ca.odell.glazedlists.impl.SimpleFunctionList Maven / Gradle / Ivy
package ca.odell.glazedlists.impl;
import ca.odell.glazedlists.EventList;
import ca.odell.glazedlists.TransformedList;
import ca.odell.glazedlists.FunctionList.Function;
import ca.odell.glazedlists.event.ListEvent;
/**
* A {@link TransformedList} that maps each element of a source list to a target element by use
* of a specified {@link Function}.
*
* Warning: This class is thread ready but not
* thread safe. See {@link EventList} for an example of thread safe code.
*
* @see TransformedList
* @author Holger Brands
*/
public final class SimpleFunctionList extends TransformedList {
/** function to transform each list element. */
private final Function function;
/**
* Constructs a SimpleFunctionList that maps the elements of the given source list by the
* specified function.
*
* @param source the source list to transform
* @param function the mapping function
*/
public SimpleFunctionList(EventList source, Function function) {
super(source);
Preconditions.checkNotNull(function, "mapping function is undefined");
this.function = function;
source.addListEventListener(this);
}
/**
* {@inheritDoc}
*/
@Override
public E get(int index) {
final S elem = source.get(index);
return function.evaluate(elem);
}
/** {@inheritDoc} */
@Override
public void listChanged(ListEvent listChanges) {
updates.forwardEvent(listChanges);
}
/** {@inheritDoc} */
@Override
protected boolean isWritable() {
return false;
}
}