private static void OnAutoSwitchToNextTaskChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            TasksTimerControl c = (TasksTimerControl)d;

            if (c != null)
            {
                c.AutoSwitchToNextTask = (bool)e.NewValue;
            }
        }
        private static void OnTotalTimeChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            TasksTimerControl c = (TasksTimerControl)d;

            if (c != null)
            {
                c.TotalTimeChanged();
            }
        }
        private static void OnTasksChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            TasksTimerControl c = (TasksTimerControl)d;

            if (c != null)
            {
                c.UpdateTasks((IList <TaskViewModel>)e.OldValue, (IList <ViewModels.TaskViewModel>)e.NewValue);
            }
        }
        private static void OnElapsedTimeChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            TasksTimerControl c = (TasksTimerControl)d;

            if (c != null)
            {
                c.UpdateIndicator();
                c.UpdateCurrentTask();
            }
        }