Geometry Calculations

	Geometry Calculations

Changing the preferred size of an object does not change its size, or trigger any geometry negotiation e.g. resetting the label of a Button does not change the size
Changing the preferred size of an object automatically invalidates it.
To force a size recalculation for invalid children of a Container call layout() on the Container.

This will force a resize each time the label is reset:

class AutoResizeButton extends Button {
    public void setLabel(String name) {
        super.setLabel(name);
        getParent().layout();
    }
}

(See GrowMe.java)

Slide 58

Jan Newmarch