[ios, osx] Split MGLDirectionFormatter in two

Split MGLDirectionFormatter into MGLClockDirectionFormatter, which specializes in clock positions, and MGLCompassDirectionFormatter, which boxes the compass. This neatly avoids any confusion that might arise if the developer fails to read the documentation and thinks the original unified formatter can convert between the two types of directions.

.jazzy.yaml

@@ -57,6 +57,8 @@ custom_categories:
       - NSValue(MGLOfflinePackAdditions)
   - name: Geometry
     children:
+      - MGLClockDirectionFormatter
+      - MGLCompassDirectionFormatter
       - MGLCoordinateBounds
       - MGLCoordinateBoundsEqualToCoordinateBounds
       - MGLCoordinateBoundsGetCoordinateSpan
@@ -69,8 +71,6 @@ custom_categories:
       - MGLCoordinateSpanMake
       - MGLCoordinateSpanZero
       - MGLDegreesFromRadians
-      - MGLDirectionFormatter
-      - MGLDirectionFormatterOrigin
       - MGLRadiansFromDegrees
       - MGLStringFromCoordinateBounds
       - NSValue(MGLGeometryAdditions)

platform/darwin/include/MGLClockDirectionFormatter.h

@@ -0,0 +1,52 @@
+#import <Foundation/Foundation.h>
+#import <CoreLocation/CoreLocation.h>
+
+#import "MGLTypes.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ The `MGLClockDirectionFormatter` class provides properly formatted descriptions
+ of headings relative to the user, known as <i>clock positions</i>. For
+ example, a value of `90` may be formatted as “3 o’clock”, depending on the
+ locale.
+ 
+ Use this class to create localized heading strings when displaying directions
+ relative to the user’s current location and heading. To format a direction
+ irrespective of the user’s orientation, use `MGLCompassDirectionFormatter`
+ instead.
+ */
+@interface MGLClockDirectionFormatter : NSFormatter
+
+/**
+ The unit style used by this formatter.
+ 
+ This property defaults to `NSFormattingUnitStyleMedium`.
+ */
+@property (nonatomic) NSFormattingUnitStyle unitStyle;
+
+/**
+ The locale of the receiver.
+ 
+ The locale determines the output language and numeral system of the output.
+ */
+@property (copy) NSLocale *locale;
+
+/**
+ Returns a clock position string for the provided value.
+ 
+ @param direction The heading, measured in degrees, where 0° means “straight
+    ahead” and 90° means “directly to your right”.
+ @return The clock position string appropriately formatted for the receiver’s
+    locale.
+ */
+- (NSString *)stringFromDirection:(CLLocationDirection)direction;
+
+/**
+ This method is not supported for the `MGLDirectionFormatter` class.
+ */
+- (BOOL)getObjectValue:(out id __nullable * __nullable)obj forString:(NSString *)string errorDescription:(out NSString * __nullable * __nullable)error;
+
+@end
+
+NS_ASSUME_NONNULL_END

platform/darwin/include/MGLCompassDirectionFormatter.h

@@ -0,0 +1,42 @@
+#import <Foundation/Foundation.h>
+#import <CoreLocation/CoreLocation.h>
+
+#import "MGLTypes.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ The `MGLCompassDirectionFormatter` class provides properly formatted
+ descriptions of absolute headings. For example, a value of `90` may be
+ formatted as “east”, depending on the locale.
+ 
+ Use this class to create localized heading strings when displaying directions
+ irrespective of the user’s current location. To format a direction relative to
+ the user’s current location, use `MGLCompassDirectionFormatter` instead.
+ */
+@interface MGLCompassDirectionFormatter : NSFormatter
+
+/**
+ The unit style used by this formatter.
+ 
+ This property defaults to `NSFormattingUnitStyleMedium`.
+ */
+@property (nonatomic) NSFormattingUnitStyle unitStyle;
+
+/**
+ Returns a heading string for the provided value.
+ 
+ @param direction The heading, measured in degrees, where 0° means “due north”
+    and 90° means “due east”.
+ @return The heading string appropriately formatted for the formatter’s locale.
+ */
+- (NSString *)stringFromDirection:(CLLocationDirection)direction;
+
+/**
+ This method is not supported for the `MGLDirectionFormatter` class.
+ */
+- (BOOL)getObjectValue:(out id __nullable * __nullable)obj forString:(NSString *)string errorDescription:(out NSString * __nullable * __nullable)error;
+
+@end
+
+NS_ASSUME_NONNULL_END

platform/darwin/src/MGLClockDirectionFormatter.m

@@ -0,0 +1,64 @@
+#import "MGLClockDirectionFormatter.h"
+
+#define wrap(value, min, max) \
+    (fmod((fmod((value - min), (max - min)) + (max - min)), (max - min)) + min)
+
+@implementation MGLClockDirectionFormatter {
+    NSNumberFormatter *_numberFormatter;
+}
+
+- (instancetype)init {
+    if (self = [super init]) {
+        _unitStyle = NSFormattingUnitStyleMedium;
+        _numberFormatter = [[NSNumberFormatter alloc] init];
+    }
+    return self;
+}
+
+- (NSLocale *)locale {
+    return _numberFormatter.locale;
+}
+
+- (void)setLocale:(NSLocale *)locale {
+    _numberFormatter.locale = locale;
+}
+
+- (NSString *)stringFromDirection:(CLLocationDirection)direction {
+    NSInteger hour = round(-wrap(-direction, -360, 0) / 360 * 12);
+    NSString *format;
+    NSNumberFormatterStyle style = NSNumberFormatterDecimalStyle;
+    switch (self.unitStyle) {
+        case NSFormattingUnitStyleShort:
+            format = NSLocalizedString(@"%@:00", @"Clock position format, short style");
+            break;
+
+        case NSFormattingUnitStyleMedium:
+            format = NSLocalizedString(@"%@ o’clock", @"Clock position format, medium style");
+
+            break;
+
+        case NSFormattingUnitStyleLong:
+            format = NSLocalizedString(@"%@ o’clock", @"Clock position format, long style");
+            style = NSNumberFormatterSpellOutStyle;
+            break;
+
+        default:
+            break;
+    }
+    _numberFormatter.numberStyle = style;
+    return [NSString stringWithFormat:format, [_numberFormatter stringFromNumber:@(hour)]];
+}
+
+- (nullable NSString *)stringForObjectValue:(id)obj {
+    if (![obj isKindOfClass:[NSValue class]]) {
+        return nil;
+    }
+    return [self stringFromDirection:[obj doubleValue]];
+}
+
+- (BOOL)getObjectValue:(out id __nullable * __nullable)obj forString:(NSString *)string errorDescription:(out NSString * __nullable * __nullable)error {
+    NSAssert(NO, @"-getObjectValue:forString:errorDescription: has not been implemented");
+    return NO;
+}
+
+@end

platform/darwin/src/MGLDirectionFormatter.m → platform/darwin/src/MGLCompassDirectionFormatter.m

@@ -1,63 +1,18 @@
-#import "MGLDirectionFormatter.h"
+#import "MGLCompassDirectionFormatter.h"
 
 #define wrap(value, min, max) \
     (fmod((fmod((value - min), (max - min)) + (max - min)), (max - min)) + min)
 
-@implementation MGLDirectionFormatter {
-    NSNumberFormatter *_numberFormatter;
-}
+@implementation MGLCompassDirectionFormatter
 
 - (instancetype)init {
     if (self = [super init]) {
         _unitStyle = NSFormattingUnitStyleMedium;
-        _numberFormatter = [[NSNumberFormatter alloc] init];
     }
     return self;
 }
 
-- (NSLocale *)locale {
-    return _numberFormatter.locale;
-}
-
-- (void)setLocale:(NSLocale *)locale {
-    _numberFormatter.locale = locale;
-}
-
 - (NSString *)stringFromDirection:(CLLocationDirection)direction {
-    if (self.origin == MGLDirectionFormatterOriginNorth) {
-        return [self stringFromAbsoluteDirection:direction];
-    } else {
-        return [self stringFromRelativeDirection:direction];
-    }
-}
-
-- (NSString *)stringFromRelativeDirection:(CLLocationDirection)direction {
-    NSInteger hour = round(-wrap(-direction, -360, 0) / 360 * 12);
-    NSString *format;
-    NSNumberFormatterStyle style = NSNumberFormatterDecimalStyle;
-    switch (self.unitStyle) {
-        case NSFormattingUnitStyleShort:
-            format = NSLocalizedString(@"%@:00", @"Relative heading format, short style");
-            break;
-
-        case NSFormattingUnitStyleMedium:
-            format = NSLocalizedString(@"%@ o’clock", @"Relative heading format, medium style");
-
-            break;
-
-        case NSFormattingUnitStyleLong:
-            format = NSLocalizedString(@"%@ o’clock", @"Relative heading format, long style");
-            style = NSNumberFormatterSpellOutStyle;
-            break;
-
-        default:
-            break;
-    }
-    _numberFormatter.numberStyle = style;
-    return [NSString stringWithFormat:format, [_numberFormatter stringFromNumber:@(hour)]];
-}
-
-- (NSString *)stringFromAbsoluteDirection:(CLLocationDirection)direction {
     static NS_ARRAY_OF(NSString *) *shortStrings;
     static NS_ARRAY_OF(NSString *) *longStrings;
     static dispatch_once_t onceToken;
@@ -138,7 +93,7 @@ - (NSString *)stringFromAbsoluteDirection:(CLLocationDirection)direction {
             NSLocalizedString(@"north by west", @"North by west, long"),
         ];
 
-        NSAssert(shortStrings.count == longStrings.count, @"Long and short direction string arrays must have the same size.");
+        NSAssert(shortStrings.count == longStrings.count, @"Long and short compass direction string arrays must have the same size.");
     });
 
     NSInteger cardinalPoint = round(wrap(direction, 0, 360) / 360 * shortStrings.count);

platform/darwin/test/MGLClockDirectionFormatterTests.m

@@ -0,0 +1,49 @@
+#import <Mapbox/Mapbox.h>
+#import <XCTest/XCTest.h>
+
+static NSString * const MGLTestLocaleIdentifier = @"en-US";
+
+@interface MGLClockDirectionFormatterTests : XCTestCase
+
+@end
+
+@implementation MGLClockDirectionFormatterTests
+
+- (void)testClockDirections {
+    MGLClockDirectionFormatter *shortFormatter = [[MGLClockDirectionFormatter alloc] init];
+    shortFormatter.unitStyle = NSFormattingUnitStyleShort;
+    shortFormatter.locale = [NSLocale localeWithLocaleIdentifier:MGLTestLocaleIdentifier];
+
+    MGLClockDirectionFormatter *mediumFormatter = [[MGLClockDirectionFormatter alloc] init];
+    mediumFormatter.locale = [NSLocale localeWithLocaleIdentifier:MGLTestLocaleIdentifier];
+
+    MGLClockDirectionFormatter *longFormatter = [[MGLClockDirectionFormatter alloc] init];
+    longFormatter.unitStyle = NSFormattingUnitStyleLong;
+    longFormatter.locale = [NSLocale localeWithLocaleIdentifier:MGLTestLocaleIdentifier];
+
+    XCTAssertEqualObjects(@"9:00", [shortFormatter stringFromDirection:-90]);
+    XCTAssertEqualObjects(@"9 o’clock", [mediumFormatter stringFromDirection:-90]);
+    XCTAssertEqualObjects(@"nine o’clock", [longFormatter stringFromDirection:-90]);
+
+    XCTAssertEqualObjects(@"12:00", [shortFormatter stringFromDirection:0]);
+    XCTAssertEqualObjects(@"12 o’clock", [mediumFormatter stringFromDirection:0]);
+    XCTAssertEqualObjects(@"twelve o’clock", [longFormatter stringFromDirection:0]);
+
+    XCTAssertEqualObjects(@"2:00", [shortFormatter stringFromDirection:45]);
+    XCTAssertEqualObjects(@"2 o’clock", [mediumFormatter stringFromDirection:45]);
+    XCTAssertEqualObjects(@"two o’clock", [longFormatter stringFromDirection:45]);
+
+    XCTAssertEqualObjects(@"3:00", [shortFormatter stringFromDirection:90]);
+    XCTAssertEqualObjects(@"3 o’clock", [mediumFormatter stringFromDirection:90]);
+    XCTAssertEqualObjects(@"three o’clock", [longFormatter stringFromDirection:90]);
+
+    XCTAssertEqualObjects(@"6:00", [shortFormatter stringFromDirection:180]);
+    XCTAssertEqualObjects(@"6 o’clock", [mediumFormatter stringFromDirection:180]);
+    XCTAssertEqualObjects(@"six o’clock", [longFormatter stringFromDirection:180]);
+
+    XCTAssertEqualObjects(@"9:00", [shortFormatter stringFromDirection:270]);
+    XCTAssertEqualObjects(@"9 o’clock", [mediumFormatter stringFromDirection:270]);
+    XCTAssertEqualObjects(@"nine o’clock", [longFormatter stringFromDirection:270]);
+}
+
+@end