private Dimension layoutSize(Container target, boolean preferred) {
		synchronized (target.getTreeLock()) {
			// Each row must fit with the width allocated to the containter.
			// When the container width = 0, the preferred width of the
			// container
			// has not yet been calculated so lets ask for the maximum.

			int targetWidth = target.getSize().width;

			if (targetWidth == 0)
				targetWidth = Integer.MAX_VALUE;

			int hgap = getHgap();
			int vgap = getVgap();
			Insets insets = target.getInsets();
			int horizontalInsetsAndGap = insets.left + insets.right
					+ (hgap * 2);
			int maxWidth = targetWidth - horizontalInsetsAndGap;

			// Fit components into the allowed width

			Dimension dim = new Dimension(0, 0);
			int rowWidth = 0;
			int rowHeight = 0;

			int nmembers = target.getComponentCount();

			for (int i = 0; i < nmembers; i++) {
				Component m = target.getComponent(i);

				if (m.isVisible()) {
					Dimension d = preferred ? m.getPreferredSize() : m
							.getMinimumSize();

					// Can't add the component to current row. Start a new row.

					if (rowWidth + d.width > maxWidth) {
						addRow(dim, rowWidth, rowHeight);
						rowWidth = 0;
						rowHeight = 0;
					}

					// Add a horizontal gap for all components after the first

					if (rowWidth != 0) {
						rowWidth += hgap;
					}

					rowWidth += d.width;
					rowHeight = Math.max(rowHeight, d.height);
				}
			}

			addRow(dim, rowWidth, rowHeight);

			dim.width += horizontalInsetsAndGap;
			dim.height += insets.top + insets.bottom + vgap * 2;

			// When using a scroll pane or the DecoratedLookAndFeel we need to
			// make sure the preferred size is less than the size of the
			// target containter so shrinking the container size works
			// correctly. Removing the horizontal gap is an easy way to do this.

			Container scrollPane = SwingUtilities.getAncestorOfClass(
					JScrollPane.class, target);

			if (scrollPane != null) {
				dim.width -= (hgap + 1);
			}

			return dim;
		}
	}