feat(audio): add audio fading capabilities with configurable duration (in settings) by httperry · Pull Request #438 · sozercan/kaset

httperry · 2026-08-13T12:58:05Z

Description

Adds smooth, natural audio fade-in and fade-out functionality on play, pause, and track resume. Instead of abrupt audio cuts or linear volume steps that feel sudden to human hearing, volume changes are interpolated over an Equal-Power sine/cosine curve matching Apple Music and Spotify player standards. Also adds a configurable fade duration control under Music Settings.

Type of Change

🐛 Bug fix (non-breaking change that fixes an issue)
✨ New feature (non-breaking change that adds functionality)
💥 Breaking change (fix or feature that would cause existing functionality to change)
📚 Documentation update
🎨 UI/UX improvement
♻️ Refactoring (no functional changes)
🧪 Test update
🔧 Build/CI configuration

Related Issues

N/A

Changes Made

Equal-Power Volume Curve Math: Implemented logarithmic sine/cosine gain ramps ($V = \sin(p \cdot \frac{\pi}{2})$ on fade-in, $V = \text{startVol} \cdot \cos(p \cdot \frac{\pi}{2})$ on fade-out) in SingletonPlayerWebView+PlaybackControls to align with logarithmic human auditory perception.
Configurable Fade Duration: Added an audio fading toggle and customizable fade duration slider (0.3s–2.5s, default 0.5s) in SettingsManager and integrated seamlessly into MusicSettingsView.
Re-Entry & Autoplay Oscillation Prevention: Added isFadeOutInProgress state guard in MiniPlayerWebView to prevent rapid play/pause toggle glitches, and guarded enforceVolumeNow() against active fade intervals.
Unit Testing: Added test coverage in AudioFaderServiceTests covering fade progression calculations, duration clamping, and coordinator lifecycle.

Usage

Enable the feature in settings if not already enabled, try pausing/playing the music

Testing

Unit tests pass (xcodebuild test -only-testing:KasetTests / swift test)
Manual testing performed
UI tested on macOS 26+

Checklist

My code follows the project's style guidelines
I have run swiftlint --strict && swiftformat .
I have added tests that prove my fix/feature works
New and existing unit tests pass locally
I have updated documentation if needed
I have checked for any performance implications
My changes generate no new warnings

Screenshots

N/A

Additional Notes

All changes are self-contained within playback controls and user settings.
Preserves native macOS keyboard shortcuts and Apple Music media control conventions.

…View

…tions

…MainWindow and AudioFadingSettingsSection into MusicSettingsView

…mbnail in PlayerBar

…e on play

…de Apple Music split layout

…deo on fade out completion

…o fade and add trace logs

…io ramp

…active fade

…Progress guard

Copilot