capture method

Future<CockpitCapturedScreenshot> capture({ required GlobalKey<State<StatefulWidget>> repaintBoundaryKey, required CockpitScreenshotRequest request, CockpitSnapshot? snapshot, double pixelRatio = 1.0, Rect? cropRect, })

Implementation

Future<CockpitCapturedScreenshot> capture({
  required GlobalKey repaintBoundaryKey,
  required CockpitScreenshotRequest request,
  CockpitSnapshot? snapshot,
  double pixelRatio = 1.0,
  ui.Rect? cropRect,
}) async {
  if (SchedulerBinding.instance.schedulerPhase != SchedulerPhase.idle) {
    await WidgetsBinding.instance.endOfFrame;
  }

  final context = repaintBoundaryKey.currentContext;
  if (context == null) {
    throw StateError('CockpitSurface capture boundary is not mounted.');
  }

  final boundary = context.findRenderObject();
  if (boundary is! RenderRepaintBoundary) {
    throw StateError(
      'CockpitSurface capture boundary is not a RepaintBoundary.',
    );
  }

  var image = await boundary.toImage(pixelRatio: pixelRatio);
  if (cropRect != null) {
    final left = (cropRect.left * pixelRatio).floor().clamp(0, image.width);
    final top = (cropRect.top * pixelRatio).floor().clamp(0, image.height);
    final right = (cropRect.right * pixelRatio).ceil().clamp(
      left,
      image.width,
    );
    final bottom = (cropRect.bottom * pixelRatio).ceil().clamp(
      top,
      image.height,
    );
    final width = right - left;
    final height = bottom - top;
    if (width == 0 || height == 0) {
      image.dispose();
      throw StateError('Screenshot crop region is empty.');
    }
    final recorder = ui.PictureRecorder();
    final canvas = ui.Canvas(recorder);
    canvas.drawImageRect(
      image,
      ui.Rect.fromLTWH(
        left.toDouble(),
        top.toDouble(),
        width.toDouble(),
        height.toDouble(),
      ),
      ui.Rect.fromLTWH(0, 0, width.toDouble(), height.toDouble()),
      ui.Paint(),
    );
    final cropped = await recorder.endRecording().toImage(width, height);
    image.dispose();
    image = cropped;
  }
  final byteData = await image.toByteData(format: ui.ImageByteFormat.png);
  image.dispose();

  if (byteData == null) {
    throw StateError('Failed to encode CockpitSurface capture as PNG.');
  }

  final bytes = byteData.buffer.asUint8List(
    byteData.offsetInBytes,
    byteData.lengthInBytes,
  );
  if (bytes.isEmpty) {
    throw StateError('CockpitSurface capture encoded an empty PNG.');
  }

  return CockpitCapturedScreenshot(
    artifact: CockpitArtifactRef(
      role: 'screenshot',
      relativePath: cockpitScreenshotRelativePathFor(request),
    ),
    bytes: bytes,
    snapshot: snapshot,
  );
}