/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.uima.caseditor.editor.contextmenu;

import java.util.Iterator;
import java.util.List;

import org.apache.uima.cas.Type;
import org.apache.uima.cas.TypeSystem;
import org.eclipse.jface.action.ContributionItem;
import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.MenuItem;

/**
 * Abstract base class for menus which display the type hierarchy.
 */
abstract class TypeMenu extends ContributionItem {
    private Type mParentType;

    private TypeSystem mTypeSystem;

    /**
     * Initializes a new instance.
     *
     * @param parentType
     * @param typeSystem
     */
    TypeMenu(Type parentType, TypeSystem typeSystem) {
      mParentType = parentType;
      mTypeSystem = typeSystem;
    }

    /**
     * Fills the menu with type entries.
     *
     * @param menu
     * @param index
     */
    @Override
    public void fill(Menu menu, int index) {
      fillTypeMenu(mParentType, menu, false);
    }

    private void fillTypeMenu(Type parentType, Menu parentMenu, 
    		boolean isParentIncluded) {
     
      List<Type> childs = mTypeSystem.getDirectSubtypes(parentType);

      Menu newSubMenu;

      // has this type sub types ?
      // yes
      if (childs.size() != 0) {

        if (isParentIncluded) {
          MenuItem  subMenuItem = new MenuItem(parentMenu, SWT.CASCADE);
          subMenuItem.setText(parentType.getName());

          newSubMenu = new Menu(subMenuItem);
          subMenuItem.setMenu(newSubMenu);
        }
        else {
          newSubMenu = parentMenu;
        }

        insertAction(parentType, newSubMenu);

        Iterator<Type> childsIterator = childs.iterator();

        while (childsIterator.hasNext()) {
          Type child = childsIterator.next();

          fillTypeMenu(child, newSubMenu, true);
        }
      }
      // no
      else {
        insertAction(parentType, parentMenu);
      }
    }
    
    /**
     * Implementing classes must implement this method to insert
     * actions into the type menu.
     * 
     * @param type
     * @param parentMenu
     */
    protected abstract void insertAction(final Type type, Menu parentMenu);

  }