Padding at top of NSView in an NSScrollView

I have an NSView as the document of an NSScrollView. I would like to have a few pixels of padding at the top and bottom of the visible part of the view, regardless of where the scroller is positioned (not just at the top and bottom of the document as described here). For an example of an app that does this, look at Terminal.app. Regardless of the background color of the text, the top two visible rows of pixels are always the default background color.

I know I 开发者_JAVA百科could simply draw everything two pixels lower and draw a rectangle at the top and bottom of the document-visible rect, but that will require changing a lot of complex code that I didn't write. Simpler ideas are welcomed!

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The answer to the question you linked is actually a good solution for this problem too. In fact if your view is anything but an NSTextView, I'd say it's easier to implement.

Specifically: make your actual document view a subview of some other view, leaving room around the edges and make that view the scroll view's document view. If your content view (the one you wish to pad) changes sizes, have your "padding view" observe it for frame changes and resize to maintain the padding.

2015 Update

Content inset has been added to NSScrollView as of 10.10, making my older answer obsolete.