com.github.peholmst.mvp4vaadin.navigation.ui.NavigationControllerViewComponent.java Source code

Introduction

Here is the source code for com.github.peholmst.mvp4vaadin.navigation.ui.NavigationControllerViewComponent.java

Source

/*
 * Copyright (c) 2011 Petter Holmstrm
 *
 * 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.github.peholmst.mvp4vaadin.navigation.ui;

import com.github.peholmst.mvp4vaadin.AbstractViewComponent;
import com.github.peholmst.mvp4vaadin.VaadinView;
import com.github.peholmst.mvp4vaadin.navigation.NavigationController;
import com.github.peholmst.mvp4vaadin.navigation.NavigationControllerEvent;
import com.github.peholmst.mvp4vaadin.navigation.NavigationControllerListener;
import com.github.peholmst.mvp4vaadin.navigation.events.CurrentNavigationControllerViewChangedEvent;
import com.vaadin.ui.ComponentContainer;
import com.vaadin.ui.VerticalLayout;

/**
 * This component displays the current view of a {@link NavigationController},
 * provided that the view implements the {@link VaadinView} interface (see
 * {@link AbstractViewComponent} for example). When the current view changes,
 * this component will update itself accordingly.
 * 
 * @see #setController(NavigationController)
 * 
 * @author Petter Holmstrm
 * @since 1.0
 */
public class NavigationControllerViewComponent extends VerticalLayout implements NavigationControllerListener {

    private static final long serialVersionUID = -8383927952103198829L;

    private NavigationController controller;

    private ComponentContainer viewComponent;

    /**
     * Sets the navigation controller whose current view will be shown inside
     * this component. This component will register itself as a listener with
     * the controller, so if you no longer need it you should set the controller
     * to <code>null</code>.
     */
    public void setController(NavigationController controller) {
        if (this.controller != null) {
            this.controller.removeListener(this);
        }
        this.controller = controller;
        setCurrentViewComponent();
        if (this.controller != null) {
            this.controller.addListener(this);
        }
    }

    /**
     * Returns the navigation controller whose current view will be shown inside
     * this component. If no controller has been set, this method returns
     * <code>null</code>.
     */
    public NavigationController getController() {
        return controller;
    }

    @Override
    public void handleNavigationControllerEvent(NavigationControllerEvent event) {
        if (event.getSource() == this.controller && event instanceof CurrentNavigationControllerViewChangedEvent) {
            setCurrentViewComponent();
        }
    }

    private void setCurrentViewComponent() {
        if (viewComponent != null) {
            removeComponent(viewComponent);
            viewComponent = null;
        }

        if (controller != null && controller.getCurrentView() instanceof VaadinView) {
            viewComponent = ((VaadinView) controller.getCurrentView()).getViewComponent();
            addComponent(viewComponent);
        }
    }
}