public void setAdapter(Adapter adapter) {
if (adapter instanceof SectionIndexer) {
mIndexer = (SectionIndexer) adapter;
mSections = (String[]) mIndexer.getSections();
} else if (adapter instanceof HeaderViewListAdapter) {
hasHead = true;
mIndexer = (SectionIndexer) (((HeaderViewListAdapter) adapter).getWrappedAdapter());
mSections = (String[]) mIndexer.getSections();
}
}
public Object[] getSections() {
if (mIndexer == null) {
return new String[] {" "};
} else {
return mIndexer.getSections();
}
}
/** @param position relative position in the indexed partition */
public int getSectionForPosition(int position) {
if (mIndexer == null) {
return -1;
}
return mIndexer.getSectionForPosition(position);
}
/** @return relative position of the section in the indexed partition */
public int getPositionForSection(int sectionIndex) {
if (mIndexer == null) {
return -1;
}
return mIndexer.getPositionForSection(sectionIndex);
}
public boolean onTouchEvent(MotionEvent ev) {
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
// If down event occurs inside index bar region, start indexing
if (mState != STATE_HIDDEN && contains(ev.getX(), ev.getY())) {
setState(STATE_SHOWN);
// It demonstrates that the motion event started from index bar
mIsIndexing = true;
// Determine which section the point is in, and move the list to that section
mCurrentSection = getSectionByPoint(ev.getY());
int offset = 0;
if (hasHead) {
offset = 1;
}
mListView.setSelection(mIndexer.getPositionForSection(mCurrentSection) + offset);
return true;
}
break;
case MotionEvent.ACTION_MOVE:
if (mIsIndexing) {
// If this event moves inside index bar
if (contains(ev.getX(), ev.getY())) {
// Determine which section the point is in, and move the list to that section
mCurrentSection = getSectionByPoint(ev.getY());
int offset = 0;
if (hasHead) {
offset = 1;
}
mListView.setSelection(mIndexer.getPositionForSection(mCurrentSection) + offset);
}
return true;
}
break;
case MotionEvent.ACTION_UP:
if (mIsIndexing) {
mIsIndexing = false;
mCurrentSection = -1;
}
if (mState == STATE_SHOWN) setState(STATE_HIDING);
break;
}
return false;
}
public boolean onTouchEvent(MotionEvent ev) {
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN: // 按下，开始索引
// If down event occurs inside index bar region, start indexing
if (mState != STATE_HIDDEN && contains(ev.getX(), ev.getY())) {
// 设置索引条状态:已显示
setState(STATE_SHOWN);
// It demonstrates that the motion event started from index bar
mIsIndexing = true;
// Determine which section the point is in, and move the list to
// that section
// 根据纵坐标点获取当前字母位置
mCurrentSection = getSectionByPoint(ev.getY());
// ListView定位到指定Item
mListView.setSelection(mIndexer.getPositionForSection(mCurrentSection));
return true;
}
break;
case MotionEvent.ACTION_MOVE: // 移动
// 正在索引
if (mIsIndexing) {
// If this event moves inside index bar
if (contains(ev.getX(), ev.getY())) {
// Determine which section the point is in, and move the
// list to that section
mCurrentSection = getSectionByPoint(ev.getY());
mListView.setSelection(mIndexer.getPositionForSection(mCurrentSection));
}
return true;
}
break;
case MotionEvent.ACTION_UP: // 抬起
// 没有在索引
if (mIsIndexing) {
mIsIndexing = false;
mCurrentSection = -1;
}
if (mState == STATE_SHOWN) setState(STATE_HIDING);
break;
}
return false;
}
int findCurrentSectionPosition(int fromPosition) {
ListAdapter adapter = getAdapter();
if (adapter instanceof SectionIndexer) {
// try fast way by asking section indexer
SectionIndexer indexer = (SectionIndexer) adapter;
int sectionPosition = indexer.getSectionForPosition(fromPosition);
int itemPosition = indexer.getPositionForSection(sectionPosition);
int typeView = adapter.getItemViewType(itemPosition);
if (isItemViewTypePinned(adapter, typeView)) {
return itemPosition;
} // else, no luck
}
// try slow way by looking through to the next section item above
for (int position = fromPosition; position >= 0; position--) {
int viewType = adapter.getItemViewType(position);
if (isItemViewTypePinned(adapter, viewType)) return position;
}
return -1; // no candidate found
}
@Override
public void configurePinnedHeaders(PinnedHeaderListView listView) {
super.configurePinnedHeaders(listView);
if (!isSectionHeaderDisplayEnabled()) {
return;
}
int index = getPinnedHeaderCount() - 1;
if (mIndexer == null || getCount() == 0) {
listView.setHeaderInvisible(index, false);
} else {
int listPosition = listView.getPositionAt(listView.getTotalTopPinnedHeaderHeight());
int position = listPosition - listView.getHeaderViewsCount();
int section = -1;
int partition = getPartitionForPosition(position);
if (partition == mIndexedPartition) {
int offset = getOffsetInPartition(position);
if (offset != -1) {
section = getSectionForPosition(offset);
}
}
if (section == -1) {
listView.setHeaderInvisible(index, false);
} else {
setPinnedSectionTitle(mHeader, (String) mIndexer.getSections()[section]);
if (section == 0) {
setPinnedHeaderContactsCount(mHeader);
} else {
clearPinnedHeaderContactsCount(mHeader);
}
// Compute the item position where the current partition begins
int partitionStart = getPositionForPartition(mIndexedPartition);
if (hasHeader(mIndexedPartition)) {
partitionStart++;
}
// Compute the item position where the next section begins
int nextSectionPosition = partitionStart + getPositionForSection(section + 1);
boolean isLastInSection = position == nextSectionPosition - 1;
listView.setFadingHeader(index, listPosition, isLastInSection);
}
}
}
public void setAdapter(Adapter adapter) {
if (adapter instanceof SectionIndexer) {
mIndexer = (SectionIndexer) adapter;
mSections = (String[]) mIndexer.getSections();
}
}
