src/main/java/net/pterodactylus/sone/notify/ReplyVisibilityFilter.java

   1 package net.pterodactylus.sone.notify;
   2
   3 import static com.google.common.base.Preconditions.checkNotNull;
   4
   5 import javax.annotation.Nonnull;
   6 import javax.annotation.Nullable;
   7 import javax.inject.Inject;
   8 import javax.inject.Singleton;
   9
  10 import net.pterodactylus.sone.data.Post;
  11 import net.pterodactylus.sone.data.PostReply;
  12 import net.pterodactylus.sone.data.Sone;
  13
  14 import com.google.common.base.Optional;
  15 import com.google.common.base.Predicate;
  16
  17 /**
  18  * Filter that checks a {@link PostReply} for visibility.
  19  */
  20 @Singleton
  21 public class ReplyVisibilityFilter {
  22
  23         private final PostVisibilityFilter postVisibilityFilter;
  24
  25         @Inject
  26         public ReplyVisibilityFilter(@Nonnull PostVisibilityFilter postVisibilityFilter) {
  27                 this.postVisibilityFilter = postVisibilityFilter;
  28         }
  29
  30         /**
  31          * Checks whether a reply is visible to the given Sone. A reply is not
  32          * considered visible if one of the following statements is true:
  33          * <ul>
  34          * <li>The reply does not have a post.</li>
  35          * <li>The reply’s post {@link PostVisibilityFilter#isPostVisible(Sone, Post) is not visible}.</li>
  36          * <li>The reply’s {@link PostReply#getTime() time} is in the future.</li>
  37          * </ul>
  38          * If none of these statements is true the reply is considered visible.
  39          *
  40          * @param sone
  41          *              The Sone that checks for a post’s visibility (may be
  42          *              {@code null} to skip Sone-specific checks, such as trust)
  43          * @param reply
  44          *              The reply to check for visibility
  45          * @return {@code true} if the reply is considered visible, {@code false}
  46          * otherwise
  47          */
  48         boolean isReplyVisible(@Nullable Sone sone, @Nonnull PostReply reply) {
  49                 checkNotNull(reply, "reply must not be null");
  50                 Optional<Post> post = reply.getPost();
  51                 if (!post.isPresent()) {
  52                         return false;
  53                 }
  54                 if (!postVisibilityFilter.isPostVisible(sone, post.get())) {
  55                         return false;
  56                 }
  57                 return reply.getTime() <= System.currentTimeMillis();
  58         }
  59
  60         @Nonnull
  61         public Predicate<PostReply> isVisible(@Nullable final Sone currentSone) {
  62                 return new Predicate<PostReply>() {
  63                         @Override
  64                         public boolean apply(@Nullable PostReply postReply) {
  65                                 return (postReply != null) && isReplyVisible(currentSone, postReply);
  66                         }
  67                 };
  68         }
  69
  70 }