Inverted ColorToHexConverter

[sissto]

Hi all,
I'm using the ColorPickerButton which only accepts a value of type Color. But I need the hex code of the selected color. Therefore I was happy to find the HexToColorConverter. Unfortunately it only converts in the wrong direction. So my idea is to add a new property for inverting the conversion.

What do you think? May I miss something and there is already such a feature?

Best regards
sissto

[timunie]

should be there?

Avalonia/src/Avalonia.Controls.ColorPicker/Converters/ColorToHexConverter.cs

Lines 67 to 75 in ff021aa

	public object? ConvertBack(
	object? value,
	Type targetType,
	object? parameter,
	CultureInfo culture)
	{
	string hexValue = value?.ToString() ?? string.Empty;
	return ParseHexString(hexValue, AlphaPosition) ?? AvaloniaProperty.UnsetValue;
	}

[sissto]

Whoops, sorry.. It is defined like this:

xmlns:converters="clr-namespace:Avalonia.Controls.Converters;assembly=Avalonia.Controls.ColorPicker"

<UserControl.Resources>
    <converters:ColorToHexConverter x:Key="HexConverter" /> 
</UserControl.Resources>

[timunie]

okay sometimes you need to do it to understand it. Yeah I believe a HexToColorConverter could be a useful addition. Do you want to file a PR for this?

/cc @robloo if you are against it?

[robloo]

I disagree with this so far. Are you really asking for an inverted HexToColorConverter?

Is your HexColor in the view model an int or a string? Generally, we should internally be using the most type-safe specific primitives to pass data internally. In this case you should be using Color or HslColor for the property on your view model and the binding will just work. This is easy to do on the view model level and at that layer you should already be using colors or brushes IMO.

Note that I kept ColorToHexConverter in the ColorPicker package because I didn't consider it general-purpose enough for wide use.

[sissto]

Yes I'm asking for an inverted HexToColorConverter.

The HexColorproperty is a string as you can see in the first reply of this post.

I totally understand your point of view. I get the hex code from a backend and I always try to keep my view models clean of any conversion code. To me a binding converter is the perfect solution for this, but no worries! Was just an idea and if you don't like it, it's ok for me :)

[robloo]

Yea, storing as a string internally is not ideal here. Not only is the overhead much higher than an int or Color it's a bit unsafe. This is why I think you should pursue another option.

That said, I am not fundamentally against a HexToColorConverter. It could make sense some place else.

[robloo]

Note the ColorPickerButton from the Windows Community Toolkit is just the ColorPicker here in Avalonia. The naming was aligned to match correctly with all other "pickers".

[sissto]

Yeah, to be fair the ColorPickerButton is from the FluentAvalonia package 😇