' ***********************************************************************
' Author   : Elektro
' Modified : 14-February-2015
' ***********************************************************************
 
#Region " Usage Examples "
 
 ' he eliminado esto por el límite de caracteres del foro
 
#End Region
 
#Region " Option Statements "
 
Option Explicit On
Option Strict On
Option Infer Off
 
#End Region
 
#Region " Imports "
 
Imports System.IO
Imports System.Collections.Concurrent
Imports System.Threading.Tasks
 
#End Region
 
#Region " File Dir Searcher "
 
''' <summary>
''' Searchs for files and directories.
''' </summary>
Public NotInheritable Class FileDirSearcher
 
#Region " Public Methods "
 
    ''' <summary>
    ''' Gets the files those matches the criteria inside the specified directory and/or sub-directories.
    ''' </summary>
    ''' <param name="dirPath">The root directory path to search for files.</param>
    ''' <param name="searchOption">The searching mode.</param>
    ''' <param name="fileNamePatterns">The file name pattern(s) to match.</param>
    ''' <param name="fileExtPatterns">The file extension pattern(s) to match.</param>
    ''' <param name="ignoreCase">If <c>True</c>, ignores the comparing case of <paramref name="fileNamePatterns"/> and <paramref name="fileExtPatterns"/> patterns.</param>
    ''' <param name="throwOnError">If set to <c>true</c>, exceptions will be thrown, like access denied to file or directory.</param>
    ''' <returns>An <see cref="IEnumerable(Of FileInfo)"/> instance containing the files information.</returns>
    ''' <exception cref="System.ArgumentException">dirPath or searchOption</exception>
    Public Shared Function GetFiles(ByVal dirPath As String,
                                    ByVal searchOption As SearchOption,
                                    Optional ByVal fileNamePatterns As IEnumerable(Of String) = Nothing,
                                    Optional ByVal fileExtPatterns As IEnumerable(Of String) = Nothing,
                                    Optional ByVal ignoreCase As Boolean = True,
                                    Optional ByVal throwOnError As Boolean = False) As IEnumerable(Of FileInfo)
 
        ' Analyze and resolve path problems. (eg. 'C:' -> 'C:\')
        AnalyzePath(dirPath)
 
        ' Analyze the passed arguments.
        AnalyzeArgs(dirPath, searchOption)
 
        ' Get and return the files.
        Dim queue As New ConcurrentQueue(Of FileInfo)
        CollectFiles(queue, dirPath, searchOption, fileNamePatterns, fileExtPatterns, ignoreCase, throwOnError)
        Return queue.AsEnumerable
 
    End Function
 
    ''' <summary>
    ''' Gets the filepaths those matches the criteria inside the specified directory and/or sub-directories.
    ''' </summary>
    ''' <param name="dirPath">The root directory path to search for files.</param>
    ''' <param name="searchOption">The searching mode.</param>
    ''' <param name="fileNamePatterns">The file name pattern(s) to match.</param>
    ''' <param name="fileExtPatterns">The file extension pattern(s) to match.</param>
    ''' <param name="ignoreCase">If <c>True</c>, ignores the comparing case of <paramref name="fileNamePatterns"/> and <paramref name="fileExtPatterns"/> patterns.</param>
    ''' <param name="throwOnError">If set to <c>true</c>, exceptions will be thrown, like access denied to file or directory.</param>
    ''' <returns>An <see cref="IEnumerable(Of String)"/> instance containing the filepaths.</returns>
    ''' <exception cref="System.ArgumentException">dirPath or searchOption</exception>
    Public Shared Function GetFilePaths(ByVal dirPath As String,
                                        ByVal searchOption As SearchOption,
                                        Optional ByVal fileNamePatterns As IEnumerable(Of String) = Nothing,
                                        Optional ByVal fileExtPatterns As IEnumerable(Of String) = Nothing,
                                        Optional ByVal ignoreCase As Boolean = True,
                                        Optional ByVal throwOnError As Boolean = False) As IEnumerable(Of String)
 
        ' Analyze and resolve path problems. (eg. 'C:' -> 'C:\')
        AnalyzePath(dirPath)
 
        ' Analyze the passed arguments.
        AnalyzeArgs(dirPath, searchOption)
 
        ' Get and return the filepaths.
        Dim queue As New ConcurrentQueue(Of String)
        CollectFilePaths(queue, dirPath, searchOption, fileNamePatterns, fileExtPatterns, ignoreCase, throwOnError)
        Return queue.AsEnumerable
 
    End Function
 
    ''' <summary>
    ''' Gets the directories those matches the criteria inside the specified directory and/or sub-directories.
    ''' </summary>
    ''' <param name="dirPath">The root directory path to search for directories.</param>
    ''' <param name="searchOption">The searching mode.</param>
    ''' <param name="dirPathPatterns">The directory path pattern(s) to match.</param>
    ''' <param name="dirNamePatterns">The directory name pattern(s) to match.</param>
    ''' <param name="ignoreCase">If <c>True</c>, ignores the comparing case of <paramref name="dirPathPatterns"/> and <paramref name="dirNamePatterns"/> patterns.</param>
    ''' <param name="throwOnError">If set to <c>true</c>, exceptions will be thrown, like access denied to directory.</param>
    ''' <returns>An <see cref="IEnumerable(Of DirectoryInfo)"/> instance containing the dirrectories information.</returns>
    ''' <exception cref="System.ArgumentException">dirPath or searchOption</exception>
    Public Shared Function GetDirs(ByVal dirPath As String,
                                   ByVal searchOption As SearchOption,
                                   Optional ByVal dirPathPatterns As IEnumerable(Of String) = Nothing,
                                   Optional ByVal dirNamePatterns As IEnumerable(Of String) = Nothing,
                                   Optional ByVal ignoreCase As Boolean = True,
                                   Optional ByVal throwOnError As Boolean = False) As IEnumerable(Of DirectoryInfo)
 
        ' Analyze and resolve path problems. (eg. 'C:' -> 'C:\')
        AnalyzePath(dirPath)
 
        ' Analyze the passed arguments.
        AnalyzeArgs(dirPath, searchOption)
 
        ' Get and return the directories.
        Dim queue As New ConcurrentQueue(Of DirectoryInfo)
        CollectDirs(queue, dirPath, searchOption, dirPathPatterns, dirNamePatterns, ignoreCase, throwOnError)
        Return queue.AsEnumerable
 
    End Function
 
    ''' <summary>
    ''' Gets the filepaths those matches the criteria inside the specified directory and/or sub-directories.
    ''' </summary>
    ''' <param name="dirPath">The root directory path to search for directories.</param>
    ''' <param name="searchOption">The searching mode.</param>
    ''' <param name="dirPathPatterns">The directory path pattern(s) to match.</param>
    ''' <param name="dirNamePatterns">The directory name pattern(s) to match.</param>
    ''' <param name="ignoreCase">If <c>True</c>, ignores the comparing case of <paramref name="dirPathPatterns"/> and <paramref name="dirNamePatterns"/> patterns.</param>
    ''' <param name="throwOnError">If set to <c>true</c>, exceptions will be thrown, like access denied to directory.</param>
    ''' <returns>An <see cref="IEnumerable(Of String)"/> instance containing the directory paths.</returns>
    ''' <exception cref="System.ArgumentException">dirPath or searchOption</exception>
    Public Shared Function GetDirPaths(ByVal dirPath As String,
                                       ByVal searchOption As SearchOption,
                                       Optional ByVal dirPathPatterns As IEnumerable(Of String) = Nothing,
                                       Optional ByVal dirNamePatterns As IEnumerable(Of String) = Nothing,
                                       Optional ByVal ignoreCase As Boolean = True,
                                       Optional ByVal throwOnError As Boolean = False) As IEnumerable(Of String)
 
        ' Analyze and resolve path problems. (eg. 'C:' -> 'C:\')
        AnalyzePath(dirPath)
 
        ' Analyze the passed arguments.
        AnalyzeArgs(dirPath, searchOption)
 
        ' Get and return the directory paths.
        Dim queue As New ConcurrentQueue(Of String)
        CollectDirPaths(queue, dirPath, searchOption, dirPathPatterns, dirNamePatterns, ignoreCase, throwOnError)
        Return queue.AsEnumerable
 
    End Function
 
#End Region
 
#Region " Private Methods "
 
    ''' <summary>
    ''' Analyzes a directory path and perform specific changes on it.
    ''' </summary>
    ''' <param name="dirPath">The directory path.</param>
    ''' <exception cref="System.ArgumentNullException">dirPath;Value is null, empty, or white-spaced.</exception>
    Private Shared Sub AnalyzePath(ByRef dirPath As String)
 
        If String.IsNullOrEmpty(dirPath) OrElse String.IsNullOrWhiteSpace(dirPath) Then
            Throw New ArgumentNullException("dirPath", "Value is null, empty, or white-spaced.")
 
        Else
            ' Trim unwanted characters.
            dirPath = dirPath.TrimStart({" "c}).TrimEnd({" "c})
 
            If Path.IsPathRooted(dirPath) Then
                ' The root paths contained on the returned FileInfo objects will start with the same string-case as this root path.
                ' So just for a little visual improvement, I'll treat this root path as a Drive-Letter and I convert it to UpperCase.
                dirPath = Char.ToUpper(dirPath.First) & dirPath.Substring(1)
            End If
 
            If Not dirPath.EndsWith("\"c) Then
                ' Possibly its a drive letter without backslash ('C:') or else just a normal path without backslash ('C\Dir').
                ' In any case, fix the ending backslash.
                dirPath = dirPath.Insert(dirPath.Length, "\"c)
            End If
 
        End If
 
    End Sub
 
    ''' <summary>
    ''' Analyzes the specified directory values.
    ''' </summary>
    ''' <param name="dirPath">The root directory path to search for files.</param>
    ''' <param name="searchOption">The searching mode.</param>
    ''' <exception cref="System.ArgumentException">dirPath or searchOption</exception>
    Private Shared Sub AnalyzeArgs(ByVal dirPath As String, ByVal searchOption As SearchOption)
 
        If Not Directory.Exists(dirPath) Then
            Throw New ArgumentException(String.Format("Directory doesn't exists: '{0}'", dirPath), "dirPath")
 
        ElseIf (searchOption <> searchOption.TopDirectoryOnly) AndAlso (searchOption <> searchOption.AllDirectories) Then
            Throw New ArgumentException(String.Format("Value of '{0}' is not valid enumeration value.", CStr(searchOption)), "searchOption")
 
        End If
 
    End Sub
 
    ''' <summary>
    ''' Tries to instance the byreferred <see cref="DirectoryInfo"/> object using the given directory path.
    ''' </summary>
    ''' <param name="dirPath">The directory path used to instance the byreffered <see cref="DirectoryInfo"/> object.</param>
    ''' <param name="dirInfo">The byreffered <see cref="DirectoryInfo"/> object to instance it using the given directory path.</param>
    ''' <param name="throwOnError">If set to <c>true</c>, exceptions will be thrown, like access denied to directory.</param>
    Private Shared Sub SetupDirInfoObject(ByVal dirPath As String,
                                          ByRef dirInfo As DirectoryInfo,
                                          ByVal throwOnError As Boolean)
 
        Try
            dirInfo = New DirectoryInfo(dirPath)
 
        Catch ex As Exception
 
            Select Case ex.GetType ' Handle or suppress exceptions by its type, 
 
                ' I've wrote different types just to feel free to expand this feature in the future.
                Case GetType(ArgumentNullException),
                     GetType(ArgumentException),
                     GetType(Security.SecurityException),
                     GetType(PathTooLongException),
                     ex.GetType
 
                    If throwOnError Then
                        Throw
                    End If
 
            End Select
 
        End Try
 
    End Sub
 
    ''' <summary>
    ''' Tries to instance the byreferred <paramref name="col"/> object using the given directory path.
    ''' </summary>
    ''' <typeparam name="A">The type of the <paramref name="col"/> object used to cast and fill the byreffered collection.</typeparam>
    ''' <param name="objectAction">The method to invoke, only for <see cref="FileInfo"/> or <see cref="DirectoryInfo"/> objects, this parameter can be <c>Nothing</c>.</param>
    ''' <param name="sharedAction">The method to invoke, only for filepaths or directorypaths, this parameter can be <c>Nothing</c>.</param>
    ''' <param name="dirPath">The directory path used to instance the byreffered <paramref name="col"/> object.</param>
    ''' <param name="searchPattern">The search pattern to list files or directories.</param>
    ''' <param name="col">The byreffered <see cref="IEnumerable(Of A)"/> object to instance it using the given directory path.</param>
    ''' <param name="throwOnError">If set to <c>true</c>, exceptions will be thrown, like access denied to file or directory.</param>
    Private Shared Sub SetupFileDirCollection(Of A)(ByVal objectAction As Func(Of String, 
                                                                               SearchOption, 
                                                                               IEnumerable(Of A)),
                                                    ByVal sharedAction As Func(Of String,
                                                                             String, 
                                                                             SearchOption, 
                                                                             IEnumerable(Of A)),
                                                    ByVal dirPath As String,
                                                    ByVal searchPattern As String,
                                                    ByRef col As IEnumerable(Of A),
                                                    ByVal throwOnError As Boolean)
 
        Try
            If objectAction IsNot Nothing Then
                col = objectAction.Invoke(searchPattern, SearchOption.TopDirectoryOnly)
 
            ElseIf sharedAction IsNot Nothing Then
                col = sharedAction.Invoke(dirPath, searchPattern, SearchOption.TopDirectoryOnly)
 
            Else
                Throw New ArgumentException("Any Action has been defined.")
 
            End If
 
        Catch ex As Exception
 
            Select Case ex.GetType ' Handle or suppress exceptions by its type, 
 
                ' I've wrote different types just to feel free to expand this feature in the future.
                Case GetType(UnauthorizedAccessException),
                     GetType(DirectoryNotFoundException),
                     ex.GetType
 
                    If throwOnError Then
                        Throw
                    End If
 
            End Select
 
        End Try
 
    End Sub
 
    ''' <summary>
    ''' Determines whether at least one of the specified patterns matches the given value.
    ''' </summary>
    ''' <param name="value">The value, which can be a filename, file extension, direcrory path, or directory name.</param>
    ''' <param name="patterns">The patterns to match the given value.</param>
    ''' <param name="ignoreCase">if set to <c>true</c>, compares ignoring string-case rules.</param>
    ''' <returns><c>true</c> at least one of the specified patterns matches the given value; <c>false</c> otherwise.</returns>
    Private Shared Function IsMatchPattern(ByVal value As String,
                                           ByVal patterns As IEnumerable(Of String),
                                           ByVal ignoreCase As Boolean) As Boolean
 
        ' Iterate the filename pattern(s) to match each name pattern on the current name.
        For Each pattern As String In patterns
 
            ' Supress consecuent conditionals if pattern its an asterisk.
            If pattern.Equals("*", StringComparison.OrdinalIgnoreCase) Then
                Return True
 
            ElseIf ignoreCase Then ' Compare name ignoring string-case rules.
                If value.ToLower Like pattern.ToLower Then
                    Return True
                End If
 
            Else ' Compare filename unignoring string-case rules.
                If value Like pattern Then
                    Return True
                End If
 
            End If ' ignoreCase
 
        Next pattern
 
        Return False
 
    End Function
 
    ''' <summary>
    ''' Runs the next collector tasks synchronouslly.
    ''' </summary>
    ''' <typeparam name="T"></typeparam>
    ''' <param name="action">The collector method to invoke.</param>
    ''' <param name="queue">The <see cref="ConcurrentQueue(Of FileInfo)"/> instance.</param>
    ''' <param name="dirPath">The directory path.</param>
    ''' <param name="firstPatterns">The first comparison patterns.</param>
    ''' <param name="secondPatterns">The second comparison patterns.</param>
    ''' <param name="ignoreCase">if set to <c>true</c>, compares ignoring string-case rules.</param>
    ''' <param name="throwOnError">If set to <c>true</c>, exceptions will be thrown, like access denied to file or directory.</param>
    Private Shared Sub RunNextTasks(Of T)(ByVal action As Action(Of ConcurrentQueue(Of T),
                                                                 String, 
                                                                 SearchOption, 
                                                                 IEnumerable(Of String), 
                                                                 IEnumerable(Of String),
                                                                 Boolean,
                                                                 Boolean),
                                          ByVal queue As ConcurrentQueue(Of T),
                                          ByVal dirPath As String,
                                          ByVal firstPatterns As IEnumerable(Of String),
                                          ByVal secondPatterns As IEnumerable(Of String),
                                          ByVal ignoreCase As Boolean,
                                          ByVal throwOnError As Boolean)
 
        Try
            Task.WaitAll(New DirectoryInfo(dirPath).
                             GetDirectories.
                             Select(Function(dir As DirectoryInfo)
                                        Return Task.Factory.StartNew(Sub()
                                                                         action.Invoke(queue,
                                                                                       dir.FullName, SearchOption.AllDirectories,
                                                                                       firstPatterns, secondPatterns,
                                                                                       ignoreCase, throwOnError)
                                                                     End Sub)
                                    End Function).ToArray)
 
        Catch ex As Exception
 
            Select Case ex.GetType ' Handle or suppress exceptions by its type, 
 
                ' I've wrote different types just to feel free to expand this feature in the future.
                Case GetType(UnauthorizedAccessException),
                     GetType(DirectoryNotFoundException),
                     ex.GetType
 
                    If throwOnError Then
                        Throw
                    End If
 
            End Select
 
        End Try
 
    End Sub
 
    ''' <summary>
    ''' Collects the files those matches the criteria inside the specified directory and/or sub-directories.
    ''' </summary>
    ''' <param name="queue">The <see cref="ConcurrentQueue(Of FileInfo)"/> instance to enqueue new files.</param>
    ''' <param name="dirPath">The root directory path to search for files.</param>
    ''' <param name="searchOption">The searching mode.</param>
    ''' <param name="fileNamePatterns">The file name pattern(s) to match.</param>
    ''' <param name="fileExtPatterns">The file extension pattern(s) to match.</param>
    ''' <param name="ignoreCase">If <c>True</c>, ignores the comparing case of <paramref name="fileNamePatterns"/> and <paramref name="fileExtPatterns"/> patterns.</param>
    ''' <param name="throwOnError">If set to <c>true</c>, exceptions will be thrown, like access denied to file or directory.</param>
    Private Shared Sub CollectFiles(ByVal queue As ConcurrentQueue(Of FileInfo),
                                    ByVal dirPath As String,
                                    ByVal searchOption As SearchOption,
                                    ByVal fileNamePatterns As IEnumerable(Of String),
                                    ByVal fileExtPatterns As IEnumerable(Of String),
                                    ByVal ignoreCase As Boolean,
                                    ByVal throwOnError As Boolean)
 
        ' Initialize a FileInfo collection.
        Dim fileInfoCol As IEnumerable(Of FileInfo) = Nothing
 
        ' Initialize a DirectoryInfo.
        Dim dirInfo As DirectoryInfo = Nothing
        SetupDirInfoObject(dirPath, dirInfo, throwOnError)
 
        If fileExtPatterns IsNot Nothing Then
            ' Decrease time execution by searching for files that has extension.
            SetupFileDirCollection(Of FileInfo)(AddressOf dirInfo.GetFiles, Nothing, 
                                                dirInfo.FullName, "*.*", fileInfoCol, throwOnError)
        Else
            ' Search for all files.
            SetupFileDirCollection(Of FileInfo)(AddressOf dirInfo.GetFiles, Nothing,
                                                dirInfo.FullName, "*", fileInfoCol, throwOnError)
        End If
 
        ' If the fileInfoCol collection is not empty then...
        If fileInfoCol IsNot Nothing Then
 
            ' Iterate the files.
            For Each fInfo As FileInfo In fileInfoCol
 
                ' Flag to determine whether a filename pattern is matched. Activated by default.
                Dim flagNamePattern As Boolean = True
 
                ' Flag to determine whether a file extension pattern is matched. Activated by default.
                Dim flagExtPattern As Boolean = True
 
                ' If filename patterns collection is not empty then...
                If fileNamePatterns IsNot Nothing Then
                    flagNamePattern = IsMatchPattern(fInfo.Name, fileNamePatterns, ignoreCase)
                End If
 
                ' If file extension patterns collection is not empty then...
                If fileExtPatterns IsNot Nothing Then
                    flagExtPattern = IsMatchPattern(fInfo.Extension, fileExtPatterns, ignoreCase)
                End If
 
                ' If fileName and also fileExtension patterns are matched then...
                If flagNamePattern AndAlso flagExtPattern Then
                    queue.Enqueue(fInfo) ' Enqueue this FileInfo object.
                End If
 
            Next fInfo
 
        End If ' fileInfoCol IsNot Nothing
 
        ' If searchOption is recursive then...
        If searchOption = searchOption.AllDirectories Then
            RunNextTasks(Of FileInfo)(AddressOf CollectFiles,
                                      queue, dirInfo.FullName, fileNamePatterns, fileExtPatterns, ignoreCase, throwOnError)
        End If
 
    End Sub
 
    ''' <summary>
    ''' Collects the filepaths those matches the criteria inside the specified directory and/or sub-directories.
    ''' </summary>
    ''' <param name="queue">The <see cref="ConcurrentQueue(Of String)"/> instance to enqueue new filepaths.</param>
    ''' <param name="dirPath">The root directory path to search for files.</param>
    ''' <param name="searchOption">The searching mode.</param>
    ''' <param name="fileNamePatterns">The file name pattern(s) to match.</param>
    ''' <param name="fileExtPatterns">The file extension pattern(s) to match.</param>
    ''' <param name="ignoreCase">If <c>True</c>, ignores the comparing case of <paramref name="fileNamePatterns"/> and <paramref name="fileExtPatterns"/> patterns.</param>
    ''' <param name="throwOnError">If set to <c>true</c>, exceptions will be thrown, like access denied to file or directory.</param>
    Private Shared Sub CollectFilePaths(ByVal queue As ConcurrentQueue(Of String),
                                        ByVal dirPath As String,
                                        ByVal searchOption As SearchOption,
                                        ByVal fileNamePatterns As IEnumerable(Of String),
                                        ByVal fileExtPatterns As IEnumerable(Of String),
                                        ByVal ignoreCase As Boolean,
                                        ByVal throwOnError As Boolean)
 
        ' Initialize a filepath collection.
        Dim filePathCol As IEnumerable(Of String) = Nothing
 
        If fileExtPatterns IsNot Nothing Then
            ' Decrease time execution by searching for files that has extension.
            SetupFileDirCollection(Of String)(Nothing, AddressOf Directory.GetFiles,
                                              dirPath, "*.*", filePathCol, throwOnError)
        Else
            ' Search for all files.
            SetupFileDirCollection(Of String)(Nothing, AddressOf Directory.GetFiles,
                                              dirPath, "*", filePathCol, throwOnError)
        End If
 
        ' If the filepath collection is not empty then...
        If filePathCol IsNot Nothing Then
 
            ' Iterate the filepaths.
            For Each filePath As String In filePathCol
 
                ' Flag to determine whether a filename pattern is matched. Activated by default.
                Dim flagNamePattern As Boolean = True
 
                ' Flag to determine whether a file extension pattern is matched. Activated by default.
                Dim flagExtPattern As Boolean = True
 
                ' If filename patterns collection is not empty then...
                If fileNamePatterns IsNot Nothing Then
                    flagNamePattern = IsMatchPattern(Path.GetFileNameWithoutExtension(filePath), fileNamePatterns, ignoreCase)
                End If
 
                ' If file extension patterns collection is not empty then...
                If fileExtPatterns IsNot Nothing Then
                    flagExtPattern = IsMatchPattern(Path.GetExtension(filePath), fileExtPatterns, ignoreCase)
                End If
 
                ' If fileName and also fileExtension patterns are matched then...
                If flagNamePattern AndAlso flagExtPattern Then
                    queue.Enqueue(filePath) ' Enqueue this filepath.
                End If
 
            Next filePath
 
        End If ' filePathCol IsNot Nothing
 
        ' If searchOption is recursive then...
        If searchOption = searchOption.AllDirectories Then
            RunNextTasks(Of String)(AddressOf CollectFilePaths,
                                    queue, dirPath, fileNamePatterns, fileExtPatterns, ignoreCase, throwOnError)
        End If
 
    End Sub
 
    ''' <summary>
    ''' Collects the directories those matches the criteria inside the specified directory and/or sub-directories.
    ''' </summary>
    ''' <param name="queue">The <see cref="ConcurrentQueue(Of DirectoryInfo)"/> instance to enqueue new directories.</param>
    ''' <param name="dirPath">The root directory path to search for directories.</param>
    ''' <param name="searchOption">The searching mode.</param>
    ''' <param name="dirPathPatterns">The directory path pattern(s) to match.</param>
    ''' <param name="dirNamePatterns">The directory name pattern(s) to match.</param>
    ''' <param name="ignoreCase">If <c>True</c>, ignores the comparing case of <paramref name="dirPathPatterns"/> and <paramref name="dirNamePatterns"/> patterns.</param>
    ''' <param name="throwOnError">If set to <c>true</c>, exceptions will be thrown, like access denied to directory.</param>
    Private Shared Sub CollectDirs(ByVal queue As ConcurrentQueue(Of DirectoryInfo),
                                   ByVal dirPath As String,
                                   ByVal searchOption As SearchOption,
                                   ByVal dirPathPatterns As IEnumerable(Of String),
                                   ByVal dirNamePatterns As IEnumerable(Of String),
                                   ByVal ignoreCase As Boolean,
                                   ByVal throwOnError As Boolean)
 
        ' Initialize a DirectoryInfo collection.
        Dim dirInfoCol As IEnumerable(Of DirectoryInfo) = Nothing
 
        ' Initialize a DirectoryInfo.
        Dim dirInfo As DirectoryInfo = Nothing
        SetupDirInfoObject(dirPath, dirInfo, throwOnError)
 
        ' Get the top directories of the current directory.
        SetupFileDirCollection(Of DirectoryInfo)(AddressOf dirInfo.GetDirectories, Nothing,
                                                 dirInfo.FullName, "*", dirInfoCol, throwOnError)
 
        ' If the fileInfoCol collection is not empty then...
        If dirInfoCol IsNot Nothing Then
 
            ' Iterate the files.
            For Each dir As DirectoryInfo In dirInfoCol
 
                ' Flag to determine whether a directory path pattern is matched. Activated by default.
                Dim flagPathPattern As Boolean = True
 
                ' Flag to determine whether a directory name pattern is matched. Activated by default.
                Dim flagNamePattern As Boolean = True
 
                ' If directory path patterns collection is not empty then...
                If dirPathPatterns IsNot Nothing Then
                    flagPathPattern = IsMatchPattern(dir.FullName, dirPathPatterns, ignoreCase)
                End If
 
                ' If directory name patterns collection is not empty then...
                If dirNamePatterns IsNot Nothing Then
                    flagNamePattern = IsMatchPattern(dir.Name, dirNamePatterns, ignoreCase)
                End If
 
                ' If directory path and also directory name patterns are matched then...
                If flagPathPattern AndAlso flagNamePattern Then
                    queue.Enqueue(dir) ' Enqueue this DirectoryInfo object.
                End If
 
            Next dir
 
        End If ' dirInfoCol IsNot Nothing
 
        ' If searchOption is recursive then...
        If searchOption = searchOption.AllDirectories Then
            RunNextTasks(Of DirectoryInfo)(AddressOf CollectDirs,
                                           queue, dirPath, dirPathPatterns, dirNamePatterns, ignoreCase, throwOnError)
        End If
 
    End Sub
 
    ''' <summary>
    ''' Collects the directory paths those matches the criteria inside the specified directory and/or sub-directories.
    ''' </summary>
    ''' <param name="queue">The <see cref="ConcurrentQueue(Of String)"/> instance to enqueue new directory paths.</param>
    ''' <param name="dirPath">The root directory path to search for directories.</param>
    ''' <param name="searchOption">The searching mode.</param>
    ''' <param name="dirPathPatterns">The directory path pattern(s) to match.</param>
    ''' <param name="dirNamePatterns">The directory name pattern(s) to match.</param>
    ''' <param name="ignoreCase">If <c>True</c>, ignores the comparing case of <paramref name="dirPathPatterns"/> and <paramref name="dirNamePatterns"/> patterns.</param>
    ''' <param name="throwOnError">If set to <c>true</c>, exceptions will be thrown, like access denied to directory.</param>
    Private Shared Sub CollectDirPaths(ByVal queue As ConcurrentQueue(Of String),
                                       ByVal dirPath As String,
                                       ByVal searchOption As SearchOption,
                                       ByVal dirPathPatterns As IEnumerable(Of String),
                                       ByVal dirNamePatterns As IEnumerable(Of String),
                                       ByVal ignoreCase As Boolean,
                                       ByVal throwOnError As Boolean)
 
        ' Initialize a directory paths collection.
        Dim dirPathCol As IEnumerable(Of String) = Nothing
 
        ' Get the top directory paths of the current directory.
        SetupFileDirCollection(Of String)(Nothing, AddressOf Directory.GetDirectories,
                                          dirPath, "*", dirPathCol, throwOnError)
 
        ' If the fileInfoCol collection is not empty then...
        If dirPathCol IsNot Nothing Then
 
            ' Iterate the files.
            For Each dir As String In dirPathCol
 
                ' Flag to determine whether a directory path pattern is matched. Activated by default.
                Dim flagPathPattern As Boolean = True
 
                ' Flag to determine whether a directory name pattern is matched. Activated by default.
                Dim flagNamePattern As Boolean = True
 
                ' If directory path patterns collection is not empty then...
                If dirPathPatterns IsNot Nothing Then
                    flagPathPattern = IsMatchPattern(dir, dirPathPatterns, ignoreCase)
                End If
 
                ' If directory name patterns collection is not empty then...
                If dirNamePatterns IsNot Nothing Then
                    flagNamePattern = IsMatchPattern(Path.GetFileName(dir), dirNamePatterns, ignoreCase)
                End If
 
                ' If directory path and also directory name patterns are matched then...
                If flagPathPattern AndAlso flagNamePattern Then
                    queue.Enqueue(dir) ' Enqueue this directory path.
                End If
 
            Next dir
 
        End If ' dirPathCol IsNot Nothing
 
        ' If searchOption is recursive then...
        If searchOption = searchOption.AllDirectories Then
            RunNextTasks(Of String)(AddressOf CollectDirPaths,
                                    queue, dirPath, dirPathPatterns, dirNamePatterns, ignoreCase, throwOnError)
        End If
 
    End Sub
 
#End Region
 
End Class
 
#End Region

Public Class Form1
 
    ''' <summary>
    ''' The <see cref="FormDragger"/> instance that manages the form(s) dragging.
    ''' </summary>
    Private formDragger As FormDragger = FormDragger.Empty
 
    Private Sub Test() Handles MyBase.Shown
        Me.InitializeDrag()
    End Sub
 
    Private Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs) _
    Handles Button1.Click
 
        Me.AlternateDragEnabled(Me)
 
    End Sub
 
    Private Sub InitializeDrag()
 
        ' 1st way, using the single-Form constructor:
        Me.formDragger = New FormDragger(Me, enabled:=True, cursor:=Cursors.SizeAll)
 
        ' 2nd way, using the multiple-Forms constructor:
        ' Me.formDragger = New FormDragger({Me, Form2, form3})
 
        ' 3rd way, using the default constructor then adding a Form into the collection:
        ' Me.formDragger = New FormDragger
        ' Me.formDragger.AddForm(Me, enabled:=True, cursor:=Cursors.SizeAll)
 
    End Sub
 
    ''' <summary>
    ''' Alternates the dragging of the specified form.
    ''' </summary>
    ''' <param name="form">The form.</param>
    Private Sub AlternateDragEnabled(ByVal form As Form)
 
        Dim formInfo As FormDragger.FormDragInfo = Me.formDragger.FindFormDragInfo(form)
        formInfo.Enabled = Not formInfo.Enabled
 
    End Sub
 
End Class

' ***********************************************************************
' Author   : Elektro
' Modified : 15-March-2015
' ***********************************************************************
' <copyright file="FormDragger.vb" company="Elektro Studios">
'     Copyright (c) Elektro Studios. All rights reserved.
' </copyright>
' ***********************************************************************
 
#Region " Option Statements "
 
Option Explicit On
Option Strict On
Option Infer Off
 
#End Region
 
#Region " Usage Examples "
 
'Public Class Form1
 
'    ''' <summary>
'    ''' The <see cref="FormDragger"/> instance that manages the form(s) dragging.
'    ''' </summary>
'    Private formDragger As FormDragger = FormDragger.Empty
 
'    Private Sub Test() Handles MyBase.Shown
'        Me.InitializeDrag()
'    End Sub
 
'    Private Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs) _
'    Handles Button1.Click
 
'        Me.AlternateDragEnabled(Me)
 
'    End Sub
 
'    Private Sub InitializeDrag()
 
'        ' 1st way, using the single-Form constructor:
'        Me.formDragger = New FormDragger(Me, enabled:=True, cursor:=Cursors.SizeAll)
 
'        ' 2nd way, using the multiple-Forms constructor:
'        ' Me.formDragger = New FormDragger({Me, Form2, form3})
 
'        ' 3rd way, using the default constructor then adding a Form into the collection:
'        ' Me.formDragger = New FormDragger
'        ' Me.formDragger.AddForm(Me, enabled:=True, cursor:=Cursors.SizeAll)
 
'    End Sub
 
'    ''' <summary>
'    ''' Alternates the dragging of the specified form.
'    ''' </summary>
'    ''' <param name="form">The form.</param>
'    Private Sub AlternateDragEnabled(ByVal form As Form)
 
'        Dim formInfo As FormDragger.FormDragInfo = Me.formDragger.FindFormDragInfo(form)
'        formInfo.Enabled = Not formInfo.Enabled
 
'    End Sub
 
'End Class
 
#End Region
 
#Region " Imports "
 
Imports System.ComponentModel
 
#End Region
 
#Region " Form Dragger "
 
''' <summary>
''' Enable or disable drag at runtime on a <see cref="Form"/>.
''' </summary>
Public NotInheritable Class FormDragger : Implements IDisposable
 
#Region " Properties "
 
    ''' <summary>
    ''' Gets an <see cref="IEnumerable(Of Form)"/> collection that contains the Forms capables to perform draggable operations.
    ''' </summary>
    ''' <value>The <see cref="IEnumerable(Of Form)"/>.</value>
    <EditorBrowsable(EditorBrowsableState.Always)>
    Public ReadOnly Property Forms As IEnumerable(Of FormDragInfo)
        Get
            Return Me.forms1
        End Get
    End Property
    ''' <summary>
    ''' An <see cref="IEnumerable(Of Form)"/> collection that contains the Forms capables to perform draggable operations.
    ''' </summary>
    Private forms1 As IEnumerable(Of FormDragInfo) = {}
 
    ''' <summary>
    ''' Represents a <see cref="FormDragger"/> instance that is <c>Nothing</c>.
    ''' </summary>
    ''' <value><c>Nothing</c></value>
    <EditorBrowsable(EditorBrowsableState.Always)>
    Public Shared ReadOnly Property Empty As FormDragger
        Get
            Return Nothing
        End Get
    End Property
 
#End Region
 
#Region " Types "
 
    ''' <summary>
    ''' Defines the draggable info of a <see cref="Form"/>.
    ''' </summary>
    <Serializable>
    Public NotInheritable Class FormDragInfo
 
#Region " Properties "
 
        ''' <summary>
        ''' Gets the associated <see cref="Form"/> used to perform draggable operations.
        ''' </summary>
        ''' <value>The associated <see cref="Form"/>.</value>
        <EditorBrowsable(EditorBrowsableState.Always)>
        Public ReadOnly Property Form As Form
            Get
                Return form1
            End Get
        End Property
        ''' <summary>
        ''' The associated <see cref="Form"/>
        ''' </summary>
        <NonSerialized>
        Private ReadOnly form1 As Form
 
        ''' <summary>
        ''' Gets the name of the associated <see cref="Form"/>.
        ''' </summary>
        ''' <value>The Form.</value>
        <EditorBrowsable(EditorBrowsableState.Always)>
        Public ReadOnly Property Name As String
            Get
                If Me.Form IsNot Nothing Then
                    Return Form.Name
                Else
                    Return String.Empty
                End If
            End Get
        End Property
 
        ''' <summary>
        ''' Gets or sets a value indicating whether drag is enabled on the associated <see cref="Form"/>.
        ''' </summary>
        ''' <value><c>true</c> if drag is enabled; otherwise, <c>false</c>.</value>
        <EditorBrowsable(EditorBrowsableState.Always)>
        Public Property Enabled As Boolean
 
        ''' <summary>
        ''' A <see cref="FormDragger"/> instance instance containing the draggable information of the associated <see cref="Form"/>.
        ''' </summary>
        ''' <value>The draggable information.</value>
        <EditorBrowsable(EditorBrowsableState.Never)>
        Public Property DragInfo As FormDragger = FormDragger.Empty
 
        ''' <summary>
        ''' Gets or sets the <see cref="Cursor"/> used to drag the associated <see cref="Form"/>.
        ''' </summary>
        ''' <value>The <see cref="Cursor"/>.</value>
        <EditorBrowsable(EditorBrowsableState.Always)>
        Public Property Cursor As Cursor = Cursors.SizeAll
 
        ''' <summary>
        ''' Gets or sets the old form's cursor to restore it after dragging.
        ''' </summary>
        ''' <value>The old form's cursor.</value>
        <EditorBrowsable(EditorBrowsableState.Never)>
        Public Property OldCursor As Cursor = Nothing
 
        ''' <summary>
        ''' Gets or sets the initial mouse coordinates, normally <see cref="Form.MousePosition"/>.
        ''' </summary>
        ''' <value>The initial mouse coordinates.</value>
        <EditorBrowsable(EditorBrowsableState.Never)>
        Public Property InitialMouseCoords As Point = Point.Empty
 
        ''' <summary>
        ''' Gets or sets the initial <see cref="Form"/> location, normally <see cref="Form.Location"/>.
        ''' </summary>
        ''' <value>The initial location.</value>
        <EditorBrowsable(EditorBrowsableState.Never)>
        Public Property InitialLocation As Point = Point.Empty
 
#End Region
 
#Region " Constructors "
 
        ''' <summary>
        ''' Initializes a new instance of the <see cref="FormDragInfo"/> class.
        ''' </summary>
        ''' <param name="form">The form.</param>
        Public Sub New(ByVal form As Form)
            Me.form1 = form
            Me.Cursor = form.Cursor
        End Sub
 
        ''' <summary>
        ''' Prevents a default instance of the <see cref="FormDragInfo"/> class from being created.
        ''' </summary>
        Private Sub New()
        End Sub
 
#End Region
 
#Region " Hidden Methods "
 
        ''' <summary>
        ''' Serves as a hash function for a particular type.
        ''' </summary>
        <EditorBrowsable(EditorBrowsableState.Never)>
        Public Shadows Function GetHashCode() As Integer
            Return MyBase.GetHashCode
        End Function
 
        ''' <summary>
        ''' Gets the System.Type of the current instance.
        ''' </summary>
        ''' <returns>The exact runtime type of the current instance.</returns>
        <EditorBrowsable(EditorBrowsableState.Never)>
        Public Shadows Function [GetType]() As Type
            Return MyBase.GetType
        End Function
 
        ''' <summary>
        ''' Determines whether the specified System.Object instances are considered equal.
        ''' </summary>
        <EditorBrowsable(EditorBrowsableState.Never)>
        Public Shadows Function Equals(ByVal obj As Object) As Boolean
            Return MyBase.Equals(obj)
        End Function
 
        ''' <summary>
        ''' Determines whether the specified System.Object instances are the same instance.
        ''' </summary>
        <EditorBrowsable(EditorBrowsableState.Never)>
        Private Shadows Sub ReferenceEquals()
        End Sub
 
        ''' <summary>
        ''' Returns a String that represents the current object.
        ''' </summary>
        <EditorBrowsable(EditorBrowsableState.Never)>
        Public Shadows Function ToString() As String
            Return MyBase.ToString
        End Function
 
#End Region
 
    End Class
 
#End Region
 
#Region " Constructors "
 
    ''' <summary>
    ''' Initializes a new instance of the <see cref="FormDragger"/> class.
    ''' </summary>
    Public Sub New()
        Me.forms1={}
    End Sub
 
    ''' <summary>
    ''' Initializes a new instance of the <see cref="FormDragger"/> class.
    ''' </summary>
    ''' <param name="form">The <see cref="Form"/> used to perform draggable operations.</param>
    ''' <param name="enabled">If set to <c>true</c>, enable dragging on the <see cref="Form"/>.</param>
    ''' <param name="cursor">The <see cref="Cursor"/> used to drag the specified <see cref="Form"/>.</param>
    Public Sub New(ByVal form As Form,
                   Optional enabled As Boolean = False,
                   Optional cursor As Cursor = Nothing)
 
        Me.forms1 =
            {
                New FormDragInfo(form) With
                         {
                             .Enabled = enabled,
                             .Cursor = cursor
                         }
            }
 
        Me.AssocHandlers(form)
 
    End Sub
 
    ''' <summary>
    ''' Initializes a new instance of the <see cref="FormDragger"/> class.
    ''' </summary>
    ''' <param name="forms">The <see cref="Forms"/> used to perform draggable operations.</param>
    Public Sub New(ByVal forms As IEnumerable(Of Form))
 
        Me.forms1 = (From form As Form In forms
                     Select New FormDragInfo(form)).ToArray
 
        For Each form As Form In forms
            Me.AssocHandlers(form)
        Next form
 
    End Sub
 
    ''' <summary>
    ''' Initializes a new instance of the <see cref="FormDragger"/> class.
    ''' </summary>
    ''' <param name="formInfo">
    ''' The <see cref="FormDragInfo"/> instance 
    ''' that contains the <see cref="Form"/> reference and its draggable info.
    ''' </param>
    ''' <param name="mouseCoordinates">The current mouse coordinates.</param>
    ''' <param name="location">The current location.</param>
    Private Sub New(ByVal formInfo As FormDragInfo,
                    ByVal mouseCoordinates As Point,
                    ByVal location As Point)
 
        formInfo.InitialMouseCoords = mouseCoordinates
        formInfo.InitialLocation = location
 
    End Sub
 
#End Region
 
#Region " Public Methods "
 
    ''' <summary>
    ''' Adds the specified <see cref="Form"/> into the draggable <see cref="Forms"/> collection.
    ''' </summary>
    ''' <param name="form">The <see cref="Form"/>.</param>
    ''' <param name="enabled">If set to <c>true</c>, enable dragging on the <see cref="Form"/>.</param>
    ''' <param name="cursor">The <see cref="Cursor"/> used to drag the specified <see cref="Form"/>.</param>
    ''' <exception cref="System.ArgumentException">The specified form is already added.;form</exception>
    Public Function AddForm(ByVal form As Form,
                            Optional enabled As Boolean = False,
                            Optional cursor As Cursor = Nothing) As FormDragInfo
 
        For Each formInfo As FormDragInfo In Me.forms1
 
            If formInfo.Form.Equals(form) Then
                Throw New ArgumentException("The specified form is already added.", "form")
                Exit Function
            End If
 
        Next formInfo
 
        Dim newFormInfo As New FormDragInfo(form) With {.Enabled = enabled, .Cursor = cursor}
        Me.forms1 = Me.forms1.Concat({newFormInfo})
        Me.AssocHandlers(form)
 
        Return newFormInfo
 
    End Function
 
    ''' <summary>
    ''' Removes the specified <see cref="Form"/> from the draggable <see cref="Forms"/> collection.
    ''' </summary>
    ''' <param name="form">The form.</param>
    ''' <exception cref="System.ArgumentException">The specified form is not found.;form</exception>
    Public Sub RemoveForm(ByVal form As Form)
 
        Dim formInfoToRemove As FormDragInfo = Nothing
 
        For Each formInfo As FormDragInfo In Me.forms1
 
            If formInfo.Form.Equals(form) Then
                formInfoToRemove = formInfo
                Exit For
            End If
 
        Next formInfo
 
        If formInfoToRemove IsNot Nothing Then
 
            Me.forms1 = From formInfo As FormDragInfo In Me.forms1
                        Where Not formInfo Is formInfoToRemove
 
            formInfoToRemove.Enabled = False
            Me.DeassocHandlers(formInfoToRemove.Form)
 
        Else
            Throw New ArgumentException("The specified form is not found.", "form")
 
        End If
 
    End Sub
 
    ''' <summary>
    ''' Finds the <see cref="FormDragInfo"/> instance that is associated with the specified <see cref="Form"/> reference.
    ''' </summary>
    ''' <param name="form">The <see cref="Form"/>.</param>
    ''' <returns>The <see cref="FormDragInfo"/> instance that is associated with the specified <see cref="Form"/> reference.</returns>
    Public Function FindFormDragInfo(ByVal form As Form) As FormDragInfo
 
        Return (From formInfo As FormDragger.FormDragInfo In Me.forms1
                Where formInfo.Form Is form).FirstOrDefault
 
    End Function
 
    ''' <summary>
    ''' Finds the <see cref="FormDragInfo"/> instance that is associated with the specified <see cref="Form"/> reference.
    ''' </summary>
    ''' <param name="name">The <see cref="Form"/> name.</param>
    ''' <returns>The <see cref="FormDragInfo"/> instance that is associated with the specified <see cref="Form"/> reference.</returns>
    Public Function FindFormDragInfo(ByVal name As String,
                                     Optional stringComparison As StringComparison =
                                              StringComparison.OrdinalIgnoreCase) As FormDragInfo
 
        Return (From formInfo As FormDragger.FormDragInfo In Me.forms1
                Where formInfo.Name.Equals(name, stringComparison)).FirstOrDefault
 
    End Function
 
#End Region
 
#Region " Private Methods "
 
    ''' <summary>
    ''' Associates the <see cref="Form"/> handlers to enable draggable operations.
    ''' </summary>
    ''' <param name="form">The form.</param>
    Private Sub AssocHandlers(ByVal form As Form)
 
        AddHandler form.MouseDown, AddressOf Me.Form_MouseDown
        AddHandler form.MouseUp, AddressOf Me.Form_MouseUp
        AddHandler form.MouseMove, AddressOf Me.Form_MouseMove
        AddHandler form.MouseEnter, AddressOf Me.Form_MouseEnter
        AddHandler form.MouseLeave, AddressOf Me.Form_MouseLeave
 
    End Sub
 
    ''' <summary>
    ''' Deassociates the <see cref="Form"/> handlers to disable draggable operations.
    ''' </summary>
    ''' <param name="form">The form.</param>
    Private Sub DeassocHandlers(ByVal form As Form)
 
        If Not form.IsDisposed AndAlso Not form.Disposing Then
 
            RemoveHandler form.MouseDown, AddressOf Me.Form_MouseDown
            RemoveHandler form.MouseUp, AddressOf Me.Form_MouseUp
            RemoveHandler form.MouseMove, AddressOf Me.Form_MouseMove
            RemoveHandler form.MouseEnter, AddressOf Me.Form_MouseEnter
            RemoveHandler form.MouseLeave, AddressOf Me.Form_MouseLeave
 
        End If
 
    End Sub
 
    ''' <summary>
    ''' Return the new location.
    ''' </summary>
    ''' <param name="formInfo">
    ''' The <see cref="FormDragInfo"/> instance 
    ''' that contains the <see cref="Form"/> reference and its draggable info.
    ''' </param>
    ''' <param name="mouseCoordinates">The current mouse coordinates.</param>
    ''' <returns>The new location.</returns>
    Private Function GetNewLocation(ByVal formInfo As FormDragInfo,
                                    ByVal mouseCoordinates As Point) As Point
 
        Return New Point(formInfo.InitialLocation.X + (mouseCoordinates.X - formInfo.InitialMouseCoords.X),
                         formInfo.InitialLocation.Y + (mouseCoordinates.Y - formInfo.InitialMouseCoords.Y))
 
    End Function
 
#End Region
 
#Region " Hidden Methods "
 
    ''' <summary>
    ''' Serves as a hash function for a particular type.
    ''' </summary>
    <EditorBrowsable(EditorBrowsableState.Never)>
    Public Shadows Function GetHashCode() As Integer
        Return MyBase.GetHashCode
    End Function
 
    ''' <summary>
    ''' Gets the System.Type of the current instance.
    ''' </summary>
    ''' <returns>The exact runtime type of the current instance.</returns>
    <EditorBrowsable(EditorBrowsableState.Never)>
    Public Shadows Function [GetType]() As Type
        Return MyBase.GetType
    End Function
 
    ''' <summary>
    ''' Determines whether the specified System.Object instances are considered equal.
    ''' </summary>
    <EditorBrowsable(EditorBrowsableState.Never)>
    Public Shadows Function Equals(ByVal obj As Object) As Boolean
        Return MyBase.Equals(obj)
    End Function
 
    ''' <summary>
    ''' Determines whether the specified System.Object instances are the same instance.
    ''' </summary>
    <EditorBrowsable(EditorBrowsableState.Never)>
    Private Shadows Sub ReferenceEquals()
    End Sub
 
    ''' <summary>
    ''' Returns a String that represents the current object.
    ''' </summary>
    <EditorBrowsable(EditorBrowsableState.Never)>
    Public Shadows Function ToString() As String
        Return MyBase.ToString
    End Function
 
#End Region
 
#Region " Event Handlers "
 
    ''' <summary>
    ''' Handles the MouseEnter event of the Form.
    ''' </summary>
    ''' <param name="sender">The source of the event.</param>
    ''' <param name="e">The <see cref="EventArgs"/> instance containing the event data.</param>
    Private Sub Form_MouseEnter(ByVal sender As Object, ByVal e As EventArgs)
 
        Dim formInfo As FormDragInfo = FindFormDragInfo(DirectCast(sender, Form))
 
        formInfo.OldCursor = formInfo.Form.Cursor
 
        If formInfo.Enabled Then
            formInfo.Form.Cursor = formInfo.Cursor
            ' Optional:
            ' formInfo.Form.BringToFront() 
        End If
 
    End Sub
 
    ''' <summary>
    ''' Handles the MouseLeave event of the Form.
    ''' </summary>
    ''' <param name="sender">The source of the event.</param>
    ''' <param name="e">The <see cref="EventArgs"/> instance containing the event data.</param>
    Private Sub Form_MouseLeave(ByVal sender As Object, ByVal e As EventArgs)
 
        Dim formInfo As FormDragInfo = FindFormDragInfo(DirectCast(sender, Form))
 
        formInfo.Form.Cursor = formInfo.OldCursor
 
    End Sub
 
    ''' <summary>
    ''' Handles the MouseDown event of the Form.
    ''' </summary>
    ''' <param name="sender">The source of the event.</param>
    ''' <param name="e">The <see cref="MouseEventArgs"/> instance containing the event data.</param>
    Private Sub Form_MouseDown(ByVal sender As Object, ByVal e As MouseEventArgs)
 
        Dim formInfo As FormDragInfo = FindFormDragInfo(DirectCast(sender, Form))
 
        If formInfo.Enabled Then
            formInfo.DragInfo = New FormDragger(formInfo, Form.MousePosition, formInfo.Form.Location)
        End If
 
    End Sub
 
    ''' <summary>
    ''' Handles the MouseMove event of the Form.
    ''' </summary>
    ''' <param name="sender">The source of the event.</param>
    ''' <param name="e">The <see cref="MouseEventArgs"/> instance containing the event data.</param>
    Private Sub Form_MouseMove(ByVal sender As Object, ByVal e As MouseEventArgs)
 
        Dim formInfo As FormDragInfo = FindFormDragInfo(DirectCast(sender, Form))
 
        If formInfo.Enabled AndAlso (formInfo.DragInfo IsNot FormDragger.Empty) Then
            formInfo.Form.Location = formInfo.DragInfo.GetNewLocation(formInfo, Form.MousePosition)
        End If
 
    End Sub
 
    ''' <summary>
    ''' Handles the MouseUp event of the Form.
    ''' </summary>
    ''' <param name="sender">The source of the event.</param>
    ''' <param name="e">The <see cref="MouseEventArgs"/> instance containing the event data.</param>
    Private Sub Form_MouseUp(ByVal sender As Object, ByVal e As MouseEventArgs)
 
        Dim formInfo As FormDragInfo = FindFormDragInfo(DirectCast(sender, Form))
 
        formInfo.DragInfo = FormDragger.Empty
 
    End Sub
 
#End Region
 
#Region " IDisposable "
 
    ''' <summary>
    ''' To detect redundant calls when disposing.
    ''' </summary>
    Private isDisposed As Boolean = False
 
    ''' <summary>
    ''' Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
    ''' </summary>
    Public Sub Dispose() Implements IDisposable.Dispose
        Me.Dispose(True)
        GC.SuppressFinalize(Me)
    End Sub
 
    ''' <summary>
    ''' Releases unmanaged and - optionally - managed resources.
    ''' </summary>
    ''' <param name="IsDisposing">
    ''' <c>true</c> to release both managed and unmanaged resources; 
    ''' <c>false</c> to release only unmanaged resources.
    ''' </param>
    Protected Sub Dispose(ByVal isDisposing As Boolean)
 
        If Not Me.isDisposed Then
 
            If isDisposing Then
 
                For Each formInfo As FormDragInfo In Me.forms1
 
                    With formInfo
 
                        .Enabled = False
                        .OldCursor = Nothing
                        .DragInfo = FormDragger.Empty
                        .InitialMouseCoords = Point.Empty
                        .InitialLocation = Point.Empty
 
                        Me.DeassocHandlers(.Form)
 
                    End With ' form
 
                Next formInfo
 
                Me.forms1 = Nothing
 
            End If ' IsDisposing
 
        End If ' Not Me.IsDisposed
 
        Me.isDisposed = True
 
    End Sub
 
#End Region
 
End Class
 
#End Region