Snowmint Creative Solutions LLC has released an open source double
slider for Cocoa development on MacOS X. The SMDoubleSlider
distribution is available at (http://developer.snowmintcs.com/).
The distribution provides NSSlider and NSSliderCell subclasses which
have two knobs instead of one. The user can slide either of the knobs,
with the limitation that the lower knob is always less than the higher
knob. The SMDoubleSlider class also supports tabbing through both
knobs if keyboard access is turned on.
Complete documentation and an Interface Builder palette are included so
it’s very easy to include a double slider in any Cocoa project.
(http://www.snowmintcs.com/) – personal finance software
(http://www.codeblazer.com/) – multimedia software solutions