Force proportional windowed initial size for Zed; shrink Chrome MCP viewport - #2300
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Upstream Zed commit a0d0195ca9 ("Add onboarding for parallel agents",
PR #52940, 2026-04-07) bumped DEFAULT_WINDOW_SIZE from 1536x864 to
1536x1095. That commit landed in the Helix Zed fork via the 001864 merge
on 2026-04-24, and CI built the new binary the same day.
On a 1920x1080 virtual monitor, default_bounds() clips the new value to
1536x1080 — exactly the work-area height — which trips Mutter's
auto-maximize=true and the user sees a fullscreen Zed instead of the
centered floating window they used to see.
Fix part 1: set ZED_WINDOW_SIZE / ZED_WINDOW_POSITION env vars in the
Ubuntu Zed launcher, sized to 80% of the logical work area (logical =
GAMESCOPE_WIDTH/HEIGHT divided by GDK_SCALE) with a 10% margin on each
side. Zed wraps env-var bounds as WindowBounds::Windowed so the
auto-maximize path is skipped entirely. The formula lands on 1536x864 at
1920x1080/100% — the exact size Zed defaulted to before a0d0195ca9 — and
scales proportionally to 4K, 5K, and HiDPI sessions.
Fix part 2: shrink the chrome-devtools MCP viewport from 1600x1080 to
1280x800. The 1600x1080 chosen in task 001532 produced a ~1600x1160
Chrome window (page + decorations) that also tripped Mutter's
auto-maximize. 1280 is the canonical desktop-vs-mobile breakpoint, so
sites still render in desktop mode, and the resulting window fits
comfortably on every supported display.
Sway desktop is unaffected — its tiling behaviour is a separate dynamic
and the Sway launcher is not changed.
Spec-Ref: helix-specs:001916_why-do-the-zed-windows
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Summary
Zed has been launching maximised in every new spectask on the Ubuntu/GNOME desktop, and unmaximising it leaves a window taller than the streamed viewport. Root cause: upstream Zed commit
a0d0195ca9("Add onboarding for parallel agents", 2026-04-07) bumpedDEFAULT_WINDOW_SIZEfrom1536×864to1536×1095. That commit landed in the Helix Zed fork via the 001864 merge on 2026-04-24. On a 1920×1080 virtual monitordefault_bounds()clips the new value to1536×1080— exactly the work-area height — which trips Mutter'sauto-maximize=trueand the user sees a fullscreen Zed.Coincidentally, the chrome-devtools MCP
--viewport 1600x1080set in task 001532 produced a ~1600×1160 Chrome window that also tripped the same auto-maximise threshold; shrinking it is a one-line follow-on that gets Chrome out of the same trap.Changes
desktop/ubuntu-config/start-zed-helix.sh: exportZED_WINDOW_SIZEandZED_WINDOW_POSITIONcomputed dynamically as 80% ofGAMESCOPE_WIDTH/HEIGHTdivided byGDK_SCALE, with a 10% margin on each side. Zed wraps env-var bounds asWindowBounds::Windowed, which skips the auto-maximise path entirely. Formula lands on1536×864at 1920×1080/100% — exactly the dimensions Zed defaulted to beforea0d0195ca9— and scales proportionally to 4K (3072×1728), 5K (2048×1152 at 200% zoom), etc.api/pkg/external-agent/zed_config.go: shrink the chrome-devtools MCP viewport from1600x1080to1280x800.1280is the canonical desktop-vs-mobile breakpoint, so sites still render in desktop mode, and the resulting Chrome window leaves a wide margin on a 1920×1080 monitor.The Sway desktop is untouched — its tiling behaviour is a different dynamic and out of scope for this task.
Test plan
GAMESCOPE_WIDTH=3840 GAMESCOPE_HEIGHT=2160: Zed scales to ~3072×1728 centredHELIX_ZOOM_LEVEL=200: Zed at the scaled logical sizeSpec:
helix-specs:001916_why-do-the-zed-windows🔗 Open in Helix
📋 Spec:
🚀 Built with Helix