public PromptMarginVisualManager(PromptMargin margin, IEditorFormatMap editorFormatMap) {
            _margin = margin;

            _editorFormatMap = editorFormatMap;
            _editorFormatMap.FormatMappingChanged += OnFormatMappingChanged;
            margin.TextView.Closed += OnTextViewClosed;

            _glyphs = new Dictionary<UIElement, GlyphData>();

            _glyphMarginGrid = new Grid();
            _glyphMarginGrid.Width = 17.0;

            UpdateBackgroundColor();
            
            Canvas canvas = new Canvas();
            canvas.Background = Brushes.Transparent;
            canvas.ClipToBounds = true;

            _glyphMarginGrid.Children.Add(canvas);
            _canvas = canvas;
        }
        public PromptMarginVisualManager(PromptMargin margin, IEditorFormatMap editorFormatMap)
        {
            _margin = margin;

            _editorFormatMap = editorFormatMap;
            _editorFormatMap.FormatMappingChanged += OnFormatMappingChanged;
            margin.TextView.Closed += OnTextViewClosed;

            _glyphs = new Dictionary <UIElement, GlyphData>();

            _glyphMarginGrid       = new Grid();
            _glyphMarginGrid.Width = 17.0;

            UpdateBackgroundColor();

            Canvas canvas = new Canvas();

            canvas.Background   = Brushes.Transparent;
            canvas.ClipToBounds = true;

            _glyphMarginGrid.Children.Add(canvas);
            _canvas = canvas;
        }