iOS Stacking Screenshots

recording.mp4

LSPosed-based prototype for Android 15 screenshot UX on a rooted POCO F1 running crDroid 11.9.

Project goal:

• keep the screenshot shelf visible on screen across repeated screenshots
• exclude that visible shelf from screenshot N+1
• move toward an iOS-like stacked thumbnail UX without needing a full custom ROM

Quick Install

./gradlew :app:assembleDebug
adb -s 192.168.2.56:5555 install -r app/build/outputs/apk/debug/app-debug.apk
adb -s 192.168.2.56:5555 shell su -c 'killall com.android.systemui'

Then:

• open LSPosed
• enable iOS Stacking Screenshots for com.android.systemui
• take two screenshots in quick succession
• confirm the old shelf stays visible on-screen and does not appear in screenshot N+1

Build And Install

Build:

./gradlew :app:assembleDebug

APK output:

app/build/outputs/apk/debug/app-debug.apk

Install to the current device:

adb -s 192.168.2.56:5555 install -r app/build/outputs/apk/debug/app-debug.apk

Reload the hook immediately:

adb -s 192.168.2.56:5555 shell su -c 'killall com.android.systemui'

This session successfully:

• built :app:assembleDebug
• installed the debug APK to 192.168.2.56:5555
• restarted SystemUI

Zero-To-Active ADB Guide

This is the full deploy path from a clean device state using ADB.

Prerequisites:

• the device is rooted
• LSPosed is already installed
• ADB over USB or TCP is working
• the LSPosed manager app is installed on the device

1. Build the module:

./gradlew :app:assembleDebug

2. Install or update the APK:

adb -s 192.168.2.56:5555 install -r app/build/outputs/apk/debug/app-debug.apk

3. If you renamed the package or are replacing an old module build, remove the obsolete package:

adb -s 192.168.2.56:5555 uninstall OLD_PACKAGE_NAME

4. Enable the module in LSPosed and add com.android.systemui to its scope.

Manual path in LSPosed Manager:

• open LSPosed Manager
• open iOS Stacking Screenshots
• enable the module
• set scope to com.android.systemui

ADB/root path used in this repo during this session:

adb -s 192.168.2.56:5555 shell "su -c 'echo \"begin; update modules set enabled=1 where module_pkg_name=\\\"fuck.iosstackingscreenshots.droidvendorssuck\\\"; insert or ignore into scope(mid, app_pkg_name, user_id) values((select mid from modules where module_pkg_name=\\\"fuck.iosstackingscreenshots.droidvendorssuck\\\"), \\\"com.android.systemui\\\", 0); commit;\" | sqlite3 /data/adb/lspd/config/modules_config.db'"

5. Restart SystemUI so the screenshot process respawns under the updated LSPosed scope:

adb -s 192.168.2.56:5555 shell su -c 'killall com.android.systemui'

6. Verify LSPosed state if needed:

adb -s 192.168.2.56:5555 shell "su -c 'echo \"select * from modules where module_pkg_name=\\\"fuck.iosstackingscreenshots.droidvendorssuck\\\"; select * from scope where mid=(select mid from modules where module_pkg_name=\\\"fuck.iosstackingscreenshots.droidvendorssuck\\\");\" | sqlite3 /data/adb/lspd/config/modules_config.db'"

Expected result:

• the module row shows enabled=1
• scope includes com.android.systemui|0

7. Verify behavior:

• take a screenshot
• take a second screenshot while the first shelf is still visible
• tap the screenshot preview to confirm the current tap-to-toast debug hook is loaded
• confirm the previous shelf remains visible on-screen and is absent from screenshot N+1

When killall com.android.systemui is enough:

• normal code changes inside the module
• enabling the module or changing its scope
• reinstalling a new APK over the same package

When a reboot may still be useful:

• LSPosed manager UI looks stale after a package rename
• Zygisk/LSPosed itself was just updated
• SystemUI restart did not pick up the new module state
• you suspect a cached or half-dead process outside com.android.systemui

Current Status

What is already working on the target device:

• hook loads in com.android.systemui:screenshot
• the stock screenshot preview can be restyled, proving the hook is in the right process
• ImageCaptureImpl.captureDisplay(...) is intercepted
• the attached ScreenshotUI surface is injected into ScreenCapture.CaptureArgs.Builder.setExcludeLayers(...)
• repeated-shot testing showed byte-identical saved outputs when screenshot N+1 was taken while screenshot N's shelf was visible
• the stock screenshot timeout is overridden to 5000 ms
• stacked-shelf rendering for burst screenshots exists as a prototype
• left-swipe dismissal now tracks a screenshot batch and deletes already-saved files plus late export completions from that same dismissed batch

What is still not fully closed out:

• visual confirmation that there is no blink on the physical display for every entry path
• cleanup of diagnostic logging and hardening of runtime guards
• deciding how much stock screenshot UI to keep versus replacing with custom interactions

Why Root / LSPosed

Public Android APIs are close, but not enough for the exact requirement.

Relevant Android docs:

• https://developer.android.com/about/versions/14/behavior-changes-14#media-projection-consent
• https://developer.android.com/about/versions/14/features/app-screen-sharing
• https://developer.android.com/security/fraud-prevention/activities#flag_secure
• https://developer.android.com/reference/android/view/View#setContentSensitivity(int)
• https://developer.android.com/reference/android/view/WindowManager.LayoutParams#TYPE_APPLICATION_OVERLAY

Important platform constraints:

• MediaProjection requires user consent for each capture session on Android 14+.
• Android app screen sharing can exclude system UI and capture only one app window, but that is not the same thing as "capture full display except my overlay".
• FLAG_SECURE prevents the secure window from appearing in screenshots, but it blanks protected content instead of revealing the pixels underneath.
• View.setContentSensitivity(...) hides marked content during screen sharing, again aimed at protection rather than compositor-style subtraction.
• A normal app overlay uses TYPE_APPLICATION_OVERLAY, but public docs do not expose any full-display screenshot exclusion list for arbitrary app layers.

That is why this repo targets the rooted/system path: hook SystemUI's real screenshot pipeline and inject excluded layers directly.

Current Architecture

• Target process: com.android.systemui:screenshot
• Entry point: HookEntry.java
• Main hook logic: ScreenshotHooks.java
• Runtime state: HookState.java

Current strategy:

1. Let stock SystemUI own the screenshot shelf.
2. Resolve the live ScreenshotUI surface from the attached screenshot window.
3. Intercept ImageCaptureImpl.captureDisplay(...).
4. Rebuild capture args with setExcludeLayers(...).
5. Keep burst state in the hook so repeated screenshots can form a stack and support batch actions.

iOS-Inspired Feature Map

Features observed from iOS screenshot UX and how they map to this project:

• Swipe left to dismiss without saving

  • Status: mostly implemented in the rooted prototype.
  • Notes: left-swipe explicit dismissal now deletes the active batch's saved Uris and late exports for that batch. This still needs on-device UX validation.

• Auto close after 5 seconds while still saving screenshots

  • Status: implemented.
  • Notes: the hook overrides SystemUI's stock screenshot timeout to 5000 ms.

• Share screenshot menu on long press

  • Status: not implemented.
  • Feasibility: easy to medium.
  • Notes: the current hook hides stock chrome, so this is mainly a UX decision. It can be done either by restoring selected stock actions or by attaching a custom long-press menu to the shelf.

• Markup mode on single tap

  • Status: not implemented.
  • Feasibility: easy to medium.
  • Notes: Android's stock screenshot flow already has edit/share affordances in SystemUI. Rewiring single tap to launch markup for the latest screenshot should be straightforward from the current hook position.

• Swipe horizontally through screenshots in a stack

  • Status: not implemented.
  • Feasibility: medium.
  • Notes: the hook already maintains stack state and saved Uris, so this is mostly gesture handling plus view-state switching.

• Drag screenshot into another app / onto an app icon / paste

  • Status: not implemented.
  • Feasibility: medium to hard.
  • Notes: Android has drag-and-drop APIs, but cross-app drag from a transient SystemUI shelf is a bigger integration task than the other items. It is plausible with LSPosed/SystemUI control, but it is not a small follow-up patch.

Practical completion view:

• the hard platform problem, "visible shelf but excluded from screenshot N+1", is already prototyped
• the remaining iOS-style interactions are mostly product/UI work on top of that rooted capture path
• among those, single-tap edit, long-press share, and swipe-through-stack are the most straightforward next additions

Repository Notes

Read these before substantial work:

• TODO.md
• WORKLOG.md
• docs/android-screenshot-research.md
• docs/android15-rooted-hook-plan.md
• docs/lsposed-hook-blueprint.md

Target Environment

• Device: POCO F1 (beryllium)
• ROM: crDroid 11.9
• Android: 15
• Root/tooling: KernelSU, LSPosed, Shizuku
• Module package: fuck.iosstackingscreenshots.droidvendorssuck