debugPaint method

  1. @override
void debugPaint (
  1. PaintingContext context,
  2. Offset offset
)
inherited

Override this method to paint debugging information.

Implementation

@override
void debugPaint(PaintingContext context, Offset offset) {
  assert(() {
    if (debugPaintSizeEnabled) {
      final double strokeWidth = math.min(4.0, geometry.paintExtent / 30.0);
      final Paint paint = Paint()
        ..color = const Color(0xFF33CC33)
        ..strokeWidth = strokeWidth
        ..style = PaintingStyle.stroke
        ..maskFilter = MaskFilter.blur(BlurStyle.solid, strokeWidth);
      final double arrowExtent = geometry.paintExtent;
      final double padding = math.max(2.0, strokeWidth);
      final Canvas canvas = context.canvas;
      canvas.drawCircle(
        offset.translate(padding, padding),
        padding * 0.5,
        paint,
      );
      switch (constraints.axis) {
        case Axis.vertical:
          canvas.drawLine(
            offset,
            offset.translate(constraints.crossAxisExtent, 0.0),
            paint,
          );
          _debugDrawArrow(
            canvas,
            paint,
            offset.translate(constraints.crossAxisExtent * 1.0 / 4.0, padding),
            offset.translate(constraints.crossAxisExtent * 1.0 / 4.0, arrowExtent - padding),
            constraints.normalizedGrowthDirection,
          );
          _debugDrawArrow(
            canvas,
            paint,
            offset.translate(constraints.crossAxisExtent * 3.0 / 4.0, padding),
            offset.translate(constraints.crossAxisExtent * 3.0 / 4.0, arrowExtent - padding),
            constraints.normalizedGrowthDirection,
          );
          break;
        case Axis.horizontal:
          canvas.drawLine(
            offset,
            offset.translate(0.0, constraints.crossAxisExtent),
            paint,
          );
          _debugDrawArrow(
            canvas,
            paint,
            offset.translate(padding, constraints.crossAxisExtent * 1.0 / 4.0),
            offset.translate(arrowExtent - padding, constraints.crossAxisExtent * 1.0 / 4.0),
            constraints.normalizedGrowthDirection,
          );
          _debugDrawArrow(
            canvas,
            paint,
            offset.translate(padding, constraints.crossAxisExtent * 3.0 / 4.0),
            offset.translate(arrowExtent - padding, constraints.crossAxisExtent * 3.0 / 4.0),
            constraints.normalizedGrowthDirection,
          );
          break;
      }
    }
    return true;
  }());
}