Open Radar

 
Area:
CarPlay

Summary:
When the application shows a trip preview and the user shows additional route choices, sometimes the route choices take up much more room than they should on screen.

Steps to Reproduce:
1. Call CPMapTemplate.showTripPreviews(_:textConfiguration:). Some sample code is attached, but it can apparently happen with a wide variety of values for the route choices.
2. Tap the More Routes button to show additional route choices.
3. If the problem doesn’t occur, go back and try previewing again.

Expected Results:
At both steps, the top of the route preview panel is approximately 10 points below the bottom of the navigation bar. After the second step, each route choice is separated by a few points of whitespace, a hairline, and a few more points of whitespace.

Actual Results:
At both steps, the top of the route preview panel is far above the top of the window. After the second step, each route choice is separated by about 60 points of whitespace, a hairline, and 60 more points of whitespace.

See the attached screen recording, which shows the correct and incorrect behavior in the iOS simulator.

Using Console.app, I see warnings about unsatisfiable constraints coming from Springboard (UIKitCore). These warnings always appear when previewing routes, mentioning a hairline view (benign-spew.txt). But it seems that different constraints are broken whenever the route choices are separated by too much whitespace (broken-spew.txt).

Version/Build:
iPhone 8 simulator
iOS 12.2
Xcode 10.2.1 (10E1001)

Configuration:

In the screen recording, the screen measures 1,280×1,024 at 3× resolution. This issue has also been reported by a customer on a real-world, high-resolution OEM unit.