doRenderMarker method

@override void doRenderMarker({ required Canvas canvas, required GChart chart, required GPanel panel, required GComponent<GComponentTheme> component, required GShapeMarker marker, required Rect area, required GOverlayMarkerTheme theme, required GPointViewPort pointViewPort, required GValueViewPort valueViewPort, })

Implementation

@override
void doRenderMarker({
  required Canvas canvas,
  required GChart chart,
  required GPanel panel,
  required GComponent component,
  required GShapeMarker marker,
  required Rect area,
  required GOverlayMarkerTheme theme,
  required GPointViewPort pointViewPort,
  required GValueViewPort valueViewPort,
}) {
  if (marker.keyCoordinates.isNotEmpty) {
    // radius with anchor point and alignment
    final anchor = marker.keyCoordinates[0].toPosition(
      area: area,
      valueViewPort: valueViewPort,
      pointViewPort: pointViewPort,
    );
    radius = marker.radiusSize.toViewSize(
      area: area,
      pointViewPort: pointViewPort,
      valueViewPort: valueViewPort,
    );
    final centerTranslate =
        ((marker.alignment.x.abs() + marker.alignment.y.abs()).round() >= 2)
        ? radius / 1.41421356237
        : radius;
    // calculate the center point from marker.alignment and anchor
    // the alignment is the direction to the anchor point
    center = anchor;
    if (marker.alignment == Alignment.center) {
      center = anchor;
    } else {
      center = Offset(
        anchor.dx + centerTranslate * marker.alignment.x,
        anchor.dy + centerTranslate * marker.alignment.y,
      );
    }

    canvas.save();
    canvas.translate(center.dx, center.dy);
    if (marker.rotation > 1e-6) {
      canvas.rotate(marker.rotation);
    }
    shapePath = marker.pathGenerator(radius);
    drawPath(canvas: canvas, path: shapePath!, style: theme.markerStyle);
    canvas.restore();

    shapePath = shapePath!.shift(Offset(center.dx, center.dy));
    super.controlHandles.clear();
    if (chart.hitTestEnable && marker.hitTestEnable) {
      super.controlHandles.addAll({
        "align": GControlHandle(
          position: center,
          type: GControlHandleType.align,
          keyCoordinateIndex: 0,
        ),
        "anchor": GControlHandle(
          position: anchor,
          type: GControlHandleType.move,
          keyCoordinateIndex: 0,
        ),
        "size": (marker.alignment == Alignment.center)
            ? GControlHandle(
                position: Offset(center.dx + radius, center.dy),
                type: GControlHandleType.resize,
              )
            : GControlHandle(
                position: Offset(
                  center.dx + centerTranslate * marker.alignment.x,
                  center.dy + centerTranslate * marker.alignment.y,
                ),
                type: GControlHandleType.resize,
              ),
      });
    }
    if (marker.highlighted || marker.selected) {
      super.drawControlHandles(
        canvas: canvas,
        marker: marker,
        theme: theme,
        area: area,
        valueViewPort: valueViewPort,
        pointViewPort: pointViewPort,
      );
    }
  }
}