LockInteractionEvent.java

/*
 * Copyright 2012 Cedric Hauber
 *
 *    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 org.jboss.errai.mvp.client.events;

import com.google.gwt.event.shared.GwtEvent;
import com.google.gwt.event.shared.HasHandlers;

/**
 * This event is fired whenever interaction should be locked throughout the application,
 * usually because a navigation operation is taking place and interacting could cause
 * unexpected state switches.
 * <p />
 * This event is typically fired by the {@link PlaceManager} whenever a navigation operation
 * starts or stops. It is handled by the default {@link com.gwtplatform.mvp.client.RootPresenter} implementation.
 * Override {@link com.gwtplatform.mvp.client.RootPresenter#lockInteraction(boolean)} to customize the behaviour.
 *
 * @author Philippe Beaudoin
 */
public class LockInteractionEvent extends GwtEvent<LockInteractionHandler> {

  private static Type<LockInteractionHandler> TYPE;

  /**
   * Fires a {@link org.jboss.errai.mvp.client.events.LockInteractionEvent}
   * into a source that has access to an {@link com.google.web.bindery.event.shared.EventBus}
   * specifying whether interaction should be locked or unlocked.
   *
   * @param source The source that fires this event ({@link com.google.gwt.event.shared.HasHandlers}).
   * @param lock {@code true} to lock interaction, {@code false} to unlock it.
   */
  public static void fire(HasHandlers source, boolean lock) {
    source.fireEvent(new LockInteractionEvent(lock));
  }

  public static Type<LockInteractionHandler> getType() {
    if (TYPE == null) {
      TYPE = new Type<LockInteractionHandler>();
    }
    return TYPE;
  }

  private final boolean lock;

  public LockInteractionEvent(boolean lock) {
    this.lock = lock;
  }

  @Override
  public Type<LockInteractionHandler> getAssociatedType() {
    return getType();
  }

  public boolean shouldLock() {
    return lock;
  }

  @Override
  protected void dispatch(LockInteractionHandler handler) {
    handler.onLockInteraction(this);
  }

}