COSMIC Desktop 1.6 adds per-app sound controls and compositor protocol updates

COSMIC Desktop 1.6 introduces per-application sound controls, a feature that shifts audio management from system-wide settings to individual app volumes. This change requires updates to the COSMIC settings daemon to handle playback-specific configurations and backward-compatible audio events. The audio applet now debounces volume updates by 128 milliseconds, preventing rapid fluctuations during adjustments. For engineers, this means integrating app-specific audio logic into their desktop environments or applications, which may require revisiting existing audio handling code.

The compositor improvements in this release focus on protocol support and rendering reliability. Version 1.6 adds wl-dmabuf-v6 and EI protocol compatibility, while fullscreen surfaces now provide presentation feedback. These changes primarily benefit developers working on Wayland clients or fullscreen applications, as they enable more predictable rendering behavior. The compositor updates may require adjustments in applications that rely on low-level surface management or fullscreen rendering paths.

Core components like COSMIC Terminal, Files, and Settings receive targeted fixes and usability enhancements. Terminal borders are now configurable, and rendering optimizations reduce unnecessary redraws. The file manager gains context menus for text fields and fixes for network share dialogs. Settings improvements include better handling of brightness values and AC power events. These changes address common pain points but may require testing for edge cases, particularly in environments with unusual hardware configurations or network setups.

The release also includes smaller but meaningful quality-of-life improvements. COSMIC Greeter now detects logind at runtime and supports modern image formats like JPEG XL and AVIF. Notification popups delay creation until parent size is available, reducing visual glitches. While these changes are less disruptive than the audio or compositor updates, they contribute to a more polished user experience. Engineers should note that some improvements, like the login screen changes, may require coordination with system-level components or display managers.