My animation duration seems to be ignored, why?

An outer CATransaction may be overriding your settings. This skill helps you identify if CATransaction.setAnimationDuration is globally affecting your animations.

How do I prevent retain cycles in CAAnimation?

CAAnimation holds a strong reference to its completion block. This skill enforces the mandatory use of [weak self] within completion handlers to prevent memory leaks.

Why does my animation completion handler work on the simulator but not the device?

This often stems from timing differences, background pressure, or layer state issues. This skill provides diagnostics to verify CATransaction state and layer speed to identify the root cause on real hardware.

How can I fix jank when using gestures and animations together?

Gestures and animations can run at different rates. The skill suggests using CADisplayLink to synchronize updates to the native screen refresh rate, ensuring smooth interaction.

UIKit Animation Debugger

Name: UIKit Animation Debugger
Author: CharlesWiltgen

byCharlesWiltgen

•

233

Mobile Development

Diagnoses and resolves complex Core Animation issues including timing mismatches, completion handler failures, and device-specific performance jank.

About

This skill provides a systematic framework for debugging Core Animation (CAAnimation) issues across the xOS ecosystem. It offers a disciplined approach to identifying common pitfalls such as CATransaction timing conflicts, improper layer state management, and frame rate discrepancies between simulators and real hardware. By enforcing mandatory diagnostic steps and providing battle-tested implementation patterns, it helps developers eliminate visual jank and ensure animation logic remains consistent across different device performance classes, specifically targeting iOS, iPadOS, watchOS, and tvOS.

Key Features

233 GitHub stars
Systematic CAAnimation diagnostic workflows and mandatory first steps
Proper CATransaction and duration management patterns to prevent overrides
Memory-safe completion handler implementation with mandatory weak self enforcement
Real-device performance class optimization vs. hardcoded model values
High-performance gesture and animation synchronization using CADisplayLink

Use Cases

Fixing completion handlers that fire on the simulator but fail on real hardware
Resolving visual stuttering (jank) during simultaneous gesture and animation interactions
Debugging duration mismatches where visual animation time doesn't match the code

About

Key Features

233 GitHub stars
Systematic CAAnimation diagnostic workflows and mandatory first steps
Proper CATransaction and duration management patterns to prevent overrides
Memory-safe completion handler implementation with mandatory weak self enforcement
Real-device performance class optimization vs. hardcoded model values
High-performance gesture and animation synchronization using CADisplayLink

Use Cases

Fixing completion handlers that fire on the simulator but fail on real hardware
Resolving visual stuttering (jank) during simultaneous gesture and animation interactions
Debugging duration mismatches where visual animation time doesn't match the code