Bugs in Swift/Cocoa that are worth calling out.
Jan 29 2019
Xcode 10, Swift 4.2, macOS 10.13. I have two text fields in my preference controller. Their purpose is to allow users to set a preferred default text style, which I will use elsewhere in my application. (This can be handled much more smoothly, but I have other problems to work out, and right now, working […]
May 27 2018
Xcode 9.3; macOS 10.12.6 This came out of the strange case of the scrolling SpriteKit View, which did – in the end – work fine (as in, my SpriteKit scene was displaying) and failed when I tried to add interactions to it. As a result, I went back to the drawing board, played some more […]
May 22 2018
(Xcode 9.3; macOS 10.12.6, Swift 4) If you want a challenge, I recommend you try to implement ‘scrolling SpriteKitView’ yourself before you read the rest of this article. Update (and spoiler): Due to a bug in InterfaceBuilder’s ‘SKView’, you need to use a ‘custom View’ (NSView) in Interface Builder, and change its type to SKView. […]
May 12 2018
(Xcode 9, macOS 10.12, Swift 4) Stackviews exist mainly to make layout easier (we’ll not go much into NSGridView here, which is the ‘we found another use case for which stackViews aren’t all that great’ variant). In this post, we’ll see what else we can do with stackviews, and where the pitfalls are. I find […]
Mar 13 2018
This is a lovely, and lovingly details explanation of how a rare bug was identified, what steps were taken to isolate it, and how it was finally resolved. Debugging is a skillset of its own, and this article walks you through the process. https://topologyeyewear.github.io/engineering-blog/2018/03/07/heap_corruption/ (warning: the main blog autoplays _something_ and doesn’t stop, so enter […]
Jan 27 2018
Toolbars have been an integral part of macOS since the beginning. They provide the opportunity to display frequently used controls to the user. Where older macOS applications might have presented a pallet with certain options, modern macOS apps tend to use toolbars. While Apple provides an extensive guide for macOS toolbars, it was last updated […]
Dec 29 2017
Edited to add: This, apparently, works as intended – you need to assign the button’s _target_ with testButton.target = self. It doesn’t completely explain why the code is working under some circumstances, but it’s not a bug as such. This thoroughly spoilt my day today. I was convinced I’d gotten the ‘assign-an-action-on-the-fly’ code correctly, but […]
Dec 27 2017
macOS 10.12, Xcode 9.2 Do not use the name of a viewController subclass as your Storyboard ID. I’ve had both ‘Storyboard […] doesn’t contain a controller with identifier ‘MyCustomController’ and the cast to MyCustomController failing randomly; in one instance a cast to NSViewController worked, but MyCustomController did not. When I set the identifier to “CustomVC” […]
Jun 25 2017
MacOS 10.12.5; Xcode 9b. I’m filing this under the ‘bug reports’ tag though I think it falls under ‘expected behaviour’, but this is a bit of a knotty problem. I had an app with a notecard, which has a title (NSTextField) and a body (NSTextView). I wanted the title to be first responder. Sadly, my […]
Sep 15 2019
Disclosure Triangle (Autolayout)
(Xcode 10, Swift 4.2, macOS 13.6) This is a common use case: users who just want an overview get a smaller window with the most important content, users who want more detail can click a triangular button and more details unfold. I seem to have tackled this problem several times without feeling completely happy with […]
By Extelligent Cocoa • Application Design, Bug Reports, Interface, Tutorials • • Tags: Autolayout, disclosure, embed view