Add video codec setting to AppRTCMobile on iOS.

webrtc/examples/objc/AppRTCMobile/ios/ARDSettingsViewController.m

Index: webrtc/examples/objc/AppRTCMobile/ios/ARDSettingsViewController.m
diff --git a/webrtc/examples/objc/AppRTCMobile/ios/ARDSettingsViewController.m b/webrtc/examples/objc/AppRTCMobile/ios/ARDSettingsViewController.m
index 815b14799f7cf388c2a4813620954ce6f676fec9..6c33d63aaf0cb57a68de93dbaf943d7502cfe016 100644
--- a/webrtc/examples/objc/AppRTCMobile/ios/ARDSettingsViewController.m
+++ b/webrtc/examples/objc/AppRTCMobile/ios/ARDSettingsViewController.m
@@ -15,7 +15,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 typedef NS_ENUM(int, ARDSettingsSections) {
   ARDSettingsSectionMediaConstraints = 0,
-  ARDSettingsSectionBitRate
+  ARDSettingsSectionVideoCodec,
+  ARDSettingsSectionBitRate,
 };
 
 @interface ARDSettingsViewController () <UITextFieldDelegate> {
@@ -43,9 +44,14 @@ typedef NS_ENUM(int, ARDSettingsSections) {
   [self addDoneBarButton];
 }
 
+- (void)viewWillAppear:(BOOL)animated {
+  [super viewWillAppear:animated];
+  [self decorateCurrentlyStoredOrDefaultMediaConstraints];
+  [self decorateCurrentlyStoredOrDefaultVideoCodec];

[kthelgason, 2017/03/09 13:39:43]

Is this safe to do here? Why not in viewDidAppear?

[sakal, 2017/03/10 10:25:28]

I didn't notice any problems in my testing. If we do this in viewDidAppear, the
checkmarks appear after the view has animated to the place, which is ugly.

+}
+
 - (void)viewDidAppear:(BOOL)animated {
   [super viewDidAppear:animated];
-  [self selectCurrentlyStoredOrDefaultMediaConstraints];
 }
 
 #pragma mark - Data source
@@ -54,6 +60,10 @@ typedef NS_ENUM(int, ARDSettingsSections) {
   return _settingsModel.availableVideoResoultionsMediaConstraints;
 }
 
+- (NSArray<NSString *> *)videoCodecArray {
+  return _settingsModel.availableVideoCodecs;
+}
+
 #pragma mark -
 
 - (void)addDoneBarButton {
@@ -64,16 +74,24 @@ typedef NS_ENUM(int, ARDSettingsSections) {
   self.navigationItem.leftBarButtonItem = barItem;
 }
 
-- (void)selectCurrentlyStoredOrDefaultMediaConstraints {
+- (void)decorateCurrentlyStoredOrDefaultMediaConstraints {
   NSString *currentSelection = [_settingsModel currentVideoResoultionConstraintFromStore];
 
   NSUInteger indexOfSelection = [[self mediaConstraintsArray] indexOfObject:currentSelection];
-  NSIndexPath *pathToBeSelected = [NSIndexPath indexPathForRow:indexOfSelection inSection:0];
-  [self.tableView selectRowAtIndexPath:pathToBeSelected
-                              animated:NO
-                        scrollPosition:UITableViewScrollPositionNone];
-  // Manully invoke the delegate method because the previous invocation will not.
-  [self tableView:self.tableView didSelectRowAtIndexPath:pathToBeSelected];
+  NSIndexPath *pathToBeDecorated = [NSIndexPath indexPathForRow:indexOfSelection
+                                                      inSection:ARDSettingsSectionMediaConstraints];
+  UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:pathToBeDecorated];
+  cell.accessoryType = UITableViewCellAccessoryCheckmark;
+}
+
+- (void)decorateCurrentlyStoredOrDefaultVideoCodec {
+  NSString *currentSelection = [_settingsModel currentVideoCodecSettingFromStore];
+
+  NSUInteger indexOfSelection = [[self videoCodecArray] indexOfObject:currentSelection];
+  NSIndexPath *pathToBeDecorated = [NSIndexPath indexPathForRow:indexOfSelection
+                                                      inSection:ARDSettingsSectionVideoCodec];
+  UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:pathToBeDecorated];
+  cell.accessoryType = UITableViewCellAccessoryCheckmark;
 }
 
 #pragma mark - Dismissal of view controller
@@ -85,13 +103,16 @@ typedef NS_ENUM(int, ARDSettingsSections) {
 #pragma mark - Table view data source
 
 - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
-  return 2;
+  return 3;
 }
 
 - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
   if ([self sectionIsMediaConstraints:section]) {
     return self.mediaConstraintsArray.count;
   }
+  if ([self sectionIsVideoCodec:section]) {
+    return self.videoCodecArray.count;
+  }

[kthelgason, 2017/03/09 13:39:43]

I'd prefer a switch-case on section here.

[sakal, 2017/03/10 10:25:28]

Done.

 
   return 1;
 }
@@ -102,6 +123,10 @@ typedef NS_ENUM(int, ARDSettingsSections) {
   return section == ARDSettingsSectionMediaConstraints;
 }
 
+- (BOOL)sectionIsVideoCodec:(int)section {
+  return section == ARDSettingsSectionVideoCodec;
+}
+
 - (BOOL)sectionIsBitrate:(int)section {
   return section == ARDSettingsSectionBitRate;
 }
@@ -110,10 +135,26 @@ typedef NS_ENUM(int, ARDSettingsSections) {
   return [self sectionIsMediaConstraints:indexPath.section];
 }
 
+- (BOOL)indexPathIsVideoCodec:(NSIndexPath *)indexPath {
+  return [self sectionIsVideoCodec:indexPath.section];
+}
+
 - (BOOL)indexPathIsBitrate:(NSIndexPath *)indexPath {
   return [self sectionIsBitrate:indexPath.section];
 }
 
+#pragma mark - Table view delegate helpers
+
+- (void)removeAllAccessories:(UITableView *)tableView
+                   inSection:(int)section
+{
+  for (int i = 0; i < [tableView numberOfRowsInSection:section]; i++) {
+    NSIndexPath *rowPath = [NSIndexPath indexPathForRow:i inSection:section];
+    UITableViewCell *cell = [tableView cellForRowAtIndexPath:rowPath];
+    cell.accessoryType = UITableViewCellAccessoryNone;
+  }
+}
+
 #pragma mark - Table view delegate
 
 - (nullable NSString *)tableView:(UITableView *)tableView
@@ -126,6 +167,10 @@ typedef NS_ENUM(int, ARDSettingsSections) {
     return @"Maximum bitrate";
   }
 
+  if ([self sectionIsVideoCodec:section]) {
+    return @"Video codec";
+  }
+
   return @"";
 }
 
@@ -135,6 +180,10 @@ typedef NS_ENUM(int, ARDSettingsSections) {
     return [self mediaConstraintsTableViewCellForTableView:tableView atIndexPath:indexPath];
   }
 
+  if ([self indexPathIsVideoCodec:indexPath]) {
+    return [self videoCodecTableViewCellForTableView:tableView atIndexPath:indexPath];
+  }
+
   if ([self indexPathIsBitrate:indexPath]) {
     return [self bitrateTableViewCellForTableView:tableView atIndexPath:indexPath];
   }
@@ -143,18 +192,13 @@ typedef NS_ENUM(int, ARDSettingsSections) {
                                 reuseIdentifier:@"identifier"];
 }
 
-- (nullable NSIndexPath *)tableView:(UITableView *)tableView
-           willSelectRowAtIndexPath:(nonnull NSIndexPath *)indexPath {
-  if ([self indexPathIsMediaConstraints:indexPath]) {
-    return [self tableView:tableView willDeselectMediaConstraintsRowAtIndexPath:indexPath];
-  }
-  return indexPath;
-}
-
 - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
   if ([self indexPathIsMediaConstraints:indexPath]) {
     [self tableView:tableView didSelectMediaConstraintsCellAtIndexPath:indexPath];
   }
+  if ([self indexPathIsVideoCodec:indexPath]) {
+    [self tableView:tableView didSelectVideoCodecCellAtIndexPath:indexPath];
+  }
 }
 
 #pragma mark - Table view delegate(Media Constraints)
@@ -173,19 +217,41 @@ typedef NS_ENUM(int, ARDSettingsSections) {
 
 - (void)tableView:(UITableView *)tableView
     didSelectMediaConstraintsCellAtIndexPath:(NSIndexPath *)indexPath {
+  [self removeAllAccessories:tableView inSection:ARDSettingsSectionMediaConstraints];
   UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
   cell.accessoryType = UITableViewCellAccessoryCheckmark;
 
   NSString *mediaConstraintsString = self.mediaConstraintsArray[indexPath.row];
   [_settingsModel storeVideoResoultionConstraint:mediaConstraintsString];
+
+  [tableView deselectRowAtIndexPath:indexPath animated:YES];
 }
 
-- (NSIndexPath *)tableView:(UITableView *)tableView
-    willDeselectMediaConstraintsRowAtIndexPath:(NSIndexPath *)indexPath {
-  NSIndexPath *oldSelection = [tableView indexPathForSelectedRow];
-  UITableViewCell *cell = [tableView cellForRowAtIndexPath:oldSelection];
-  cell.accessoryType = UITableViewCellAccessoryNone;
-  return indexPath;
+#pragma mark - Table view delegate(Video Codec)
+
+- (UITableViewCell *)videoCodecTableViewCellForTableView:(UITableView *)tableView
+                                             atIndexPath:(NSIndexPath *)indexPath {
+  NSString *dequeueIdentifier = @"ARDSettingsVideoCodecCellIdentifier";
+  UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:dequeueIdentifier];
+  if (!cell) {
+    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
+                                  reuseIdentifier:dequeueIdentifier];
+  }
+  cell.textLabel.text = self.videoCodecArray[indexPath.row];
+
+  return cell;
+}

[kthelgason, 2017/03/09 13:39:43]

It seems to me that there is a lot of shared code with the Media Costraints.
Perhaps we can refactor this to reduce the duplication?

[sakal, 2017/03/10 10:25:28]

Done.

+
+- (void)tableView:(UITableView *)tableView
+    didSelectVideoCodecCellAtIndexPath:(NSIndexPath *)indexPath {
+  [self removeAllAccessories:tableView inSection:ARDSettingsSectionVideoCodec];
+  UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
+  cell.accessoryType = UITableViewCellAccessoryCheckmark;
+
+  NSString *videoCodec = self.videoCodecArray[indexPath.row];
+  [_settingsModel storeVideoCodecSetting:videoCodec];
+
+  [tableView deselectRowAtIndexPath:indexPath animated:YES];
 }
 
 #pragma mark - Table view delegate(Bitrate)