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Capability Matrix

Every ComposeShield capability resolves a SupportLevel per platform, per OS version, and — for one capability on Android — per currently-active capability. This page is the published form of that matrix.

It is a contract, not documentation: CapabilityMatrixTest asserts that runtime ComposeShield.supportLevel() matches these rows on every tier.

Support is evaluated at call time, never cached at startup. Read Platform Notes for details.

Cross-platform summary

Capability Android iOS
ScreenshotPrevention Supported (24+) Supported (15+)
RecordingPrevention Supported (24+) Supported (15+)
CaptureDetection Supported (35+) Supported (15+)
ScreenshotEvents Supported (34+), precluded by active prevention Supported (15+)
TaskSwitcherProtection Supported (24+ with prevention; 33+ standalone) Supported (15+)

Android (minSdk 24)

Capability Mechanism Supported from Permission Level
ScreenshotPrevention FLAG_SECURE 24 (all) none Supported
RecordingPrevention FLAG_SECURE 24 (all) none Supported
CaptureDetection — recording WindowManager.addScreenRecordingCallback 35 DETECT_SCREEN_RECORDING (normal) Supported ≥35, else Unsupported(OsVersionTooLow)
CaptureDetection — external display DisplayManager + DisplayListener 24 none Supported
ScreenshotEvents Activity.registerScreenCaptureCallback 34 DETECT_SCREEN_CAPTURE (normal) see conflict below
TaskSwitcherProtection — with prevention FLAG_SECURE (covers recents) 24 none Supported
TaskSwitcherProtection — standalone setRecentsScreenshotEnabled(false) 33 none Supported ≥33, else Unsupported(OsVersionTooLow)

Both permissions are protectionLevel="normal" — install-time, no runtime prompt, no user-facing dialog, no data access.

The Android prevention/detection conflict

ScreenshotEvents resolves dynamically:

Condition Result
API < 34 Unsupported(OsVersionTooLow)
API ≥ 34, no prevention active Supported
API ≥ 34, prevention active Unsupported(PrecludedByActiveCapability)

This is platform behaviour, not a library design choice — see Platform Notes.

Android coverage gaps

  • Recording detection sees only MediaProjection-based capture. Not scrcpy, ADB screenrecord, HDMI capture, or OEM recorders that bypass MediaProjection.
  • Screenshot detection fires only for hardware-button screenshots; ADB captures are invisible. The system also shows the user a toast on every detection.
  • FLAG_SECURE does not block autofill services (working as intended per AOSP).

iOS (15+)

Capability Mechanism Supported from Level
ScreenshotPrevention Secure-container reparenting 15 Supported
RecordingPrevention Secure-container reparenting 15 Supported
CaptureDetection UITraitSceneCaptureState on UIWindowScene 17 Supported
CaptureDetection (fallback) UIScreen.capturedDidChangeNotification 15 Supported
ScreenshotEvents userDidTakeScreenshotNotification 15 Supported
TaskSwitcherProtection Overlay on scene resign-active 15 Supported

ScreenshotPrevention and RecordingPrevention share the single secure-container mechanism on iOS.

See Platform Notes for iOS platform details.

iOS coverage gaps

  • CaptureDetection reports scene-level capture participation, not device-level recording.
  • Screenshot events are strictly post-hoc and cannot prevent the capture that triggered them.
  • Neither prevention nor detection can be verified in the Simulator; both are device-only.

What this library does not claim

No software mechanism prevents photographing a screen with a second device, or capture on a rooted or jailbroken device. On Android, FLAG_SECURE is trivially bypassed by LSPosed or Frida hooks.

CaptureState.Inactive means "no evidence of capture," never "not being captured." Both platforms' detection has the documented blind spots listed above. Do not treat Inactive as a security guarantee, and do not gate the display of sensitive content on it alone — use prevention for that.