iconDataToImageBytes function

Future<Uint8List?> iconDataToImageBytes(IconData iconData, { double size = 25.0, Color color = CupertinoColors.black, })

Renders an IconData to PNG bytes for use in native platform views.

The size parameter controls the logical pixel size of the icon. This function renders the icon at the native size and proper pixel density.

Implementation

Future<Uint8List?> iconDataToImageBytes(
  IconData iconData, {
  double size = 25.0,
  Color color = CupertinoColors.black,
}) async {
  try {
    final RenderRepaintBoundary repaintBoundary = RenderRepaintBoundary();
    final PipelineOwner pipelineOwner = PipelineOwner();
    final BuildOwner buildOwner = BuildOwner(focusManager: FocusManager());

    final RenderView renderView = RenderView(
      view: ui.PlatformDispatcher.instance.views.first,
      child: RenderPositionedBox(
        alignment: Alignment.center,
        child: repaintBoundary,
      ),
      configuration: ViewConfiguration.fromView(
        ui.PlatformDispatcher.instance.views.first,
      ),
    );

    pipelineOwner.rootNode = renderView;
    renderView.prepareInitialFrame();

    final RenderObjectToWidgetElement<RenderBox> rootElement =
        RenderObjectToWidgetAdapter<RenderBox>(
          container: repaintBoundary,
          child: Directionality(
            textDirection: TextDirection.ltr,
            child: Icon(
              iconData,
              size: size,
              color: color, // Will be tinted by native platform
            ),
          ),
        ).attachToRenderTree(buildOwner);

    buildOwner.buildScope(rootElement);
    buildOwner.finalizeTree();

    pipelineOwner.flushLayout();
    pipelineOwner.flushCompositingBits();
    pipelineOwner.flushPaint();

    final ui.Image image = await repaintBoundary.toImage(
      pixelRatio: ui.PlatformDispatcher.instance.views.first.devicePixelRatio,
    );
    final ByteData? byteData = await image.toByteData(
      format: ui.ImageByteFormat.png,
    );

    return byteData?.buffer.asUint8List();
  } catch (e) {
    debugPrint('Error rendering icon to image: $e');
    return null;
  }
}