Add internal pre-alpha libsignal support for reactions.

libsignal/service/protobuf/SignalService.proto

@@ -176,6 +176,14 @@ message DataMessage {
     optional AttachmentPointer data      = 4;
   }
 
+  message Reaction {
+    optional string emoji               = 1;
+    optional bool   remove              = 2;
+    optional string targetAuthorE164    = 3;
+    optional string targetAuthorUuid    = 4;
+    optional uint64 targetSentTimestamp = 5;
+  }
+
   enum ProtocolVersion {
     option allow_alias = true;
 
@@ -183,7 +191,8 @@ message DataMessage {
     MESSAGE_TIMERS  = 1;
     VIEW_ONCE       = 2;
     VIEW_ONCE_VIDEO = 3;
-    CURRENT         = 3;
+    REACTIONS       = 4;
+    CURRENT         = 4;
   }
 
   optional string             body                    = 1;
@@ -199,6 +208,7 @@ message DataMessage {
   optional Sticker            sticker                 = 11;
   optional uint32             requiredProtocolVersion = 12;
   optional bool               isViewOnce              = 14;
+  optional Reaction           reaction                = 16;
 }
 
 message NullMessage {

libsignal/service/src/main/java/org/whispersystems/signalservice/api/SignalServiceMessageSender.java

@@ -543,6 +543,24 @@ public class SignalServiceMessageSender {
       builder.setRequiredProtocolVersion(Math.max(DataMessage.ProtocolVersion.VIEW_ONCE_VIDEO_VALUE, builder.getRequiredProtocolVersion()));
     }
 
+    if (message.getReaction().isPresent()) {
+      DataMessage.Reaction.Builder reactionBuilder = DataMessage.Reaction.newBuilder()
+                                                                         .setEmoji(message.getReaction().get().getEmoji())
+                                                                         .setRemove(message.getReaction().get().isRemove())
+                                                                         .setTargetSentTimestamp(message.getReaction().get().getTargetSentTimestamp());
+
+      if (message.getReaction().get().getTargetAuthor().getNumber().isPresent()) {
+        reactionBuilder.setTargetAuthorE164(message.getReaction().get().getTargetAuthor().getNumber().get());
+      }
+
+      if (message.getReaction().get().getTargetAuthor().getUuid().isPresent()) {
+        reactionBuilder.setTargetAuthorUuid(message.getReaction().get().getTargetAuthor().getUuid().get().toString());
+      }
+
+      builder.setReaction(reactionBuilder.build());
+      builder.setRequiredProtocolVersion(Math.max(DataMessage.ProtocolVersion.REACTIONS_VALUE, builder.getRequiredProtocolVersion()));
+    }
+
     builder.setTimestamp(message.getTimestamp());
 
     return container.setDataMessage(builder).build().toByteArray();

libsignal/service/src/main/java/org/whispersystems/signalservice/api/crypto/SignalServiceCipher.java

@@ -45,6 +45,7 @@ import org.whispersystems.signalservice.api.messages.SignalServiceAttachmentPoin
 import org.whispersystems.signalservice.api.messages.SignalServiceContent;
 import org.whispersystems.signalservice.api.messages.SignalServiceDataMessage;
 import org.whispersystems.signalservice.api.messages.SignalServiceDataMessage.Preview;
+import org.whispersystems.signalservice.api.messages.SignalServiceDataMessage.Reaction;
 import org.whispersystems.signalservice.api.messages.SignalServiceDataMessage.Sticker;
 import org.whispersystems.signalservice.api.messages.SignalServiceEnvelope;
 import org.whispersystems.signalservice.api.messages.SignalServiceGroup;
@@ -308,6 +309,7 @@ public class SignalServiceCipher {
     List<SharedContact>            sharedContacts   = createSharedContacts(content);
     List<Preview>                  previews         = createPreviews(content);
     Sticker                        sticker          = createSticker(content);
+    Reaction                       reaction         = createReaction(content);
 
     if (content.getRequiredProtocolVersion() > DataMessage.ProtocolVersion.CURRENT.getNumber()) {
       throw new UnsupportedDataMessageException(DataMessage.ProtocolVersion.CURRENT.getNumber(),
@@ -340,7 +342,8 @@ public class SignalServiceCipher {
                                         sharedContacts,
                                         previews,
                                         sticker,
-                                        content.getIsViewOnce());
+                                        content.getIsViewOnce(),
+                                        reaction);
   }
 
   private SignalServiceSyncMessage createSynchronizeMessage(Metadata metadata, SyncMessage content)
@@ -618,6 +621,23 @@ public class SignalServiceCipher {
                        createAttachmentPointer(sticker.getData()));
   }
 
+  private Reaction createReaction(DataMessage content) {
+    if (!content.hasReaction()                                                                        ||
+        !content.getReaction().hasEmoji()                                                             ||
+        !(content.getReaction().hasTargetAuthorE164() || content.getReaction().hasTargetAuthorUuid()) ||
+        !content.getReaction().hasTargetSentTimestamp())
+    {
+      return null;
+    }
+
+    DataMessage.Reaction reaction = content.getReaction();
+
+    return new Reaction(reaction.getEmoji(),
+                        reaction.getRemove(),
+                        new SignalServiceAddress(UuidUtil.parseOrNull(reaction.getTargetAuthorUuid()), reaction.getTargetAuthorE164()),
+                        reaction.getTargetSentTimestamp());
+  }
+
   private List<SharedContact> createSharedContacts(DataMessage content) {
     if (content.getContactCount() <= 0) return null;
 

libsignal/service/src/main/java/org/whispersystems/signalservice/api/messages/SignalServiceDataMessage.java

@@ -32,6 +32,7 @@ public class SignalServiceDataMessage {
   private final Optional<List<Preview>>                 previews;
   private final Optional<Sticker>                       sticker;
   private final boolean                                 viewOnce;
+  private final Optional<Reaction>                      reaction;
 
   /**
    * Construct a SignalServiceDataMessage with a body and no attachments.
@@ -105,7 +106,7 @@ public class SignalServiceDataMessage {
    * @param expiresInSeconds The number of seconds in which a message should disappear after having been seen.
    */
   public SignalServiceDataMessage(long timestamp, SignalServiceGroup group, List<SignalServiceAttachment> attachments, String body, int expiresInSeconds) {
-    this(timestamp, group, attachments, body, false, expiresInSeconds, false, null, false, null, null, null, null, false);
+    this(timestamp, group, attachments, body, false, expiresInSeconds, false, null, false, null, null, null, null, false, null);
   }
 
   /**
@@ -123,7 +124,7 @@ public class SignalServiceDataMessage {
                                   String body, boolean endSession, int expiresInSeconds,
                                   boolean expirationUpdate, byte[] profileKey, boolean profileKeyUpdate,
                                   Quote quote, List<SharedContact> sharedContacts, List<Preview> previews,
-                                  Sticker sticker, boolean viewOnce)
+                                  Sticker sticker, boolean viewOnce, Reaction reaction)
   {
     this.timestamp             = timestamp;
     this.body                  = Optional.fromNullable(body);
@@ -136,6 +137,7 @@ public class SignalServiceDataMessage {
     this.quote                 = Optional.fromNullable(quote);
     this.sticker               = Optional.fromNullable(sticker);
     this.viewOnce              = viewOnce;
+    this.reaction              = Optional.fromNullable(reaction);
 
     if (attachments != null && !attachments.isEmpty()) {
       this.attachments = Optional.of(attachments);
@@ -232,6 +234,10 @@ public class SignalServiceDataMessage {
     return viewOnce;
   }
 
+  public Optional<Reaction> getReaction() {
+    return reaction;
+  }
+
   public static class Builder {
 
     private List<SignalServiceAttachment> attachments    = new LinkedList<>();
@@ -249,6 +255,7 @@ public class SignalServiceDataMessage {
     private Quote              quote;
     private Sticker            sticker;
     private boolean            viewOnce;
+    private Reaction           reaction;
 
     private Builder() {}
 
@@ -340,12 +347,17 @@ public class SignalServiceDataMessage {
       return this;
     }
 
+    public Builder withReaction(Reaction reaction) {
+      this.reaction = reaction;
+      return this;
+    }
+
     public SignalServiceDataMessage build() {
       if (timestamp == 0) timestamp = System.currentTimeMillis();
       return new SignalServiceDataMessage(timestamp, group, attachments, body, endSession,
                                           expiresInSeconds, expirationUpdate, profileKey,
                                           profileKeyUpdate, quote, sharedContacts, previews,
-                                          sticker, viewOnce);
+                                          sticker, viewOnce, reaction);
     }
   }
 
@@ -456,4 +468,34 @@ public class SignalServiceDataMessage {
       return attachment;
     }
   }
+
+  public static class Reaction {
+    private final String               emoji;
+    private final boolean              remove;
+    private final SignalServiceAddress targetAuthor;
+    private final long                 targetSentTimestamp;
+
+    public Reaction(String emoji, boolean remove, SignalServiceAddress targetAuthor, long targetSentTimestamp) {
+      this.emoji               = emoji;
+      this.remove              = remove;
+      this.targetAuthor        = targetAuthor;
+      this.targetSentTimestamp = targetSentTimestamp;
+    }
+
+    public String getEmoji() {
+      return emoji;
+    }
+
+    public boolean isRemove() {
+      return remove;
+    }
+
+    public SignalServiceAddress getTargetAuthor() {
+      return targetAuthor;
+    }
+
+    public long getTargetSentTimestamp() {
+      return targetSentTimestamp;
+    }
+  }
 }