Option Compare Database
Option Explicit

Sub Test()
    With New VisioInterface
        .OpenVisioDrawing "C:myVisioFile.vsd", "Custom drawing title"
    End With
End Sub

Option Compare Database
Option Explicit

Private Const VISIO_CLASS_ID As String = "Visio.Application"

Public Sub OpenVisioDrawing(ByVal filename As String, someData As String)
    Dim app As Object
    Set app = GetVisioInstance()

    ActivateVisioInstance app

    Dim drawing As Object
    Set drawing = LoadVisioDrawing(app, filename)

    VisioScreenUpdating app, False

    SyncVisioDrawing drawing, someData

    Dim window As Object
    Set window = DetermineDesiredVisioWindow(app, drawing)

    ActivateVisioWindow window

    MaximizeVisioWindow window

    VisioScreenUpdating app, True
End Sub

Private Function GetVisioInstance() As Object
    If VisioInstanceExist() Then
        Set GetVisioInstance = AttachVisioInstance()
    Else
        Set GetVisioInstance = StartVisioInstance()
    End If
End Function

Private Function VisioInstanceExist() As Boolean
    On Error Resume Next
    Dim visioApp As Object
    Set visioApp = GetObject(, VISIO_CLASS_ID)
    VisioInstanceExist = Not visioApp Is Nothing
End Function

Private Function AttachVisioInstance() As Object
    Set AttachVisioInstance = GetObject(, VISIO_CLASS_ID)
End Function

Private Function StartVisioInstance() As Object
    Set StartVisioInstance = CreateObject(VISIO_CLASS_ID)
End Function

Private Sub ActivateVisioInstance(ByRef app As Object)
    AppActivate app.window.Caption
End Sub

Private Function LoadVisioDrawing(ByRef app As Object, ByVal filename As String) As Object
    Const visOpenRW = &H20
    Set LoadVisioDrawing = app.Documents.OpenEx(filename, visOpenRW)
End Function

Private Sub SyncVisioDrawing(ByRef drawing As Object, ByVal someData As String)
    drawing.Title = someData
End Sub

Private Function DetermineDesiredVisioWindow(ByRef app As Object, ByRef drawing As Object) As Object
    Dim window As Object
    For Each window In app.Windows
        If window.Document Is drawing Then
            Set DetermineDesiredVisioWindow = window
            If window.Caption Like "*:2 *" Then
                Set DetermineDesiredVisioWindow = window
                Exit Function
            End If
        End If
    Next
End Function

Private Sub ActivateVisioWindow(ByRef window As Object)
    window.Activate
End Sub

Private Sub MaximizeVisioWindow(ByRef window As Object)
    Const visWSMaximized = &H40000000
    window.WindowState = visWSMaximized
End Sub

Private Sub VisioScreenUpdating(ByRef app As Object, ByVal allow As Boolean)
    app.ScreenUpdating = allow
End Sub

Private Function VisioInstanceExist() As Boolean
    On Error Resume Next
    Dim visioApp As Object
    Set visioApp = GetObject(, VISIO_CLASS_ID)
    VisioInstanceExist = Not visioApp Is Nothing
End Function

Private Function GetVisioInstance() As Object
    Dim visioApp As Object
    On Error Resume Next
    Set visioApp = GetObject(, VISIO_CLASS_ID)
    If visioApp Is Nothing Then
        GetVisioInstance = StartVisioInstance
    Else
        Set GetVisioInstance = visioApp()
    End If
End Function