Circular Progress Bar Issue

Question

I have adapted some code I found online for a circular progress bar, it works, until the progress bar gets to 100%, then it disappears...

I can't work out what is wrong, and i'm assuming it's something to do with how ArcSegment works but I don't FULLY understand the mathematics behind it, could someone advise me?

Here is the ProgressBar and the Slider:

Here is the style and the converters

ArcEndPointConverter.cs

using System;
using System.Globalization;
using System.Windows;
using System.Windows.Data;

namespace Test_Project.Converters
{
    public class ArcEndPointConverter : IMultiValueConverter
    {
        public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
        {
            var actualWidth = values[0].ExtractDouble();
            var value = values[1].ExtractDouble();
            var minimum = values[2].ExtractDouble();
            var maximum = values[3].ExtractDouble();

            if (new[] { actualWidth, value, minimum, maximum }.AnyNan())
                return Binding.DoNothing;

            if (values.Length == 5)
            {
                var fullIndeterminateScaling = values[4].ExtractDouble();
                if (!double.IsNaN(fullIndeterminateScaling) && fullIndeterminateScaling > 0.0)
                {
                    value = (maximum - minimum) * fullIndeterminateScaling;
                }
            }

            var percent = maximum <= minimum ? 1.0 : (value - minimum) / (maximum - minimum);
            var degrees = 360 * percent;
            var radians = degrees * (Math.PI / 180);

            var centre = new Point(actualWidth / 2, actualWidth / 2);
            var hypotenuseRadius = (actualWidth / 2);

            var adjacent = Math.Cos(radians) * hypotenuseRadius;
            var opposite = Math.Sin(radians) * hypotenuseRadius;

            return new Point(centre.X + opposite, centre.Y - adjacent);
        }

        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }
}

ArcSizeConverter.cs

using System;
using System.Globalization;
using System.Windows;
using System.Windows.Data;

namespace Test_Project.Converters
{
    public class ArcSizeConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (value is double && ((double)value > 0.0))
            {
                return new Size((double)value / 2, (double)value / 2);
            }

            return new Point();
        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            return Binding.DoNothing;
        }
    }
}

LargeArcConverter.cs

using System;
using System.Globalization;
using System.Windows.Data;

namespace Test_Project.Converters
{
    public class LargeArcConverter : IMultiValueConverter
    {
        public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
        {
            var value = values[0].ExtractDouble();
            var minimum = values[1].ExtractDouble();
            var maximum = values[2].ExtractDouble();

            if (new[] { value, minimum, maximum }.AnyNan())
                return Binding.DoNothing;

            if (values.Length == 4)
            {
                var fullIndeterminateScaling = values[3].ExtractDouble();
                if (!double.IsNaN(fullIndeterminateScaling) && fullIndeterminateScaling > 0.0)
                {
                    value = (maximum - minimum) * fullIndeterminateScaling;
                }
            }

            var percent = maximum <= minimum ? 1.0 : (value - minimum) / (maximum - minimum);

            return percent > 0.5;
        }

        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }
}

StartPointConverter.cs

using System;
using System.Globalization;
using System.Windows;
using System.Windows.Data;

namespace Test_Project.Converters
{
    public class StartPointConverter : IValueConverter
    {
        [Obsolete]
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (value is double && ((double)value > 0.0))
            {
                return new Point((double)value / 2, 0);
            }

            return new Point();
        }

        [Obsolete]
        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            return Binding.DoNothing;
        }

    }
}

kirotab · Accepted Answer

I have a very quick workaround for you, where you won't have to change anything but it's a workaround nevertheless ;)

in your ArcEndPointConverter just add this row

if (degrees == 360) degrees = 359.99;

Just before converting to Radians, I think otherwise the value is equal to the value when your end degree is 0° so we just trick it to be almost 360° so that it could draw itself (with my test it's not visible for human eye)

...
var percent = maximum <= minimum ? 1.0 : (value - minimum) / (maximum - minimum);
var degrees = 360 * percent;
if (degrees == 360) degrees = 359.99;
var radians = degrees * (Math.PI / 180);
...

Circular Progress Bar Issue

Answers (1)

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