Imports System.Data.SqlClient
Imports System.IO
Imports System.Xml.Xsl
Imports System.Collections.Generic
Imports System.Windows.Forms

Public Class MyGlobals
    Public Shared g_objDatabaseLayer As clsDatabaseLayer
    Public Shared g_objCachedObjects As Hashtable
    Public Shared g_objObjectTypesCached As New List(Of String)

    Public Const COMPOSER_NAME_SIZE As Integer = 60
    Public Const PUBLISHER_NAME_SIZE As Integer = 60
    Public Const PUBLISHER_STREAMING_ALLOWED_SIZE As Integer = 7
    Public Const HYMNAL_NAME_SIZE As Integer = 60
    Public Const HYMNAL_ABBREVIATION_SIZE As Integer = 10
    Public Const BOOK_TITLE_SIZE As Integer = 120
    Public Const HYMN_TUNE_NAME_SIZE As Integer = 60
    Public Const HYMN_NAME_SIZE As Integer = 120
    Public Const WORK_NAME_SIZE As Integer = 150
    Public Const OPUS_INFO_SIZE As Integer = 50
    Public Const INSTRUMENTATION_NAME_SIZE As Integer = 60
    Public Const COLLECTION_STRING As String = "(Collection)"
    Public Const NONE_STRING As String = "(None)"
    Public Const PUBLISHER_STREAMING_ALLOWED_UNKNOWN As String = "Unknown"

    Public Shared Function GetItemFromHashWithStringKey(ByVal strKeyValue As String, ByVal objHash As Hashtable) As Object
        If objHash.ContainsKey(strKeyValue) Then
            Return objHash.Item(strKeyValue)
        Else
            Return Nothing
        End If
    End Function

    Public Shared Sub FlushCachedObjects()
        If g_objCachedObjects Is Nothing Then
            g_objCachedObjects = New Hashtable
        Else
            g_objCachedObjects.Clear()
        End If
        g_objObjectTypesCached.Clear()
    End Sub

    Public Shared Sub AddCachedObject(ByRef objObject As Object, ByVal strKeyValue As String)
        If g_objCachedObjects Is Nothing Then
            FlushCachedObjects()
        End If

        If g_objCachedObjects.ContainsKey(strKeyValue) Then
            g_objCachedObjects.Remove(strKeyValue)
        End If
        g_objCachedObjects.Add(strKeyValue, objObject)
    End Sub

    Public Shared Sub RemoveCachedObject(ByVal strKeyValue As String)
        If g_objCachedObjects Is Nothing Then
            FlushCachedObjects()
        End If

        If g_objCachedObjects.ContainsKey(strKeyValue) Then
            g_objCachedObjects.Remove(strKeyValue)
        End If
    End Sub

    Public Shared Function CachedObjectExists(ByVal strKeyValue As String) As Boolean
        If g_objCachedObjects Is Nothing Then
            FlushCachedObjects()
        End If

        Return g_objCachedObjects.ContainsKey(strKeyValue)
    End Function

    Public Shared Function CachedObjectRetrieve(ByVal strKeyValue As String) As Object
        If g_objCachedObjects Is Nothing Then
            FlushCachedObjects()
        End If

        Return GetItemFromHashWithStringKey(strKeyValue, g_objCachedObjects)
    End Function

    Public Shared Function AllowKeypressInNumericTextBox(ByVal sChar As Char) As Boolean
        If Not Char.IsDigit(sChar) Then
            Select Case Asc(sChar)
                Case 8, 3, 24   '8=Backspace,3=ctrlC,24=ctrlX
                    'Let these through
                Case 22 '22=ctrlV
                    If Clipboard.GetDataObject.GetDataPresent("System.String", True) Then
                        Dim sClipboardText As String
                        sClipboardText = Clipboard.GetDataObject.GetData("System.String", True).ToString
                        Dim sCharInClipboard As Char
                        For Each sCharInClipboard In sClipboardText
                            If Not Char.IsDigit(sCharInClipboard) Then
                                'There is a non-digit in the clipboard - don't allow the paste
                                Return False
                            End If
                        Next
                    Else
                        Return False
                    End If
                Case Else
                    Return False
            End Select
        End If

        Return True

    End Function

End Class