render method

@override void render(Buffer buffer, Rect area)

Renders the widget onto the provided buffer within the specified area.

Implementation

@override
void render(Buffer buffer, Rect area) {
  int childWidth = area.width;
  int childHeight = area.height;

  if (child is SizedBox) {
    final sb = child as SizedBox;
    childWidth = sb.width ?? area.width;
    childHeight = sb.height ?? area.height;
  } else if (child is ConstrainedBox) {
    final cb = child as ConstrainedBox;
    childWidth = area.width.clamp(
      cb.constraints.minWidth,
      cb.constraints.maxWidth,
    );
    childHeight = area.height.clamp(
      cb.constraints.minHeight,
      cb.constraints.maxHeight,
    );
  }

  if (widthFactor != null) {
    childWidth = (childWidth * widthFactor!).round();
  }
  if (heightFactor != null) {
    childHeight = (childHeight * heightFactor!).round();
  }

  childWidth = childWidth.clamp(0, area.width);
  childHeight = childHeight.clamp(0, area.height);

  final double remainingWidth = (area.width - childWidth).toDouble();
  final int offsetX = (remainingWidth * (alignment.x + 1.0) / 2.0).round();

  final double remainingHeight = (area.height - childHeight).toDouble();
  final int offsetY = (remainingHeight * (alignment.y + 1.0) / 2.0).round();

  final childArea = Rect(
    area.x + offsetX,
    area.y + offsetY,
    childWidth,
    childHeight,
  );

  final childViewport = Viewport(buffer, childArea);
  child.render(childViewport, Rect(0, 0, childWidth, childHeight));
}