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package eu.etaxonomy.vaadin.ui.navigation;

import java.util.Collection;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.context.annotation.Lazy;

import org.vaadin.spring.events.EventBus.UIEventBus;

import com.vaadin.navigator.View;

import com.vaadin.navigator.ViewChangeListener;

import com.vaadin.spring.annotation.SpringComponent;

import com.vaadin.spring.annotation.UIScope;

@SpringComponent("viewChangeListenerBean")

@UIScope

class ViewChangeListenerBean implements ViewChangeListener {

	private static final long serialVersionUID = 1913421359807383L;

	@Autowired(required=false)

	private Collection<ViewChangeAllowedVerifier> verifiers = null;

	@Autowired

	@Lazy

	private NavigationManager navigationManager;

	@Autowired

    UIEventBus uiEventBus;

	@Override

	public boolean beforeViewChange(ViewChangeEvent event) {

		View currentView = navigationManager.getCurrentView();

		if (currentView != null && verifiers != null) {

			for (ViewChangeAllowedVerifier verifier : verifiers) {

				if (currentView.equals(verifier)) {

					if (!verifier.isViewChangeAllowed()) {

						return false;

					}

				}

			}

		}

		return true;

	}

	@Override

	public void afterViewChange(ViewChangeEvent event) {

	    uiEventBus.publish(this, new AfterViewChangeEvent());

	}

}