInfo.CurrentCulture);
        var anim = new DoubleAnimation(nextVal, new Duration(TimeSpan.FromSeconds(0.5)))
        {
            FillBehavior = FillBehavior.Stop
        };
        Storyboard.SetTarget(anim, container);
        Storyboard.SetTargetProperty(anim, new PropertyPath("(Canvas.Left)"));
        sb.Children.Add(anim);
        currentVal = Canvas.GetTop(container);
        nextVal = (double)converter.Convert(new object[] { item.Y, lvKernelItems.ActualHeight, zoom }, typeof(double), null, CultureInfo.CurrentCulture);
        anim = new DoubleAnimation(nextVal, new Duration(TimeSpan.FromSeconds(0.5)))
        {
            FillBehavior = FillBehavior.Stop
        };
        Storyboard.SetTarget(anim, container);
        Storyboard.SetTargetProperty(anim, new PropertyPath("(Canvas.Top)"));
        sb.Children.Add(anim);
    }
    sb.Completed += sb_Completed;
    sb.Begin();
}

void sb_Completed(object sender, EventArgs e)
{
    foreach (var child in lvKernelItems.Items)
    {
        var item = (KernelItem)child;
        item.RefreshCoordinates();  //method that finally fires the OnPropertyChanged event on the X and Y properties, causing the final value to be set.
    }
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media.Animation;

namespace Siderite.AttachedProperties
{
    public static class UIElementProperties
    {
        public static readonly DependencyProperty CanvasLeftProperty = DependencyProperty.RegisterAttached("CanvasLeft", typeof(double), typeof(UIElementProperties), new FrameworkPropertyMetadata(
                                                                                            0.0,
                                                                                            FrameworkPropertyMetadataOptions.OverridesInheritanceBehavior,
                                                                                            CanvasLeftChanged));

        [AttachedPropertyBrowsableForType(typeof(UIElement))]
        public static double GetCanvasLeft(DependencyObject element)
        {
            if (element == null)
            {
                throw new ArgumentNullException("element");
            }
            return (double)element.GetValue(CanvasLeftProperty);
        }

        [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
        public static void SetCanvasLeft(DependencyObject element, double value)
        {
            if (element == null)
            {
                throw new ArgumentNullException("element");
            }
            element.SetValue(CanvasLeftProperty, value);
        }

        private static void CanvasLeftChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            var sb = new Storyboard();
            var oldVal = (double)e.OldValue;
            if (double.IsNaN(oldVal)) oldVal = 0;
            var newVal = (double)e.NewValue;
            if (double.IsNaN(newVal)) newVal = oldVal;
            var anim = new DoubleAnimation
            {
                From = oldVal,
                To = newVal,
                Duration = new Duration(TimeSpan.FromSeconds(1)),
                FillBehavior = FillBehavior.Stop
            };
            Storyboard.SetTarget(anim, d);
            Storyboard.SetTargetProperty(anim, new PropertyPath("(Canvas.Left)"));
            sb.Children.Add(anim);
            sb.Completed += (s, ev) =>
            {
                d.SetValue(Canvas.LeftProperty, newVal);
            };
            var fe = d as FrameworkElement;
            if (fe != null)
            {
                sb.Begin(fe, HandoffBehavior.Compose);
                return;
            }
            var fce = d as FrameworkContentElement;
            if (fce != null)
            {
                sb.Begin(fce, HandoffBehavior.Compose);
                return;
            }
            sb.Begin();
        }
        

        public static readonly DependencyProperty CanvasTopProperty = DependencyProperty.RegisterAttached("CanvasTop", typeof(double), typeof(UIElementProperties), new FrameworkPropertyMetadata(
                                                                                        0.0,
                                                                                        FrameworkPropertyMetadataOptions.OverridesInheritanceBehavior,
                                                                                        CanvasTopChanged));

        [AttachedPropertyBrowsableForType(typeof(UIElement))]
        public static double GetCanvasTop(DependencyObject element)
        {
            if (element == null)
            {
                throw new ArgumentNullException("element");
            }
            return (double)element.GetValue(CanvasTopProperty);
        }

        [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
        public static void SetCanvasTop(DependencyObject element, double value)
        {
            if (element == null)
            {
                throw new ArgumentNullException("element");
            }
            element.SetValue(CanvasTopProperty, value);
        }

        private static void CanvasTopChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            var sb = new Storyboard();
            var oldVal = (double)e.OldValue;
            if (double.IsNaN(oldVal)) oldVal = 0;
            var newVal = (double)e.NewValue;
            if (double.IsNaN(newVal)) newVal = oldVal;
            var anim = new DoubleAnimation
            {
                From = oldVal,
                To = newVal,
                Duration = new Duration(TimeSpan.FromSeconds(1)),
                FillBehavior = FillBehavior.Stop
            };
            Storyboard.SetTarget(anim, d);
            Storyboard.SetTargetProperty(anim, new PropertyPath("(Canvas.Top)"));
            sb.Children.Add(anim);
            sb.Completed += (s, ev) =>
            {
                d.SetValue(Canvas.TopProperty, newVal);
            };
            var fe = d as FrameworkElement;
            if (fe != null)
            {
                sb.Begin(fe, HandoffBehavior.Compose);
                return;
            }
            var fce = d as FrameworkContentElement;
            if (fce != null)
            {
                sb.Begin(fce, HandoffBehavior.Compose);
                return;
            }
            sb.Begin();
        }
    }
}

<ListView ItemsSource="{Binding KernelItems}" 
          SelectedItem="{Binding SelectedItem,Mode=TwoWay}"
          SelectionMode="Single"
          >
    <ListView.ItemsPanel>
        <ItemsPanelTemplate>
            <Canvas HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Background="Black" />
        </ItemsPanelTemplate>
    </ListView.ItemsPanel>
    <ListView.ItemContainerStyle>
        <Style TargetType="{x:Type ListViewItem}">
            <Setter Property="FocusVisualStyle" Value="{x:Null}"/>
            <Setter Property="Foreground" Value="White"/>
            <Setter Property="att:UIElementProperties.CanvasLeft" >
                <Setter.Value>
                    <MultiBinding Converter="{StaticResource CoordinateConverter}">
                        <Binding Path="X"/>
                        <Binding Path="ActualWidth" ElementName="lvKernelItems"/>
                        <Binding Path="DataContext.Zoom" RelativeSource="{RelativeSource AncestorType={x:Type Window}}"/>
                    </MultiBinding>
                </Setter.Value>
            </Setter>
            <Setter Property="att:UIElementProperties.CanvasTop" >
                <Setter.Value>
                    <MultiBinding Converter="{StaticResource CoordinateConverter}">
                        <Binding Path="Y"/>
                        <Binding Path="ActualHeight" ElementName="lvKernelItems"/>
                        <Binding Path="DataContext.Zoom" RelativeSource="{RelativeSource AncestorType={x:Type Window}}"/>
                    </MultiBinding>
                </Setter.Value>
            </Setter>
            <Style.Resources>
                <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" Color="Transparent" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlBrushKey}" Color="Transparent" />
                <SolidColorBrush x:Key="{x:Static SystemColors.HighlightTextBrushKey}" Color="Black" />
                <SolidColorBrush x:Key="{x:Static SystemColors.ControlTextBrushKey}" Color="Black" />
            </Style.Resources>
            <Style.Triggers>
                <Trigger Property="IsSelected" Value="True">
                    <Setter Property="Foreground" Value="Cyan"/>
                    <Setter Property="Effect">
                        <Setter.Value>
                            <DropShadowEffect ShadowDepth="0" Color="White" Opacity="0.5" BlurRadius="10"/>
                        </Setter.Value>
                    </Setter>
                    <Setter Property="Canvas.ZIndex" Value="1000"/>
                </Trigger>
            </Style.Triggers>
        </Style>
    </ListView.ItemContainerStyle>
</ListView>

<Window.Resources>
        <local:CoordinateConverter x:Key="CoordinateConverter"/>
        <DataTemplate DataType="{x:Type vm:KernelItem}"> <!-- the template for the data items -->
            <Grid>
                <Ellipse Fill="{Binding Background}" Width="100" Height="100" Stroke="DarkGray" Name="ellipse"
                         ToolTip="{Binding Tooltip}"/>
                <TextBlock Text="{Binding Text}" MaxWidth="75"  MaxHeight="75"
                           HorizontalAlignment="Center" VerticalAlignment="Center"
                           TextAlignment="Center"
                           TextWrapping="Wrap"
                           ToolTip="{Binding Tooltip}" />
            </Grid>
        </DataTemplate>
    </Window.Resources>
    <ListView ItemsSource="{Binding KernelItems}" Name="lvKernelItems"
              SelectedItem="{Binding SelectedItem,Mode=TwoWay}"
              SelectionMode="Single"
              >
        <ListView.ItemsPanel>
            <ItemsPanelTemplate>
                <Canvas HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Background="Black" />
            </ItemsPanelTemplate>
        </ListView.ItemsPanel>
        <ListView.ItemContainerStyle>
            <Style TargetType="{x:Type ListViewItem}">
                <Setter Property="FocusVisualStyle" Value="{x:Null}"/><!-- no highlight of selected items -->
                <Setter Property="Foreground" Value="White"/>
                <Setter Property="(Canvas.Left)" >
                    <Setter.Value>
                        <MultiBinding Converter="{StaticResource CoordinateConverter}">
                            <Binding Path="X"/>
                            <Binding Path="ActualWidth" ElementName="lvKernelItems"/>
                            <Binding Path="DataContext.Zoom" RelativeSource="{RelativeSource AncestorType={x:Type Window}}"/>
                        </MultiBinding>
                    </Setter.Value>
                </Setter>
                <Setter Property="(Canvas.Top)" >
                    <Setter.Value>
                        <MultiBinding Converter="{StaticResource CoordinateConverter}">
                            <Binding Path="Y"/>
                            <Binding Path="ActualHeight" ElementName="lvKernelItems"/>
                            <Binding Path="DataContext.Zoom" RelativeSource="{RelativeSource AncestorType={x:Type Window}}"/>
                        </MultiBinding>
                    </Setter.Value>
                </Setter>
                <Style.Resources><!-- no highlight of selected items -->
                    <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" Color="Transparent" />
                    <SolidColorBrush x:Key="{x:Static SystemColors.ControlBrushKey}" Color="Transparent" />
                    <SolidColorBrush x:Key="{x:Static SystemColors.HighlightTextBrushKey}" Color="Black" />
                    <SolidColorBrush x:Key="{x:Static SystemColors.ControlTextBrushKey}" Color="Black" />
                </Style.Resources>
                <Style.Triggers>
                    <Trigger Property="IsSelected" Value="True"><!-- custom selected item template -->
                        <Setter Property="Foreground" Value="Cyan"/>
                        <Setter Property="Effect">
                            <Setter.Value>
                                <DropShadowEffect ShadowDepth="0" Color="White" Opacity="0.5" BlurRadius="10"/>
                            </Setter.Value>
                        </Setter>
                        <Setter Property="Canvas.ZIndex" Value="1000"/>
                    </Trigger>
                </Style.Triggers>
            </Style>
        </ListView.ItemContainerStyle>
    </ListView>