Tweak disappearing messages indicator.

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

@@ -14,7 +14,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 @property (nonatomic) UILabel *timestampLabel;
 @property (nonatomic) UIImageView *statusIndicatorImageView;
-@property (nonatomic, nullable) OWSMessageTimerView *messageTimerView;
+@property (nonatomic) OWSMessageTimerView *messageTimerView;
 
 @end
 
@@ -44,6 +44,9 @@ NS_ASSUME_NONNULL_BEGIN
     self.timestampLabel = [UILabel new];
     [self addArrangedSubview:self.timestampLabel];
 
+    self.messageTimerView = [OWSMessageTimerView new];
+    [self addArrangedSubview:self.messageTimerView];
+
     self.statusIndicatorImageView = [UIImageView new];
     [self.statusIndicatorImageView setContentHuggingHigh];
     [self addArrangedSubview:self.statusIndicatorImageView];
@@ -92,6 +95,18 @@ NS_ASSUME_NONNULL_BEGIN
     }
     self.timestampLabel.textColor = textColor;
 
+    if ([self isDisappearingMessage:viewItem]) {
+        TSMessage *message = (TSMessage *)viewItem.interaction;
+        uint64_t expirationTimestamp = message.expiresAt;
+        uint32_t expiresInSeconds = message.expiresInSeconds;
+        [self.messageTimerView configureWithExpirationTimestamp:expirationTimestamp
+                                         initialDurationSeconds:expiresInSeconds
+                                                      tintColor:textColor];
+        self.messageTimerView.hidden = NO;
+    } else {
+        self.messageTimerView.hidden = YES;
+    }
+
     if (viewItem.interaction.interactionType == OWSInteractionType_OutgoingMessage) {
         TSOutgoingMessage *outgoingMessage = (TSOutgoingMessage *)viewItem.interaction;
 
@@ -257,8 +272,7 @@ NS_ASSUME_NONNULL_BEGIN
 {
     [self.statusIndicatorImageView.layer removeAllAnimations];
 
-    [self.messageTimerView removeFromSuperview];
-    self.messageTimerView = nil;
+    [self.messageTimerView prepareForReuse];
 }
 
 @end

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

@@ -8,12 +8,15 @@ NS_ASSUME_NONNULL_BEGIN
 
 @interface OWSMessageTimerView : UIView
 
-- (instancetype)init NS_UNAVAILABLE;
+- (instancetype)init NS_DESIGNATED_INITIALIZER;
 - (instancetype)initWithFrame:(CGRect)frame NS_UNAVAILABLE;
 - (nullable instancetype)initWithCoder:(NSCoder *)aDecoder NS_UNAVAILABLE;
 
-- (instancetype)initWithExpiration:(uint64_t)expirationTimestamp
-            initialDurationSeconds:(uint32_t)initialDurationSeconds NS_DESIGNATED_INITIALIZER;
+- (void)configureWithExpirationTimestamp:(uint64_t)expirationTimestamp
+                  initialDurationSeconds:(uint32_t)initialDurationSeconds
+                               tintColor:(UIColor *)tintColor;
+
+- (void)prepareForReuse;
 
 + (CGSize)measureSize;
 

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

@@ -25,6 +25,7 @@ const CGFloat kDisappearingMessageIconSize = 12.f;
 
 @property (nonatomic, nullable) NSTimer *animationTimer;
 
+// 0 == about to expire, 12 == just started countdown.
 @property (nonatomic) NSInteger progress12;
 
 
@@ -36,23 +37,16 @@ const CGFloat kDisappearingMessageIconSize = 12.f;
 
 - (void)dealloc
 {
-    [self.animationTimer invalidate];
-    self.animationTimer = nil;
+    [self clearAnimation];
 }
 
-- (instancetype)initWithExpiration:(uint64_t)expirationTimestamp
-            initialDurationSeconds:(uint32_t)initialDurationSeconds
-                         tintColor:(UIColor *)tintColor;
+- (instancetype)init
 {
     self = [super initWithFrame:CGRectZero];
     if (!self) {
         return self;
     }
 
-    self.expirationTimestamp = expirationTimestamp;
-    self.initialDurationSeconds = initialDurationSeconds;
-    self.tintColor = tintColor;
-
     [self commonInit];
 
     return self;
@@ -65,15 +59,19 @@ const CGFloat kDisappearingMessageIconSize = 12.f;
     [self.imageView autoPinToSuperviewEdges];
     [self.imageView autoSetDimension:ALDimensionWidth toSize:kDisappearingMessageIconSize];
     [self.imageView autoSetDimension:ALDimensionHeight toSize:kDisappearingMessageIconSize];
+}
+
+- (void)configureWithExpirationTimestamp:(uint64_t)expirationTimestamp
+                  initialDurationSeconds:(uint32_t)initialDurationSeconds
+                               tintColor:(UIColor *)tintColor;
+{
+    self.expirationTimestamp = expirationTimestamp;
+    self.initialDurationSeconds = initialDurationSeconds;
+    self.tintColor = tintColor;
 
     [self updateProgress12];
     [self updateIcon];
-
-    self.animationTimer = [NSTimer weakScheduledTimerWithTimeInterval:1.f
-                                                               target:self
-                                                             selector:@selector(updateProgress12)
-                                                             userInfo:nil
-                                                              repeats:YES];
+    [self startAnimation];
 }
 
 - (void)updateProgress12
@@ -81,7 +79,7 @@ const CGFloat kDisappearingMessageIconSize = 12.f;
     CGFloat secondsLeft = MAX(0, (self.expirationTimestamp - [NSDate ows_millisecondTimeStamp]) / 1000.f);
     CGFloat progress = 0.f;
     if (self.initialDurationSeconds > 0) {
-        progress = CGFloatClamp(1.f - (secondsLeft / self.initialDurationSeconds), 0.f, 1.f);
+        progress = CGFloatClamp(secondsLeft / self.initialDurationSeconds, 0.f, 1.f);
     }
     OWSAssert(progress >= 0.f);
     OWSAssert(progress <= 1.f);
@@ -159,6 +157,28 @@ const CGFloat kDisappearingMessageIconSize = 12.f;
     return image;
 }
 
+- (void)startAnimation
+{
+    [self clearAnimation];
+
+    self.animationTimer = [NSTimer weakScheduledTimerWithTimeInterval:0.1f
+                                                               target:self
+                                                             selector:@selector(updateProgress12)
+                                                             userInfo:nil
+                                                              repeats:YES];
+}
+
+- (void)clearAnimation
+{
+    [self.animationTimer invalidate];
+    self.animationTimer = nil;
+}
+
+- (void)prepareForReuse
+{
+    [self clearAnimation];
+}
+
 + (CGSize)measureSize
 {
     return CGSizeMake(kDisappearingMessageIconSize, kDisappearingMessageIconSize);