M7350/base/core/java/android/widget/SectionIndexer.java

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2024-09-09 08:52:07 +00:00
/*
* 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);
}