/**
* Implements the algorithm to layout the components of the given container figure. Each component
* is laid out using its own layout constraint specifying its size and position.
*
* @see LayoutManager#layout(IFigure)
*/
public void layout(IFigure parent) {
Iterator children = parent.getChildren().iterator();
Point offset = getOrigin(parent);
IFigure f;
while (children.hasNext()) {
f = (IFigure) children.next();
Rectangle bounds = (Rectangle) getConstraint(f);
if (bounds == null) continue;
if (bounds.width == -1 || bounds.height == -1) {
Dimension preferredSize = f.getPreferredSize(bounds.width, bounds.height);
bounds = bounds.getCopy();
if (bounds.width == -1) bounds.width = preferredSize.width;
if (bounds.height == -1) bounds.height = preferredSize.height;
}
bounds = bounds.getTranslated(offset);
f.setBounds(bounds);
}
}
/**
* Calculates and returns the preferred size of the input figure. Since in XYLayout the location
* of the child should be preserved, the preferred size would be a region which would hold all the
* children of the input figure. If no constraint is set, that child is ignored for calculation.
* If width and height are not positive, the preferred dimensions of the child are taken.
*
* @see AbstractLayout#calculatePreferredSize(IFigure, int, int)
* @since 2.0
*/
protected Dimension calculatePreferredSize(IFigure f, int wHint, int hHint) {
Rectangle rect = new Rectangle();
ListIterator children = f.getChildren().listIterator();
while (children.hasNext()) {
IFigure child = (IFigure) children.next();
Rectangle r = (Rectangle) constraints.get(child);
if (r == null) continue;
if (r.width == -1 || r.height == -1) {
Dimension preferredSize = child.getPreferredSize(r.width, r.height);
r = r.getCopy();
if (r.width == -1) r.width = preferredSize.width;
if (r.height == -1) r.height = preferredSize.height;
}
rect.union(r);
}
Dimension d = rect.getSize();
Insets insets = f.getInsets();
return new Dimension(d.width + insets.getWidth(), d.height + insets.getHeight())
.union(getBorderPreferredSize(f));
}
