Cool Textbox Class

[Kaverin]

Here's some other stuff you may want to add to the class. I see people asking about getting/changing lines in text files/boxes, and about the row/column numbers too. These props will do those for you. There's an API method of the property get version of Lines which I'd say is faster because it doesn't use the split method, but I don't know of a way to implement the API in a property let version. I had to do that with Split().

Private Const EM_GETLINE As Long = &HC4
Private Const EM_GETLINECOUNT As Long = &HBA
Private Const EM_GETSEL As Long = &HB0
Private Const EM_LINEFROMCHAR As Long = &HC9
Private Const EM_LINEINDEX As Long = &HBB
Private Const EM_LINELENGTH As Long = &HC1
 
'here's the API way if anyone wants to know how it was done
Public Property Get LinesAPI(ByVal lngLineNumber As Long) As String
   Dim lngLineCount As Long
   Dim lngFirstChar As Long
   Dim lngLineLength As Long
   Dim hWnd As Long
   Dim abyteBuffer() As Byte
   LinesAPI = ""
   If Not blnClassBound Then Exit Property
   hWnd = txtSource.hWnd
   lngLineCount = SendMessage(hWnd, EM_GETLINECOUNT, 0, 0)
   If (lngLineNumber < 0) Or (lngLineNumber > (lngLineCount - 1)) Then Exit Property
   lngFirstChar = SendMessage(hWnd, EM_LINEINDEX, lngLineNumber, 0)
   lngLineLength = SendMessage(hWnd, EM_LINELENGTH, lngFirstChar, 0)
   If lngLineLength = 0 Then Exit Property
   ReDim abyteBuffer(0 To (lngLineLength - 1))
   abyteBuffer(0) = lngLineLength And &HFF
   If lngLineLength > 255 Then abyteBuffer(1) = lngLineLength And &H100
   SendMessage hWnd, EM_GETLINE, lngLineNumber, VarPtr(abyteBuffer(0))
   LinesAPI = StrConv(abyteBuffer, vbUnicode)
End Property
 
'this is the Split() way, which takes less work, but may be slower for longer text
Public Property Get Lines(ByVal lngLineNumber As Long) As String
   Dim astrLines As Variant 'may be astrLines() As String for VB6 users
   Lines = ""
   If Not blnClassBound Then Exit Property
   If txtSource.Text = "" Then Exit Property
   astrLines = Split(txtSource.Text, vbCrLf)
   If (lngLineNumber < 0) Or (lngLineNumber > UBound(astrLines)) Then Exit Property
   Lines = astrLines(lngLineNumber)
End Property
 
Public Property Let Lines(ByVal lngLineNumber As Long, ByVal strNewLine As String)
   Dim astrLines As Variant 'may be astrLines() As String for VB6 users
   If Not blnClassBound Then Exit Property
   If txtSource.Text = "" Then
      txtSource.Text = strNewLine
      Exit Property
   End If
   astrLines = Split(txtSource.Text, vbCrLf)
   If (lngLineNumber < 0) Or (lngLineNumber > UBound(astrLines)) Then Exit Property
   astrLines(lngLineNumber) = strNewLine
   txtSource.Text = Join(astrLines, vbCrLf)
End Property
 
'the next two are mainly for multiline textboxes, but work on single line ones too
'the row will always be 1 for a single line textbox
Public Property Get Column() As Long
   Dim lngReturn As Long
   Dim lngCharIndex As Long
   Dim lngRow As Long
   If Not blnClassBound Then Exit Property
   lngReturn = SendMessage(txtSource.hWnd, EM_GETSEL, 0, 0)
   lngCharIndex = (lngReturn / 65536) And &HFFFF
   lngReturn = SendMessage(txtSource.hWnd, EM_LINEINDEX, -1, 0)
   Column = lngCharIndex - lngReturn + 1
End Property
 
Public Property Get Row() As Long
   Dim lngReturn As Long
   Dim lngCharIndex As Long
   If Not blnClassBound Then Exit Property
   lngReturn = SendMessage(txtSource.hWnd, EM_GETSEL, 0, 0)
   lngCharIndex = (lngReturn / 65536) And &HFFFF
   Row = SendMessage(txtSource.hWnd, EM_LINEFROMCHAR, lngCharIndex, 0) + 1
End Property