dsh-window-size-lock

dsh-window-size-lock

A DeepSeek Harness (DSH) host plugin that remembers your main-window size and position: restore both on every launch, lock them against the default layout, and persist them across sessions.

What it does

1. Restore on launch — when the DSH main window appears, the last saved rect (x, y, width, height) is applied immediately and re-asserted for a short grace period, so neither DSH's default 1280×820 layout nor Windows' default window placement wins. This is what stops the window from creeping down-right on every reopen.
2. Adopt on resize — after you drag the window edge/corner and the new size stays stable, it is saved as the new lock automatically.
3. Maximize-safe — a maximized (double-click fullscreen) window is never recorded. While the window is zoomed all size recording pauses; when you restore it, the saved non-fullscreen size is re-applied. The same freeze applies to minimized windows (which report the classic offscreen -32000,-32000 rect) and borderless fullscreen (F11-style, detected by a monitor-cover heuristic since it is not WS_MAXIMIZE).
4. Persist — the rect is stored in %APPDATA%\@deepseek-ai\dsh-desktop\window-size-lock.json as {x, y, width, height} and survives restarts. Files written by v1.3.0 (size only) are still read; the position is learned on the first stable read after upgrading.

The factory default size (1280×820) is never adopted as a lock, so a late default-layout reset cannot silently overwrite your saved size.

Install

Via the DSH plugin CLI (replace the exe path with your DSH install location):

set ELECTRON_RUN_AS_NODE=1
"D:\WorkStation\DeepSeek Harness\DeepSeek Harness.exe" --expose-internals ^
  "D:\WorkStation\DeepSeek Harness\resources\app.asar\dsh\node_modules\@deepseek-ai\dsh-desktop-host\lib\cli.js" ^
  plugin --profile desktop add https://github.com/Koewen/dsh-window-size-lock

Then restart DeepSeek Harness. (The CLI runs pnpm, which installs the plugin's koffi dependency automatically.)

Configure

Edit the config: block in cordis.patch.yml, then reinstall/restart:

Key	Default	Meaning
enabled	true	Master switch. false = DSH default behavior, no lock.
pollMs	500	Watch-loop interval in milliseconds.
graceMs	3000	How long after the window appears the saved rect is re-asserted. Raise it (e.g. 6000) if DSH re-applies its own layout later than 3s.
adoptFactoryDefault	false	Allow 1280×820 (DSH factory default) to be adopted as a size lock. Position is always adopted regardless of this flag.
persistPosition	true	Remember and restore the window origin too. false restores the v1.3.0 behavior (size only).

Reset

Delete the stored rect file and restart DSH:

del "%APPDATA%\@deepseek-ai\dsh-desktop\window-size-lock.json"

How it works

DSH host plugins run in a plain-Node child process (spawned with ELECTRON_RUN_AS_NODE=1), so the Electron API is unavailable. This plugin loads the window handle from the OS instead:

• runs in the same interactive desktop session as the main window, and
• is a direct child of the Electron main process, so process.ppid is exactly the PID that owns the main window.

It binds user32.dll through koffi (bundled as a dependency), walks the Z-order for the largest visible top-level window owned by the parent PID, and applies/observes sizes with MoveWindow / GetWindowRect on a pollMs interval.

Limitation

Electron enforces a minimum window size (~520×600) at the Chromium message layer. No external caller can shrink the window below that floor — this plugin locks sizes within the allowed range only.

DPI: the plugin requests per-monitor DPI awareness v2 at startup (best effort) so coordinates are physical pixels. If the host process already fixed its DPI context before this call, mixed-DPI multi-monitor setups may restore sizes with a scale offset.

Compatibility

Built and tested against DeepSeek Harness 0.2.1-rc.3. Optional peerDependencies are declared with that exact version so the compatibility gate passes.

Tests

test/wsl-edge-tests.mjs drives the real plugin against real Win32 windows created in the test process (ownerPid: process.pid), with an isolated APPDATA and a message pump so minimize/maximize states are genuine:

node test/wsl-edge-tests.mjs     # 21 checks, exit code 1 on any failure

Covered: adoption, move-only, resize-only, minimize (-32000 rect must never be recorded), maximize, off-screen saved origin, legacy size-only store, persistPosition:false, drag (no mid-drag adoption), close & reopen, multi-window (largest wins), corrupt store, dispose, monitor-cover freeze, factory-default size, and the v1.3.0 → v1.4.0 upgrade path.

Changelog

v1.4.0 — remember the position too

Fixes "the window reopens slightly down-right": the old code restored the saved size only and passed the window's current origin to MoveWindow, so the position was never persisted and every launch fell back to Windows' default placement (which cascades down-right).

• save/restore {x, y, width, height}; a saved origin that no longer intersects any monitor (unplugged display) is ignored instead of dragging the window off-screen,
• position and size are adopted independently: the factory-default 1280×820 guard blocks size adoption only, so a user who never resizes can still save a position,
• a size-only v1.3.0 store is upgraded in place — the origin is learned on the first stable read (previously lastApplied swallowed it forever),
• diagnostics: window-too-large-for-monitor warning, freeze reason at startup, "no window found for pid" warning, DPI-awareness level.