Selecting more than one file and choosing Rename now opens a pattern dialog rather than the
single-file one: a name, the number to start at, and a live preview of the names it will produce.
The number is the part that makes the feature worth having. A batch rename that always starts at 1
is useless the second time it is used, because the first batch already owns 1 to 12, so the dialog
reads the names already in the folder and starts at the highest "base (n)" it finds: a folder
holding "series (1)" and "series (2)" makes the next batch start at 3, which is the market survey's
most-helpful complaint answered exactly ("if I later find another group of photos which I want to
continue the batch naming with 'Ice (3)...'"). Three rules in core/BatchRename are decisions rather
than defaults, and are written down as such: the extension is kept per file, so a mixed batch of
.jpg and .png keeps each file's own; the series is counted across extensions, because "Holiday
(9).png" making the next number 10 is one series while "Holiday (10).jpg" beside "Holiday (1).png"
is two; and it continues from the highest number rather than from the first gap, because someone
renaming a second batch is carrying a series on rather than filling in the holes of one, with the
start number theirs to type where a gap matters more.
The batch is planned in full before a single file moves, and the plan has three answers and
deliberately no fourth: Ready, Blocked (naming the target that is already in the folder) or
NothingToDo. A batch that renamed nine files of twelve and then stopped would leave the user to work
out which nine and to guess whether the last three crashed or were skipped, so a collision refuses
the whole batch, the dialog names the file in the way and disables its button as the name is typed,
and a chain is declined outright - "a.txt" taking "a (1).txt" while "a (1).txt" is itself in the
batch would need the files shuffled through temporary names. Every rename still goes through the
same FileOperations.rename a single rename uses, so the refusal to overwrite anything is the same
one, and the successful renames are collected into the single Undo.Relocate step that already
existed: a feature that touches twelve files at once owes the user one tap back. The action bar now
offers Rename to any selection, since which of the two dialogs a tap means is described by the
dialog that opens rather than by the bar; Details stays single, because "the details" of twelve
files is not a screen.
Writing it turned up a quieter bug in the rename that was already there. rename(path,
"notes/final.txt") built a child path, which resolves into the subfolder rather than alongside the
file, so a name containing a separator moved the file instead of renaming it and nothing in the
dialog or the listing showed that anything had happened. Both rename paths now refuse a name that is
not one path segment (core/FileNames.isUsableName), and the dialog says which rule it is while it is
typed, which is where the user can still do something about it.
Twenty new core tests (BatchRenameTest, FileNamesTest) and six through the view model, 350 JVM
tests in total, lint clean. Verified by driving it on the phone against a folder that already held
"series (1).txt" and "series (2).txt": with three files selected and "series" typed in, Start at
moved to 3 on its own and the preview listed "series (3).txt, series (4).txt, series (5).txt";
afterwards the folder held all five series files, each file's contents having travelled with its
rename and the two originals untouched, and the snackbar's Undo put a later batch of three back in
one step. The collision and the slash were driven the same way - the file in the way named with the
button disabled, and "A name cannot contain a slash" - and the scratch folder was removed from the
device afterwards. CHANGELOG, ROADMAP (M14), COMPETITIVE_ANALYSIS (the gap moves from candidate to
closed), STORE_LISTING and EDGE_CASE_TESTING carry the feature, its decisions and the pass itself;
two tooling notes went into the last of them, that "adb input text" does not deliver a slash and
that the dialog lifts once the keyboard appears.
14 KiB
Roadmap
File Manager is built against a fixed milestone plan (M0–M14). This file is the single source of truth for what is done and what remains.
Legend: ✅ done · 🚧 in progress · ⏳ not started · 💡 candidate (proposed, not scheduled)
Milestones
| # | Milestone | Status | Evidence / notes |
|---|---|---|---|
| M0 | Toolchain & scaffold | ✅ | Gradle 9.3.1 + AGP 9.1.0 wrapper, version catalog, app module, Compose theme, debug APK builds, installs and runs on the phone AVD: package de.softwareapp_hb.filemanager.debug, versionCode 1, minSdk 26/targetSdk 36, no INTERNET permission, lintDebug clean (one expected UnusedResources for the not-yet-used notification icon) |
| M1 | Pure-Kotlin core + JVM tests | ✅ | core/ is Android-free: StoragePath (normalised absolute paths that cannot escape the root), FileEntry + FileKind classification, MimeTypes, NaturalOrder + SortSpec (directories first; file2 before file10), FileSize, NameMatcher (substring + */? glob), NameAllocator ("name (1)") and TransferPlanner (conflict policies, move-into-self). 44 JVM tests across 10 classes, all green |
| M2 | Storage layer | ✅ | StorageSource with two backends — AllFilesSource (java.io.File under all-files access) and SafSource (DocumentsContract over a persisted tree URI), the latter split so the tree↔path mapping (SafDocumentIds) is exhaustively testable; SafGrant for the picker and its persistence; VolumeRepository (StorageManager/StorageVolume + StatFs); StorageAccess + StorageAccessPolicy for the all-files/SAF decision. 76 JVM tests total (32 added here) |
| M3 | Operations engine + service | ✅ | domain/FileOperations composes the backend primitives into copy/move/delete/rename with recursive walking, an honest progress total, cooperative cancellation between entries and per-item failure reporting; conflicts are decided through the M1 TransferPlanner (ASK is surfaced for the UI to resolve). service/FileOpService is a dataSync foreground service mirroring progress into a notification (FileOpNotifications + text/TextRes). 99 JVM tests total (23 added here) |
| M4 | Compose UI | ✅ | BrowserViewModel + BrowserUiState over StorageLocation; browser screen with list/grid, breadcrumbs, in-folder search, a sort/hidden-files/view sheet, multi-select action bar, details sheet, and new-folder/rename/delete/conflict dialogs; a roots view and the "All files access" + SAF-folder prompts; data/MediaStoreDeleter routes a delete through the platform's own dialog where it can and falls back to a direct delete; a FileProvider backs "open with" and share. 115 JVM tests total (16 added here) |
| M5 | Analysis, archives, viewers | ✅ | domain/UsageAnalysis measures recursive folder sizes and finds the largest files, shown by a bar-per-row storage-usage screen; domain/ArchiveEngine creates ZIP and extracts ZIP/TAR/TAR.GZ/GZ/BZ2/XZ/7z using java.util.zip + Commons Compress + XZ for Java (no native code), with every entry name filtered through core/ArchivePath against zip-slip; a Coil-backed image viewer, thumbnails in the list and grid, a text editor, and compress/extract in the selection bar. 141 JVM tests total (26 added here) |
| M6 | Release config & Play readiness | ✅ | Upload keystore generated (4096-bit RSA, CN=Hadrian Burkhardt) and wired through the git-ignored keystore.properties; bundleRelease + assembleRelease verified — 4 682 814-byte .aab (sha256 9014627a…), 2 081 955-byte APK signed by the upload key, R8 mapping kept. PLAY_RELEASE_CHECKLIST (incl. the Permissions Declaration Form for "All files access", the Data safety answers and the shipped-permission audit) and PRIVACY.md written for a restricted-permission app. Shipped permission set audited: no INTERNET |
| M7 | On-device validation & hardening | ✅ | Run on a real Xiaomi M2101K7AG (Android 12 / MIUI V140) — see EDGE_CASE_TESTING. Verified on hardware: the first-run permission prompt, granting "All files access" while the app is alive (picked up on resume), browsing real storage, the text editor's read and write path (independently checked with adb shell cat), the storage-usage screen, landscape layout, and graceful degradation when access is revoked mid-use. Found and fixed two real defects: misleading first-run copy ("Full access was declined" on a device where nothing had been declined), and a usage screen that stayed blank for ~45–60 s on a 55 GB volume — now one listing per directory instead of a stat per node, with rows streamed out as they are measured. 142 JVM tests |
| M8 | Localisation groundwork | ✅ | Every user-visible string is in res/values/strings.xml with real <plurals>, and text/TextRes.kt maps both OperationKind and FileKind onto resources so the screen, the notification and the details sheet cannot drift. The audit found a genuine miss: the details sheet rendered FileKind.name, i.e. untranslatable English — now a resource. isPseudoLocalesEnabled = true on the debug build makes "did every string come from resources?" mechanically checkable; verified en-rXA is present in the debug APK and the flag is debug-only. Byte units and the timestamp pattern are deliberately unlocalised, and the README says why. 142 JVM tests |
| M9 | Monetisation | ✅ | Decided: one-time paid — €4.49 base with a 14-day launch price of €2.29, both set in the Play Console (Products › App pricing), so there is no Billing client, no com.android.vending.BILLING permission and no purchase code. Rationale, market anchors and Console steps: MONETISATION. Verified against the release APK: zero billing and zero INTERNET references. The price must be set before the first upload — Play allows paid → free but never free → paid |
| M10 | Store assets | ✅ | Name decided: Plain Files (one string; applicationId already locked). tools/make-store-assets.sh renders the 512×512 RGBA icon and the 1024×500 RGB feature graphic from the app's own vectors, so the store icon is the launcher icon; tools/make-store-screenshots.sh normalises adb captures to Play's 2:1 cap per form factor (phone crop default 93/130 px, tablets 0). STORE_LISTING carries length-checked copy (name 11/30, short 67/80, full 2730/4000), the permissions paragraph the MANAGE_EXTERNAL_STORAGE declaration requires, and the graphics table. The feature graphic's copy was verified to survive Play's centre-square crop by cropping the rendered PNG. Screenshots captured: 5 phone (1080×2160), 4 on a 7-inch tablet (1200×1920) and 4 on a 10-inch tablet (2560×1600), all 24-bit RGB, inside the 2:1 cap. The tablet sets came from AOSP AVDs. The normaliser refuses a capture whose app area is blank, which is how a pure-background capture was caught before it reached the listing |
| M11 | Library views | ✅ | A Libraries section on the root screen — Images, Videos, Audio, Documents, Archives, Recent — each row carrying how many files the index knows of that kind, each opening an ordinary listing (thumbnails, sort, multi-select, details, the existing viewers) answered from the index instead of from a directory. core/FileCategory groups FileKinds and is asserted to leave DIRECTORY, APK and OTHER out deliberately; SearchIndex gained byKind/recent/kindCounts, and SQLite schema v3 adds the derived kind column — the migration rebuilds the table and drops the volume stamps, because a stamp whose rows have gone would make the next search trust an empty index. A library obeys the indexed search's own two rules: the answer comes first with the walk behind it, and every row is confirmed against the filesystem before it is shown. Not included, and recorded in the CHANGELOG as decisions rather than omissions: Downloads and New files, and restoring a library across process death. 308 JVM tests (19 added here) |
| M12 | Duplicate finder | ✅ | Find duplicates in the overflow. Three passes, cheapest first: size (the index's duplicateCandidates query — one query and no reading at all), the first 64 KB of every candidate (a filter that may only rule files out), and the whole file to confirm (domain/DuplicateFinder, SHA-256, cancellable between files and between read buffers). Groups are ordered by reclaimable space; each header states the copies and what they cost; every row carries its folder, because identical names with no paths are unactionable; and nothing is preselected — the delete is the app's ordinary one, through the trash and the undo snackbar. A file that cannot be read is counted and reported rather than skipped, and the empty state says how many files were compared — or that the index has never run and there was nothing to compare. 323 JVM tests (15 added). Verified on the Xiaomi phone against four genuine groups in its own storage; the delete was deliberately not pressed on a device that is not ours — see EDGE_CASE_TESTING |
| M13 | Video thumbnails | ✅ | A video row shows a frame of the video instead of a film icon: images and videos take the same path through Coil, with the video request asking for a frame a second in. One dependency — coil-video at the Coil version already pinned, whose POM adds only coil-core/stdlib/core-ktx — the platform's own MediaMetadataRetriever behind it, no new permission (no READ_MEDIA_VIDEO), and the decoder registered explicitly against an ImageLoader in FileManagerApplication — because R8 strips coil-video's ServiceLoader entry from a release build, which would otherwise have left frames decoding in debug and quietly falling back to icons for real users. A decode that fails settles on the icon rather than an empty square. Verified on the phone against two purpose-made clips and a real video of the device's own, with the demo library's stand-ins falling back as intended, and re-verified on the release APK. 324 JVM tests |
| M14 | Batch rename with sequence continuation | ✅ | Selecting more than one file and choosing Rename opens a pattern dialog: a name, a start number, and a live preview of the names it will produce. core/BatchRename plans the whole batch before a single file moves and returns one of three answers — Ready, Blocked (naming the target the folder already holds) or NothingToDo — with the deliberate absence of a fourth: a batch that renamed nine of twelve and stopped would leave the user to work out which nine. The numbering continues the folder's own series nextNumber from the highest base (n) it finds, which is the market survey's most-helpful complaint answered by name; the extension is kept per file, the series is counted across extensions, and continuing beats filling the first gap. SelectionBar now offers Rename to any selection (one file keeps the name dialog, several get the pattern one), and the batch's renames are one Undo.Relocate step. The same commit hardens the single rename: core/FileNames.isUsableName refuses a name that is not one path segment, because notes/final.txt was being resolved as a path and moved the file instead of renaming it. 350 JVM tests (26 added) |
Key decisions
| Decision | Choice | Rationale |
|---|---|---|
| Language / UI | Kotlin + Jetpack Compose | Mirrors the sibling app's proven, installed toolchain; no NDK |
| Storage access | MANAGE_EXTERNAL_STORAGE first, SAF fallback |
Google Play explicitly permits "All files access" for file managers; SAF keeps the app usable if the user declines |
| Connectivity | Local-first (no INTERNET in v1) |
Preserves the "nothing leaves the device" claim and keeps the Data Safety form trivial |
| File sharing | Receives SEND/SEND_MULTIPLE, serves GET_CONTENT/OPEN_DOCUMENT, and deliberately does not register ACTION_VIEW |
A file manager should be able to receive a file and to supply one, and neither costs a permission. Registering as a viewer as well would put Plain Files in the "open with" chooser the app itself uses, offering it back to itself |
| Monetisation | One-time paid (€4.49; €2.29 launch price), set in the Console | No Billing client, no BILLING permission, no purchase code — which is what keeps "nothing leaves the device" true in the shipped APK. Free → paid is impossible after the first upload, so the price must be set beforehand. See MONETISATION |
Deliberately deferred (post-1.0)
- Cloud storage (Drive/OneDrive/Dropbox/…); network clients (SMB/FTP/SFTP/WebDAV); FTP/Web
server. All of these need
INTERNET, which is the one permission the app deliberately does not declare — see the connectivity decision above. - App manager (
QUERY_ALL_PACKAGES), APK installation (REQUEST_INSTALL_PACKAGES). - RAR archives (the format needs native code) and 7z creation; root explorer; encryption vault; themes/icon packs.
Candidates from the competitive analysis
A survey of the market leader (its features, and what its users praise and complain about) is in COMPETITIVE_ANALYSIS. Its gaps that cost no new permission are listed there as 💡 candidates. Category libraries were the first of them and are now M11, the duplicate finder the second (M12) and batch rename with sequence continuation the third (M14); the rest — bookmarks, and the post-paste "copy again" / "return to source folder" — are proposals, not scheduled work, and adding one is a roadmap decision rather than a side effect of reading that document.