performPaint method

@override void performPaint(Buffer buffer, Offset offset)

Hook for subclasses to implement actual painting.

Implementation

@override
void performPaint(Buffer buffer, Offset offset) {
  if (size.width <= 0 || size.height <= 0) return;

  final hasOverflow = _overflowTop > 0 || _overflowBottom > 0;
  if (hasOverflow) {
    buffer.pushClip(
      Rect(offset.dx.toInt(), offset.dy.toInt(), size.width, size.height),
    );
  }

  for (final child in childElements) {
    child.paint(buffer, offset + child.relativeOffset);
  }

  if (_overflowTop > 0 || _overflowBottom > 0) {
    final tapeHeight = size.height < 3 ? size.height : 3;

    if (_overflowTop > 0) {
      final bounds = Rect(
        offset.dx.toInt(),
        offset.dy.toInt(),
        size.width,
        tapeHeight,
      );
      buffer.drawCautionTape(bounds, offset.dx.toInt(), offset.dy.toInt());
    }

    if (_overflowBottom > 0) {
      final bounds = Rect(
        offset.dx.toInt(),
        (offset.dy + size.height - tapeHeight).toInt(),
        size.width,
        tapeHeight,
      );
      buffer.drawCautionTape(bounds, offset.dx.toInt(), bounds.top);
    }
  }

  if (hasOverflow) {
    buffer.popClip();
  }
}