content: /*
   * Copyright (C) 2007 The Android Open Source Project
   *
   * 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 android.widget;
  
  import android.database.DataSetObservable;
  import android.database.DataSetObserver;
  
  /**
   * Base class for a {@link ExpandableListAdapter} used to provide data and Views
   * from some data to an expandable list view.
   * <p>
   * Adapters inheriting this class should verify that the base implementations of
   * {@link #getCombinedChildId(long, long)} and {@link #getCombinedGroupId(long)}
   * are correct in generating unique IDs from the group/children IDs.
   * <p>
   * @see SimpleExpandableListAdapter
   * @see SimpleCursorTreeAdapter
   */
  public abstract class BaseExpandableListAdapter implements ExpandableListAdapter, 
          HeterogeneousExpandableList {
      private final DataSetObservable mDataSetObservable = new DataSetObservable();
      
      public void registerDataSetObserver(DataSetObserver observer) {
          mDataSetObservable.registerObserver(observer);
      }
  
      public void unregisterDataSetObserver(DataSetObserver observer) {
          mDataSetObservable.unregisterObserver(observer);
      }
      
      /**
       * @see DataSetObservable#notifyInvalidated()
       */
      public void notifyDataSetInvalidated() {
          mDataSetObservable.notifyInvalidated();
      }
      
      /**
       * @see DataSetObservable#notifyChanged()
       */
      public void notifyDataSetChanged() {
          mDataSetObservable.notifyChanged();
      }
  
      public boolean areAllItemsEnabled() {
          return true;
      }
  
      public void onGroupCollapsed(int groupPosition) {
      }
  
      public void onGroupExpanded(int groupPosition) {
      }
  
      /**
       * Override this method if you foresee a clash in IDs based on this scheme:
       * <p>
       * Base implementation returns a long:
       * <li> bit 0: Whether this ID points to a child (unset) or group (set), so for this method
       *             this bit will be 1.
       * <li> bit 1-31: Lower 31 bits of the groupId
       * <li> bit 32-63: Lower 32 bits of the childId.
       * <p> 
       * {@inheritDoc}
       */
      public long getCombinedChildId(long groupId, long childId) {
          return 0x8000000000000000L | ((groupId & 0x7FFFFFFF) << 32) | (childId & 0xFFFFFFFF);
      }
  
      /**
       * Override this method if you foresee a clash in IDs based on this scheme:
       * <p>
       * Base implementation returns a long:
       * <li> bit 0: Whether this ID points to a child (unset) or group (set), so for this method
       *             this bit will be 0.
       * <li> bit 1-31: Lower 31 bits of the groupId
       * <li> bit 32-63: Lower 32 bits of the childId.
       * <p> 
       * {@inheritDoc}
       */
      public long getCombinedGroupId(long groupId) {
          return (groupId & 0x7FFFFFFF) << 32;
      }
  
      /**
       * {@inheritDoc}
       */
      public boolean isEmpty() {
          return getGroupCount() == 0;
      }
  
  
      /**
       * {@inheritDoc}
       * @return 0 for any group or child position, since only one child type count is declared.
       */
      public int getChildType(int groupPosition, int childPosition) {
          return 0;
      }
  
      /**
       * {@inheritDoc}
       * @return 1 as a default value in BaseExpandableListAdapter.
       */
      public int getChildTypeCount() {
          return 1;
      }
  
      /**
       * {@inheritDoc}
       * @return 0 for any groupPosition, since only one group type count is declared.
       */
      public int getGroupType(int groupPosition) {
          return 0;
      }
  
      /**
       * {@inheritDoc}
       * @return 1 as a default value in BaseExpandableListAdapter.
       */
      public int getGroupTypeCount() {
          return 1;
      }
  }
  