B4J Question Width - textfield - change

Textfield1.As(B4XView).Width = 150

Sub Class_Globals
    Dim codmtotxt1 As B4XView
End Sub
....
codmtotxt1.As(B4XView).Width = 20

Dim jo As JavaObject = codmtotxt1
jo.runMethod("setMaxWidth",Array(datasize*9.00d))

'What should be the pixel width of a label/textfield that can have a maximum of n characters of a particular font and size?
Private Sub computeWidth(n As Int, fnt As B4XFont) As Int
    Dim testString As String = "XXXXXXXXXX"
    Dim cv As B4XCanvas        'ignore, since we don't need to initialize it for this purpose
    Dim w As Float = cv.MeasureText(testString, fnt).width
    Return Floor((n + 1) * w / 10)
End Sub

Public Sub B4XPage_Created (Root1 As B4XView)
    Root = Root1
    Dim fnt As B4XFont = xui.CreateDefaultFont(11)
    Dim tf As TextField
    tf.Initialize("input")
    Dim tfx As B4XView = tf
    tfx.Font = fnt
    tfx.Text = "The World Turns"
    Root.AddView(tf, 100, 200, tf.Width, 30)
    'After added to the panel the view is fully formed and can be modified
    tfx.Width = computeWidth(tfx.Text.Length, fnt) 
    tfx.RequestFocus
    tfx.SetSelection(tfx.Text.Length, 0)
End Sub