# File Manager An **ad-free**, **one-time-paid** Android file manager. It browses and manages the files on your device — locally, with no ads, no account and no analytics. Nothing ever leaves the device: the app declares no network permission and contains no advertising or tracking SDKs. > **Working title.** The display name and the store listing are decided before the > first Play upload (see [docs/ROADMAP.md](docs/ROADMAP.md), M10). The `applicationId` > is already fixed and can never change after the first release. ## Status **M12 — duplicate finder: done.** The browser scans for files that hold the same bytes — size first, then the head of every candidate, then the survivors in full — and shows what deleting the spare copies would give back. Before it: **M11 — library views**, a **Libraries** section on the root screen (Images, Videos, Audio, Documents, Archives and Recent) whose rows open ordinary listings of those files, each carrying a count from the search index. And **M10 — store assets**: the app is named **Plain Files**, the icon and feature graphic come from the app's own vectors, and [docs/STORE_LISTING.md](docs/STORE_LISTING.md) holds length-checked listing copy. Screenshots exist for 5 phone (1080×2160), 4 on a 7-inch tablet (1200×1920) and 4 on a 10-inch tablet (2560×1600) — but they **predate M11**, so the home screen in them is the old volume list and they will need re-shooting, which the library views make a privacy question as well as a cosmetic one ([docs/STORE_LISTING.md](docs/STORE_LISTING.md)). ## Tech stack | Area | Choice | |---|---| | Language | Kotlin 2.4.10 (using AGP 9 *built-in Kotlin*) | | UI | Jetpack Compose, BOM 2026.06.01, Material 3 | | Build | Gradle 9.3.1, Android Gradle Plugin 9.1.0 | | Storage access | `MANAGE_EXTERNAL_STORAGE` ("All files access") with a Storage Access Framework fallback | | Archives | Apache Commons Compress + XZ for Java (both pure Java — no NDK) | | SDK levels | `compileSdk`/`targetSdk` 36, `minSdk` 26 | `targetSdk` is 36 because Google Play requires new apps and updates to target Android 16 (API 36) from 31 August 2026. ## Project layout ``` app/src/main/java/de/softwareapp_hb/filemanager/ ├── core/ Pure-Kotlin engine (no Android imports!) — paths, sorting, formatting, │ search matching, copy/move planning, conflict policy ├── data/ Storage backends (all-files access + SAF), volumes, shares coming in │ from other apps, the trash index (SQLite), file operations, archives, │ deletion ├── domain/ Browser + operation controllers, models, permission state ├── service/ Foreground service for long-running file operations ├── ui/ Compose theme, browser screen, components, ViewModels └── text/ Domain enum → string-resource mapping app/src/test/java/… JVM unit tests for the core engine ``` `core/` deliberately has **no Android dependencies**, so the trickiest logic is covered by fast JVM tests. ## Building Prerequisites: - JDK 17+ (JDK 25 verified) - Android SDK with `platforms;android-36` and `build-tools;36.0.0` ```bash # Tell Gradle where the SDK lives (this file is git-ignored) echo "sdk.dir=$HOME/Android/Sdk" > local.properties ./gradlew :app:assembleDebug # debug APK ./gradlew :app:testDebugUnitTest # JVM unit tests for the engine ./gradlew :app:lintDebug # Android Lint ./gradlew :app:bundleRelease # Play upload bundle (.aab) ``` Release signing is optional and driven by a git-ignored `keystore.properties` (see `keystore.properties.example`); without it the release build still runs R8/minification but produces an unsigned artefact. ## Tracked in git - Source, resources and Gradle build files. - `docs/` — roadmap and release documentation. - `PRIVACY.md`, `CHANGELOG.md`, and (from M10) `store-assets/`. Not tracked: `local.properties`, `keystore.properties`, `*.jks`, build outputs. ## Releasing Release signing is driven by the git-ignored `keystore.properties` (see `keystore.properties.example`). Without that file the release build still runs R8 and resource shrinking, but produces an unsigned artefact that cannot be uploaded. ```bash ./gradlew :app:bundleRelease # Play upload bundle (.aab) ./gradlew :app:assembleRelease # APK, for local checks # Audit what is actually shipped — in particular that there is no INTERNET permission: $ANDROID_HOME/build-tools/36.0.0/aapt2 dump permissions \ app/build/outputs/apk/release/app-release.apk ``` Read [docs/PLAY_RELEASE_CHECKLIST.md](docs/PLAY_RELEASE_CHECKLIST.md) before uploading. Step 4 is the one that matters most for this app: a file manager must declare **"All files access"** through Play's Permissions Declaration Form, and have the core purpose documented in its store description. [PRIVACY.md](PRIVACY.md) is written to match the shipped permissions. ## Localisation All user-visible text lives in `app/src/main/res/values/strings.xml`, with real `` wherever a count can be one, and the screen and the progress notification resolve their labels through `text/TextRes.kt` so the two cannot drift apart. **English is currently the only locale.** Adding a language is then a file, not a refactor: ``` app/src/main/res/values-de/strings.xml # same keys, translated values ``` Deliberately **not** localised, and why: - **Byte units** ("KB", "MB") — symbols, not words, and every file manager and the system Settings app show them the same way. - **The timestamp pattern** (`yyyy-MM-dd HH:mm`) — a fixed, sortable format; the zone is passed in explicitly rather than assumed. ### Checking that nothing was missed Two things are easy to get wrong: a literal typed into a composable, and showing an enum constant directly (`FileKind.name` puts untranslatable English on screen — the details sheet used to do exactly that). The mechanical check is the pseudo-locale: ```bash ./gradlew :app:assembleDebug # Settings > System > Languages > English (XA), then launch the debug build. ``` The debug build type sets `isPseudoLocalesEnabled = true`, so every string that came from `strings.xml` renders accented and bracketed (`[Îmàgé]`). **Anything that looks normal is a string that never went through resources.** The release build is unaffected. One caveat: **Google Play's automatic translation translates your store listing, not the app UI.** Translated UI text has to be supplied in `values-/`. ## Known limitations - **The trash is a time window, not a bin you manage.** A delete stages the item in a hidden `.plainfiles-trash` folder on the same volume and keeps it for 24 hours; the **Trash** entry in the overflow menu lists what is still there and puts a whole batch back. There is no "empty it now" action — expired batches are swept the next time something is deleted — and a name taken again in the meantime is never overwritten, so a restored item can arrive beside the new one rather than replacing it. - **Where a trashed item came from is remembered in the app's own database**, not on the volume. The staged files are the truth and the database is only an index, so the two are reconciled in both directions: an entry whose file has gone is not offered back, and a batch folder no entry mentions is swept. - **Sharing a file *out* only works in the all-files mode.** A SAF path is relative to the granted tree rather than a filesystem path, so it cannot be handed to `FileProvider`. Receiving a share and being picked from another app's chooser work either way: the first needs no filesystem path, and the second falls back to `RESULT_CANCELED` rather than returning a URI the caller could not read. - **RAR, CAB, ISO and WIM are refused**, not supported — they need native code, which this project deliberately does not ship. (The Commons Compress jar contains no RAR classes at all.) **7z is different**: Commons Compress reads it in pure Java, so it *is* supported — but the format needs a seekable channel rather than a stream, because its header lives at the end of the file. All-files access can supply one; the SAF fallback cannot, so 7z extraction reports that plainly in folder mode instead of half-working. - **7z files can be opened but not created** — writing stays ZIP-only. - **Archive extraction does not restore original timestamps or permissions**, and there is no archive encryption or password support. - **Cancellation happens between entries**, so a single very large file finishes before a stop is honoured. - **A library is not restored across process death.** The persisted view state holds a path, and a library has none, so a restart returns to the root screen rather than to Images or Recent. - **Long-press multi-select is awkward to script from the host.** The gesture that opens the selection bar (`input swipe x y x y 900`) works on the MIUI test device but has also registered as a plain tap, so compress/extract from the UI wants a manual pass (see [docs/EDGE_CASE_TESTING.md](docs/EDGE_CASE_TESTING.md)). - The display name is still the working title — decided before the first upload (M10). ## Monetisation **One-time paid: €4.49 base, with a €2.29 launch price for the first 14 days.** No ads, no subscription, no in-app purchases, no free tier. The price lives on the Play listing, not in the build, which is why there is no Billing client in the dependencies and no `com.android.vending.BILLING` permission in the APK — that is what keeps "no network permission, nothing leaves your device" true of the *shipped artefact* rather than just the source. Rationale, market anchors, the rejected alternatives and the Console steps: [docs/MONETISATION.md](docs/MONETISATION.md). ⚠️ **The price must be set before the first upload** — Play allows paid → free but never free → paid. ## Competitive context The category leader is **File Manager Plus** (AlphaInventor; 100 M+ installs, 4.7–4.8★, free with ads and in-app purchases, and a Data Safety form that shares device IDs with third parties). What it offers, what its users praise, what they complain about, and which of those complaints this app can answer without asking for a single new permission: [docs/COMPETITIVE_ANALYSIS.md](docs/COMPETITIVE_ANALYSIS.md). ## Licence Proprietary — all rights reserved.