react-native/React/Modules/RCTI18nUtil.m
Frank Manns 09680f71df Return instancetype for shared RCTI18nUtil instance
Summary:
In modern Objective-C you should use the `instancetype` keyword for methods which return an instance of the class they are called on. See Apple's [Adopting Modern Objective-C](https://developer.apple.com/library/content/releasenotes/ObjectiveC/ModernizationObjC/AdoptingModernObjective-C/AdoptingModernObjective-C.html) guide.

Because `sharedInstance` was returning an object of type `id`, the returned value needed to be cast before it could be used in Swift.

I also changed the implementation of `sharedInstance` to use Grand Central Dispatch, which is the generally accepted best way of creating a singleton in Objective-C.

I verified my changes with the "RTLExample" app in RNTester.

| LTR | RTL |
|---|---|
|<img width="300" src="https://user-images.githubusercontent.com/1413388/31155210-6454b4d6-a87a-11e7-9dd7-9a52f3924737.png">|<img width="300" src="https://user-images.githubusercontent.com/1413388/31155233-8702aff6-a87a-11e7-8028-51cf2b3eb0c4.png">|
Closes https://github.com/facebook/react-native/pull/16196

Differential Revision: D5971898

Pulled By: shergin

fbshipit-source-id: dfa375c89248adfc9fd885cacc6a6d4cbfea6e90
2017-10-03 20:11:16 -07:00

97 lines
2.6 KiB
Objective-C

/**
* Copyright (c) 2015-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*/
#import <Foundation/Foundation.h>
#import "RCTI18nUtil.h"
@implementation RCTI18nUtil
+ (instancetype)sharedInstance
{
static RCTI18nUtil *sharedInstance;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sharedInstance = [self new];
});
return sharedInstance;
}
/**
* Check if the app is currently running on an RTL locale.
* This only happens when the app:
* - is forcing RTL layout, regardless of the active language (for development purpose)
* - allows RTL layout when using RTL locale
*/
- (BOOL)isRTL
{
if ([self isRTLForced]) {
return YES;
}
if ([self isRTLAllowed] && [self isApplicationPreferredLanguageRTL]) {
return YES;
}
return NO;
}
/**
* Should be used very early during app start up
* Before the bridge is initialized
* @return whether the app allows RTL layout, default is true
*/
- (BOOL)isRTLAllowed
{
NSNumber *value = [[NSUserDefaults standardUserDefaults] objectForKey:@"RCTI18nUtil_allowRTL"];
if (value == nil) {
return YES;
}
return [value boolValue];
}
- (void)allowRTL:(BOOL)rtlStatus
{
[[NSUserDefaults standardUserDefaults] setBool:rtlStatus forKey:@"RCTI18nUtil_allowRTL"];
[[NSUserDefaults standardUserDefaults] synchronize];
}
/**
* Could be used to test RTL layout with English
* Used for development and testing purpose
*/
- (BOOL)isRTLForced
{
BOOL rtlStatus = [[NSUserDefaults standardUserDefaults]
boolForKey:@"RCTI18nUtil_forceRTL"];
return rtlStatus;
}
- (void)forceRTL:(BOOL)rtlStatus
{
[[NSUserDefaults standardUserDefaults] setBool:rtlStatus forKey:@"RCTI18nUtil_forceRTL"];
[[NSUserDefaults standardUserDefaults] synchronize];
}
// Check if the current device language is RTL
- (BOOL)isDevicePreferredLanguageRTL
{
NSLocaleLanguageDirection direction = [NSLocale characterDirectionForLanguage:[[NSLocale preferredLanguages] objectAtIndex:0]];
return direction == NSLocaleLanguageDirectionRightToLeft;
}
// Check if the current application language is RTL
- (BOOL)isApplicationPreferredLanguageRTL
{
NSString *preferredAppLanguage = [[[NSBundle mainBundle] preferredLocalizations] objectAtIndex:0];
NSLocaleLanguageDirection direction = [NSLocale characterDirectionForLanguage:preferredAppLanguage];
return direction == NSLocaleLanguageDirectionRightToLeft;
}
@end