Question

As described in http://support.microsoft.com/kb/278591 PowerPoint will usually combine all changes that a macro or add-in makes to a single undo step. So if you put the following code into VBA and execute it twice by pressing F5 there
will only be one undo step.

Sub Move()
    If ActiveWindow.Selection.Type = ppSelectionShapes Then
        ActiveWindow.Selection.ShapeRange.IncrementLeft 10
    End If
End Sub

I am looking for a way to change this behavior in a more complex scenario where the user can make multiple changes without directly accessing PowerPoint. Ideally, it should be possible to undo a set of modifications that corresponds to one change from the user’s perspective.

What I found out is that ExecuteMso seems to break the undo transaction. So if you execute the following code twice it results in 4 undo steps (first increment, ExecuteMso, second increment, ExecuteMso).

Sub Move()
    If ActiveWindow.Selection.Type = ppSelectionShapes Then
        ActiveWindow.Selection.ShapeRange.IncrementLeft 10
        Application.CommandBars.ExecuteMso "Bold"
    End If
End Sub

Anyone knows a real solution for the problem or a better workaround? Although I didn’t find it maybe there is a solution for Word or Excel that can be ported to PowerPoint?

Answer 1

If you replace the ExecuteMso line with this one, the entire procedure remains one Undo:

ActiveWindow.Selection.ShapeRange.TextEffect.FontBold = msoTrue

Update

If you are using PowerPoint 2010 or later put this line before each block of code that you want the user to be able to undo a step at a time:

Application.StartNewUndoEntry