circular-slider

When do you use a circular slider/knob in a good user interface?

As I am familiar with some synthesizers, I often user real life circular sliders (e.g. to control the master volume), also called knobs. Like this one: Sometimes I also find these controls in virtual applications (yes I like extreme minimalism =P): But most of them are irritating, confusing or just wrong, and simple sliders could be ...

Making a circular NSSlide look and behave like in GarageBand

I am new to drawing with Cocoa, and I am making some software which will have sliders similar to these found in GarageBand: These look beautiful and can be controld by moving the mouse up and down. Can you help me with customizing NSSliders by subclassing them, so I can make them look and behave exactly as in GarageBand? Thanks. I...