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Diffstat (limited to 'server/src/com/vaadin/data/util/AbstractProperty.java')
| -rw-r--r-- | server/src/com/vaadin/data/util/AbstractProperty.java | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/server/src/com/vaadin/data/util/AbstractProperty.java b/server/src/com/vaadin/data/util/AbstractProperty.java new file mode 100644 index 0000000000..373a8dfd58 --- /dev/null +++ b/server/src/com/vaadin/data/util/AbstractProperty.java @@ -0,0 +1,226 @@ +/* +@VaadinApache2LicenseForJavaFiles@ + */ +package com.vaadin.data.util; + +import java.util.Collection; +import java.util.Collections; +import java.util.LinkedList; + +import com.vaadin.data.Property; + +/** + * Abstract base class for {@link Property} implementations. + * + * Handles listener management for {@link ValueChangeListener}s and + * {@link ReadOnlyStatusChangeListener}s. + * + * @since 6.6 + */ +public abstract class AbstractProperty<T> implements Property<T>, + Property.ValueChangeNotifier, Property.ReadOnlyStatusChangeNotifier { + + /** + * List of listeners who are interested in the read-only status changes of + * the Property + */ + private LinkedList<ReadOnlyStatusChangeListener> readOnlyStatusChangeListeners = null; + + /** + * List of listeners who are interested in the value changes of the Property + */ + private LinkedList<ValueChangeListener> valueChangeListeners = null; + + /** + * Is the Property read-only? + */ + private boolean readOnly; + + /** + * {@inheritDoc} + * + * Override for additional restrictions on what is considered a read-only + * property. + */ + @Override + public boolean isReadOnly() { + return readOnly; + } + + @Override + public void setReadOnly(boolean newStatus) { + boolean oldStatus = isReadOnly(); + readOnly = newStatus; + if (oldStatus != isReadOnly()) { + fireReadOnlyStatusChange(); + } + } + + /** + * Returns the value of the <code>Property</code> in human readable textual + * format. + * + * @return String representation of the value stored in the Property + * @deprecated use {@link #getValue()} instead and possibly toString on that + */ + @Deprecated + @Override + public String toString() { + throw new UnsupportedOperationException( + "Use Property.getValue() instead of " + getClass() + + ".toString()"); + } + + /* Events */ + + /** + * An <code>Event</code> object specifying the Property whose read-only + * status has been changed. + */ + protected static class ReadOnlyStatusChangeEvent extends + java.util.EventObject implements Property.ReadOnlyStatusChangeEvent { + + /** + * Constructs a new read-only status change event for this object. + * + * @param source + * source object of the event. + */ + protected ReadOnlyStatusChangeEvent(Property source) { + super(source); + } + + /** + * Gets the Property whose read-only state has changed. + * + * @return source Property of the event. + */ + @Override + public Property getProperty() { + return (Property) getSource(); + } + + } + + /** + * Registers a new read-only status change listener for this Property. + * + * @param listener + * the new Listener to be registered. + */ + @Override + public void addListener(Property.ReadOnlyStatusChangeListener listener) { + if (readOnlyStatusChangeListeners == null) { + readOnlyStatusChangeListeners = new LinkedList<ReadOnlyStatusChangeListener>(); + } + readOnlyStatusChangeListeners.add(listener); + } + + /** + * Removes a previously registered read-only status change listener. + * + * @param listener + * the listener to be removed. + */ + @Override + public void removeListener(Property.ReadOnlyStatusChangeListener listener) { + if (readOnlyStatusChangeListeners != null) { + readOnlyStatusChangeListeners.remove(listener); + } + } + + /** + * Sends a read only status change event to all registered listeners. + */ + protected void fireReadOnlyStatusChange() { + if (readOnlyStatusChangeListeners != null) { + final Object[] l = readOnlyStatusChangeListeners.toArray(); + final Property.ReadOnlyStatusChangeEvent event = new ReadOnlyStatusChangeEvent( + this); + for (int i = 0; i < l.length; i++) { + ((Property.ReadOnlyStatusChangeListener) l[i]) + .readOnlyStatusChange(event); + } + } + } + + /** + * An <code>Event</code> object specifying the Property whose value has been + * changed. + */ + private static class ValueChangeEvent extends java.util.EventObject + implements Property.ValueChangeEvent { + + /** + * Constructs a new value change event for this object. + * + * @param source + * source object of the event. + */ + protected ValueChangeEvent(Property source) { + super(source); + } + + /** + * Gets the Property whose value has changed. + * + * @return source Property of the event. + */ + @Override + public Property getProperty() { + return (Property) getSource(); + } + + } + + @Override + public void addListener(ValueChangeListener listener) { + if (valueChangeListeners == null) { + valueChangeListeners = new LinkedList<ValueChangeListener>(); + } + valueChangeListeners.add(listener); + + } + + @Override + public void removeListener(ValueChangeListener listener) { + if (valueChangeListeners != null) { + valueChangeListeners.remove(listener); + } + + } + + /** + * Sends a value change event to all registered listeners. + */ + protected void fireValueChange() { + if (valueChangeListeners != null) { + final Object[] l = valueChangeListeners.toArray(); + final Property.ValueChangeEvent event = new ValueChangeEvent(this); + for (int i = 0; i < l.length; i++) { + ((Property.ValueChangeListener) l[i]).valueChange(event); + } + } + } + + public Collection<?> getListeners(Class<?> eventType) { + if (Property.ValueChangeEvent.class.isAssignableFrom(eventType)) { + if (valueChangeListeners == null) { + return Collections.EMPTY_LIST; + } else { + return Collections.unmodifiableCollection(valueChangeListeners); + } + } else if (Property.ReadOnlyStatusChangeEvent.class + .isAssignableFrom(eventType)) { + if (readOnlyStatusChangeListeners == null) { + return Collections.EMPTY_LIST; + } else { + return Collections + .unmodifiableCollection(readOnlyStatusChangeListeners); + } + } + + return Collections.EMPTY_LIST; + } + +} |