Dynamically show user names on public chat.

This fixes the issue where identicons weren't matching up to the one on desktop

Signal/src/Loki/LokiGroupChatPoller.swift

@@ -50,6 +50,7 @@ public final class LokiGroupChatPoller : NSObject {
             let endIndex = senderHexEncodedPublicKey.endIndex
             let cutoffIndex = senderHexEncodedPublicKey.index(endIndex, offsetBy: -8)
             let senderDisplayName = "\(message.displayName) (...\(senderHexEncodedPublicKey[cutoffIndex..<endIndex]))"
+
             let id = group.id.data(using: String.Encoding.utf8)!
             let x1 = SSKProtoGroupContext.builder(id: id, type: .deliver)
             x1.setName(group.displayName)
@@ -65,11 +66,14 @@ public final class LokiGroupChatPoller : NSObject {
             let x3 = SSKProtoContent.builder()
             x3.setDataMessage(try! x2.build())
             let x4 = SSKProtoEnvelope.builder(type: .ciphertext, timestamp: message.timestamp)
-            x4.setSource(senderDisplayName)
+            x4.setSource(senderHexEncodedPublicKey)
             x4.setSourceDevice(OWSDevicePrimaryDeviceId)
             x4.setContent(try! x3.build().serializedData())
+            
             let storage = OWSPrimaryStorage.shared()
             storage.dbReadWriteConnection.readWrite { transaction in
+                // Set the display name of the user
+                transaction.setObject(senderDisplayName, forKey: senderHexEncodedPublicKey, inCollection: group.id)
                 SSKEnvironment.shared.messageManager.throws_processEnvelope(try! x4.build(), plaintextData: try! x3.build().serializedData(), wasReceivedByUD: false, transaction: transaction)
             }
         }

Signal/src/ViewControllers/ConversationView/ConversationViewModel.m

@@ -21,6 +21,8 @@
 #import <SignalServiceKit/TSIncomingMessage.h>
 #import <SignalServiceKit/TSOutgoingMessage.h>
 #import <SignalServiceKit/TSThread.h>
+#import <SignalServiceKit/TSGroupThread.h>
+#import <SignalServiceKit/TSGroupModel.h>
 #import <YapDatabase/YapDatabase.h>
 #import <YapDatabase/YapDatabaseAutoView.h>
 #import <YapDatabase/YapDatabaseViewChange.h>
@@ -1514,6 +1516,22 @@ static const int kYapDatabaseRangeMaxLength = 25000;
                                                      senderNamePrimaryAttributes]
                                   secondaryAttributes:[OWSMessageBubbleView
                                                        senderNameSecondaryAttributes]];
+                    
+                    if ([self.thread isKindOfClass:[TSGroupThread class]]) {
+                        TSGroupThread *groupThread = (TSGroupThread *)self.thread;
+                        NSData *groupId = groupThread.groupModel.groupId;
+                        NSString *stringGroupId = [[NSString alloc] initWithData:groupId encoding:NSUTF8StringEncoding];
+                        
+                        if (stringGroupId != nil) {
+                            NSString __block *displayName;
+                            [self.uiDatabaseConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
+                               displayName = [transaction objectForKey:incomingSenderId inCollection:stringGroupId];
+                            }];
+                            if (displayName != nil) {
+                                senderName = [[NSAttributedString alloc] initWithString:displayName attributes:[OWSMessageBubbleView senderNamePrimaryAttributes]];
+                            }
+                        }
+                    }
                 }
 
                 // Show the sender avatar for incoming group messages unless

SignalMessaging/Loki/JazzIcon.swift

@@ -1,6 +1,12 @@
 
 import CryptoSwift
 
+extension String {
+    func matches(_ regex: String) -> Bool {
+        return self.range(of: regex, options: .regularExpression, range: nil, locale: nil) != nil
+    }
+}
+
 private class RNG {
     private var seed: UInt
     private var initial: UInt
@@ -59,8 +65,11 @@ public class JazzIcon {
     }
     
     convenience init(seed: String, colours: [UIColor]? = nil) {
-        let hash = seed.md5()
-        guard let number = UInt(hash.substring(to: min(hash.count, 12)), radix: 16) else {
+        // Ensure we have a correct hash
+        var hash = seed
+        if !hash.matches("^[0-9A-Fa-f]+$") || hash.count < 12 { hash = seed.sha512() }
+        
+        guard let number = UInt(hash.substring(to: 12), radix: 16) else {
             owsFailDebug("[JazzIcon] Failed to generate number from seed string: \(seed)")
             self.init(seed: 1234, colours: colours)
             return