LockInteractionEvent.java

/*
 * Copyright 2011 ArcBees 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.gwtplatform.mvp.client.proxy;

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.
 */
public class LockInteractionEvent extends GwtEvent<LockInteractionHandler> {
    private static Type<LockInteractionHandler> TYPE;

    private final boolean lock;

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

    /**
     * Fires a {@link 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 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<>();
        }
        return TYPE;
    }

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

    public boolean shouldLock() {
        return lock;
    }

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