testsAndMisc/phone_focus_mode

Phone Focus Mode

Location-based app restriction for a rooted Android phone using wireless ADB.

When within ~500m of home: only whitelisted productive apps remain usable. When outside that radius: all apps work normally.

Requirements

• Rooted phone with Magisk installed
• Wireless ADB enabled (Settings → Developer options → Wireless debugging)
• adb installed on your PC (sudo apt install adb on Debian/Ubuntu)
• GPS/Location enabled on the phone

Setup (first time)

1. Find your home coordinates

Open Google Maps, right-click your apartment → copy the coordinates shown.

2. Edit config_secrets.sh

HOME_LAT="-48.876667"   # your latitude
HOME_LON="-123.393333"  # your longitude

3. (Optional) Adjust the whitelist in config.sh

To find the exact package name of any app:

./deploy.sh <phone_ip> --find-pkg stronglift
./deploy.sh <phone_ip> --find-pkg anki
./deploy.sh <phone_ip> --find-pkg pomodoro

Then add the correct package name to WHITELIST in config.sh.

4. Deploy

chmod +x deploy.sh
./deploy.sh 192.168.1.42        # replace with your phone's IP

This:

1. Pushes all scripts to /data/local/tmp/focus_mode/ on the device
2. Installs a Magisk service.d script so the daemon auto-starts on boot
3. Starts the daemon immediately

Usage

./deploy.sh <ip> --status    # Current mode, location, distance from home
./deploy.sh <ip> --log       # View recent daemon log
./deploy.sh <ip> --list      # List all apps + whitelist status
./deploy.sh <ip> --enable    # Force focus mode ON (for testing)
./deploy.sh <ip> --disable   # Force focus mode OFF
./deploy.sh <ip> --stop      # Stop daemon entirely (restores all apps)
./deploy.sh <ip> --start     # Start daemon
./deploy.sh <ip> --restart   # Restart daemon (picks up config changes)
./deploy.sh <ip> --pull-log  # Download log file to your PC

How it works

Every 60 seconds:
  get_location()  ─── dumpsys location ──► lat,lon
        │
        ▼
  calc_distance()  ─── Haversine formula ──► meters
        │
        ├── within radius?  ──► enable_focus_mode()
        │                           pm disable-user all non-whitelisted apps
        │                           record which apps were disabled
        │
        └── outside radius? ──► disable_focus_mode()
                                    pm enable each app in the disabled list

Hysteresis: 50m buffer prevents rapid toggling at the boundary. You must travel radius - 50m inward to trigger lock, and radius + 50m outward to unlock.

Fail-safe: If location is unavailable for 5 consecutive checks (~5 minutes), focus mode is automatically disabled so you can't be locked out.

State persistence: The daemon records exactly which apps it disabled (in /data/local/tmp/focus_mode/disabled_by_focus.txt), so it never accidentally re-enables apps that were already disabled by the user before focus mode ran.

On-device control (without PC)

From a root terminal app (e.g. Termux + tsu):

su --mount-master -c 'sh /data/local/tmp/focus_mode/focus_ctl.sh status'
su --mount-master -c 'sh /data/local/tmp/focus_mode/focus_ctl.sh disable'

Why --mount-master: MagiskSU puts each su -c session in an isolated mount namespace by default, so bind mounts made by the hosts enforcer would be invisible (and /data/adb/focus_mode/* checks would fail due to SELinux interactions). --mount-master joins the global namespace where the daemons (started from Magisk service.d at boot) actually live. The boot autostart script doesn't need this flag because post-fs-data already runs there.

File layout

File	Purpose
config.sh	Coordinates, radius, whitelist, constants
focus_daemon.sh	Main daemon — runs on device, loops every 60s
focus_ctl.sh	Control utility — runs on device
curfew_enforcer.sh	Night-curfew enforcer — grayscale + DND + optional net
hosts_enforcer.sh	Bind-mounts hosts.canonical over /system/etc/hosts
magisk_service.sh	Magisk boot hook → auto-starts both daemons
deploy.sh	PC-side ADB deployment and control script

Hosts hardening

A second daemon, hosts_enforcer.sh, locks the phone's /system/etc/hosts to the same blocklist installed by linux_configuration/hosts/install.sh on the PC. Three layers:

1. Canonical copy at /data/adb/focus_mode/hosts.canonical is chattr +i.
2. It is bind-mounted read-only over /system/etc/hosts at boot.
3. A watchdog verifies a sha256 every 15 seconds and restores on mismatch.

This blocks the common echo > /etc/hosts one-liner from a terminal app. It is NOT a guarantee against a determined root user on the device itself — a real "impossible without USB" gate would require removing su access, which would break the rest of this system. The watchdog at least ensures tampering is logged and reverted within ~15s.

Status and logs:

./deploy.sh <ip> --hosts-status
./deploy.sh <ip> --hosts-log

Periodic rescan / Play Store

The focus daemon now re-scans every tick (not just on first entry). If you re-enable an app via Play Store or pm enable, it gets re-disabled within CHECK_INTERVAL_FOCUS seconds. com.android.vending (Play Store), com.*.packageinstaller, and popular terminal apps are also uninstalled --user 0 in focus mode to close the usual bypass paths. Google Play Services (com.google.android.gms) is left alone so banking apps work.

Night curfew (after 23:00 at home)

On top of the location-based focus mode, a time-gated curfew makes the phone boring and largely unusable late at night so you go to sleep instead of doom- scrolling. It activates only when focus mode is already ON (i.e. you are at home) and the local clock is inside the curfew window (default 23:00–05:00). Out of that window, or away from home, nothing changes.

While the curfew is active it applies three allow-list layers — block everything except a short essential list:

1. Apps. The daemon swaps the permissive WHITELIST for the strict NIGHT_WHITELIST (banking, maps, calendar, clock, authenticators, gov ID, workout/diet). Everything else — browsers, social, messaging, email, media, manga, stores — is pm disable-user'd and re-enabled automatically at 05:00. Same proven mechanism as location focus; no new disable path.
2. Display + notifications. curfew_enforcer.sh forces the screen to grayscale and DND to alarms-only, re-applying every 5s so toggling them off in Settings snaps back. (Snap-back is the realistic lock; truly blocking Settings risks system instability, so it is deliberately avoided.)
3. Internet (optional, default OFF). A per-UID iptables allow-list that gives network only to the NIGHT_WHITELIST apps (plus root/system/shell + DNS) and cuts off every other app. Enable CURFEW_NET_ENABLED=1 in config.sh only after validating it on-device (see test hook below).

Configuration (config.sh)

NIGHT_CURFEW_ENABLED=1       # master switch
NIGHT_CURFEW_START="2300"    # local HHMM; window wraps past midnight
NIGHT_CURFEW_END="0500"
CURFEW_GRAYSCALE_ENABLED=1   # force monochrome
CURFEW_DND_ENABLED=1         # force DND alarms-only
CURFEW_NET_ENABLED=0         # per-UID internet allow-list (prove first!)

Edit NIGHT_WHITELIST (right below WHITELIST) to choose what stays usable at night. Allow-list by design: when in doubt, leave it out. The active keyboard and the core dialer/SMS/home apps are always protected automatically (a 1am reboot can never strand you without a keyboard), and the default browser is intentionally not protected at night so it can be disabled.

Control

# On-device (root shell):
focus_ctl.sh curfew-status     # window, enforcer state, what's applied
focus_ctl.sh curfew-test-on    # FORCE curfew now (daytime validation)
focus_ctl.sh curfew-test-off   # clear the force
focus_ctl.sh curfew-off        # escape hatch: suspend curfew now
focus_ctl.sh curfew-on         # re-arm (clear the override)
focus_ctl.sh curfew-log        # enforcer log

Opting out at 2am (no PC)

The companion status notification grows a "Suspend curfew till morning" action while the curfew is active. Tapping it drops the override file (curfew off until you re-arm); the label flips to "Re-arm curfew". The action is hidden during the day so it is not a casual temptation. Without the PC this is the only on-device opt-out — by design. From the PC you can always ./deploy.sh <ip> --restart or run focus_ctl.sh curfew-off over ADB.

Validating before you trust it overnight

Because a misconfigured curfew can lock apps at 2am, validate it during the day with the force hook, not by waiting for 23:00:

focus_ctl.sh curfew-test-on    # mBank + keyboard work, Firefox gone, gray, DND
focus_ctl.sh curfew-test-off   # blocked apps come BACK (the reconcile path)

The clock parser fails open (treated as daytime) on a malformed time, so a broken date can never trap you behind the strict list.

Updating

After editing config.sh (e.g. changing whitelist):

./deploy.sh <ip>             # re-pushes all files
# or just the config:
adb push config.sh /data/local/tmp/focus_mode/config.sh
./deploy.sh <ip> --restart

Troubleshooting

Location always unavailable:

• Enable GPS and network location on the phone
• Open Google Maps once to warm up the GPS provider
• The daemon logs every attempt; check with --log

App won't disable:

• Some system apps can't be disabled even as root; they're silently skipped
• Check log for "Failed to disable" warnings

Daemon not starting on boot:

• Verify Magisk is installed and service.d is supported
• Check /data/adb/service.d/99-focus-mode.sh exists and is executable
• Some Magisk versions use /data/adb/post-fs-data.d/ instead; try both

Wrong package name in whitelist:

• Use ./deploy.sh <ip> --find-pkg <keyword> to find the exact package name
• Package names are case-sensitive