private void rebuildSections() {
sectionKeys = new ArrayList<String>();
graphObjectsBySection = new HashMap<String, ArrayList<T>>();
graphObjectsById = new HashMap<String, T>();
displaySections = false;
if (cursor == null || cursor.getCount() == 0) {
return;
}
int objectsAdded = 0;
cursor.moveToFirst();
do {
T graphObject = cursor.getGraphObject();
if (!filterIncludesItem(graphObject)) {
continue;
}
objectsAdded++;
String sectionKeyOfItem = getSectionKeyOfGraphObject(graphObject);
if (!graphObjectsBySection.containsKey(sectionKeyOfItem)) {
sectionKeys.add(sectionKeyOfItem);
graphObjectsBySection.put(sectionKeyOfItem, new ArrayList<T>());
}
List<T> section = graphObjectsBySection.get(sectionKeyOfItem);
section.add(graphObject);
graphObjectsById.put(getIdOfGraphObject(graphObject), graphObject);
} while (cursor.moveToNext());
if (sortFields != null) {
final Collator collator = Collator.getInstance();
for (List<T> section : graphObjectsBySection.values()) {
Collections.sort(
section,
new Comparator<GraphObject>() {
@Override
public int compare(GraphObject a, GraphObject b) {
return compareGraphObjects(a, b, sortFields, collator);
}
});
}
}
Collections.sort(sectionKeys, Collator.getInstance());
displaySections = sectionKeys.size() > 1 && objectsAdded > DISPLAY_SECTIONS_THRESHOLD;
}
private boolean shouldShowActivityCircleCell() {
// We show the "more data" activity circle cell if we have a listener to request more data,
// we are expecting more data, and we have some data already (i.e., not on a fresh query).
return (cursor != null)
&& cursor.areMoreObjectsAvailable()
&& (dataNeededListener != null)
&& !isEmpty();
}
SectionAndItem<T> getSectionAndItem(int position) {
if (sectionKeys.size() == 0) {
return null;
}
String sectionKey = null;
T graphObject = null;
if (!displaySections) {
sectionKey = sectionKeys.get(0);
List<T> section = graphObjectsBySection.get(sectionKey);
if (position >= 0 && position < section.size()) {
graphObject = graphObjectsBySection.get(sectionKey).get(position);
} else {
// We are off the end; we must be adding an activity circle to indicate more data is coming.
assert dataNeededListener != null && cursor.areMoreObjectsAvailable();
// We return null for both to indicate this.
return new SectionAndItem<T>(null, null);
}
} else {
// Count through the sections; the "0" position in each section is the header. We decrement
// position each time we skip forward a certain number of elements, including the header.
for (String key : sectionKeys) {
// Decrement if we skip over the header
if (position-- == 0) {
sectionKey = key;
break;
}
List<T> section = graphObjectsBySection.get(key);
if (position < section.size()) {
// The position is somewhere in this section. Get the corresponding graph object.
sectionKey = key;
graphObject = section.get(position);
break;
}
// Decrement by as many items as we skipped over
position -= section.size();
}
}
if (sectionKey != null) {
// Note: graphObject will be null if this represents a section header.
return new SectionAndItem<T>(sectionKey, graphObject);
} else {
throw new IndexOutOfBoundsException("position");
}
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
SectionAndItem<T> sectionAndItem = getSectionAndItem(position);
switch (sectionAndItem.getType()) {
case SECTION_HEADER:
return getSectionHeaderView(sectionAndItem.sectionKey, convertView, parent);
case GRAPH_OBJECT:
return getGraphObjectView(sectionAndItem.graphObject, convertView, parent);
case ACTIVITY_CIRCLE:
// If we get a request for this view, it means we need more data.
assert cursor.areMoreObjectsAvailable() && (dataNeededListener != null);
dataNeededListener.onDataNeeded();
return getActivityCircleView(convertView, parent);
default:
throw new FacebookException("Unexpected type of section and item.");
}
}