// currently doesn't use any gaps or margins

sclass VScrollingWrapLayout > AbstractLayoutManager {

  settable bool centeredHorizontally;

  public void layoutContainer(Container parent) {

    L<Component> components = getComponents(parent);

    class X {

      int maxWidth = parent.getWidth();

      int x, y;

      int lineHeight;

      int componentsInLine, i;

      void finishLine {

        if (centeredHorizontally) {

          int x1 = (maxWidth-x)/2;

          for (int j = i-componentsInLine; j < i; j++) {

            var c = components.get(j);

            Rectangle r = c.getBounds();

            c.setBounds(r.x+x1, r.y, r.width, r.height);

          }

        }

      }

      void run {

        for (i = 0; i < l(components); i++) {

          var c = components.get(i);

          Dimension size = c.getPreferredSize();

          bool needNewLine = componentsInLine != 0 && x+size.width > maxWidth;

          if (needNewLine) {

            finishLine();

            y += lineHeight;

            x = componentsInLine = lineHeight = 0;

          }

          c.setBounds(x, y, size.width, size.height);

          x += size.width;

          lineHeight = max(size.height, lineHeight);

          ++componentsInLine;

        }

        finishLine();

        preferredSize(maxWidth, y+lineHeight);

      }

    }

    new X().run();

  }

}