Add initial support for Group Calling.

app/src/main/java/org/thoughtcrime/securesms/events/CallParticipantId.java

@@ -0,0 +1,52 @@
+package org.thoughtcrime.securesms.events;
+
+import androidx.annotation.NonNull;
+
+import org.signal.ringrtc.GroupCall;
+import org.thoughtcrime.securesms.recipients.Recipient;
+import org.thoughtcrime.securesms.recipients.RecipientId;
+
+import java.util.Objects;
+
+/**
+ * Allow system to identify a call participant by their device demux id and their
+ * recipient id.
+ */
+public final class CallParticipantId {
+
+  private static final long DEFAULT_ID = -1;
+
+  private final long        demuxId;
+  private final RecipientId recipientId;
+
+  public CallParticipantId(@NonNull Recipient recipient) {
+    this(DEFAULT_ID, recipient.getId());
+  }
+
+  public CallParticipantId(long demuxId, @NonNull RecipientId recipientId) {
+    this.demuxId     = demuxId;
+    this.recipientId = recipientId;
+  }
+
+  public long getDemuxId() {
+    return demuxId;
+  }
+
+  public @NonNull RecipientId getRecipientId() {
+    return recipientId;
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+    final CallParticipantId that = (CallParticipantId) o;
+    return demuxId == that.demuxId &&
+           recipientId.equals(that.recipientId);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(demuxId, recipientId);
+  }
+}

app/src/main/java/org/thoughtcrime/securesms/events/WebRtcViewModel.java

@@ -45,8 +45,45 @@ public class WebRtcViewModel {
     }
   }
 
-  private final @NonNull State     state;
-  private final @NonNull Recipient recipient;
+  public enum GroupCallState {
+    IDLE,
+    DISCONNECTED,
+    CONNECTING,
+    RECONNECTING,
+    CONNECTED,
+    CONNECTED_AND_JOINING,
+    CONNECTED_AND_JOINED;
+
+    public boolean isNotIdle() {
+      return this != IDLE;
+    }
+
+    public boolean isConnected() {
+      switch (this) {
+        case CONNECTED:
+        case CONNECTED_AND_JOINING:
+        case CONNECTED_AND_JOINED:
+          return true;
+      }
+
+      return false;
+    }
+
+    public boolean isNotIdleOrConnected() {
+      switch (this) {
+        case DISCONNECTED:
+        case CONNECTING:
+        case RECONNECTING:
+          return true;
+      }
+
+      return false;
+    }
+  }
+
+  private final @NonNull State          state;
+  private final @NonNull GroupCallState groupState;
+  private final @NonNull Recipient      recipient;
 
   private final boolean isBluetoothAvailable;
   private final boolean isRemoteVideoOffer;
@@ -56,6 +93,7 @@ public class WebRtcViewModel {
   private final List<CallParticipant> remoteParticipants;
 
   public WebRtcViewModel(@NonNull State state,
+                         @NonNull GroupCallState groupState,
                          @NonNull Recipient recipient,
                          @NonNull CameraState localCameraState,
                          @Nullable BroadcastVideoSink localSink,
@@ -66,6 +104,7 @@ public class WebRtcViewModel {
                          @NonNull List<CallParticipant> remoteParticipants)
   {
     this.state                = state;
+    this.groupState           = groupState;
     this.recipient            = recipient;
     this.isBluetoothAvailable = isBluetoothAvailable;
     this.isRemoteVideoOffer   = isRemoteVideoOffer;
@@ -79,12 +118,16 @@ public class WebRtcViewModel {
     return state;
   }
 
+  public @NonNull GroupCallState getGroupState() {
+    return groupState;
+  }
+
   public @NonNull Recipient getRecipient() {
     return recipient;
   }
 
   public boolean isRemoteVideoEnabled() {
-    return Stream.of(remoteParticipants).anyMatch(CallParticipant::isVideoEnabled);
+    return Stream.of(remoteParticipants).anyMatch(CallParticipant::isVideoEnabled) || (groupState.isNotIdle() && remoteParticipants.size() > 1);
   }
 
   public boolean isBluetoothAvailable() {