org.simplewebstack.app.vaadin.guice.ui.ScopedUIProvider.java Source code

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Here is the source code for org.simplewebstack.app.vaadin.guice.ui.ScopedUIProvider.java

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/*
 * Copyright 2012 Vaadin Community.
 *
 * 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.simplewebstack.app.vaadin.guice.ui;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.simplewebstack.app.vaadin.guice.uiscope.UIKey;
import org.simplewebstack.app.vaadin.guice.uiscope.UIKeyProvider;
import org.simplewebstack.app.vaadin.guice.uiscope.UIScope;

import com.google.inject.Inject;
import com.google.inject.Injector;
import com.vaadin.server.UICreateEvent;
import com.vaadin.server.UIProvider;
import com.vaadin.ui.UI;
import com.vaadin.util.CurrentInstance;

/**
 * A Vaadin UI provider which supports the use of Guice scoped UI (see {@link UIScoped}). If you do not need UIScope,
 * then just extend from UIProvider directly
 *
 * Subclasses should implement getUIClass(UIClassSelectionEvent event) to provide logic for selecting the UI class.
 *
 * @author David Sowerby
 *
 */
public abstract class ScopedUIProvider extends UIProvider {

    protected Logger logger;
    protected UIKeyProvider uiKeyProvider;
    protected Injector injector;

    @Inject
    protected void init(Injector injector, UIKeyProvider uiKeyProvider) {

        logger = LoggerFactory.getLogger(getClass());
        this.injector = injector;
        this.uiKeyProvider = uiKeyProvider;
    }

    @Override
    public UI createInstance(UICreateEvent event) {

        Class<? extends UI> uiClass = event.getUIClass();

        UIKey uiKey = uiKeyProvider.get();

        // hold the key while UI is created
        CurrentInstance.set(UIKey.class, uiKey);
        // and set up the scope
        UIScope scope = UIScope.getCurrent();

        scope.startScope(uiKey);

        // create the UI
        ScopedUI ui = (ScopedUI) injector.getInstance(uiClass);
        ui.setInstanceKey(uiKey);
        ui.setScope(scope);

        logger.debug(String.format("Returning instance of [%s] with key [%s]", uiClass.getName(), uiKey));
        return ui;
    }

}