NavigationActivity.java

/*
 * Copyright 2014-2016 CyberVision, 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 org.kaaproject.kaa.server.admin.client.mvp.activity;

import com.google.gwt.activity.shared.AbstractActivity;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.place.shared.Place;
import com.google.gwt.user.cellview.client.TreeNode;
import com.google.gwt.user.client.ui.AcceptsOneWidget;
import com.google.gwt.view.client.SelectionChangeEvent;
import com.google.web.bindery.event.shared.EventBus;

import org.kaaproject.kaa.server.admin.client.mvp.ClientFactory;
import org.kaaproject.kaa.server.admin.client.mvp.event.data.DataEvent;
import org.kaaproject.kaa.server.admin.client.mvp.event.data.DataEventHandler;
import org.kaaproject.kaa.server.admin.client.mvp.place.TreePlace;
import org.kaaproject.kaa.server.admin.client.mvp.view.NavigationView;

import java.util.ArrayList;
import java.util.List;

public class NavigationActivity extends AbstractActivity implements NavigationView.Presenter {

  private final ClientFactory clientFactory;
  private final NavigationView navigationView;

  protected List<HandlerRegistration> registrations = new ArrayList<HandlerRegistration>();
  private TreePlace pendingPlace;

  /**
   * Instantiates a new NavigationActivity.
   */
  public NavigationActivity(ClientFactory clientFactory, EventBus eventBus) {
    this.clientFactory = clientFactory;
    this.navigationView = clientFactory.getNavigationView();
    this.navigationView.setPresenter(this);
    this.navigationView.setEventBus(eventBus);
  }

  /**
   * On place changed.
   *
   * @param place the place.
   */
  public void onPlaceChanged(TreePlace place) {
    TreePlace selected = navigationView.getSelectionModel().getSelectedObject();
    if (!place.equals(selected)) {
      pendingPlace = place;
      selectPlace(place);
    }
  }

  private void selectPlace(TreePlace place) {
    TreeNode node = navigationView.getMenuTree().getRootTreeNode();
    if (openNode(node, place)) {
      navigationView.getSelectionModel().setSelected(place, true);
      pendingPlace = null;
    } else {
      navigationView.getSelectionModel().clear();
    }
  }

  private boolean openNode(TreeNode node, TreePlace place) {
    int childCount = node.getChildCount();
    for (int i = 0; i < childCount; i++) {
      if (node.getChildValue(i).equals(place)) {
        //node.setChildOpen(i, true, true);
        return true;
      } else if (!node.isChildLeaf(i)) {
        boolean wasOpen = node.isChildOpen(i);
        TreeNode child = node.setChildOpen(i, true);
        if (child != null && openNode(child, place)) {
          return true;
        } else if (!wasOpen) {
          node.setChildOpen(i, false);
        }
      }
    }
    return false;
  }

  private void refreshTree() {
    TreeNode node = navigationView.getMenuTree().getRootTreeNode();
    refreshTree(node);
  }

  private void refreshTree(TreeNode node) {
    int childCount = node.getChildCount();
    for (int i = 0; i < childCount; i++) {
      if (!node.isChildLeaf(i) && node.isChildOpen(i)) {
        node.setChildOpen(i, false);
        TreeNode child = node.setChildOpen(i, true);
        if (child != null) {
          refreshTree(child);
        }
      }
    }
  }

  @Override
  public void start(AcceptsOneWidget containerWidget,
                    com.google.gwt.event.shared.EventBus eventBus) {
    containerWidget.setWidget(navigationView.asWidget());
    registrations.add(navigationView.getSelectionModel().addSelectionChangeHandler(
        new SelectionChangeEvent.Handler() {
          @Override
          public void onSelectionChange(SelectionChangeEvent event) {
            TreePlace place = navigationView.getSelectionModel().getSelectedObject();
            if (place != null) {
              goTo(place);

              TreePlace current = (TreePlace) clientFactory.getPlaceController().getWhere();
              if (!current.equals(place)) {
                navigationView.getSelectionModel().setSelected(current, true);
              }
            }
          }
        }
    ));
    registrations.add(eventBus.addHandler(DataEvent.getType(), new DataEventHandler() {

      @Override
      public void onDataChanged(DataEvent event) {
        if (event.refreshTree()) {
          refreshTree();
          if (pendingPlace != null) {
            selectPlace(pendingPlace);
          }
        }
      }
    }));
  }

  @Override
  public void onStop() {
    for (HandlerRegistration registration : registrations) {
      registration.removeHandler();
    }
    registrations.clear();
  }

  @Override
  public void goTo(Place place) {
    clientFactory.getPlaceController().goTo(place);
  }

}