[global] i spent all day preventing this function from recursing

hbang · Feb 11, 2017 · aee4a68 · aee4a68
1 parent 8f5d6e3
commit aee4a68
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Showing 3 changed files with 31 additions and 18 deletions.
diff --git a/global/HBTSConversationPreferences.x b/global/HBTSConversationPreferences.x
@@ -4,6 +4,7 @@
 #import <IMCore/IMChat.h>
 #import <IMCore/IMHandle.h>
 #import <version.h>
+#include <notify.h>
 
 @implementation HBTSConversationPreferences {
 	HBPreferences *_preferences;
@@ -65,6 +66,14 @@
 	[_preferences registerPreferenceChangeBlock:callback];
 }
 
+- (void)_postReadReceiptNotification {
+	// if we do this in imagent, the callback for this notification can cause an infinite loop, so
+	// don’t post it in that case
+	if (!self._isInIMAgent) {
+		notify_post("ws.hbang.typestatus/ReadReceiptSettingsChanged");
+	}
+}
+
 #pragma mark - Keys
 
 - (NSString *)_keyForChat:(IMChat *)chat type:(NSString *)type {
@@ -101,6 +110,11 @@
 	return key ? [_preferences boolForKey:key default:self._readReceiptsEnabled] : self._readReceiptsEnabled;
 }
 
+- (NSNumber *)readReceiptsEnabledForHandleAsNumber:(NSString *)handle {
+	NSString *key = [self _keyForHandle:handle type:@"Read"];
+	return key ? [_preferences objectForKey:key] : nil;
+}
+
 #pragma mark - Setters
 
 - (void)setTypingNotificationsEnabled:(BOOL)enabled forChat:(IMChat *)chat {
@@ -109,6 +123,7 @@
 
 - (void)setReadReceiptsEnabled:(BOOL)enabled forChat:(IMChat *)chat {
 	[_preferences setBool:enabled forKey:[self _keyForChat:chat type:@"Read"]];
+	[self _postReadReceiptNotification];
 }
 
 - (void)setTypingNotificationsEnabled:(BOOL)enabled forHandle:(NSString *)handle {
@@ -117,6 +132,7 @@
 
 - (void)setReadReceiptsEnabled:(BOOL)enabled forHandle:(NSString *)handle {
 	[_preferences setBool:enabled forKey:[self _keyForHandle:handle type:@"Read"]];
+	[self _postReadReceiptNotification];
 }
 
 #pragma mark - Add/Remove

diff --git a/messages/DetailsController.x b/messages/DetailsController.x
@@ -138,7 +138,7 @@ NSBundle *bundle;
 }
 
 - (void)readReceiptsSwitchValueChanged:(UISwitch *)sender {
-	// update ours as well
+	// update our read receipt enabled state
 	[self._typeStatus_preferences setReadReceiptsEnabled:sender.on forChat:self.conversation.chat];
 }
 

diff --git a/relay/ReadReceiptMirror.x b/relay/ReadReceiptMirror.x
@@ -7,13 +7,12 @@
 
 - (BOOL)_readReceiptsEnabled;
 
+- (NSNumber *)readReceiptsEnabledForHandleAsNumber:(NSString *)handle;
+
 @end
 
 extern HBTSConversationPreferences *preferences;
 
-// ugly workaround to avoid infinite loops
-BOOL updating = YES;
-
 void mirrorNativeReadReceiptPreferences() {
 	// grab the chats, and the global state
 	NSArray <IMDChat *> *chats = ((IMDChatRegistry *)[%c(IMDChatRegistry) sharedInstance]).chats;
@@ -31,18 +30,19 @@ void mirrorNativeReadReceiptPreferences() {
 
 		// get the native read receipt value, as well as our own
 		NSNumber *value = chat.properties[@"EnableReadReceiptForChat"];
-		BOOL ourValue = [preferences readReceiptsEnabledForHandle:handle];
+		NSNumber *ourValue = [preferences readReceiptsEnabledForHandleAsNumber:handle];
 
 		// if it’s been set at least once before and is different from the global state
 		if (value && value.boolValue != globalState) {
 			// mirror it over to our side
-			updating = YES;
 			[preferences setReadReceiptsEnabled:value.boolValue forHandle:handle];
-		} else if (!value && ourValue != globalState) {
-			// if the value is nil, but we have a value that is different from the global state
+		}
+
+		// if we have a value, and the system doesn’t or it differs from ours
+		if (ourValue && (!value || value.boolValue != ourValue.boolValue)) {
 			// mirror it over to the other side
 			[chat updateProperties:@{
-				@"EnableReadReceiptForChat": @(ourValue),
+				@"EnableReadReceiptForChat": ourValue,
 				@"EnableReadReceiptForChatVersionID": @1
 			}];
 		}
@@ -52,9 +52,11 @@ void mirrorNativeReadReceiptPreferences() {
 %hook IMDChatRegistry
 
 - (void)loadChatsWithCompletionBlock:(void(^)())completion {
-	// override the completion block so we can execute our mirror logic immediately
+	// override the completion block so we can execute our mirror logic afterwards
+	__block void (^oldCompletion)() = [completion copy];
+
 	void (^newCompletion)() = ^{
-		completion();
+		oldCompletion();
 		mirrorNativeReadReceiptPreferences();
 	};
 
@@ -64,11 +66,6 @@ void mirrorNativeReadReceiptPreferences() {
 %end
 
 %ctor {
-	[preferences registerPreferenceChangeBlock:^{
-		if (updating) {
-			updating = NO;
-		} else {
-			mirrorNativeReadReceiptPreferences();
-		}
-	}];
+	// register a preference change block so we can execute another mirror
+	CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(), NULL, (CFNotificationCallback)mirrorNativeReadReceiptPreferences, CFSTR("ws.hbang.typestatus/ReadReceiptSettingsChanged"), NULL, kNilOptions);
 }