[ios] Fix and expand accessibility feature transliteration

- Fixed pre-iOS 11 compatibility.
- Expanded transliteration to all supported languages.

10 files changed, 168 insertions, 17 deletions

diff --git a/platform/darwin/src/MGLVectorSource_Private.h b/platform/darwin/src/MGLVectorSource_Private.h
index 233809aea2..7d19e03a99 100644
--- a/platform/darwin/src/MGLVectorSource_Private.h
+++ b/platform/darwin/src/MGLVectorSource_Private.h
@@ -6,6 +6,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 @property (nonatomic, readonly, getter=isMapboxStreets) BOOL mapboxStreets;
 
++ (NS_SET_OF(NSString *) *)mapboxStreetsLanguages;
+
 + (NSString *)preferredMapboxStreetsLanguage;
 
 - (NS_DICTIONARY_OF(NSString *, NSString *) *)localizedKeysByKeyForPreferredLanguage:(nullable NSString *)preferredLanguage;
diff --git a/platform/darwin/src/NSString+MGLAdditions.h b/platform/darwin/src/NSString+MGLAdditions.h
index d82ecaa671..75c593c10b 100644
--- a/platform/darwin/src/NSString+MGLAdditions.h
+++ b/platform/darwin/src/NSString+MGLAdditions.h
@@ -20,6 +20,20 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (NSString *)mgl_titleCasedStringWithLocale:(NSLocale *)locale;
 
+/**
+ Returns a transliterated representation of the receiver using the specified
+ script. If transliteration fails, the receiver will be returned.
+
+ Only supports scripts for languages used by Mapbox Streets.
+
+ On iOS 8 or older, this will method will always return the untransliterated
+ receiver.
+
+ @param script The four-letter code representing the name of the script, as
+    specified by ISO 15924.
+ */
+- (NSString *)mgl_stringByTransliteratingIntoScript:(NSString *)script;
+
 @end
 
 @interface NSAttributedString (MGLAdditions)
diff --git a/platform/darwin/src/NSString+MGLAdditions.m b/platform/darwin/src/NSString+MGLAdditions.m
index cde4bddcc3..8c9bbe3e21 100644
--- a/platform/darwin/src/NSString+MGLAdditions.m
+++ b/platform/darwin/src/NSString+MGLAdditions.m
@@ -41,6 +41,25 @@
     return string;
 }
 
+- (NSString *)mgl_stringByTransliteratingIntoScript:(NSString *)script {
+    if (@available(iOS 9.0, *)) {
+        NSMutableString *string = self.mutableCopy;
+        NSStringTransform transform;
+        if ([script isEqualToString:@"Latn"]) {
+            transform = NSStringTransformToLatin;
+        } else if ([script isEqualToString:@"Hans"]) {
+            // No transform available.
+        } else if ([script isEqualToString:@"Cyrl"]) {
+            transform = @"Any-Latin; Latin-Cyrillic";
+        } else if ([script isEqualToString:@"Arab"]) {
+            transform = @"Any-Latin; Latin-Arabic";
+        }
+        return transform ? [string stringByApplyingTransform:transform reverse:NO] : string;
+    } else {
+        return self;
+    }
+}
+
 @end
 
 @implementation NSAttributedString (MGLAdditions)
diff --git a/platform/darwin/test/MGLNSStringAdditionsTests.m b/platform/darwin/test/MGLNSStringAdditionsTests.m
index 03503b7f8a..2a8715d991 100644
--- a/platform/darwin/test/MGLNSStringAdditionsTests.m
+++ b/platform/darwin/test/MGLNSStringAdditionsTests.m
@@ -39,4 +39,38 @@
     XCTAssertEqualObjects([@"Improve This iPhone" mgl_titleCasedStringWithLocale:locale], @"Improve This iPhone");
 }
 
+- (void)testTransliteratedString {
+    if (@available(iOS 9.0, *)) {
+        XCTAssertEqualObjects([@"Portland" mgl_stringByTransliteratingIntoScript:@"Latn"], @"Portland");
+        XCTAssertEqualObjects([@"Portland" mgl_stringByTransliteratingIntoScript:@"Hans"], @"Portland");
+        XCTAssertEqualObjects([@"Portland" mgl_stringByTransliteratingIntoScript:@"Cyrl"], @"Портланд");
+        XCTAssertEqualObjects([@"Portland" mgl_stringByTransliteratingIntoScript:@"Arab"], @"پُرتلَند");
+        XCTAssertEqualObjects([@"Portland" mgl_stringByTransliteratingIntoScript:@"Fake"], @"Portland");
+
+        XCTAssertEqualObjects([@"北京" mgl_stringByTransliteratingIntoScript:@"Latn"], @"běi jīng");
+        XCTAssertEqualObjects([@"北京" mgl_stringByTransliteratingIntoScript:@"Hans"], @"北京");
+        XCTAssertEqualObjects([@"北京" mgl_stringByTransliteratingIntoScript:@"Cyrl"], @"бе̌и йӣнг");
+        XCTAssertEqualObjects([@"北京" mgl_stringByTransliteratingIntoScript:@"Arab"], @"بِِ̌ جِينگ");
+        XCTAssertEqualObjects([@"北京" mgl_stringByTransliteratingIntoScript:@"Fake"], @"北京");
+
+        XCTAssertEqualObjects([@"Mосква" mgl_stringByTransliteratingIntoScript:@"Latn"], @"Moskva");
+        XCTAssertEqualObjects([@"Mосква" mgl_stringByTransliteratingIntoScript:@"Hans"], @"Mосква");
+        XCTAssertEqualObjects([@"Mосква" mgl_stringByTransliteratingIntoScript:@"Cyrl"], @"Москва");
+        XCTAssertEqualObjects([@"Mосква" mgl_stringByTransliteratingIntoScript:@"Arab"], @"مُسكڤَ");
+        XCTAssertEqualObjects([@"Mосква" mgl_stringByTransliteratingIntoScript:@"Fake"], @"Mосква");
+
+        XCTAssertEqualObjects([@"ロンドン" mgl_stringByTransliteratingIntoScript:@"Latn"], @"rondon");
+        XCTAssertEqualObjects([@"ロンドン" mgl_stringByTransliteratingIntoScript:@"Hans"], @"ロンドン");
+        XCTAssertEqualObjects([@"ロンドン" mgl_stringByTransliteratingIntoScript:@"Cyrl"], @"рондон");
+        XCTAssertEqualObjects([@"ロンドン" mgl_stringByTransliteratingIntoScript:@"Arab"], @"رُندُن");
+        XCTAssertEqualObjects([@"ロンドン" mgl_stringByTransliteratingIntoScript:@"Fake"], @"ロンドン");
+    } else {
+        XCTAssertEqualObjects([@"Made-up Place" mgl_stringByTransliteratingIntoScript:@"Latn"], @"Made-up Place");
+        XCTAssertEqualObjects([@"Made-up Place" mgl_stringByTransliteratingIntoScript:@"Hans"], @"Made-up Place");
+        XCTAssertEqualObjects([@"Made-up Place" mgl_stringByTransliteratingIntoScript:@"Cyrl"], @"Made-up Place");
+        XCTAssertEqualObjects([@"Made-up Place" mgl_stringByTransliteratingIntoScript:@"Arab"], @"Made-up Place");
+        XCTAssertEqualObjects([@"Made-up Place" mgl_stringByTransliteratingIntoScript:@"Fake"], @"Made-up Place");
+    }
+}
+
 @end
diff --git a/platform/ios/ios.xcodeproj/project.pbxproj b/platform/ios/ios.xcodeproj/project.pbxproj
index 324ab1fc8f..fb268fab1d 100644
--- a/platform/ios/ios.xcodeproj/project.pbxproj
+++ b/platform/ios/ios.xcodeproj/project.pbxproj
@@ -227,6 +227,11 @@
 		927FBD021F4DB05500F8BF1F /* MGLMapSnapshotter.mm in Sources */ = {isa = PBXBuildFile; fileRef = 927FBCFE1F4DB05500F8BF1F /* MGLMapSnapshotter.mm */; };
 		929EFFAB1F56DCD4003A77D5 /* MGLAnnotationView.mm in Sources */ = {isa = PBXBuildFile; fileRef = 4018B1C41CDC277F00F666AF /* MGLAnnotationView.mm */; };
 		92F2C3ED1F0E3C3A00268EC0 /* MGLRendererFrontend.h in Headers */ = {isa = PBXBuildFile; fileRef = 92F2C3EC1F0E3C3A00268EC0 /* MGLRendererFrontend.h */; };
+		96036A01200565C700510F3D /* NSOrthography+MGLAdditions.h in Headers */ = {isa = PBXBuildFile; fileRef = 960369FF200565C700510F3D /* NSOrthography+MGLAdditions.h */; };
+		96036A02200565C700510F3D /* NSOrthography+MGLAdditions.h in Headers */ = {isa = PBXBuildFile; fileRef = 960369FF200565C700510F3D /* NSOrthography+MGLAdditions.h */; };
+		96036A03200565C700510F3D /* NSOrthography+MGLAdditions.m in Sources */ = {isa = PBXBuildFile; fileRef = 96036A00200565C700510F3D /* NSOrthography+MGLAdditions.m */; };
+		96036A04200565C700510F3D /* NSOrthography+MGLAdditions.m in Sources */ = {isa = PBXBuildFile; fileRef = 96036A00200565C700510F3D /* NSOrthography+MGLAdditions.m */; };
+		96036A0620059BBA00510F3D /* MGLNSOrthographyAdditionsTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 96036A0520059BBA00510F3D /* MGLNSOrthographyAdditionsTests.m */; };
 		960D0C361ECF5AAF008E151F /* Images.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 960D0C351ECF5AAF008E151F /* Images.xcassets */; };
 		960D0C371ECF5AAF008E151F /* Images.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 960D0C351ECF5AAF008E151F /* Images.xcassets */; };
 		9620BB381E69FE1700705A1D /* MGLSDKUpdateChecker.h in Headers */ = {isa = PBXBuildFile; fileRef = 9620BB361E69FE1700705A1D /* MGLSDKUpdateChecker.h */; };
@@ -764,6 +769,9 @@
 		927FBCFD1F4DB05500F8BF1F /* MGLMapSnapshotter.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MGLMapSnapshotter.h; sourceTree = "<group>"; };
 		927FBCFE1F4DB05500F8BF1F /* MGLMapSnapshotter.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = MGLMapSnapshotter.mm; sourceTree = "<group>"; };
 		92F2C3EC1F0E3C3A00268EC0 /* MGLRendererFrontend.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MGLRendererFrontend.h; sourceTree = "<group>"; };
+		960369FF200565C700510F3D /* NSOrthography+MGLAdditions.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "NSOrthography+MGLAdditions.h"; sourceTree = "<group>"; };
+		96036A00200565C700510F3D /* NSOrthography+MGLAdditions.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = "NSOrthography+MGLAdditions.m"; sourceTree = "<group>"; };
+		96036A0520059BBA00510F3D /* MGLNSOrthographyAdditionsTests.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = MGLNSOrthographyAdditionsTests.m; sourceTree = "<group>"; };
 		960D0C351ECF5AAF008E151F /* Images.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = Images.xcassets; sourceTree = "<group>"; };
 		9620BB361E69FE1700705A1D /* MGLSDKUpdateChecker.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MGLSDKUpdateChecker.h; sourceTree = "<group>"; };
 		9620BB371E69FE1700705A1D /* MGLSDKUpdateChecker.mm */ = {isa = PBXFileReference; explicitFileType = sourcecode.cpp.objcpp; fileEncoding = 4; path = MGLSDKUpdateChecker.mm; sourceTree = "<group>"; };
@@ -1231,6 +1239,8 @@
 			children = (
 				357FE2DB1E02D2B20068B753 /* NSCoder+MGLAdditions.h */,
 				357FE2DC1E02D2B20068B753 /* NSCoder+MGLAdditions.mm */,
+				960369FF200565C700510F3D /* NSOrthography+MGLAdditions.h */,
+				96036A00200565C700510F3D /* NSOrthography+MGLAdditions.m */,
 				35CE61801D4165D9004F2359 /* UIColor+MGLAdditions.h */,
 				35CE61811D4165D9004F2359 /* UIColor+MGLAdditions.mm */,
 				30E578111DAA7D690050F07E /* UIImage+MGLAdditions.h */,
@@ -1413,6 +1423,7 @@
 				35E208A61D24210F00EC9A46 /* MGLNSDataAdditionsTests.m */,
 				1F95931C1E6DE2E900D5B294 /* MGLNSDateAdditionsTests.mm */,
 				DAE7DEC11E245455007505A6 /* MGLNSStringAdditionsTests.m */,
+				96036A0520059BBA00510F3D /* MGLNSOrthographyAdditionsTests.m */,
 				DA2E885D1CC0382C00F24E7B /* MGLOfflinePackTests.m */,
 				DA2E885E1CC0382C00F24E7B /* MGLOfflineRegionTests.m */,
 				55E2AD121E5B125400E8C587 /* MGLOfflineStorageTests.mm */,
@@ -1871,6 +1882,7 @@
 				353933F21D3FB753003F57D7 /* MGLCircleStyleLayer.h in Headers */,
 				DA8847F31CBAFA5100AB86E3 /* MGLMultiPoint.h in Headers */,
 				30E578171DAA85520050F07E /* UIImage+MGLAdditions.h in Headers */,
+				96036A01200565C700510F3D /* NSOrthography+MGLAdditions.h in Headers */,
 				1F7454961ECD450D00021D39 /* MGLLight_Private.h in Headers */,
 				DAD1656C1CF41981001FF4B9 /* MGLFeature.h in Headers */,
 				40EDA1C01CFE0E0200D9EA68 /* MGLAnnotationContainerView.h in Headers */,
@@ -1925,6 +1937,7 @@
 				DABFB8641CBE99E500D62B32 /* MGLOfflineStorage.h in Headers */,
 				96E516E32000552A00A02306 /* MGLAccountManager_Private.h in Headers */,
 				96E5170420005A6B00A02306 /* SMCalloutView.h in Headers */,
+				96036A02200565C700510F3D /* NSOrthography+MGLAdditions.h in Headers */,
 				DAD165791CF4CDFF001FF4B9 /* MGLShapeCollection.h in Headers */,
 				4049C29E1DB6CD6C00B3F799 /* MGLPointCollection.h in Headers */,
 				3566C7671D4A77BA008152BC /* MGLShapeSource.h in Headers */,
@@ -2378,6 +2391,7 @@
 				40CFA6511D7875BB008103BD /* MGLShapeSourceTests.mm in Sources */,
 				DA35A2C51CCA9F8300E826B2 /* MGLClockDirectionFormatterTests.m in Sources */,
 				35B8E08C1D6C8B5100E768D2 /* MGLPredicateTests.mm in Sources */,
+				96036A0620059BBA00510F3D /* MGLNSOrthographyAdditionsTests.m in Sources */,
 				1F95931D1E6DE2E900D5B294 /* MGLNSDateAdditionsTests.mm in Sources */,
 				DD58A4C61D822BD000E1F038 /* MGLExpressionTests.mm in Sources */,
 				3575798B1D502B0C000B822E /* MGLBackgroundStyleLayerTests.mm in Sources */,
@@ -2420,6 +2434,7 @@
 				DA6408DD1DA4E7D300908C90 /* MGLVectorStyleLayer.m in Sources */,
 				3566C7681D4A77BA008152BC /* MGLShapeSource.mm in Sources */,
 				400533021DB0862B0069F638 /* NSArray+MGLAdditions.mm in Sources */,
+				96036A03200565C700510F3D /* NSOrthography+MGLAdditions.m in Sources */,
 				35136D421D42274500C20EFD /* MGLRasterStyleLayer.mm in Sources */,
 				3538AA1F1D542239008EC33D /* MGLForegroundStyleLayer.mm in Sources */,
 				DA00FC901D5EEB0D009AABC8 /* MGLAttributionInfo.mm in Sources */,
@@ -2508,6 +2523,7 @@
 				3566C7691D4A77BA008152BC /* MGLShapeSource.mm in Sources */,
 				400533031DB086490069F638 /* NSArray+MGLAdditions.mm in Sources */,
 				35136D431D42274500C20EFD /* MGLRasterStyleLayer.mm in Sources */,
+				96036A04200565C700510F3D /* NSOrthography+MGLAdditions.m in Sources */,
 				3538AA201D542239008EC33D /* MGLForegroundStyleLayer.mm in Sources */,
 				DA00FC911D5EEB0D009AABC8 /* MGLAttributionInfo.mm in Sources */,
 				DAA4E4201CBB730400178DFB /* MGLOfflinePack.mm in Sources */,
diff --git a/platform/ios/src/MGLMapAccessibilityElement.mm b/platform/ios/src/MGLMapAccessibilityElement.mm
index 1a2953b0bb..79dcda4054 100644
--- a/platform/ios/src/MGLMapAccessibilityElement.mm
+++ b/platform/ios/src/MGLMapAccessibilityElement.mm
@@ -7,6 +7,8 @@
 #import "MGLVectorSource_Private.h"
 
 #import "NSBundle+MGLAdditions.h"
+#import "NSOrthography+MGLAdditions.h"
+#import "NSString+MGLAdditions.h"
 
 @implementation MGLMapAccessibilityElement
 
@@ -49,24 +51,16 @@
         NSString *languageCode = [MGLVectorSource preferredMapboxStreetsLanguage];
         NSString *nameAttribute = [NSString stringWithFormat:@"name_%@", languageCode];
         NSString *name = [feature attributeForKey:nameAttribute];
-        
+
         // If a feature hasn’t been translated into the preferred language, it
         // may be in the local language, which may be written in another script.
-        // Romanize it.
-        NSLocale *locale = [NSLocale localeWithLocaleIdentifier:languageCode];
-        NSOrthography *orthography;
-#if __IPHONE_OS_VERSION_MAX_ALLOWED >= 110000
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wunguarded-availability-new"
-        if ([NSOrthography respondsToSelector:@selector(defaultOrthographyForLanguage:)]) {
-            orthography = [NSOrthography defaultOrthographyForLanguage:locale.localeIdentifier];
-        }
-#pragma clang diagnostic pop
-#endif
-        if ([orthography.dominantScript isEqualToString:@"Latn"]) {
-            name = [name stringByApplyingTransform:NSStringTransformToLatin reverse:NO];
+        // Attempt to transform to the script of the preferred language, keeping
+        // the original string if no transform exists or if transformation fails.
+        if (@available(iOS 9.0, *)) {
+            NSString *dominantScript = [NSOrthography mgl_dominantScriptForMapboxStreetsLanguage:languageCode];
+            name = [name mgl_stringByTransliteratingIntoScript:dominantScript];
         }
-        
+
         self.accessibilityLabel = name;
     }
     return self;
diff --git a/platform/ios/src/NSOrthography+MGLAdditions.h b/platform/ios/src/NSOrthography+MGLAdditions.h
new file mode 100644
index 0000000000..a552fc7774
--- /dev/null
+++ b/platform/ios/src/NSOrthography+MGLAdditions.h
@@ -0,0 +1,18 @@
+#import <Foundation/Foundation.h>
+
+@interface NSOrthography (NSOrthography_MGLAdditions)
+
+/**
+ Returns a four-letter ISO 15924 code representing the name of the dominant
+ script for a given language.
+
+ On iOS 11 or newer, this method wraps
+ `+[NSOrthography defaultOrthographyForLanguage:]` and supports any language.
+ On iOS 10 and older, this method only returns values for Mapbox
+ Streets-supported languages.
+
+ @param language The ISO-639 code representing a language.
+ */
++ (NSString *)mgl_dominantScriptForMapboxStreetsLanguage:(NSString *)language;
+
+@end
diff --git a/platform/ios/src/NSOrthography+MGLAdditions.m b/platform/ios/src/NSOrthography+MGLAdditions.m
new file mode 100644
index 0000000000..99258862cc
--- /dev/null
+++ b/platform/ios/src/NSOrthography+MGLAdditions.m
@@ -0,0 +1,31 @@
+#import "NSOrthography+MGLAdditions.h"
+
+@implementation NSOrthography (MGLAdditions)
+
++ (NSString *)mgl_dominantScriptForMapboxStreetsLanguage:(NSString *)language {
+    if (@available(iOS 11.0, *)) {
+        NSLocale *locale = [NSLocale localeWithLocaleIdentifier:language];
+        NSOrthography *orthography = [NSOrthography defaultOrthographyForLanguage:locale.localeIdentifier];
+
+        return orthography.dominantScript;
+    }
+
+    // Manually map Mapbox Streets languages to ISO 15924 script codes.
+    NSSet *latinLanguages = [NSSet setWithObjects:@"de", @"en", @"es", @"fr", @"pt", nil];
+    NSSet *hansLanguages = [NSSet setWithObjects:@"zh", @"zh-Hans", nil];
+
+    if ([latinLanguages containsObject:language]) {
+        return @"Latn";
+    } else if ([hansLanguages containsObject:language]) {
+        return @"Hans";
+    } else if ([language isEqualToString:@"ru"]) {
+        return @"Cyrl";
+    } else if ([language isEqualToString:@"ar"]) {
+        return @"Arab";
+    } else {
+        // Code for undetermined script
+        return @"Zyyy";
+    }
+}
+
+@end
diff --git a/platform/ios/test/MGLMapAccessibilityElementTests.m b/platform/ios/test/MGLMapAccessibilityElementTests.m
index 5c79d85de1..89a595421e 100644
--- a/platform/ios/test/MGLMapAccessibilityElementTests.m
+++ b/platform/ios/test/MGLMapAccessibilityElementTests.m
@@ -19,13 +19,17 @@
     };
     MGLFeatureAccessibilityElement *element = [[MGLFeatureAccessibilityElement alloc] initWithAccessibilityContainer:self feature:feature];
     XCTAssertEqualObjects(element.accessibilityLabel, @"English", @"Accessibility label should be localized.");
-    
+
     feature.attributes = @{
         @"name": @"Цинциннати",
         @"name_en": @"Цинциннати",
     };
     element = [[MGLFeatureAccessibilityElement alloc] initWithAccessibilityContainer:self feature:feature];
-    XCTAssertEqualObjects(element.accessibilityLabel, @"Cincinnati", @"Accessibility label should be romanized.");
+    if (@available(iOS 9.0, *)) {
+        XCTAssertEqualObjects(element.accessibilityLabel, @"Cincinnati", @"Accessibility label should be romanized.");
+    } else {
+        XCTAssertEqualObjects(element.accessibilityLabel, @"Цинциннати", @"Accessibility label should not be romanized.");
+    }
 }
 
 - (void)testPlaceFeatureValues {
diff --git a/platform/ios/test/MGLNSOrthographyAdditionsTests.m b/platform/ios/test/MGLNSOrthographyAdditionsTests.m
new file mode 100644
index 0000000000..351fe4227e
--- /dev/null
+++ b/platform/ios/test/MGLNSOrthographyAdditionsTests.m
@@ -0,0 +1,19 @@
+#import <XCTest/XCTest.h>
+
+#import "NSOrthography+MGLAdditions.h"
+#import "MGLVectorSource_Private.h"
+
+@interface MGLNSOrthographyAdditionsTests : XCTestCase
+
+@end
+
+@implementation MGLNSOrthographyAdditionsTests
+
+- (void)testStreetsLanguages {
+    for (NSString *language in [MGLVectorSource mapboxStreetsLanguages]) {
+        NSString *dominantScript = [NSOrthography mgl_dominantScriptForMapboxStreetsLanguage:language];
+        XCTAssertNotEqualObjects(dominantScript, @"Zyyy", @"Mapbox Streets languages should have dominant script");
+    }
+}
+
+@end