| /* |
| * Copyright (C) 2008 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; |
| |
| /** |
| * Interface that should be implemented on Adapters to enable fast scrolling |
| * in an {@link AbsListView} between sections of the list. A section is a group of list items |
| * to jump to that have something in common. For example, they may begin with the |
| * same letter or they may be songs from the same artist. |
| */ |
| public interface SectionIndexer { |
| /** |
| * This provides the list view with an array of section objects. In the simplest |
| * case these are Strings, each containing one letter of the alphabet. |
| * They could be more complex objects that indicate the grouping for the adapter's |
| * consumption. The list view will call toString() on the objects to get the |
| * preview letter to display while scrolling. |
| * @return the array of objects that indicate the different sections of the list. |
| */ |
| Object[] getSections(); |
| |
| /** |
| * Provides the starting index in the list for a given section. |
| * @param section the index of the section to jump to. |
| * @return the starting position of that section. If the section is out of bounds, the |
| * position must be clipped to fall within the size of the list. |
| */ |
| int getPositionForSection(int section); |
| |
| /** |
| * This is a reverse mapping to fetch the section index for a given position |
| * in the list. |
| * @param position the position for which to return the section |
| * @return the section index. If the position is out of bounds, the section index |
| * must be clipped to fall within the size of the section array. |
| */ |
| int getSectionForPosition(int position); |
| } |