Determining cause of IEditorViewSelectionChangeEventSink NotifySelectionChanged event

Hi Matt,

Perhaps you could look at the undo history?  There's nothing passed along in the SelectionChanged event that says why it was called.

Does this look reasonable? I'm guessing that GetTextChange(0) always returns the most recent item in the stack but I can't see that documented anywhere...

        private static bool IsTypingSelectionChange(ITextView view)
        {
            var undoStack = view.SyntaxEditor.Document.UndoHistory.UndoStack;
            if (undoStack.Count > 0)
            {
                var change = undoStack.GetTextChange(0);
                if (change.Operations.Count == 1)
                {
                    var operation = change.Operations[0];
                    if (operation.HasInsertion && operation.InsertionEndOffset == view.SyntaxEditor.Caret.Offset)
                    {
                        return true;
                    }
                    if (operation.HasDeletion && (operation.DeletionEndOffset - operation.DeletionLength) == view.SyntaxEditor.Caret.Offset)
                    {
                        return true;
                    }
                }
            }
            return false;
        }

You probably also want to ensure that the text change's IsUndo and IsRedo properties return false and that the change.Type == TextChangeTypes.Typing too.  I assume there is other text scanning criteria you'd want to do like making sure there's an alpha character that was typed, etc.

I can't actually see IsUndo or IsRedo properties on either IUndoableTextChange or ITextChangeOperation. For now the type classification seems to work ok though, thanks.

Sorry, the IsUndo and IsRedo are on ITextChange, but aren't on IUndoableTextChange because undo/redo changes aren't logged on the stack.  Undo/redo changes are the IUndoableTextChanges as they flip from the undo stack to the redo stack or vice versa.  So ignore the comment about IsUndo/IsRedo.  But as you saw, looking at the change type at least is helpful.