Summary: Methods | [Expand All]
Since: API Level 3
public interface

SectionIndexer

android.widget.SectionIndexer
Known Indirect Subclasses

Class Overview

Interface that should be implemented on Adapters to enable fast scrolling in an 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.

Summary

Public Methods
abstract int getPositionForSection(int section)
Provides the starting index in the list for a given section.
abstract int getSectionForPosition(int position)
This is a reverse mapping to fetch the section index for a given position in the list.
abstract Object[] getSections()
This provides the list view with an array of section objects.

Public Methods

public abstract int getPositionForSection (int section)

Since: API Level 3

Provides the starting index in the list for a given section.

Parameters
section the index of the section to jump to.
Returns
  • 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.

public abstract int getSectionForPosition (int position)

Since: API Level 3

This is a reverse mapping to fetch the section index for a given position in the list.

Parameters
position the position for which to return the section
Returns
  • 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.

public abstract Object[] getSections ()

Since: API Level 3

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.

Returns
  • the array of objects that indicate the different sections of the list.