macOS Custom views

[T'hain Esh Kelch]

Trying to get the hang of things. How often are custom views used? Examples of things I like, that aren't available in Interface Builder as far as I can see: Safari tabs, iTunes scrollbars, the small 'bar' at the bottom of the left view of Mail (Below Mail activity).

Also, are they very hard to add, or is it something worth looking at for an inexperienced newcomer?

 

[Blakeasd]

The iTunes scrollbars are just a subclass of NSScroller. The bar under Mail is probably a content bottom bar(not sure if that's what your talking about) you can set this in interface builder. The Safari tabs might be NSViews but I'm not really sure. NSViews aren't hard at all to add it is pretty straight forward, draw them with drawRect: and allow clicks with mouseDown: and mouseUp:.
Here is a link for iTunes Scrollbars: http://cocoacontrols.com/platforms/mac-os-x/controls/esscrollview

Is you need controls that aren't standard then you can find a lot at Cocoa Controls.