RadTimeBar with Non-Gregorian Calendar

[Liam]

Does the RadTimeBar support when Windows has a non-Gregorian calendar set? Specifically this one: https://docs.microsoft.com/en-us/dotnet/api/system.globalization.umalquracalendar?view=net-5.0. I get an exception that says this when I change my Windows settings to get that calendar:

Exception Stack Trace: System.Windows.Markup.XamlParseException: Specified time is not supported in this calendar. It should be between 04/30/1900 00:00:00 (Gregorian date) and 11/16/2077 23:59:59 (Gregorian date), inclusive.

I can reproduce it with XAML as simple as this:

		<telerik:RadTimeBar x:Name="TimeBar"
                            PeriodStart="1-Jan-2019 12:00:00 AM"
                            PeriodEnd="31-Dec-2019 11:59:59 PM"
                            VisiblePeriodStart="14-March-2019 12:00:00 AM"
                            VisiblePeriodEnd="11-Nov-2019 11:59:59 PM">
			<telerik:RadTimeBar.Intervals>
				<telerik:YearInterval />
				<telerik:MonthInterval />
				<telerik:WeekInterval />
				<telerik:DayInterval />
			</telerik:RadTimeBar.Intervals>
		</telerik:RadTimeBar>

[Stenly]

Hello Liam,

RadTimeBar control supports non-Gregorian calendars. That said, I have tested the control with every region possible, but I could not reproduce the exception message.

I have attached a sample project, so, could you modify it to match the behavior from your side?

Regards,
Stenly
Progress Telerik

[Liam]

Hmm. You might be right. Although I think I am closer to identifying the issue. When I was testing this, I tested it in my actual project by creating a simple RadTimeBar. However, it didn't occur to me that all the styling we have associated with RadTimeBar would have also been applied to my simple RadTimeBar experiment.

What I have now realized is that it seems that I can reproduce the problem with the TimeBar.SelectionThumb control (which is what my project's styling had included when I use RadTimeBar). With an empty project, I can reproduce an issue with this:

	public partial class MainWindow : Window
	{
		public MainWindow()
		{
			CultureInfo culture = CultureInfo.CreateSpecificCulture("ar-EG");
			culture.DateTimeFormat.Calendar = new UmAlQuraCalendar();
			CultureInfo.CurrentCulture = culture;
			InitializeComponent();
		}
	}

<Window x:Class="TelerikWpfApp2.MainWindow"
                xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"
        	    xmlns:timeBars="clr-namespace:Telerik.Windows.Controls.TimeBar;assembly=Telerik.Windows.Controls.DataVisualization"
                Title="MainWindow" Height="350" Width="525">
        <Grid>
        <timeBars:SelectionThumb
            PeriodStart="1-Jan-2019 12:00:00 AM"
            PeriodEnd="31-Dec-2019 11:59:59 PM">
        </timeBars:SelectionThumb>

    </Grid>
</Window>

There might also potentially be a difference in DLLs that are being used, as I believe the actual project we are working in is using a 2019.1.116.40 version

[Liam]

Yeah it is looking like an upgrade in my project's Telerik version will be in order. Thanks for helping me look into this.

[Stenly]

Hello Liam,

After testing with the specified assemblies, the exception was present on my side as well. This behavior was reported as a bug and fixed in the 2019 R3 official release. There is also a possible workaround, which I implemented in an example project for you to test. To fix this behavior, create a new class that extends the SelectionThumb class and set the TitleFormatString property to " " string. 

public class CustomSelectionThumb : SelectionThumb
{
    public CustomSelectionThumb()
    {
        this.TitleFormatString = " ";
    }
}

And you can use it in XAML as follows:

<local:CustomThumb
        PeriodStart="1-Jan-2019 12:00:00 AM"
        PeriodEnd="31-Dec-2019 11:59:59 PM">
</local:CustomThumb>

There might be some design time issues, so clean and rebuild the project and then run it, and the issues will be gone.

Also, I have attached the aforementioned project, so could you try it out?

Regards,
Stenly
Progress Telerik

[Liam]

This suggestion fixes the issue and provides us with a stopgap until we get Telerik updated. Thank you.