markbattistella/maskingtape

Installation

Add MaskingTape to your Swift project using Swift Package Manager:

dependencies: [
  .package(url: "https://github.com/markbattistella/MaskingTape", from: "1.0.0")
]

Alternatively, add it using Xcode via File > Add Packages and entering the package repository URL.

How Capture Protection Works (iOS)

MaskingTape uses the UITextField.isSecureTextEntry rendering side-effect. Content hosted inside the private secure container remains visible in the live app, but iOS omits it from screenshots, screen recordings, and mirroring capture pipelines.

When you provide a replacement overlay with maskingTape { ... }, that replacement is placed behind the secure content so it becomes visible in captured output, like tape appearing on a photocopy.

Quick Start

import MaskingTape

Hide sensitive content in captures

Text("4111 1111 1111 1111")
  .maskingTape()

Hide content and show replacement UI in captures

CardView()
  .maskingTape {
    VStack(spacing: 8) {
      Image(systemName: "lock.fill")
      Text("Protected")
    }
    .frame(maxWidth: .infinity, maxHeight: .infinity)
    .background(.background)
  }

Capture-reactive watermark (recording / mirroring)

DocumentView()
  .watermark {
    Text("CONFIDENTIAL")
      .font(.title.bold())
      .foregroundStyle(.red.opacity(0.22))
      .rotationEffect(.degrees(-30))
  }

Always-visible watermark (use SwiftUI directly)

DocumentView()
  .overlay {
    Text("CONFIDENTIAL")
      .font(.title.bold())
      .foregroundStyle(.red.opacity(0.22))
      .rotationEffect(.degrees(-30))
  }

Public API (Simplified)

Capture Protection

• .maskingTape()
• .maskingTape { replacement }
• MaskingTapeView { ... }

Capture-Reactive Watermark

• .watermark { overlay }
• WatermarkView { ... }

watermark is intentionally capture-aware only. If you want a watermark that is always visible, use SwiftUI's built-in .overlay.

Full-Screen Usage (Scrolling Screens)

To keep protection/watermarking tied to the visible viewport while content scrolls, apply the modifier to the outer container (NavigationStack, TabView, etc.), not the inner ScrollView content:

NavigationStack {
  ScrollView {
    // content
  }
}
.maskingTape {
  Color(uiColor: .systemBackground)
}

NavigationStack {
  ScrollView {
    // content
  }
}
.watermark {
  Text("MASKINGTAPE")
}

Platform Notes

• iOS: maskingTape uses the secure text-field container technique; watermark reacts to UIScreen.isCaptured
• macOS: maskingTape uses NSWindow.sharingType = .none (window-wide); capture state for reactive watermarking is not publicly available without extra permissions
• tvOS: secure masking is not applied; capture-reactive watermarking is available
• watchOS: watermark APIs fall back to always-hidden-unless-explicit behavior (no capture-state concept)
• visionOS: secure masking behavior is unverified and currently treated conservatively

Important Limitations

• iOS does not provide a public "will screenshot" callback
• UIApplication.userDidTakeScreenshotNotification fires after the screenshot is already captured
• You cannot insert a watermark into a system screenshot after the capture has occurred
• The iOS secure masking technique depends on UIKit internals and may break if Apple changes the private view hierarchy

Example App

The included example demonstrates:

• maskingTape() on individual views
• maskingTape { replacement } with custom capture replacement content
• Capture-reactive .watermark { ... }
• Full-screen masking and full-screen watermarking on scrolling screens
• A bottom inset watermark pattern for active recording / mirroring sessions

Contributing

Contributions are welcome. Please open an Issue or PR for fixes, feature proposals, or documentation improvements.

PR titles should follow the format: YYYY-mm-dd - Title

Licence

MaskingTape is released under the MIT licence.

Package Metadata

Repository: markbattistella/maskingtape

Default branch: main

README: README.md