com.google.gwt.view.client.SelectionChangeEvent Maven / Gradle / Ivy
/*
* Copyright 2010 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.gwt.view.client;
import com.google.gwt.event.shared.EventHandler;
import com.google.gwt.event.shared.GwtEvent;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.event.shared.HasHandlers;
/**
* Represents a selection change event.
*/
public class SelectionChangeEvent extends
GwtEvent {
/**
* Handler interface for {@link SelectionChangeEvent} events.
*/
public static interface Handler extends EventHandler {
/**
* Called when a {@link SelectionChangeEvent} is fired.
*
* @param event the {@link SelectionChangeEvent} that was fired
*/
void onSelectionChange(SelectionChangeEvent event);
}
/**
* Interface specifying that a class can add
* {@code SelectionChangeEvent.Handler}s.
*/
public interface HasSelectionChangedHandlers extends HasHandlers {
/**
* Adds a {@link SelectionChangeEvent} handler.
*
* @param handler the handler
* @return {@link HandlerRegistration} used to remove this handler
*/
HandlerRegistration addSelectionChangeHandler(Handler handler);
}
/**
* Handler type.
*/
private static Type TYPE;
/**
* Fires a selection change event on all registered handlers in the handler
* manager. If no such handlers exist, this method will do nothing.
*
* @param source the source of the handlers
*/
public static void fire(HasSelectionChangedHandlers source) {
if (TYPE != null) {
SelectionChangeEvent event = new SelectionChangeEvent();
source.fireEvent(event);
}
}
/**
* Gets the type associated with this event.
*
* @return returns the handler type
*/
public static Type getType() {
if (TYPE == null) {
TYPE = new Type();
}
return TYPE;
}
/**
* Creates a selection change event.
*/
SelectionChangeEvent() {
}
@Override
public final Type getAssociatedType() {
return TYPE;
}
@Override
protected void dispatch(SelectionChangeEvent.Handler handler) {
handler.onSelectionChange(this);
}
}