paper_scanner_platform_interface 0.1.0

A common platform interface for the paper_scanner plugin. Defines the detection, perspective-crop and filter operations every platform must implement.

paper_scanner_platform_interface

The common platform interface for the paper_scanner federated plugin.

Apps should depend on paper_scanner, not this package. Implement this interface only if you are writing a new platform implementation.

The contract

PaperScannerPlatform defines four operations:

Method	Purpose
detectInImage(path)	Detect the document quad in a captured still.
detectInFrame(frame)	Realtime detection on a downscaled preview frame.
cropPerspective(path, quad)	Warp the four corners to a flat rectangle.
applyFilter(path, filter)	Enhance / grayscale / black-and-white.

Coordinates are normalized (0..1, top-left origin) and quads are ordered TL, TR, BR, BL.

Channel

The default implementation, MethodChannelPaperScanner, talks over the paper_scanner MethodChannel. Native packages register a handler on that same channel name, so the bundled Android/iOS implementations need no extra Dart registration.

Pigeon migration

A typed equivalent of the channel lives in pigeons/messages.dart. To switch to generated code:

dart run pigeon --input pigeons/messages.dart

This emits lib/src/messages.g.dart plus Messages.g.kt / Messages.g.swift in the implementation packages. Then route MethodChannelPaperScanner through the generated PaperScannerApi and implement the generated host interfaces natively. The hand-authored channel is shipped by default so the package builds without running codegen.