MacTerm constantly uses 10–20% CPU when any tab is open, even idle/minimized

[PrestonCS]

Description

MacTerm consistently uses around 10–20% CPU whenever at least one tab is open, even when the shell is completely idle and the application is minimized.

This happens even when there is no visible terminal activity, no scrolling output, and no active command running in the shell.

Steps to reproduce

1. Open MacTerm with any shell session.
2. Leave the shell idle with no commands running.
3. Minimize the application.
4. CPU usage remains around 10–20% continuously.

Expected behavior

When the shell is idle and MacTerm is minimized, CPU usage should drop close to zero, similar to ghostty itself.

Macterm version

1.18.1

macOS version

26.5.1

Logs or screenshots

I attached a sample report captured while MacTerm was idle.

Command used:

sample 16799 10 -file ~/Desktop/macterm-sample.txt

macterm-sample.txt

[onliner10]

Fixed by implementing proper event-driven architecture instead of polling.

The root cause was a 250ms timer running unconditionally. The refactor eliminates all polling loops:

• Terminal status updates via libghostty callbacks (onCommandFinished, onProgressStarted/Finished, onTerminalActivity)
• Tab names refresh lazily on visibility/focus changes (not polling)
• Single deferred work item for "quiet settle" fires 3s after last activity (not a repeating timer)
• App activation observers pause/resume tracking when minimized/backgrounded

CPU usage now drops to ~0% when inactive.

#110