/** * Simple implementation of a singleton. * * @author [email protected] (Alex North) */ public final class ObservableSingletonImpl<V, I> implements ObservableSingleton<V, I> { /** Factory which creates value objects from abstract initial state. */ interface Factory<V, I> { V create(I initialState); } private final Factory<V, I> factory; private final CopyOnWriteSet<Listener<? super V>> listeners = CopyOnWriteSet.create(); private V value = null; public ObservableSingletonImpl(Factory<V, I> factory) { this.factory = factory; } @Override public boolean hasValue() { return value != null; } @Override public V get() { return value; } @Override public V set(I initialState) { V oldValue = value; value = factory.create(initialState); maybeTriggerOnValueChanged(oldValue, value); return value; } @Override public void clear() { V oldValue = value; value = null; maybeTriggerOnValueChanged(oldValue, value); } @Override public void addListener(Listener<? super V> listener) { listeners.add(listener); } @Override public void removeListener(Listener<? super V> listener) { listeners.remove(listener); } private void maybeTriggerOnValueChanged(V oldValue, V newValue) { if (ValueUtils.notEqual(oldValue, newValue)) { for (Listener<? super V> l : listeners) { l.onValueChanged(oldValue, newValue); } } } }
/** A wave panel, which is just a view and an event system. */
public final class WavePanelImpl implements WavePanel, Focusable {
/** Event system on which features install their controllers. */
private final EventDispatcherPanel panel;
/** Key handlers for key events that are routed to this panel. */
private final KeySignalRouter keys = new KeySignalRouter();
/** Views through which features manipulate the UI. */
private final DomAsViewProvider views;
private final CopyOnWriteSet<LifecycleListener> listeners = CopyOnWriteSet.create();
//
// Fields referencing the wave rendering are dynamically inserted and removed.
//
/** True between {@link #init} and {@link #reset}. */
private boolean initialized;
/** Main conversation shown in this panel. */
private TopConversationView main;
private WavePanelImpl(DomAsViewProvider views, EventDispatcherPanel panel) {
this.views = views;
this.panel = panel;
}
/**
* Creates a wave panel.
*
* @param views view bundle
* @param panelDom element in the DOM on which to build the wave panel
* @param container panel to adopt the wave panel's widget, or {@code null} for the wave panel to
* be a root widget
*/
public static WavePanelImpl create(
DomAsViewProvider views, Element panelDom, LogicalPanel container) {
Preconditions.checkArgument(panelDom != null);
EventDispatcherPanel events =
(container != null)
? EventDispatcherPanel.inGwtContext(panelDom, container)
: EventDispatcherPanel.of(panelDom);
WavePanelImpl panel = new WavePanelImpl(views, events);
// Existing content?
Element frameDom = panelDom.getFirstChildElement();
if (frameDom != null) {
panel.init(frameDom);
}
return panel;
}
/** Destroys this wave panel, releasing its resources. */
public void destroy() {
panel.removeFromParent();
}
@Override
public DomAsViewProvider getViewProvider() {
return views;
}
@Override
public EventHandlerRegistry getHandlers() {
return panel;
}
@Override
public LogicalPanel getGwtPanel() {
return panel;
}
@Override
public KeySignalRouter getKeyRouter() {
return keys;
}
@Override
public boolean hasContents() {
return main != null;
}
@Override
public TopConversationView getContents() {
Preconditions.checkState(main != null);
return main;
}
//
// Key plumbing.
//
@Override
public boolean onKeySignal(KeyCombo key) {
return keys.onKeySignal(key);
}
@Override
public void onFocus() {}
@Override
public void onBlur() {}
//
// Lifecycle.
//
public void init(Element main) {
Preconditions.checkState(!initialized);
boolean fireEvent; // true if onInit should be fired before exiting.
if (main != null) {
panel.getElement().appendChild(main);
this.main = views.asTopConversation(main);
fireEvent = true;
} else {
// Render empty message.
panel.getElement().setInnerHTML("No conversations in this wave.");
fireEvent = false;
}
initialized = true;
if (fireEvent) {
fireOnInit();
}
}
public void reset() {
Preconditions.checkState(initialized);
boolean fireEvent; // true if onInit should be fired before exiting.
initialized = false;
if (main != null) {
main.remove();
main = null;
fireEvent = true;
} else {
panel.getElement().setInnerHTML("");
fireEvent = false;
}
if (fireEvent) {
fireOnReset();
}
}
@Override
public void addListener(LifecycleListener listener) {
listeners.add(listener);
}
@Override
public void removeListener(LifecycleListener listener) {
listeners.remove(listener);
}
private void fireOnInit() {
for (LifecycleListener listener : listeners) {
listener.onInit();
}
}
private void fireOnReset() {
for (LifecycleListener listener : listeners) {
listener.onReset();
}
}
}
@Override
public void removeListener(LifecycleListener listener) {
listeners.remove(listener);
}
@Override
public void addListener(LifecycleListener listener) {
listeners.add(listener);
}
public class ListType extends Type implements SourcesEvents<ListType.Listener> {
public interface Listener {
public void onValueAdded(Type entry);
public void onValueRemoved(Type entry);
}
protected static Type createAndAttach(Model model, String id) {
Preconditions.checkArgument(id.startsWith(PREFIX), "ListType.createAndAttach() not a list id");
ListType list = new ListType(model);
list.attach(id);
return list;
}
public static final String TYPE_NAME = "ListType";
public static final String PREFIX = "list";
public static final String ROOT_TAG = "list";
private static final String ITEM_TAG = "item";
private ObservableElementList<Type, ListElementInitializer> observableList;
private ObservableElementList.Listener<Type> observableListListener;
private Model model;
private String backendDocumentId;
private ObservableDocument backendDocument;
private Doc.E backendRootElement;
private boolean isAttached;
private final CopyOnWriteSet<Listener> listeners = CopyOnWriteSet.create();
protected ListType(Model model) {
this.model = model;
this.isAttached = false;
observableListListener =
new ObservableElementList.Listener<Type>() {
@Override
public void onValueAdded(Type entry) {
for (ListType.Listener l : listeners) l.onValueAdded(entry);
}
@Override
public void onValueRemoved(Type entry) {
for (ListType.Listener l : listeners) l.onValueRemoved(entry);
}
};
}
//
// Type interface
//
@Override
protected String getPrefix() {
return PREFIX;
}
@Override
protected void attach(String docId) {
if (docId == null) {
docId = model.generateDocId(getPrefix());
backendDocument = model.createDocument(docId);
} else backendDocument = model.getDocument(docId);
backendDocumentId = docId;
// Create a root tag to ensure the document is persisted.
// If the doc is created empty and it's not populated with data it won't
// exist when the wavelet is open again.
backendRootElement = DocHelper.getElementWithTagName(backendDocument, ROOT_TAG);
if (backendRootElement == null)
backendRootElement =
backendDocument.createChildElement(
backendDocument.getDocumentElement(),
ROOT_TAG,
Collections.<String, String>emptyMap());
DocEventRouter router = DefaultDocEventRouter.create(backendDocument);
this.observableList =
DocumentBasedElementList.create(
router, backendRootElement, ITEM_TAG, new ListElementFactory(model));
this.observableList.addListener(observableListListener);
this.isAttached = true;
}
protected void deattach() {
Preconditions.checkArgument(isAttached, "Unable to deattach an unattached MapType");
// nothing to do. wavelet doesn't provide doc deletion
}
@Override
protected boolean isAttached() {
return isAttached;
}
@Override
protected String serializeToModel() {
Preconditions.checkArgument(isAttached, "Unable to serialize an unattached ListType");
return backendDocumentId;
}
@Override
protected ListElementInitializer getListElementInitializer() {
return new ListElementInitializer() {
@Override
public String getType() {
return PREFIX;
}
@Override
public String getBackendId() {
return serializeToModel();
}
};
}
//
// Listeners
//
@Override
public void addListener(Listener listener) {
listeners.add(listener);
}
@Override
public void removeListener(Listener listener) {
listeners.remove(listener);
}
//
// List operations
//
public Type add(Type value) {
Preconditions.checkArgument(isAttached, "ListType.add(): not attached to model");
Preconditions.checkArgument(
!value.isAttached(), "ListType.add(): forbidden to add an already attached Type");
value.attach(null);
Type listValue = observableList.add(value.getListElementInitializer());
// return the value generated from list to double check add() success
// also it is the cached value in the observable list
return listValue;
}
public Type add(int index, Type value) {
Preconditions.checkArgument(
index >= 0 && index <= observableList.size(), "ListType.add(): add to index out of bounds");
Preconditions.checkArgument(isAttached, "ListType.add(): not attached to model");
Preconditions.checkArgument(
!value.isAttached(), "ListType.add(): forbidden to add an already attached Type");
value.attach(null);
Type listValue = observableList.add(index, value.getListElementInitializer());
// return the value generated from list to double check add() success
// also it is the cached value in the observable list
return listValue;
}
public Type remove(int index) {
if (observableList == null) return null;
Type removedInstance = observableList.get(index);
if (!observableList.remove(removedInstance)) return null;
return removedInstance;
}
public Type get(int index) {
if (observableList == null) return null;
Preconditions.checkArgument(
index >= 0 && index < observableList.size(), "ListType.get(): add to index out of bounds");
return observableList.get(index);
}
public int indexOf(Type type) {
return observableList != null ? observableList.indexOf(type) : -1;
}
public int size() {
return observableList != null ? observableList.size() : 0;
}
public Iterable<Type> getValues() {
return observableList != null ? observableList.getValues() : Collections.<Type>emptyList();
}
@Override
public String getDocumentId() {
return backendDocumentId;
}
@Override
public Model getModel() {
return model;
}
@Override
public String getType() {
return TYPE_NAME;
}
}
