methods/whiteboard_methods/canvas_capture_web library

Web-specific screen annotation capture implementation using JavaScript interop.

This file replicates React's ScreenboardModal approach:

  1. Create a hidden video element to play the screen share stream
  2. Create a hidden canvas to combine video + annotations
  3. Use captureStream() to create a MediaStream of the combined output

This matches the React implementation in ScreenboardModal.tsx's annotatationPreview().

Classes

ScreenAnnotationCapture
Combines screen share video with annotation canvas into a single MediaStream.
WebCanvasCapture
Legacy class for backward compatibility. Prefer using ScreenAnnotationCapture for the React-style implementation.

Extensions

CanvasDrawImageExtension on CanvasRenderingContext2D
Extension to call drawImage with video element using proper JS interop

Functions

isWebCanvasCaptureSupported() → bool
Check if web canvas capture is supported.