Respond to CR.

// FREEBIE

Signal/src/ViewControllers/ContactsViewHelper.m

@@ -5,6 +5,7 @@
 #import "ContactsViewHelper.h"
 #import "ContactTableViewCell.h"
 #import "Environment.h"
+#import "NSString+OWS.h"
 #import "OWSProfileManager.h"
 #import "Signal-Swift.h"
 #import <SignalServiceKit/Contact.h>
@@ -205,7 +206,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (NSArray<NSString *> *)searchTermsForSearchString:(NSString *)searchText
 {
-    return [[[searchText stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]
+    return [[[searchText ows_stripped]
         componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]
         filteredArrayUsingPredicate:[NSPredicate predicateWithBlock:^BOOL(NSString *_Nullable searchTerm,
                                         NSDictionary<NSString *, id> *_Nullable bindings) {

Signal/src/ViewControllers/ConversationView/Cells/ConversationViewCell.h

@@ -58,6 +58,12 @@ NS_ASSUME_NONNULL_BEGIN
 // when visible and unload when no longer visible.  Non-visible cells can
 // cache their contents on their ConversationViewItem, but that cache may
 // be evacuated before the cell becomes visible again.
+//
+// ConversationViewController also uses this property to evacuate the cell's
+// meda views when:
+//
+// * App enters background.
+// * Users enters another view (e.g. conversation settings view, call screen, etc.).
 @property (nonatomic) BOOL isCellVisible;
 
 // The width of the collection view.

Signal/src/ViewControllers/ConversationView/Cells/OWSAudioMessageView.m

@@ -231,8 +231,7 @@ NS_ASSUME_NONNULL_BEGIN
     if (!filename) {
         filename = [[self.attachmentStream filePath] lastPathComponent];
     }
-    NSString *topText = [[filename stringByDeletingPathExtension]
-        stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
+    NSString *topText = [[filename stringByDeletingPathExtension] ows_stripped];
     if (topText.length < 1) {
         topText = [MIMETypeUtil fileExtensionForMIMEType:self.attachmentStream.contentType].uppercaseString;
     }
@@ -247,7 +246,6 @@ NS_ASSUME_NONNULL_BEGIN
     topLabel.textColor = [textColor colorWithAlphaComponent:0.85f];
     topLabel.lineBreakMode = NSLineBreakByTruncatingMiddle;
     topLabel.font = [UIFont ows_regularFontWithSize:ScaleFromIPhone5To7Plus(11.f, 13.f)];
-    topLabel.textAlignment = NSTextAlignmentLeft;
     [labelsView addSubview:topLabel];
     [topLabel autoPinEdgeToSuperviewEdge:ALEdgeTop];
     [topLabel autoPinWidthToSuperview];
@@ -267,7 +265,6 @@ NS_ASSUME_NONNULL_BEGIN
     bottomLabel.textColor = [textColor colorWithAlphaComponent:0.85f];
     bottomLabel.lineBreakMode = NSLineBreakByTruncatingMiddle;
     bottomLabel.font = [UIFont ows_regularFontWithSize:ScaleFromIPhone5To7Plus(11.f, 13.f)];
-    bottomLabel.textAlignment = NSTextAlignmentLeft;
     [labelsView addSubview:bottomLabel];
     [bottomLabel autoPinWidthToSuperview];
     [bottomLabel autoPinEdge:ALEdgeTop toEdge:ALEdgeBottom ofView:audioProgressView withOffset:kLabelVSpacing];

Signal/src/ViewControllers/ConversationView/Cells/OWSGenericAttachmentView.m

@@ -3,6 +3,7 @@
 //
 
 #import "OWSGenericAttachmentView.h"
+#import "NSString+OWS.h"
 #import "UIColor+JSQMessages.h"
 #import "UIColor+OWS.h"
 #import "UIFont+OWS.h"
@@ -162,8 +163,7 @@ NS_ASSUME_NONNULL_BEGIN
     [imageView autoSetDimension:ALDimensionWidth toSize:15.f];
 
     const CGFloat kLabelVSpacing = 2;
-    NSString *topText =
-        [self.attachmentStream.sourceFilename stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
+    NSString *topText = [self.attachmentStream.sourceFilename ows_stripped];
     if (topText.length < 1) {
         topText = [MIMETypeUtil fileExtensionForMIMEType:self.attachmentStream.contentType].uppercaseString;
     }
@@ -175,7 +175,6 @@ NS_ASSUME_NONNULL_BEGIN
     topLabel.textColor = textColor;
     topLabel.lineBreakMode = NSLineBreakByTruncatingMiddle;
     topLabel.font = [UIFont ows_regularFontWithSize:ScaleFromIPhone5To7Plus(13.f, 15.f)];
-    topLabel.textAlignment = NSTextAlignmentLeft;
     [labelsView addSubview:topLabel];
     [topLabel autoPinEdgeToSuperviewEdge:ALEdgeTop];
     [topLabel autoPinWidthToSuperview];

Signal/src/ViewControllers/ConversationView/ConversationInputTextView.m

@@ -3,6 +3,7 @@
 //
 
 #import "ConversationInputTextView.h"
+#import "NSString+OWS.h"
 #import "Signal-Swift.h"
 
 NS_ASSUME_NONNULL_BEGIN
@@ -121,7 +122,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (NSString *)trimmedText
 {
-    return [self.text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+    return [self.text ows_stripped];
 }
 
 // TODO:

Signal/src/ViewControllers/ConversationView/ConversationViewController.m

@@ -20,6 +20,7 @@
 #import "FingerprintViewController.h"
 #import "FullImageViewController.h"
 #import "NSAttributedString+OWS.h"
+#import "NSString+OWS.h"
 #import "NewGroupViewController.h"
 #import "OWSAudioAttachmentPlayer.h"
 #import "OWSContactOffersCell.h"
@@ -985,7 +986,7 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
     // Only retain the cached cell media for N cells at a time.
     const NSInteger kCellMediaCacheWindowSize = 24;
     NSInteger centerRow = (firstVisibleIndexPath.row + lastVisibleIndexPath.row) / 2;
-    // Determine the first and law rows (inclusive) of the cached cell media load window.
+    // Determine the first and last rows (inclusive) of the cached cell media load window.
     // Note these row values may not correspond to actual rows in the collection view.
     //
     // Always retain the cached cell media for any visible cells.
@@ -3698,7 +3699,7 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
         return;
     }
 
-    text = [text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+    text = [text ows_stripped];
 
     if (text.length < 1) {
         return;

Signal/src/ViewControllers/ConversationView/ConversationViewItem.m

@@ -3,6 +3,7 @@
 //
 
 #import "ConversationViewItem.h"
+#import "NSString+OWS.h"
 #import "OWSAudioMessageView.h"
 #import "OWSContactOffersCell.h"
 #import "OWSMessageCell.h"
@@ -274,14 +275,12 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType)
     if (!displayableText) {
         // Only show up to 2kb of text.
         const NSUInteger kMaxTextDisplayLength = 2 * 1024;
-        text = [text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+        text = [text ows_stripped];
         displayableText = [[DisplayableTextFilter new] displayableText:text];
         if (displayableText.length > kMaxTextDisplayLength) {
             // Trim whitespace before _AND_ after slicing the snipper from the string.
-            NSString *snippet =
-                [[[displayableText stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]
-                    substringWithRange:NSMakeRange(0, kMaxTextDisplayLength)]
-                    stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+            NSString *snippet = [
+                [[displayableText ows_stripped] substringWithRange:NSMakeRange(0, kMaxTextDisplayLength)] ows_stripped];
             displayableText = [NSString stringWithFormat:NSLocalizedString(@"OVERSIZE_TEXT_DISPLAY_FORMAT",
                                                              @"A display format for oversize text messages."),
                                         snippet];

Signal/src/ViewControllers/CountryCodeViewController.m

@@ -3,6 +3,7 @@
 //
 
 #import "CountryCodeViewController.h"
+#import "NSString+OWS.h"
 #import "PhoneNumberUtil.h"
 #import "UIColor+OWS.h"
 #import "UIFont+OWS.h"
@@ -142,8 +143,7 @@
 
 - (void)searchTextDidChange
 {
-    NSString *searchText =
-        [self.searchBar.text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+    NSString *searchText = [self.searchBar.text ows_stripped];
 
     self.countryCodes = [PhoneNumberUtil countryCodesForSearchTerm:searchText];
 

Signal/src/ViewControllers/NewGroupViewController.m

@@ -9,6 +9,7 @@
 #import "ContactTableViewCell.h"
 #import "ContactsViewHelper.h"
 #import "Environment.h"
+#import "NSString+OWS.h"
 #import "OWSContactsManager.h"
 #import "OWSNavigationController.h"
 #import "OWSTableViewController.h"
@@ -515,8 +516,7 @@ const NSUInteger kNewGroupViewControllerAvatarWidth = 68;
 
 - (TSGroupModel *)makeGroup
 {
-    NSString *groupName = [self.groupNameTextField.text
-        stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+    NSString *groupName = [self.groupNameTextField.text ows_stripped];
     NSMutableArray<NSString *> *recipientIds = [self.memberRecipientIds.allObjects mutableCopy];
     [recipientIds addObject:[self.contactsViewHelper localNumber]];
     NSData *groupId = [SecurityUtils generateRandomBytes:16];

Signal/src/ViewControllers/ProfileViewController.m

@@ -6,6 +6,7 @@
 #import "AppDelegate.h"
 #import "AvatarViewHelper.h"
 #import "HomeViewController.h"
+#import "NSString+OWS.h"
 #import "OWSNavigationController.h"
 #import "OWSProfileManager.h"
 #import "Signal-Swift.h"
@@ -410,7 +411,7 @@ NSString *const kProfileView_LastPresentedDate = @"kProfileView_LastPresentedDat
 
 - (NSString *)normalizedProfileName
 {
-    return [self.nameTextField.text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+    return [self.nameTextField.text ows_stripped];
 }
 
 - (void)updateProfileCompleted

Signal/src/ViewControllers/RegistrationViewController.m

@@ -6,6 +6,7 @@
 #import "CodeVerificationViewController.h"
 #import "CountryCodeViewController.h"
 #import "Environment.h"
+#import "NSString+OWS.h"
 #import "PhoneNumber.h"
 #import "PhoneNumberUtil.h"
 #import "Signal-Swift.h"
@@ -280,8 +281,7 @@ NSString *const kKeychainKey_LastRegisteredPhoneNumber = @"kKeychainKey_LastRegi
 
 - (void)sendCodeAction
 {
-    NSString *phoneNumberText =
-        [_phoneNumberTextField.text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+    NSString *phoneNumberText = [_phoneNumberTextField.text ows_stripped];
     if (phoneNumberText.length < 1) {
         [OWSAlerts
             showAlertWithTitle:NSLocalizedString(@"REGISTRATION_VIEW_NO_PHONE_NUMBER_ALERT_TITLE",

Signal/src/ViewControllers/SelectThreadViewController.m

@@ -7,6 +7,7 @@
 #import "ContactTableViewCell.h"
 #import "ContactsViewHelper.h"
 #import "Environment.h"
+#import "NSString+OWS.h"
 #import "OWSContactsManager.h"
 #import "OWSContactsSearcher.h"
 #import "OWSTableViewController.h"
@@ -223,8 +224,7 @@ NS_ASSUME_NONNULL_BEGIN
 {
     NSArray<TSThread *> *threads = self.threadViewHelper.threads;
 
-    NSString *searchTerm =
-        [[self.searchBar text] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+    NSString *searchTerm = [[self.searchBar text] ows_stripped];
 
     if ([searchTerm isEqualToString:@""]) {
         return threads;

Signal/src/ViewControllers/SendExternalFileViewController.m

@@ -4,6 +4,7 @@
 
 #import "SendExternalFileViewController.h"
 #import "Environment.h"
+#import "NSString+OWS.h"
 #import "Signal-Swift.h"
 #import "ThreadUtil.h"
 #import "UIColor+OWS.h"
@@ -141,8 +142,7 @@ NS_ASSUME_NONNULL_BEGIN
     // TODO: If we reuse this VC, for example to offer a "forward attachment to other thread",
     //       feature, this assumption would no longer apply.
     OWSAssert(self.attachment);
-    NSString *filename =
-        [self.attachment.sourceFilename stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
+    NSString *filename = [self.attachment.sourceFilename ows_stripped];
     OWSAssert(filename.length > 0);
     const NSUInteger kMaxFilenameLength = 20;
     if (filename.length > kMaxFilenameLength) {

Signal/src/ViewControllers/UpdateGroupViewController.m

@@ -9,6 +9,7 @@
 #import "ContactTableViewCell.h"
 #import "ContactsViewHelper.h"
 #import "Environment.h"
+#import "NSString+OWS.h"
 #import "OWSContactsManager.h"
 #import "OWSNavigationController.h"
 #import "OWSTableViewController.h"
@@ -196,8 +197,7 @@ NS_ASSUME_NONNULL_BEGIN
 
     UITextField *groupNameTextField = [UITextField new];
     _groupNameTextField = groupNameTextField;
-    self.groupNameTextField.text = [self.thread.groupModel.groupName
-        stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+    self.groupNameTextField.text = [self.thread.groupModel.groupName ows_stripped];
     groupNameTextField.textColor = [UIColor blackColor];
     groupNameTextField.font = [UIFont ows_dynamicTypeTitle2Font];
     groupNameTextField.placeholder
@@ -373,8 +373,7 @@ NS_ASSUME_NONNULL_BEGIN
 {
     OWSAssert(self.conversationSettingsViewDelegate);
 
-    NSString *groupName = [self.groupNameTextField.text
-        stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+    NSString *groupName = [self.groupNameTextField.text ows_stripped];
     TSGroupModel *groupModel = [[TSGroupModel alloc] initWithTitle:groupName
                                                          memberIds:[self.memberRecipientIds.allObjects mutableCopy]
                                                              image:self.groupAvatar

Signal/src/contact/OWSContactsSearcher.m

@@ -3,6 +3,7 @@
 //
 
 #import "OWSContactsSearcher.h"
+#import "NSString+OWS.h"
 #import <SignalServiceKit/PhoneNumber.h>
 
 @interface OWSContactsSearcher ()
@@ -22,7 +23,7 @@
 }
 
 - (NSArray<Contact *> *)filterWithString:(NSString *)string {
-    NSString *searchTerm = [string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+    NSString *searchTerm = [string ows_stripped];
 
     if ([searchTerm isEqualToString:@""]) {
         return self.contacts;

Signal/src/environment/NotificationsManager.m

@@ -4,6 +4,7 @@
 
 #import "NotificationsManager.h"
 #import "Environment.h"
+#import "NSString+OWS.h"
 #import "OWSContactsManager.h"
 #import "OWSPreferences.h"
 #import "PushManager.h"
@@ -272,8 +273,7 @@ NSString *const kNotificationsManagerNewMesssageSoundName = @"NewMessage.aifc";
         BOOL shouldPlaySound = [self shouldPlaySoundForNotification];
 
         NSString *senderName = [contactsManager displayNameForPhoneIdentifier:message.authorId];
-        NSString *groupName =
-            [thread.name stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+        NSString *groupName = [thread.name ows_stripped];
         if (groupName.length < 1) {
             groupName = [MessageStrings newGroupDefaultTitle];
         }