WIP: Support sending attachment captions

Looks fine on other clients, but locally we don't display the caption.

// FREEBIE

Signal/src/ViewControllers/DebugUI/DebugUIMessages.m

@@ -1007,6 +1007,7 @@ NS_ASSUME_NONNULL_BEGIN
                 TSOutgoingMessage *message =
                     [[TSOutgoingMessage alloc] initWithTimestamp:[NSDate ows_millisecondTimeStamp]
                                                         inThread:thread
+                                                     messageBody:nil
                                                   isVoiceMessage:NO
                                                 expiresInSeconds:0];
                 DDLogError(@"%@ sendFakeMessages outgoing attachment timestamp: %llu.", self.logTag, message.timestamp);
@@ -1043,6 +1044,7 @@ NS_ASSUME_NONNULL_BEGIN
     [TSStorageManager.dbReadWriteConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
         TSOutgoingMessage *message = [[TSOutgoingMessage alloc] initWithTimestamp:[NSDate ows_millisecondTimeStamp]
                                                                          inThread:thread
+                                                                      messageBody:nil
                                                                    isVoiceMessage:NO
                                                                  expiresInSeconds:0];
         DDLogError(@"%@ sendFakeMessages outgoing attachment timestamp: %llu.", self.logTag, message.timestamp);

SignalMessaging/attachments/AttachmentApprovalViewController.swift

@@ -211,15 +211,15 @@ public class AttachmentApprovalViewController: OWSViewController, MessagingToolb
 
     // MARK: MessagingToolbarDelegate
 
-    func messagingToolbarDidTapSend(_ messagingToolbar: MessagingToolbar) {
-        self.sendAttachment()
+    func messagingToolbarDidTapSend(_ messagingToolbar: MessagingToolbar, captionText: String?) {
+        self.sendAttachment(captionText: captionText)
     }
 
     func messagingToolbar(_ messagingToolbar: MessagingToolbar, didChangeHeight newHeight: CGFloat) {
         self.scrollView.contentInset.bottom = newHeight
     }
 
-    func sendAttachment() {
+    func sendAttachment(captionText: String?) {
         // disable controls after send was tapped.
         self.bottomToolbar.isUserInteractionEnabled = false
 
@@ -231,6 +231,7 @@ public class AttachmentApprovalViewController: OWSViewController, MessagingToolb
         activityIndicatorView.autoCenterInSuperview()
         activityIndicatorView.startAnimating()
 
+        attachment.captionText = captionText
         self.delegate?.didApproveAttachment(attachment: attachment)
     }
 }
@@ -325,7 +326,7 @@ private class GradientView: UIView {
 }
 
 protocol MessagingToolbarDelegate: class {
-    func messagingToolbarDidTapSend(_ messagingToolbar: MessagingToolbar)
+    func messagingToolbarDidTapSend(_ messagingToolbar: MessagingToolbar, captionText: String?)
     func messagingToolbar(_ messagingToolbar: MessagingToolbar, didChangeHeight newHeight: CGFloat)
 }
 
@@ -397,7 +398,7 @@ class MessagingToolbar: UIView, UITextViewDelegate {
     }
 
     func didTapSend() {
-        self.messagingToolbarDelegate?.messagingToolbarDidTapSend(self)
+        self.messagingToolbarDelegate?.messagingToolbarDidTapSend(self, captionText: self.textView.text)
     }
 
     // MARK: - UITextViewDelegate

SignalMessaging/attachments/SignalAttachment.swift

@@ -108,7 +108,10 @@ public class SignalAttachment: NSObject {
     // MARK: Properties
 
     @objc
-    let dataSource: DataSource
+    public let dataSource: DataSource
+
+    @objc
+    public var captionText: String?
 
     @objc
     public var data: Data {

SignalMessaging/utils/ThreadUtil.m

@@ -118,8 +118,10 @@ NS_ASSUME_NONNULL_BEGIN
     TSOutgoingMessage *message =
         [[TSOutgoingMessage alloc] initWithTimestamp:[NSDate ows_millisecondTimeStamp]
                                             inThread:thread
+                                         messageBody:attachment.captionText
                                       isVoiceMessage:[attachment isVoiceMessage]
                                     expiresInSeconds:(configuration.isEnabled ? configuration.durationSeconds : 0)];
+    
     [messageSender enqueueAttachment:attachment.dataSource
         contentType:attachment.mimeType
         sourceFilename:attachment.filenameOrDefault

SignalServiceKit/src/Messages/Interactions/TSOutgoingMessage.h

@@ -62,6 +62,7 @@ typedef NS_ENUM(NSInteger, TSGroupMetaMessage) {
 
 - (instancetype)initWithTimestamp:(uint64_t)timestamp
                          inThread:(nullable TSThread *)thread
+                      messageBody:(nullable NSString *)messageBody
                    isVoiceMessage:(BOOL)isVoiceMessage
                  expiresInSeconds:(uint32_t)expiresInSeconds;
 

SignalServiceKit/src/Messages/Interactions/TSOutgoingMessage.m

@@ -123,12 +123,13 @@ NSString *const kTSOutgoingMessageSentRecipientAll = @"kTSOutgoingMessageSentRec
 
 - (instancetype)initWithTimestamp:(uint64_t)timestamp
                          inThread:(nullable TSThread *)thread
+                      messageBody:(nullable NSString *)messageBody
                    isVoiceMessage:(BOOL)isVoiceMessage
                  expiresInSeconds:(uint32_t)expiresInSeconds
 {
     self = [self initWithTimestamp:timestamp
                           inThread:thread
-                       messageBody:nil
+                       messageBody:messageBody
                      attachmentIds:[NSMutableArray new]
                   expiresInSeconds:expiresInSeconds
                    expireStartedAt:0];