How to implement a gradient color picker in code?

Question

I'm wanting to program something like Photoshop's gradient color picker. I've been googling but can't find anything. Do you guys know how to do it?

Answer 1

I remember hacking up something like it with a static image and getPixel.

Answer 2

It's a bit out of date (and .NET if that's your choice of framework), but in the past I've implemented an app with this ColorPicker.