This class enables one to store an entry in the defaults
table that isn't constructed until the first time it's
looked up with one of the
getXXX(key)
methods.
Lazy values are useful for defaults that are expensive
to construct or are seldom retrieved. The first time
a
LazyValue
is retrieved its "real value" is computed
by calling
LazyValue.createValue()
and the real
value is used to replace the
LazyValue
in the
UIDefaults
table. Subsequent lookups for the same key return
the real value. Here's an example of a
LazyValue
that constructs a
Border
:
Object borderLazyValue = new UIDefaults.LazyValue() {
public Object createValue(UIDefaults table) {
return new BorderFactory.createLoweredBevelBorder();
}
};
uiDefaultsTable.put("MyBorder", borderLazyValue);
Creates the actual value retrieved from the UIDefaults
table. When an object that implements this interface is
retrieved from the table, this method is used to create
the real value, which is then stored in the table and
returned to the calling method.