# DSH Mobile Sync — Android client

An optional native Android client for the DSH Mobile Sync plugin. It is a small
WebView shell plus a native QR scanner; DSH itself still runs on the computer.
It is useful on LAN HTTP addresses, where mobile browsers refuse to open the
camera, and it can remember more than one computer.

## Features

- First launch opens the native camera scanner immediately.
- Native ZXing decoding works on plain `http://` LAN addresses and does not use
  Google Play Services.
- Saves multiple computers in a local profile list; switch, rename, delete.
- Pairs once through the DSH PWA, then opens the saved computer directly.
- PWA link `#pair=` is opened only for a new scan; later launches use the saved
  computer address, so a valid pairing is not recreated on every launch.
- A `DSHMobile.scan()` bridge lets the PWA request the native scanner from its
  own “打开相机扫描” button.

## Build

Requirements:

- JDK 17
- Android SDK Platform 34 (`platforms;android-34`)
- Android Build Tools 34.0.0 (`build-tools;34.0.0`)
- `libs/core-3.5.3.jar` (checked in; Apache-2.0 ZXing core)

```bash
export JAVA_HOME="/path/to/jdk-17"
export ANDROID_SDK_ROOT="/path/to/android-sdk"
./build.sh
```

Output: `dist/DSH-Mobile.apk` (`fun.wystan.dshmobile`, version 2.3.0).

The script creates a local `dsh-mobile.keystore` on first run and signs the APK.
Do **not** commit the keystore or `dist/`. If you publish an update, keep using
the same keystore so Android accepts it as an upgrade.

## First launch and profiles

1. Open the APK; it requests camera permission and opens the scanner.
2. Scan the QR code shown by the DSH **手机同步** panel.
3. The app extracts the computer origin, stores it as a profile, and opens the
   PWA with the one-time `#pair=` fragment.
4. The PWA creates a per-device token and remembers it. Later launches open the
   saved computer address without the fragment.
5. Use the “＋ / 扫描” button on the home list to add another computer. Tap a
   card to switch; tap `⋯` to rename or remove a profile.

If the camera is unavailable, use **手动输入电脑地址** and paste the full pairing
link or the address shown in the desktop panel.

## Notes

- `usesCleartextTraffic` is enabled because the LAN listener uses HTTP. Use
  HTTPS (Cloudflare) when the phone is not on the same LAN.
- The scanner uses the camera1 API and a single background decoder thread; it
  releases the camera in `onDestroy` and when the surface is destroyed.
- Removing a profile from the Android list does not revoke the device on the
  computer. Use the DSH side panel or the PWA **设备 → 断开** action for that.
- The PWA stores the per-device token in its own WebView `localStorage`; clearing
  app data removes it and requires pairing again.