Edit AllPages


I spent about an hour and a half trying to figure out how to get the “opacity” sliders to display in my app. It turns out that this line in my app’s controller does it:

NSColorPanel sharedColorPanel] setShowsAlpha:YES];


I had the same problem (actually it’s how I found this site!). There is another way: [NSColor setIgnoresAlpha:NO];

This appears to be an application global setting. Not sure which method is preferred…


I’m in your case, but I’m newbie in xcode dev and I don’t know how to use these codes… Should I make a custom class for [[NSColorWell? or is there a place for that? Thanks



You will need to read a tutorial on Xcode for that info. It involves making what is called a Controller. The codes you see are in the Objective-C programming language. Go to CocoaBooks and CocoaTutorials. A good free book is called “Become an Xcoder” - it teaches you both Objective-C and Xcode. Also, the Xcode Documentation contains a tutorial on developing apps in Cocoa. Just open the Xcode help file and choose the Cocoa section of the documentation. You will learn how to make a controller, connect objects to the controller, and have actions performed via the controller. - Pietro Gagliardi

Does anybody know what the little grey triangle that shows up in the top-right corner of color wells means?

It means the color it’s displaying was created in the Device space. Use the Calibrated space to make it go away.

Excellent, thanks.

There is a bug with the alpha in 10.4: Changing the color sends colorChanged: to the first responder, but changing the alpha doesn’t!

How do I add a NSColorWell to a .nib file? - Pietro Gagliardi

It’s on the buttons and sliders palette, next to the button in the upper left.

Sorry - I meant NSColorPanel. I have NSColorWells already but I need a NSColorPanel to open up when I click one. I am working on an image editor to compete with Photoshop - with all the features!

NSColorWells do that automatically, I just verified this in IB using Test Interface.

How? No matter what I do, it always displays a tiny box with the color.

OK, I got it to work with the border. How do I do it without the border?

I think you’ll have to subclass it.