DiagramShapeThumbnail constructor

DiagramShapeThumbnail(ShapeDefinition definition, { required ShapeRegistry registry, DiagramTheme theme = DiagramTheme.light, })

Implementation

factory DiagramShapeThumbnail(
  ShapeDefinition definition, {
  required ShapeRegistry registry,
  DiagramTheme theme = DiagramTheme.light,
}) {
  final shape = ShapeElement(
    id: 'thumbnail',
    type: definition.type,
    frame: DiagramRect.fromLTWH(
      0,
      0,
      definition.size.width,
      definition.size.height,
    ),
    style: definition.style,
    textStory: definition.createTextStory('thumbnail'),
    values: definition.createValues(definition.previewValues),
  );
  final scene = DiagramResolver(
    registry: registry,
    textLayout: FlutterDiagramTextLayoutEngine(),
  ).resolve(DiagramDocument(id: 'thumbnail', revision: 0, elements: [shape]));
  final bounds = scene.bounds.inflate(6);
  final size = Size(bounds.width, bounds.height);
  final cache = DiagramScenePaintCache();
  final camera = DiagramCamera.fixed(
    DiagramCameraState(
      center: bounds.center,
      zoom: 1,
      viewportSize: DiagramSize(bounds.width, bounds.height),
    ),
  );
  final recorder = ui.PictureRecorder();
  try {
    DiagramScenePainter(
      scene: scene,
      camera: camera,
      selection: const EmptySelection(),
      grid: const GridOptions(),
      lodPolicy: const DiagramLodPolicy(),
      paintCache: cache,
      theme: theme,
      contentOnly: true,
    ).paint(Canvas(recorder), size);
    return DiagramShapeThumbnail._(recorder.endRecording(), size);
  } catch (_) {
    recorder.endRecording().dispose();
    rethrow;
  } finally {
    cache.dispose();
  }
}