Question

In some applications like Sparrow Mail are set two different application icons. The default icon used in dock, in icon view e cover flow. Then a second smaller for list view, column view and title bar. How do you set the icon smaller? In file.plist there is only this.
Thanks.

Answer 1

Xcode includes the Icon Composer.app application which allows you to create .icns (Icon Suite) files which support multiple resolutions like shown in the following image:

As you can see in the image above, the Get Info panel’s “proxy” icon (in the titlebar) is using the small 16 x 16 icon, while the lower icon is using one of the larger sizes. If you are used to the single-size-only ways of UIImage, how an NSImage works in OS X may be confusing at first. In iOS, a UIImage represents a single bitmap image, and is basically a wrapper around a CoreGraphics CGImageRef. An NSImage in OS X works at a higher level, and as such, is quite different than a UIImage. An NSImage contains one or more specifically-sized NSImageReps, which are more analogous to a UIImage. In the screenshot you provided, both the window title bar button’s image and the NSImageView’s image are set to the same instance of an NSImage. When that image is asked to draw itself, however, the image is choosing 2 different NSImageReps based on the size requested. For more information on how this works, see Cocoa Drawing Guide: Image Basics – How an Image Representation is Chosen.

If you’re using the all-in-one Xcode.app app bundle, launch Xcode and choose Xcode > Open Developer Tool > Icon Composer. If you’re using the older style of the Xcode tools, with multiple folders, it’ll be at <Developer Tools>/Applications/Utilities/Icon Composer.app.