From 68476a51dc4dfbb76b74d27ed13033699d61d6c2 Mon Sep 17 00:00:00 2001
From: Michael Kirk <michael.code@endoftheworl.de>
Date: Tue, 18 Apr 2017 13:50:01 -0400
Subject: [PATCH] Download service emits progress notifications

// FREEBIE
---
 .../Attachments/OWSAttachmentsProcessor.h     |  8 +++++-
 .../Attachments/OWSAttachmentsProcessor.m     | 26 ++++++++++++++++++-
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/src/Messages/Attachments/OWSAttachmentsProcessor.h b/src/Messages/Attachments/OWSAttachmentsProcessor.h
index 9c88e4e04..1fb3ef4f2 100644
--- a/src/Messages/Attachments/OWSAttachmentsProcessor.h
+++ b/src/Messages/Attachments/OWSAttachmentsProcessor.h
@@ -1,7 +1,13 @@
-//  Copyright © 2016 Open Whisper Systems. All rights reserved.
+//
+//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//
 
 NS_ASSUME_NONNULL_BEGIN
 
+extern NSString *const kAttachmentDownloadProgressNotification;
+extern NSString *const kAttachmentDownloadProgressKey;
+extern NSString *const kAttachmentDownloadAttachmentIDKey;
+
 @class TSMessage;
 @class TSThread;
 @class TSNetworkManager;
diff --git a/src/Messages/Attachments/OWSAttachmentsProcessor.m b/src/Messages/Attachments/OWSAttachmentsProcessor.m
index 87a869a42..05a526951 100644
--- a/src/Messages/Attachments/OWSAttachmentsProcessor.m
+++ b/src/Messages/Attachments/OWSAttachmentsProcessor.m
@@ -20,6 +20,14 @@
 
 NS_ASSUME_NONNULL_BEGIN
 
+NSString *const kAttachmentDownloadProgressNotification = @"kAttachmentDownloadProgressNotification";
+NSString *const kAttachmentDownloadProgressKey = @"kAttachmentDownloadProgressKey";
+NSString *const kAttachmentDownloadAttachmentIDKey = @"kAttachmentDownloadAttachmentIDKey";
+
+// Use a slightly non-zero value to ensure that the progress
+// indicator shows up as quickly as possible.
+static const CGFloat kAttachmentDownloadProgressTheta = 0.001f;
+
 @interface OWSAttachmentsProcessor ()
 
 @property (nonatomic, readonly) TSNetworkManager *networkManager;
@@ -259,7 +267,10 @@ NS_ASSUME_NONNULL_BEGIN
                 abortDownload();
                 return;
             }
-            
+
+            [self fireProgressNotification:MAX(kAttachmentDownloadProgressTheta, progress.fractionCompleted)
+                              attachmentId:pointer.uniqueId];
+
             // We only need to check the content length header once.
             if (hasCheckedContentLength) {
                 return;
@@ -322,6 +333,19 @@ NS_ASSUME_NONNULL_BEGIN
         }];
 }
 
+- (void)fireProgressNotification:(CGFloat)progress attachmentId:(NSString *)attachmentId
+{
+    dispatch_async(dispatch_get_main_queue(), ^{
+        NSNotificationCenter *notificationCenter = [NSNotificationCenter defaultCenter];
+        [notificationCenter postNotificationName:kAttachmentDownloadProgressNotification
+                                          object:nil
+                                        userInfo:@{
+                                            kAttachmentDownloadProgressKey : @(progress),
+                                            kAttachmentDownloadAttachmentIDKey : attachmentId
+                                        }];
+    });
+}
+
 - (void)setAttachment:(TSAttachmentPointer *)pointer isDownloadingInMessage:(nullable TSMessage *)message
 {
     pointer.state = TSAttachmentPointerStateDownloading;