Xcode Debugging - How to add quick look in your custom types

今更だけど独自クラスでQuick Lookを使う方法について調べた - Qiita

WWDC 2014: Debugging in Xcode 6 で発表されたカスタムQuick Lookが面白そうなので今更ですが触ってみました。 オブジェクト変数の現在の状態を、ポップアップ表示でグラフィカルに表示してくれる機能です。クイックルックボタンをクリックするか、Xcode下部のデバッグアリアで変数を選択した状態でスペースキーを押せば見ることができます。 ...

qiita.com

How to create Quick Look debug previews for your custom types

Swift version: 5.2 Paul Hudson @twostraws Xcode's Quick Look debugging allows us to visually preview the value of our types, and is capable of showing numbers, strings, attributed strings, colors, images, PDFs, Bezier paths, and more. By default your custom types don't have a Quick Look preview, so you won't see anything useful.

www.hackingwithswift.com

Get QuickLook Preview of Swift objects in XCode

When setting breakpoints in XCode, it's quite hard to see what exactly is inside an object. All XCode give you is memory address of that object. In XCode 6 it's possible to overcome this by implementing debugQuickLookObject method in your object.

Operating System Types Supporting debugQuickLookObject

Your custom Quick Look display method, debugQuickLookObject (see Implement the Quick Look method), must return an object whose type is one of the operating system classes that supports rendering custom classes in Quick Look. The following table lists these iOS and OS X system classes, grouped by similar content.

developer.apple.com

https://developer.apple.com/library/archive/documentation/IDEs/Conceptual/CustomClassDisplay_in_QuickLook/CH01-quick_look_for_custom_objects/CH01-quick_look_for_custom_objects.html

Quick Look Debugging

Debugging can be an exercise in irony. We create programs that tell our pint-sized supercomputers to complete infinitely varied and incalculable tasks on our behalf, yet when trying to understand those same programs, we tell the computers to wait for us.

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