Enable/update group call action based on current call and thread

Signal/src/Calls/CallService.swift

@@ -7,6 +7,7 @@ import SignalRingRTC
 import PromiseKit
 
 // All Observer methods will be invoked from the main thread.
+@objc(OWSCallServiceObserver)
 protocol CallServiceObserver: class {
     /**
      * Fired whenever the call changes.
@@ -138,6 +139,7 @@ public final class CallService: NSObject {
     private var observers = WeakArray<CallServiceObserver>()
 
     // The observer-related methods should be invoked on the main thread.
+    @objc
     func addObserverAndSyncState(observer: CallServiceObserver) {
         AssertIsOnMainThread()
 
@@ -148,6 +150,7 @@ public final class CallService: NSObject {
     }
 
     // The observer-related methods should be invoked on the main thread.
+    @objc
     func removeObserver(_ observer: CallServiceObserver) {
         AssertIsOnMainThread()
         observers.removeAll { $0 === observer }

Signal/src/Calls/SignalCall.swift

@@ -92,6 +92,7 @@ public class SignalCall: NSObject, CallManagerCallReference {
         didSet { AssertIsOnMainThread() }
     }
 
+    @objc
     public let thread: TSThread?
 
     public var error: CallError?

Signal/src/ViewControllers/ConversationView/Cells/ConversationViewCell.h

@@ -44,6 +44,7 @@ NS_ASSUME_NONNULL_BEGIN
 - (void)conversationCell:(ConversationViewCell *)cell didEndLongpress:(id<ConversationViewItem>)viewItem;
 - (void)conversationCell:(ConversationViewCell *)cell didTapReactions:(id<ConversationViewItem>)viewItem;
 - (BOOL)conversationCellHasPendingMessageRequest:(ConversationViewCell *)cell;
+@property (nonatomic, readonly) BOOL isCallingSupported;
 
 #pragma mark - Selection
 

Signal/src/ViewControllers/ConversationView/Cells/OWSSystemMessageCell.m

@@ -791,6 +791,7 @@ typedef void (^SystemMessageActionBlock)(void);
         case RPRecentCallTypeIncomingAnsweredElsewhere:
         case RPRecentCallTypeIncomingDeclinedElsewhere:
         case RPRecentCallTypeIncomingBusyElsewhere:
+            // If delegate is nil, include the action. This way we always oversize instead of undersize.
             if ([self.delegate conversationCellHasPendingMessageRequest:self]) {
                 return nil;
             }
@@ -800,6 +801,7 @@ typedef void (^SystemMessageActionBlock)(void);
                              accessibilityIdentifier:ACCESSIBILITY_IDENTIFIER_WITH_NAME(self, @"call_back")];
         case RPRecentCallTypeOutgoing:
         case RPRecentCallTypeOutgoingMissed:
+            // If delegate is nil, include the action. This way we always oversize instead of undersize.
             if ([self.delegate conversationCellHasPendingMessageRequest:self]) {
                 return nil;
             }
@@ -815,21 +817,20 @@ typedef void (^SystemMessageActionBlock)(void);
 
 - (nullable SystemMessageAction *)actionForGroupCall:(OWSGroupCallMessage *)groupCallMessage
 {
-    // TODO: Check if the current call belongs to this thread.
-    if (self.callService.currentCall != nil) {
-        return nil;
-    }
-
+    // Assume the current thread supports calling if we have no delegate. This ensures we always
+    // overestimate cell measurement in cases where the current thread doesn't support calling.
+    BOOL isCallingSupported = !self.delegate || self.delegate.isCallingSupported;
     BOOL isCallActive = (!groupCallMessage.hasEnded && groupCallMessage.joinedMemberAddresses.count > 0);
 
-    // TODO: Respect -canCall from ConversationViewController
-    // TODO: "Return to call" if for the current thread. Hide the action is currently in a call
-    // For now we'll just check the feature flag
-    BOOL canCall = SSKFeatureFlags.groupCalling;
+    if (isCallingSupported && isCallActive) {
+        NSString *currentCallThreadId = self.callService.currentCall.thread.uniqueId;
+        BOOL isCurrentCallForThread = [currentCallThreadId isEqualToString:self.viewItem.thread.uniqueId];
+
+        NSString *joinTitle = NSLocalizedString(@"GROUP_CALL_JOIN_BUTTON", "Button to join an ongoing group call");
+        NSString *returnTitle = NSLocalizedString(@"CALL_RETURN_BUTTON", "Button to return to the current call");
+        NSString *actionTitle = isCurrentCallForThread ? returnTitle : joinTitle;
 
-    if (isCallActive && canCall) {
         __weak typeof(self) wSelf = self;
-        NSString *actionTitle = NSLocalizedString(@"GROUP_CALL_JOIN_BUTTON", "Button to join an ongoing group call");
         return [SystemMessageAction actionWithTitle:actionTitle
                                               block:^{ [wSelf.delegate handleGroupCallTap]; }
                             accessibilityIdentifier:actionTitle];

Signal/src/ViewControllers/ConversationView/ConversationViewController.m

@@ -1935,7 +1935,11 @@ typedef enum : NSUInteger {
 
 - (void)handleGroupCallTap
 {
-    [self showGroupCallLobby];
+    if ([self.callService.currentCall.thread.uniqueId isEqualToString:self.thread.uniqueId]) {
+        // TODO
+    } else {
+        [self showGroupCallLobby];
+    }
 }
 
 - (void)updateSystemContactWithAddress:(SignalServiceAddress *)address
@@ -2281,6 +2285,11 @@ typedef enum : NSUInteger {
     return self.threadViewModel.hasPendingMessageRequest;
 }
 
+- (BOOL)isCallingSupported
+{
+    return [self canCall];
+}
+
 - (BOOL)isShowingSelectionUI
 {
     return self.uiMode == ConversationUIMode_Selection;

Signal/src/ViewControllers/ConversationView/ConversationViewModel.m

@@ -144,7 +144,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 #pragma mark -
 
-@interface ConversationViewModel () <UIDatabaseSnapshotDelegate>
+@interface ConversationViewModel () <UIDatabaseSnapshotDelegate, OWSCallServiceObserver>
 
 @property (nonatomic, weak) id<ConversationViewModelDelegate> delegate;
 
@@ -241,6 +241,11 @@ NS_ASSUME_NONNULL_BEGIN
     return [OWSProfileManager shared];
 }
 
+- (CallService *)callService
+{
+    return AppEnvironment.shared.callService;
+}
+
 #pragma mark -
 
 - (void)addNotificationListeners
@@ -265,6 +270,7 @@ NS_ASSUME_NONNULL_BEGIN
                                              selector:@selector(localProfileDidChange:)
                                                  name:kNSNotificationNameLocalProfileDidChange
                                                object:nil];
+    [self.callService addObserverAndSyncStateWithObserver:self];
 }
 
 - (void)profileWhitelistDidChange:(NSNotification *)notification
@@ -326,6 +332,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (void)dealloc
 {
+    [self.callService removeObserver:self];
     [[NSNotificationCenter defaultCenter] removeObserver:self];
 }
 
@@ -1279,6 +1286,12 @@ NS_ASSUME_NONNULL_BEGIN
                 viewItem.senderProfileName = [self.profileManager fullNameForAddress:infoMessage.profileChangeAddress
                                                                          transaction:transaction];
             }
+        } else if (interactionType == OWSInteractionType_Call) {
+            NSString *activeCallThreadId = self.callService.currentCall.thread.uniqueId;
+            BOOL isAnotherThreadInCall = activeCallThreadId && ![self.thread.uniqueId isEqualToString:activeCallThreadId];
+
+            BOOL wasCollapsed = viewItem.shouldCollapseSystemMessageAction;
+            viewItem.shouldCollapseSystemMessageAction = wasCollapsed || isAnotherThreadInCall;
         }
 
         uint64_t collapseCutoffTimestamp = [NSDate ows_millisecondsSince1970ForDate:self.collapseCutoffDate];
@@ -1494,6 +1507,18 @@ NS_ASSUME_NONNULL_BEGIN
     return !self.canLoadOlderItems;
 }
 
+#pragma mark - <OWSCallServiceObserver>
+
+- (void)didUpdateCallFrom:(nullable SignalCall *)oldValue to:(nullable SignalCall *)newValue
+{
+    // If the call state changed for the current thread, we may want to hide the Call action.
+    // When registering, CallObserver sends the currentCall synchronously. Since we register
+    // during -viewDidLoad, ordering gets a bit messed up. It's okay if we async for a bit later.
+    dispatch_async(dispatch_get_main_queue(), ^{
+        [self updateForTransientItems];
+    });
+}
+
 @end
 
 NS_ASSUME_NONNULL_END

Signal/translations/en.lproj/Localizable.strings

@@ -481,6 +481,9 @@
 /* notification body */
 "CALL_MISSED_BECAUSE_OF_IDENTITY_CHANGE_NOTIFICATION_BODY" = "☎️ Missed call because the caller's safety number changed.";
 
+/* Button to return to the current call */
+"CALL_RETURN_BUTTON" = "Return To Call";
+
 /* Call setup status label after outgoing call times out */
 "CALL_SCREEN_STATUS_NO_ANSWER" = "No Answer";