Make voice messages seekable

Signal/src/Loki/Components/VoiceMessageView.swift

@@ -197,4 +197,18 @@ final class VoiceMessageView : UIView {
     private func updateToggleImageView() {
         toggleImageView.image = isPlaying ? #imageLiteral(resourceName: "Pause") : #imageLiteral(resourceName: "Play")
     }
+
+    // MARK: Interaction
+    @objc(getCurrentTime:)
+    func getCurrentTime(for panGestureRecognizer: UIPanGestureRecognizer) -> TimeInterval {
+        guard voiceMessage.isDownloaded else { return 0 }
+        let locationInSelf = panGestureRecognizer.location(in: self)
+        let waveformFrameOrigin = CGPoint(x: leadingInset + toggleContainerSize + Values.smallSpacing, y: vMargin)
+        let waveformFrameSize = CGSize(width: width() - leadingInset - toggleContainerSize - durationLabel.width() - 2 * Values.smallSpacing,
+            height: height() - 2 * vMargin)
+        let waveformFrame = CGRect(origin: waveformFrameOrigin, size: waveformFrameSize)
+        guard waveformFrame.contains(locationInSelf) else { return 0 }
+        let fraction = (locationInSelf.x - waveformFrame.minX) / (waveformFrame.maxX - waveformFrame.minX)
+        return Double(fraction) * Double(duration)
+    }
 }

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

@@ -36,6 +36,7 @@ typedef NS_ENUM(NSUInteger, OWSMessageGestureLocation) {
                   imageView:(UIView *)imageView;
 
 - (void)didTapAudioViewItem:(id<ConversationViewItem>)viewItem attachmentStream:(TSAttachmentStream *)attachmentStream;
+- (void)didPanAudioViewItem:(id<ConversationViewItem>)viewItem attachmentStream:(TSAttachmentStream *)attachmentStream currentTime:(NSTimeInterval)currentTime;
 
 - (void)didTapTruncatedTextMessage:(id<ConversationViewItem>)conversationItem;
 
@@ -102,6 +103,7 @@ typedef NS_ENUM(NSUInteger, OWSMessageGestureLocation) {
 - (void)addTapGestureHandler;
 
 - (void)handleTapGesture:(UITapGestureRecognizer *)sender;
+- (void)handlePanGesture:(UIPanGestureRecognizer *)sender;
 
 @end
 

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

@@ -1532,6 +1532,22 @@ NS_ASSUME_NONNULL_BEGIN
     }
 }
 
+- (void)handlePanGesture:(UIPanGestureRecognizer *)sender
+{
+    switch (self.cellType) {
+        case OWSMessageCellType_Audio: {
+            LKVoiceMessageView *voiceMessageView = self.viewItem.lastAudioMessageView;
+            NSTimeInterval currentTime = [voiceMessageView getCurrentTime:sender];
+            [self.viewItem setAudioProgress:((CGFloat)currentTime) duration:self.viewItem.audioDurationSeconds];
+            CGFloat progress = self.viewItem.audioProgressSeconds / self.viewItem.audioDurationSeconds;
+            [voiceMessageView setProgress:progress];
+            [self.delegate didPanAudioViewItem:self.viewItem attachmentStream:self.viewItem.attachmentStream currentTime:currentTime];
+            return;
+        }
+        default: return;
+    }
+}
+
 - (OWSMessageGestureLocation)gestureLocationForLocation:(CGPoint)locationInMessageBubble
 {
     if (self.quotedMessageView) {

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

@@ -78,6 +78,10 @@ NS_ASSUME_NONNULL_BEGIN
     UILongPressGestureRecognizer *longPress =
         [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongPressGesture:)];
     [self.contentView addGestureRecognizer:longPress];
+
+    UIPanGestureRecognizer *pan =
+        [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePanGesture:)];
+    [self.contentView addGestureRecognizer:pan];
 }
 
 - (void)dealloc
@@ -488,6 +492,11 @@ NS_ASSUME_NONNULL_BEGIN
     }
 }
 
+- (void)handlePanGesture:(UIPanGestureRecognizer *)sender
+{
+    [self.messageBubbleView handlePanGesture:sender];
+}
+
 - (BOOL)isGestureInCellHeader:(UIGestureRecognizer *)sender
 {
     OWSAssertDebug(self.viewItem);

Signal/src/ViewControllers/ConversationView/ConversationViewController.m

@@ -2454,6 +2454,11 @@ typedef enum : NSUInteger {
     [self.audioAttachmentPlayer play];
 }
 
+- (void)didPanAudioViewItem:(id<ConversationViewItem>)viewItem attachmentStream:(TSAttachmentStream *)attachmentStream currentTime:(NSTimeInterval)currentTime
+{
+    [self.audioAttachmentPlayer setCurrentTime:currentTime];
+}
+
 - (void)didTapTruncatedTextMessage:(id<ConversationViewItem>)conversationItem
 {
     OWSAssertIsOnMainThread();

Signal/src/ViewControllers/MessageDetailViewController.swift

@@ -669,6 +669,10 @@ class MessageDetailViewController: OWSViewController, MediaGalleryDataSourceDele
         audioAttachmentPlayer.play()
     }
 
+    func didPanAudioViewItem(_ viewItem: ConversationViewItem, attachmentStream: TSAttachmentStream, currentTime: TimeInterval) {
+        // TODO: Implement
+    }
+
     func didTapTruncatedTextMessage(_ conversationItem: ConversationViewItem) {
         guard let navigationController = self.navigationController else {
             owsFailDebug("navigationController was unexpectedly nil")

SignalMessaging/utils/OWSAudioPlayer.h

@@ -46,6 +46,7 @@ typedef NS_ENUM(NSUInteger, OWSAudioBehavior) {
                         delegate:(id<OWSAudioPlayerDelegate>)delegate;
 
 - (void)play;
+- (void)setCurrentTime:(NSTimeInterval)currentTime;
 - (void)pause;
 - (void)stop;
 - (void)togglePlayState;

SignalMessaging/utils/OWSAudioPlayer.m

@@ -156,6 +156,11 @@ NS_ASSUME_NONNULL_BEGIN
     [DeviceSleepManager.sharedInstance addBlockWithBlockObject:self];
 }
 
+- (void)setCurrentTime:(NSTimeInterval)currentTime
+{
+    [self.audioPlayer setCurrentTime:currentTime];
+}
+
 - (void)pause
 {
     OWSAssertIsOnMainThread();