Ignore hardware mute switch during video playback in messages view.

// FREEBIE

Signal/src/ViewControllers/MessagesViewController.m

@@ -43,6 +43,7 @@
 #import "UIUtil.h"
 #import "UIViewController+CameraPermissions.h"
 #import "UIViewController+OWS.h"
+#import "ViewControllerUtils.h"
 #import <AddressBookUI/AddressBookUI.h>
 #import <AssetsLibrary/AssetsLibrary.h>
 #import <ContactsUI/CNContactViewController.h>
@@ -1681,7 +1682,8 @@ typedef enum : NSUInteger {
                         if ([messageMedia isVideo]) {
                             if ([fileManager fileExistsAtPath:[attStream.mediaURL path]]) {
                                 [self dismissKeyBoard];
-                                _videoPlayer = [[MPMoviePlayerController alloc] initWithContentURL:attStream.mediaURL];
+                                self.videoPlayer =
+                                    [[MPMoviePlayerController alloc] initWithContentURL:attStream.mediaURL];
                                 [_videoPlayer prepareToPlay];
 
                                 [[NSNotificationCenter defaultCenter] addObserver:self
@@ -1876,7 +1878,14 @@ typedef enum : NSUInteger {
 - (void)clearVideoPlayer {
     [_videoPlayer stop];
     [_videoPlayer.view removeFromSuperview];
-    _videoPlayer = nil;
+    self.videoPlayer = nil;
+}
+
+- (void)setVideoPlayer:(MPMoviePlayerController *)videoPlayer
+{
+    _videoPlayer = videoPlayer;
+
+    [ViewControllerUtils setAudioIgnoresHardwareMuteSwitch:videoPlayer != nil];
 }
 
 - (void)collectionView:(JSQMessagesCollectionView *)collectionView

Signal/src/ViewControllers/ViewControllerUtils.h

@@ -16,4 +16,6 @@
                 replacementString:(NSString *)insertionText
                       countryCode:(NSString *)countryCode;
 
++ (void)setAudioIgnoresHardwareMuteSwitch:(BOOL)shouldIgnore;
+
 @end

Signal/src/ViewControllers/ViewControllerUtils.m

@@ -5,6 +5,7 @@
 #import "ViewControllerUtils.h"
 #import "PhoneNumber.h"
 #import "StringUtil.h"
+#import <AVFoundation/AVFoundation.h>
 #import <SignalServiceKit/PhoneNumberUtil.h>
 
 NS_ASSUME_NONNULL_BEGIN
@@ -68,6 +69,29 @@ NS_ASSUME_NONNULL_BEGIN
     [textField setSelectedTextRange:[textField textRangeFromPosition:pos toPosition:pos]];
 }
 
++ (void)setAudioIgnoresHardwareMuteSwitch:(BOOL)shouldIgnore
+{
+    NSError *error = nil;
+    BOOL success = [[AVAudioSession sharedInstance]
+        setCategory:(shouldIgnore ? AVAudioSessionCategoryPlayback : AVAudioSessionCategoryPlayAndRecord)error:&error];
+    OWSAssert(!error);
+    if (!success || error) {
+        DDLogError(@"%@ Error in setAudioIgnoresHardwareMuteSwitch: %d", self.tag, shouldIgnore);
+    }
+}
+
+#pragma mark - Logging
+
++ (NSString *)tag
+{
+    return [NSString stringWithFormat:@"[%@]", self.class];
+}
+
+- (NSString *)tag
+{
+    return self.class.tag;
+}
+
 @end
 
 NS_ASSUME_NONNULL_END