AbstractSessionScreen.java

/*
 * Copyright 2017 Red Hat, Inc. and/or its affiliates.
 *
 * 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.kie.workbench.common.stunner.standalone.client.screens;

import javax.enterprise.event.Observes;

import org.kie.workbench.common.stunner.client.widgets.event.SessionDiagramOpenedEvent;
import org.kie.workbench.common.stunner.core.client.canvas.AbstractCanvas;
import org.kie.workbench.common.stunner.core.client.canvas.AbstractCanvasHandler;
import org.kie.workbench.common.stunner.core.client.session.ClientSession;
import org.kie.workbench.common.stunner.core.client.session.event.SessionDestroyedEvent;
import org.kie.workbench.common.stunner.core.client.session.event.SessionOpenedEvent;
import org.kie.workbench.common.stunner.core.client.session.impl.AbstractClientSession;
import org.kie.workbench.common.stunner.core.diagram.Diagram;

import static org.uberfire.commons.validation.PortablePreconditions.checkNotNull;

public abstract class AbstractSessionScreen {

    private ClientSession<AbstractCanvas, AbstractCanvasHandler> session;

    protected abstract void doOpenSession();

    protected abstract void doOpenDiagram();

    protected abstract void doCloseSession();

    protected abstract void doUpdateTitle(String title);

    public void open(final ClientSession<AbstractCanvas, AbstractCanvasHandler> session) {
        if (null == this.session) {
            this.session = session;
            doOpenSession();
        } else if (isSameSession(session)) {
            doOpenDiagram();
            updateTitle();
        }
    }

    public void close() {
        doCloseSession();
        this.session = null;
    }

    @SuppressWarnings("unchecked")
    void onCanvasSessionOpened(@Observes SessionOpenedEvent sessionOpenedEvent) {
        checkNotNull("sessionOpenedEvent",
                     sessionOpenedEvent);
        open(sessionOpenedEvent.getSession());
    }

    void onCanvasSessionDestroyed(@Observes SessionDestroyedEvent sessionDestroyedEvent) {
        checkNotNull("sessionDestroyedEvent",
                     sessionDestroyedEvent);
        close();
    }

    void onSessionDiagramOpenedEvent(@Observes SessionDiagramOpenedEvent sessionDiagramOpenedEvent) {
        checkNotNull("sessionDiagramOpenedEvent",
                     sessionDiagramOpenedEvent);
        if (null != getCanvas() && getCanvas().equals(sessionDiagramOpenedEvent.getSession().getCanvas())) {
            // Force to reload current session, for example, when a new diagram is just created.
            open(session);
        }
    }

    protected boolean isSameSession(final ClientSession session) {
        return null != getCanvasHandler()
                && getCanvasHandler().equals(session.getCanvasHandler());
    }

    protected AbstractCanvasHandler getCanvasHandler() {
        return null != session ? session.getCanvasHandler() : null;
    }

    protected AbstractCanvas getCanvas() {
        return null != session ? session.getCanvas() : null;
    }

    protected AbstractClientSession getSession() {
        return (AbstractClientSession) session;
    }

    private void updateTitle() {
        if (null != getCanvasHandler() && null != getCanvasHandler().getDiagram()) {
            final Diagram<?, ?> diagram = getCanvasHandler().getDiagram();
            doUpdateTitle(diagram.getMetadata().getTitle());
        }
    }
}