WrapLayout with a left alignment and a
- * default 5-unit horizontal and vertical gap.
- */
- public WrapLayout() {
- super();
- }
-
- /**
- * Constructs a new FlowLayout with the specified alignment and
- * a default 5-unit horizontal and vertical gap. The value of the alignment
- * argument must be one of WrapLayout, WrapLayout,
- * or WrapLayout.
- *
- * @param align
- * the alignment value
- */
- public WrapLayout(int align) {
- super(align);
- }
-
- /**
- * Creates a new flow layout manager with the indicated alignment and the
- * indicated horizontal and vertical gaps.
- *
- * The value of the alignment argument must be one of
- * WrapLayout, WrapLayout, or
- * WrapLayout.
- *
- * @param align
- * the alignment value
- * @param hgap
- * the horizontal gap between components
- * @param vgap
- * the vertical gap between components
- */
- public WrapLayout(int align, int hgap, int vgap) {
- super(align, hgap, vgap);
- }
-
- /**
- * Returns the preferred dimensions for this layout given the visible
- * components in the specified target container.
- *
- * @param target
- * the component which needs to be laid out
- * @return the preferred dimensions to lay out the subcomponents of the
- * specified container
- */
- @Override
- public Dimension preferredLayoutSize(Container target) {
- return layoutSize(target, true);
- }
-
- /**
- * Returns the minimum dimensions needed to layout the visible
- * components contained in the specified target container.
- *
- * @param target
- * the component which needs to be laid out
- * @return the minimum dimensions to lay out the subcomponents of the
- * specified container
- */
- @Override
- public Dimension minimumLayoutSize(Container target) {
- Dimension minimum = layoutSize(target, false);
- minimum.width -= (getHgap() + 1);
- return minimum;
- }
-
- /**
- * Returns the minimum or preferred dimension needed to layout the target
- * container.
- *
- * @param target
- * target to get layout size for
- * @param preferred
- * should preferred size be calculated
- * @return the dimension to layout the target container
- */
- 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;
- Container container = target;
-
- while (container.getSize().width == 0
- && container.getParent() != null) {
- container = container.getParent();
- }
-
- targetWidth = container.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 && target.isValid()) {
- dim.width -= (hgap + 1);
- }
-
- return dim;
- }
- }
-
- /*
- * A new row has been completed. Use the dimensions of this row to update
- * the preferred size for the container.
- *
- * @param dim update the width and height when appropriate
- *
- * @param rowWidth the width of the row to add
- *
- * @param rowHeight the height of the row to add
- */
- private void addRow(Dimension dim, int rowWidth, int rowHeight) {
- dim.width = Math.max(dim.width, rowWidth);
-
- if (dim.height > 0) {
- dim.height += getVgap();
- }
-
- dim.height += rowHeight;
- }
-}
\ No newline at end of file