/**
* Finds the parent of a blip. The parent is the preceding blip in the thread, or the blip to
* which the thread is a reply for the first blip in a thread. The first blip of the root thread
* has no parent.
*
* @param blip the blip.
* @return the blip's parent, or {@code null} if the blip is the first blip in a conversation.
*/
@Override
public ConversationBlip findBlipParent(ConversationBlip blip) {
ConversationThread containingThread = blip.getThread();
if (containingThread.getFirstBlip() == blip
&& containingThread != blip.getConversation().getRootThread()) {
return containingThread.getParentBlip();
}
return findPreviousSibling(blip);
}
/**
* Retrieves the title of a {@link Wavelet}.
*
* @param wavelet The {@link Wavelet} to retrieve the title from.
* @param conversation The wavelet conversation
* @return the title of the {@link Wavelet}, or an empty string if it has no title.
*/
private static String getTitle(Wavelet wavelet, Conversation conversation) {
ConversationThread rootThread = conversation.getRootThread();
if (rootThread == null) {
return "";
}
ConversationBlip firstBlip = rootThread.getFirstBlip();
if (firstBlip == null) {
return "";
}
Document doc = firstBlip.getContent();
return TitleHelper.extractTitle(doc);
}
/**
* Finds the next sibling of a blip in a thread. The last blip in a thread has no next sibling.
*
* @param blip the blip.
* @return the next sibling of the blip, or {@code null} if blip is the last blip in a thread.
*/
@VisibleForTesting
static ConversationBlip findNextSibling(ConversationBlip blip) {
ConversationThread thread = blip.getThread();
Iterator<? extends ConversationBlip> blips = thread.getBlips().iterator();
boolean foundBlip = false;
while (!foundBlip && blips.hasNext()) {
if (blips.next() == blip) {
foundBlip = true;
}
}
return blips.hasNext() ? blips.next() : null;
}
/**
* Finds the previous sibling of a blip in a thread. The first blip in a thread has no previous
* sibling.
*
* @param blip the blip.
* @return the previous sibling of the blip, or {@code null}.
*/
@VisibleForTesting
static ConversationBlip findPreviousSibling(ConversationBlip blip) {
ConversationThread thread = blip.getThread();
ConversationBlip previous = null;
for (ConversationBlip sibling : thread.getBlips()) {
if (sibling == blip) {
break;
}
previous = sibling;
}
return previous;
}
/**
* Finds the children of a blip, defined as the next sibling blip and the first blip in each reply
* thread.
*
* @param blip the blip.
* @return the children of the given blip.
*/
@Override
public List<ConversationBlip> findBlipChildren(ConversationBlip blip) {
List<ConversationBlip> siblings = Lists.newArrayList();
ConversationBlip nextSibling = findNextSibling(blip);
if (nextSibling != null) {
siblings.add(nextSibling);
}
for (ConversationThread reply : blip.getReplyThreads()) {
if (reply.getFirstBlip() != null) {
siblings.add(reply.getFirstBlip());
}
}
return siblings;
}