remove redundant state

Signal/src/ViewControllers/ConversationView/ConversationViewController.m

@@ -2858,8 +2858,7 @@ typedef enum : NSUInteger {
             UIViewController *pickerModal;
 
             if (SSKFeatureFlags.useCustomPhotoCapture) {
-                SendMediaNavigationController *navController =
-                    [SendMediaNavigationController showingCameraFirstWithMessageText:self.inputToolbar.messageText];
+                SendMediaNavigationController *navController = [SendMediaNavigationController showingCameraFirst];
                 navController.sendMediaNavDelegate = self;
                 pickerModal = navController;
             } else {
@@ -2904,8 +2903,7 @@ typedef enum : NSUInteger {
             return;
         }
 
-        SendMediaNavigationController *pickerModal =
-            [SendMediaNavigationController showingMediaLibraryFirstWithMessageText:self.inputToolbar.messageText];
+        SendMediaNavigationController *pickerModal = [SendMediaNavigationController showingMediaLibraryFirst];
         pickerModal.sendMediaNavDelegate = self;
 
         [self dismissKeyBoard];
@@ -2941,9 +2939,26 @@ typedef enum : NSUInteger {
               messageText:(nullable NSString *)messageText
 {
     [self tryToSendAttachments:attachments messageText:messageText];
+    [self.inputToolbar clearTextMessageAnimated:NO];
+
+    // we want to already be at the bottom when the user returns, rather than have to watch
+    // the new message scroll into view.
+    [self scrollToBottomAnimated:NO];
+
     [self dismissViewControllerAnimated:YES completion:nil];
 }
 
+- (nullable NSString *)sendMediaNavInitialMessageText:(SendMediaNavigationController *)sendMediaNavigationController
+{
+    return self.inputToolbar.messageText;
+}
+
+- (void)sendMediaNav:(SendMediaNavigationController *)sendMediaNavigationController
+    didChangeMessageText:(nullable NSString *)messageText
+{
+    [self.inputToolbar setMessageText:messageText animated:NO];
+}
+
 #pragma mark - UIImagePickerControllerDelegate
 
 /*
@@ -3910,7 +3925,9 @@ typedef enum : NSUInteger {
                messageText:(NSString *_Nullable)messageText
 {
     [self tryToSendAttachments:attachments messageText:messageText];
+    [self.inputToolbar clearTextMessageAnimated:NO];
     [self dismissViewControllerAnimated:YES completion:nil];
+
     // We always want to scroll to the bottom of the conversation after the local user
     // sends a message.  Normally, this is taken care of in yapDatabaseModified:, but
     // we don't listen to db modifications when this view isn't visible, i.e. when the

Signal/src/ViewControllers/Photos/SendMediaNavigationController.swift

@@ -10,6 +10,9 @@ import PromiseKit
 protocol SendMediaNavDelegate: AnyObject {
     func sendMediaNavDidCancel(_ sendMediaNavigationController: SendMediaNavigationController)
     func sendMediaNav(_ sendMediaNavigationController: SendMediaNavigationController, didApproveAttachments attachments: [SignalAttachment], messageText: String?)
+
+    func sendMediaNavInitialMessageText(_ sendMediaNavigationController: SendMediaNavigationController) -> String?
+    func sendMediaNav(_ sendMediaNavigationController: SendMediaNavigationController, didChangeMessageText newMessageText: String?)
 }
 
 @objc
@@ -19,8 +22,6 @@ class SendMediaNavigationController: OWSNavigationController {
 
     override var prefersStatusBarHidden: Bool { return true }
 
-    var messageText: String?
-
     override func viewDidLoad() {
         super.viewDidLoad()
 
@@ -53,21 +54,19 @@ class SendMediaNavigationController: OWSNavigationController {
     public weak var sendMediaNavDelegate: SendMediaNavDelegate?
 
     @objc
-    public class func showingCameraFirst(messageText: String) -> SendMediaNavigationController {
+    public class func showingCameraFirst() -> SendMediaNavigationController {
         let navController = SendMediaNavigationController()
         navController.setViewControllers([navController.captureViewController], animated: false)
         navController.updateButtons()
-        navController.messageText = messageText
 
         return navController
     }
 
     @objc
-    public class func showingMediaLibraryFirst(messageText: String) -> SendMediaNavigationController {
+    public class func showingMediaLibraryFirst() -> SendMediaNavigationController {
         let navController = SendMediaNavigationController()
         navController.setViewControllers([navController.mediaLibraryViewController], animated: false)
         navController.updateButtons()
-        navController.messageText = messageText
 
         return navController
     }
@@ -212,9 +211,14 @@ class SendMediaNavigationController: OWSNavigationController {
     }()
 
     private func pushApprovalViewController() {
+        guard let sendMediaNavDelegate = self.sendMediaNavDelegate else {
+            owsFailDebug("sendMediaNavDelegate was unexpectedly nil")
+            return
+        }
+
         let approvalViewController = AttachmentApprovalViewController(mode: .sharedNavigation, attachments: self.attachments)
         approvalViewController.approvalDelegate = self
-        approvalViewController.messageText = messageText
+        approvalViewController.messageText = sendMediaNavDelegate.sendMediaNavInitialMessageText(self)
 
         pushViewController(approvalViewController, animated: true)
         updateButtons()
@@ -367,7 +371,7 @@ extension SendMediaNavigationController: ImagePickerGridControllerDelegate {
 
 extension SendMediaNavigationController: AttachmentApprovalViewControllerDelegate {
     func attachmentApproval(_ attachmentApproval: AttachmentApprovalViewController, didChangeMessageText newMessageText: String?) {
-        self.messageText = newMessageText
+        sendMediaNavDelegate?.sendMediaNav(self, didChangeMessageText: newMessageText)
     }
 
     func attachmentApproval(_ attachmentApproval: AttachmentApprovalViewController, didRemoveAttachment attachment: SignalAttachment) {