public object?Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
// Allow 'value' to be non-boolean, where not-null == true
if (!(value is bool b))
{
b = value != null;
}
if (!(parameter is string s))
{
return(null);
}
try
{
var c = s.Split('|');
if (c.Length != 2)
{
throw new Exception($"{nameof(BoolSelect)} parameter has the incorrect format. Expected '<true_value>|<false_value>'");
}
var val = b ? c[0] : c[1];
// Special case conversions not handled by 'ConvertTo'
if (targetType == typeof(Colour32))
{
return(Colour32.Parse(val));
}
if (targetType == typeof(Color))
{
return(Colour32.Parse(val).ToMediaColor());
}
if (targetType == typeof(Brush))
{
return(Colour32.Parse(val).ToMediaBrush());
}
if (targetType == typeof(Thickness))
{
var i = (int?)Util.ConvertTo(val, typeof(int)) ?? 0;
return(new Thickness(i));
}
if (targetType == typeof(ImageSource))
{
// Use: ConverterParameter='image_key1|image_key2'
// Image keys should be static resource keys.
// Only works if the resources are in App.xml.
var res = Application.Current.TryFindResource(val);
res ??= Application.Current.MainWindow.TryFindResource(val);
res ??= Application.Current.Windows.Cast <Window>().Select(x => x.TryFindResource(val)).FirstOrDefault(x => x != null);
return(res);
}
return(Util.ConvertTo(val, targetType));
}
catch
{
// Handle this silently so that runtime editing XML works
return(null);
}
}
// Notes:
// - Parameter should be 'case0:value0|case1:value1|case2:value2|default_value'
// where 'value' is a string that is convertable to 'targetType'.
// - Any value with no 'case' is assumed to be the default value.
// The default case should always be last
public object?Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
if (!(value is Enum e))
{
return(null);
}
if (!(parameter is string s))
{
return(null);
}
try
{
// Look for a matching case
foreach (var pair in s.Split(new[] { '|' }, StringSplitOptions.RemoveEmptyEntries))
{
var case_value = pair.Split(':');
// Default case?
if (case_value.Length == 1)
{
return(InterpretValue(case_value[0]));
}
// Valid 'case:value' pair?
if (case_value.Length != 2)
{
continue;
}
// Case name is not a member of the enum
if (!Enum.IsDefined(value.GetType(), case_value[0]))
{
continue;
}
// Case matches 'value'?
var cas = Enum.Parse(value.GetType(), case_value[0]);
if (!Equals(cas, value))
{
continue;
}
// Interpret the value to the target type
return(InterpretValue(case_value[1]));
}
return(null);
}
catch
{
// Handle this silently so that runtime editing XML works
return(null);
}
// Convert the string to the target type
object?InterpretValue(string val)
{
// Special case conversions not handled by 'ConvertTo'
if (targetType == typeof(Colour32))
{
return(Colour32.Parse(val));
}
if (targetType == typeof(Color))
{
return(Colour32.Parse(val).ToMediaColor());
}
if (targetType == typeof(Brush))
{
return(Colour32.Parse(val).ToMediaBrush());
}
if (targetType == typeof(Thickness))
{
var i = (int?)Util.ConvertTo(val, typeof(int)) ?? 0;
return(new Thickness(i));
}
if (targetType == typeof(ImageSource))
{
// Use: ConverterParameter='image_key1|image_key2'
// Image keys should be static resource keys.
// Only works if the resources are in App.xml.
var res = Application.Current.TryFindResource(val);
res ??= Application.Current.MainWindow.TryFindResource(val);
res ??= Application.Current.Windows.Cast <Window>().Select(x => x.TryFindResource(val)).FirstOrDefault(x => x != null);
return(res);
}
return(Util.ConvertTo(val, targetType));
}
}