How to create a custom NSView for NSSavePanel in Cocoa MacOS objective C?

Question

I need to add a save extension selector with a text label next to it to my NSSavePanel. In the screenshot attached I try to demonstrate that I succeeded in adding an NSComboBox to my panel with the function setAccessoryView. However I have no idea how to create a custom NSView, which includes both an NSComboBox and an NSTextView or equivalent. I found no tutorials on the internet (or if I found one it was extremely outdated) showing how to create custom NSViews in objective-C in Cocoa on MacOS.

How can I create a custom NSView containing a combobox and a text label? Or how can I add two "stock" NSViews to the same NSSavePanel? Please be as detailed in your answer as possible, as I have very limited objective-c experience.

Answer 1

Press Cmd-N to add a new file to your project. Choose a View file to add a xib file that has a custom view.

Open the xib file and add the controls to the custom view. Press the Add button in the project window toolbar to access the user interface elements.

Use the NSNib class to load the xib file and get the custom view.