In SwiftUI Charts, is it possible to change the color of linemarks and areamarks points based on custom criteria (not y)?

Question

I want to draw an AreaMark chart with SwiftUI, with different colors based on some properties of my points that are not y, like this:

Setting a foregroundStyle for each point will set the color of the last point. It looks pretty easy to set the color of linemarks and areamarks based on the y value, but I can't find how to base it on custom criteria. Is it possible to do it with Charts?

score 0 · Accepted Answer · answered Jun 06 '23 at 16:13

Ok, in the end I managed to do it. For those who would like to do the same thing, the idea is to create an image of height 1 and of width of the data array count.

Then, use the image shape style:

.foregroundStyle(.image(chartColors, scale: <Data length>))

Depending on the data size, you may want to duplicate the pixels to reduce the blur. The scale needs to be adapted then (divide by the number of duplications.

In SwiftUI Charts, is it possible to change the color of linemarks and areamarks points based on custom criteria (not y)?

1 Answers1