public interface SectionIndexer
Adapter
s to enable fast scrolling
between sections of an AbsListView
.
A section is a group of list items that have something in common. For example, they may begin with the same letter or they may be songs from the same artist.
ExpandableListAdapter
s that consider groups and sections as
synonymous should account for collapsed groups and return an appropriate
section/position.
Modifier and Type | Method and Description |
---|---|
int |
getPositionForSection(int sectionIndex)
Given the index of a section within the array of section objects, returns
the starting position of that section within the adapter.
|
int |
getSectionForPosition(int position)
Given a position within the adapter, returns the index of the
corresponding section within the array of section objects.
|
Object[] |
getSections()
Returns an array of objects representing sections of the list.
|
Object[] getSections()
The list view will call toString() on the objects to get the preview text to display while scrolling. For example, an adapter may return an array of Strings representing letters of the alphabet. Or, it may return an array of objects whose toString() methods return their section titles.
int getPositionForSection(int sectionIndex)
If the section's starting position is outside of the adapter bounds, the position must be clipped to fall within the size of the adapter.
sectionIndex
- the index of the section within the array of section
objectsint getSectionForPosition(int position)
If the section index is outside of the section array bounds, the index must be clipped to fall within the size of the section array.
For example, consider an indexer where the section at array index 0 starts at adapter position 100. Calling this method with position 10, which is before the first section, must return index 0.
position
- the position within the adapter for which to return the
corresponding section index