OpenDisk for Aether UI

A port of OpenDisk, a macOS SwiftUI disk-usage app, to Aether UI. One codebase runs on Linux (GTK4), macOS (AppKit) and Windows (Win32). Like the original, it is MIT-licensed; the notice is in opendisk/opendisk.ae and LICENSE.

It scans a disk or folder and shows where the space went. You can browse the folders from largest to smallest, read the rings chart, search every scanned name, and gather files in the Collector to delete them together.

What you need

This repo builds against three sibling checkouts:

scm/
  aether/        the Aether toolchain; `ae` must be on PATH, e.g. aether/build
  aeb/           the build runner; `aeb` on PATH
  aether-ui/     the UI toolkit — reached through this repo's `aether-ui` symlink
  macae/         macOS-only natives — reached through this repo's `macae` symlink
                 (optional: needed only when building on macOS; see below)
  OpenDisk-ae/   this repo

aether-ui, build_support and macae at the repo root are relative symlinks into ../aether-ui and ../macae. Point them at another checkout to build against it. The build takes aether-ui's ui and vg modules and its per-OS backend link setup from there, so nothing here duplicates them. (On Windows, clone with core.symlinks=true.)

opendisk/.build.ae only follows the macae symlink on a macOS build (std.os.platform() == "darwin"); a Linux or Windows build never touches it, so it doesn't need to exist there. See macae if you don't have a sibling checkout yet — mac.fsevents, mac.volume, mac.quicklook, mac.trash, mac.workspace and mac.fda are used today.

The port builds against Aether ≥ 0.766.0, the floor shared by the whole Aether family (the code itself needs 0.717.0: a trailing block on a struct-field assignment; _ bound inside a loop; fs.hard_link, used by the tests), and aeb v0.325 or later, which compiles the modules' @source C and Objective-C into the link itself.

Build, run, test

aeb opendisk/.build.ae                       # → target/build/opendisk/bin/opendisk
./target/build/opendisk/bin/opendisk         # opens on the device screen
./target/build/opendisk/bin/opendisk ~/Downloads   # opens straight into a scan

test/run_tests.sh                            # unit suites (std.spec): no window needed
test/test_watch.sh                           # od_watch: stub everywhere, real FSEvents round-trip on macOS
test/test_native.sh                          # od_native: stub everywhere, all 5 macae calls exercised for real on macOS
AETHER_UI_WITH_DRIVER=1 aeb opendisk/.build.ae
spec/run.sh                                  # AetherUIDriver specs, one fresh app each
./ci.sh                                      # all five, in that order

In a sandbox or CI job whose $HOME is read-only, set AETHER_CACHE_DIR to a writable directory: ae run caches compiled binaries there.

Layout

Path	What
opendisk/	the app: opendisk.ae builds the window, od_*.ae the rest, od_stat.c / od_text.c the per-OS C
opendisk/watch_none/, opendisk/watch_mac/	the two od_watch implementations; .build.ae puts exactly one on the module path per OS
opendisk/native_none/, opendisk/native_mac/	the two od_native implementations (volume/quicklook/trash/workspace/fda), same one-of-two-on-the-path rule
test/	unit suites, one per module area, std.spec — including test_rescan.ae (od_scan's incremental-merge logic, pure, no macae dependency) — plus test_watch.sh and test_native.sh, outside std.spec (see their headers)
spec/	AetherUIDriver specs, with od_driver.ae as their vocabulary and run.sh running them

How it maps onto OpenDisk

OpenDisk (Swift)	Here	Tested by
FileTree, roll-up, hard-link dedup	opendisk/od_tree.ae	test/test_tree.ae
TraversalScanner (allocated sizes, same device, no symlinks)	opendisk/od_scan.ae, od_stat.c	test/test_scanner.ae
FSEvents incremental merge (macOS scan cache not ported — see "Where it differs")	opendisk/od_watch.ae seam (watch_mac/watch_none), od_scan.ae's merge_changed_paths	test/test_watch.sh, test/test_rescan.ae, spec/spec_incremental_rescan.ae
Finder capacity, Quick Look, Trash, NSWorkspace, Full Disk Access probe	opendisk/od_native.ae seam, native_mac/native_none	test/test_native.sh
ChartItem, RingsChartLayout, ChartPalette	opendisk/od_chart.ae	test/test_chart.ae
RingsChartView, ChartHoverTip	opendisk/od_draw.ae	spec/spec_chart.ae, spec/spec_chart_drag.ae
SearchIndex	od_search.ae, od_text.c	test/test_search.ae, spec/spec_search.ae
Collector	od_collector.ae	test/test_collector.ae, spec/spec_collector.ae
ProtectedPaths	od_protected.ae (macOS, plus Linux and Windows rules)	test/test_protected.ae
DeviceMonitor, DevicePickerView	od_devices.ae, od_recent.ae	test/test_devices.ae, spec/spec_picker.ae
DiskAnalyzer view rules, Formatters	od_view.ae, od_fmt.ae	test/test_view.ae, test/test_formatters.ae
DiskAnalysisView and its bars	od_app.ae, opendisk.ae	spec/spec_scan_list.ae

The constants and strings are OpenDisk's own:

• chart constants: 5 rings deep, 0.15% minimum share, 0.03 rad minimum angle, the six-hue palette
• list rules: at most 100 items below the root, nothing under 1 KB once the scan is done
• ByteCountFormatter's decimal units ("Zero KB", "1.5 MB", "1.07 GB")
• the reason strings for protected paths
• the Collector's undo depth (50), and deletion that is permanent (OpenDisk has no Trash step)

Where it differs, and why

• FSEvents incremental rescan, on macOS only. A macOS build watches the scanned root (via macae's mac.fsevents, which runs FSEvents in its fine-grained FILE_EVENTS mode) and, when something changes underneath it, rescans and merges in just the affected directories — od_scan.ae's merge_changed_paths walks up from each changed path to the nearest directory the tree already has and swaps in a fresh subtree there via od_tree.ae's remove_child/node_add (Node.detached and the search index's own staleness check are what let this be safe — both already existed for exactly this). Debounced to at most once every two seconds; a dropped/wrapped FSEvents batch (rare) falls back to a full rescan for that cycle instead of trusting partial data. Not carried across merges: whole-tree hard-link dedup (each rescanned directory starts its own dedup set — see od_scan.ae's own note) and OpenDisk's macOS scan cache. opendisk/od_watch.ae is the seam (watch_mac/watch_none); Linux and Windows builds never link macae at all (gated in opendisk/.build.ae by std.os.platform()) and fall back to manual-Rescan-only, unchanged from before.
• The disk capacity bar matches Finder's number on macOS, purgeable space included, via macae's mac.volume (native_capacity in od_native.ae). Elsewhere it's fs.statvfs's raw free-block count, as before. The "Purgeable Space" row in the folder list is a separate, still cross-platform thing (OpenDisk-ae's own list of known cache folders, od_view.ae) — unrelated to and not replaced by this.
• Quick Look, on macOS, is real Quick Look (the Space-bar preview panel, via mac.quicklook) — a new context menu item next to Open, on a row and on the chart. Elsewhere "Quick Look" still falls back to opening the file in its default app, the substitution this line used to describe unconditionally.
• Deleting moves to the Trash on macOS (mac.trash; Put Back works afterwards), via a pluggable remover on od_collector.ae's Collector (default: permanent, unchanged elsewhere) that od_app.ae swaps in when native_trash_available(). The confirmation card's wording and button label switch accordingly.
• "Show in Finder" and "Open" go through NSWorkspace on macOS (mac.workspace): reveal actually selects the item instead of just opening its parent folder, and the app launches through the same API Finder itself uses. Elsewhere both still build a file:// URL and hand it to the OS's generic opener.
• A real Full Disk Access probe on macOS (mac.fda): a banner on the device-picker screen when it's actually denied, with a button straight to the Settings pane — replacing "never knowing" with the same detection OpenDisk's own prompt was built on. Suppressed under a driver spec or AETHER_UI_HEADLESS (there's no user to act on it, and probing there is noise, not signal).
• The macOS-only extras still not ported: Move to Applications, Sparkle updates and sandbox bookmarks. The last is replaced by Recent Folders: folders you scanned before, stored in the OS's config directory ($OPENDISK_CONFIG_DIR overrides it).
• Dragging from the chart is ported. The canvas is a real drag source (ui.draggable, aether-ui's generic handle-based drag API — untested on a canvas anywhere in aether-ui before this): hovering a segment keeps the canvas armed with that item's path, live, so a drag started mid-gesture always carries whatever's actually under the pointer (chart_move / update_chart_drag in od_app.ae). The centre ring ("go back") and empty space both un-arm it. The chart's context menu still offers Add to Collector too, same as a list row does alongside its own drag.
• The Collector's list is always visible under the chart, rather than OpenDisk's hover pop-up.
• Search name folding is lowercase plus composed Latin accents (od_text.c), so a user typing "Café" matches a name macOS stored decomposed. Full Unicode folding would come from utf8proc once aether's contrib/i18n exposes one.
• Windows: od_stat.c and od_text.c cross-compile and link with mingw-w64 (-Wall -Wextra, clean), but the app has not yet run on Windows. od_devices lists drive letters, but capacity shows only where statvfs exists, which excludes Windows today.

Test hooks

• $OPENDISK_SCAN or the first argument opens a folder directly.
• The chart's accessibility description names the hovered segment ("Movies, 2 MB, 80.3 percent"). The specs read it through GET /widget/{id}/a11y, and it is also what a screen reader hears.
• $OPENDISK_CHART_PNG=<file> writes the chart to a PNG on every repaint, off screen. That makes the chart visible where screenshots are not.