JarCastingVCollections
Lightweight observable collections (used by VMF and VRL).
Features
- Observable List
- Mapped List (keeps two lists with different element types in sync)
- coming sooner or later: ObservableMap and ObservableSet
Code Sample
Observing Changes
public class Main {
public static void main(String[] args) {
// creates an ordinary list
List<Integer> list = new ArrayList<>();
// to make the list observable, we wrap it in a VList
VList<Integer> vList = VList.newInstance(list);
// to get notified, we add a change listener to the VList
Subscription subscription = vList.addChangeListener((evt) -> {
// for now, we just print the changes
System.out.println(EventUtil.toStringWithDetails(evt));
});
// add individual elements (generates 3 events)
System.out.println(">> add 3 individual elements");
vList.add(1);
vList.add(2);
vList.add(3);
// add collection of elements (generates only one event)
System.out.println(">> add one collection of elements");
vList.addAll(Arrays.asList(4, 5, 6));
// remove individual elements (generates 3 events)
System.out.println(">> remove 3 individual elements");
vList.remove((Integer) 1);
vList.remove((Integer) 2);
vList.remove((Integer) 3);
// remove collection of elements (generates only one event)
System.out.println(">> remove one collection of elements");
vList.removeAll(Arrays.asList(4,5,6));
// unsubscribe the listener from vList
subscription.unsubscribe();
// add elements without generating events
System.out.println(">> add one collection of elements without notification");
vList.addAll(Arrays.asList(4, 5, 6));
}
}
Observing Unmodifiable Lists
public class Main {
public static void main(String[] args) {
// creates an ordinary list
List<Integer> list = new ArrayList<>();
// to make the list observable, we wrap it in a VList
VList<Integer> vList = VList.newInstance(list);
// How to make the list unmodifiable and still listen to changes?
// THIS DOES NOT WORK: VList.newInstance(Collections.unmodifiableList(list));
VList<Integer> vListUnmodifiable = vList.asUnmodifiable();
// to get notified, we add a change listener to the unmodifiable VList
Subscription subscription = vListUnmodifiable.addChangeListener((evt) -> {
// for now, we just print the changes
System.out.println(EventUtil.toStringWithDetails(evt));
});
// add element and generate event
vList.add(1);
// modifying the unmodifiable list results in RuntimeException...
vListUnmodifiable.add(37);
}
}
How to Build VCollections
Requirements
- Java >= 1.8
- Internet connection (dependencies are downloaded automatically)
- IDE: Gradle Plugin (not necessary for command line usage)
IDE
Open the VCollections Gradle project in your favourite IDE (tested with NetBeans 8.2) and build it by calling the assemble task.
Command Line
Navigate to the Gradle project (e.g., path/to/VCollections) and enter the following command
Bash (Linux/OS X/Cygwin/other Unix-like shell)
bash gradlew assemble
Windows (CMD)
gradlew assemble