Right alignment with SpringLayout

Question

I've just started playing with SpringLayout. I've been using mostly BoxLayout up to now but I thought it was time I gave an alternative a go. BoxLayout has it's own erratic sizing problems.
Anyway I'm trying to generate a sub panel like:
Title (centered)
Quantity1 888
Quantity2 99
<Table> <PieChart>
With the numbers against the RHS of the box
First thing I've found is that putting a zero length Spring between the NORTH of the lable and the value doesn't work, I have to set both relative to the previous line or (mysteriously) no vertical separation happens at all.
Here's the code that adds a lable/value pair:
    private static Component addPair(Component prev, String label, JLabel value) {
        Container c = prev.getParent();
        SpringLayout l = (SpringLayout)c.getLayout();
        JLabel nameLab  = new JLabel(label);
        c.add(nameLab);
        c.add(value);
        l.getConstraints(nameLab).setHeight(Spring.constant(12));
        l.putConstraint(SpringLayout.NORTH, nameLab, 2, SpringLayout.SOUTH, prev);
        l.putConstraint(SpringLayout.WEST, nameLab, 10, SpringLayout.WEST, c);
        l.putConstraint(SpringLayout.EAST, c, 10, SpringLayout.EAST, value);
        l.putConstraint(SpringLayout.NORTH, value, 2, SpringLayout.SOUTH, prev);
     //   l.putConstraint(SpringLayout.SOUTH, nameLab, 0, SpringLayout.SOUTH, value);
        l.putConstraint(SpringLayout.WEST, value, Spring.constant(10, 10, 500),
                SpringLayout.EAST, nameLab);
        return nameLab;
    }prev being the label from the previous pair.
It refuses to right align the value lable. It looks like the constraint between the EAST of the value and the EAST of the container has no effect. I've also set the alignment in the JLabels to RIGHT, which has no effect.
If I take out the constraint between the WEST of the value and the EAST of the lable It plonks the lable and value on top of one another.
Furthermore, though the hieght of the pie chart is set explictly by a constraint, the LayoutManager seems incapable of producing a sensible minimum height for the overall box.
All of which makes me wonder if SpringLayout is worth persevering with or if there are just tricks and gaps I have to learn to deal with.

Answer 1

I think I've cracked it. Some things they don't tell you about SpringLayout, which I found out mostly by reading the source.
putConstraint is not symetrical. Logically
putConstraint(SpringLayout.WEST, container, 10, SpringLayout.WEST,
valueLab);might be expected to imply:
putConstraint(SpringLayout.WEST, valueLab, -10,  SpringLayout.WEST,
container);But it doesn't. Only the first object in the call is actually constrained.
Secondly the "overconstraint" thing is very arbitary. Setting the NORTH or WEST clears the EAST or SOUTH wherease setting the EAST or SOUTH clears the height or width. Hence if you set, for example, EAST and WEST then it's essential to set EAST first, otherwise WEST will be ignored and the WEST will be set from EAST - width. There seems to be no way of clearing a constraint once set, and constraints are intialised from the objects bounds, so NORTH and WEST are always set to zero initially. If seems like the contraints are almost always going to be treated as overconstrained.
Parallel constraints don't get combined, the last one specified predominates so there doesn't seem any sensible way of, for example, setting the width of a container based on the maximum of the widths of fields contained.
There seems to be no use of the springiness of Spring objects. They are merely treated as min, pref and max values. Logically stretchiness should be used to distribute space, and to cope with springs in parallel. It doesn't appear any of that stuff is done.