Color const constructor

[grahamsmith]

It would improve the devX if Color allowed a const constructor. The would allow defaults to be used in methods and other constructors, which at the moment won't work as defaults need to be const.

Happy to help but would like to know if this would be acceptable ahead of time.

[grahamsmith]

Example

At the moment we have to pass the colours in.

ChartRequest({
    required List<ChartDataPoint> dataPoints,
    required this.width,
    required this.height,
    required this.minLineColor,
    required this.maxLineColor,
    this.font,
  })

This is not allowed as there is no const constructor for the colour.

ChartRequest({
    required List<ChartDataPoint> dataPoints,
    required this.width,
    required this.height,
    this.minLineColor =  ColorRgba8(0, 0, 0, 255),
    this.maxLineColor = ColorRgba8(0, 0, 0, 255),
    this.font,
  })

[brendan-duncan]

Hmm, the problem is that ColorUint8 has a Uint8List data member, so it's not const compatible as it is.
I'll have to make a new color class that stores the channels in an int, so that it can be made const.
If minLineColor is a Color and not specifically a ColorUint8, then you'd be able to use this new color class.

[brendan-duncan]

I added ConstColorRgba8 and ConstColorRgb8, which are immutable const compatible Color classes.

[brendan-duncan]

Added to published version 4.5.0