private static bool toolExecuting;  // tracks whether the tool is executing (i.e. dialog open).
                                            // static so that only one instance of the tool can be used
                                            // at any time in any application.

        public MeasureToolCommand()
        {
            view = new MeasureView()
            {
                Margin = new Thickness(10)
            };
        }
        private static bool toolExecuting;  // tracks whether the tool is executing (i.e. dialog open).
                                            // static so that only one instance of the tool can be used
                                            // at any time in any application.  

        public MeasureToolCommand()
        {
            view = new MeasureView() { Margin = new Thickness(10) };
        }