[core][iOS] Source iOS styles from default_styles

Moved mbgl::util::default_styles to a more appropriate location, where iOS platform code can also find it. Moved -[MGLMapView bundledStyleURLs] (which is now deprecated) and the style switcher in iosapp to default_styles.

Added a collection of convenience methods for getting style URLs. It makes little sense to layer an enum atop this, as MapKit does, because MGLMapView styles aren’t limited to this set. A good analogy is UIColor. This also makes for a good entry point for future runtime styling APIs.

Introduced independent constants for each default style, because it’s more common to need access to a particular style than to iterate over them. This fact is apparent in the MGLStyle class, which now uses macros and assertions to ensure that it’s kept up-to-date with changes in default_styles.

/ref #1462

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## iOS master
 
 - The `styleID` property has been removed from MGLMapView. Instead, set the `styleURL` property to an NSURL in the form `mapbox://styles/STYLE_ID`. If you previously set the style ID in Interface Builder’s Attributes inspector, delete the `styleID` entry from the User Defined Runtime Attributes section of the Identity inspector, then set the new “Style URL” inspectable to a value in the form `mapbox://styles/STYLE_ID`. ([#2632](https://github.com/mapbox/mapbox-gl-native/pull/2632))
+- Default styles such as Streets are no longer bundled with the SDK; instead, they are loaded at runtime from the style API on mapbox.com. As always, you can use these default styles with any valid access token, and Streets continues to be `MGLMapView`’s initial style. The `bundledStyleURLs` property on `MGLMapView` has been deprecated in favor of several class methods on `MGLStyle` that provide direct access to the default styles. ([#2746](https://github.com/mapbox/mapbox-gl-native/pull/2746))
 - The SDK now builds with Bitcode enabled. ([#2332](https://github.com/mapbox/mapbox-gl-native/issues/2332))
 - The double-tap-drag gesture for zooming in and out is now consistent with the Google Maps SDK. ([#2153](https://github.com/mapbox/mapbox-gl-native/pull/2153))
 - A new `MGLAnnotationImage.enabled` property allows you to disable touch events on individual annotations. ([#2501](https://github.com/mapbox/mapbox-gl-native/pull/2501))

gyp/platform-ios.gypi

@@ -52,6 +52,8 @@
         '../platform/ios/MGLShape.m',
         '../include/mbgl/ios/MGLAnnotationImage.h',
         '../platform/ios/MGLAnnotationImage.m',
+        '../include/mbgl/ios/MGLStyle.h',
+        '../platform/ios/MGLStyle.mm',
         '../platform/ios/NSBundle+MGLAdditions.h',
         '../platform/ios/NSBundle+MGLAdditions.m',
         '../platform/ios/NSException+MGLAdditions.h',

include/mbgl/ios/MGLMapView.h

@@ -217,8 +217,9 @@ IB_DESIGNABLE
 
 @property (nonatomic, nullable) NSString *styleID __attribute__((unavailable("Set styleURL to an NSURL of the form <mapbox://styles/STYLE_ID>, where STYLE_ID would have been the value of this property.")));
 
-/** URLs of the styles bundled with the library. */
-@property (nonatomic, readonly) NS_ARRAY_OF(NSURL *) *bundledStyleURLs;
+/** URLs of the styles bundled with the library.
+    @deprecated Call the relevant class method of `MGLStyle` for the URL of a particular default style. */
+@property (nonatomic, readonly) NS_ARRAY_OF(NSURL *) *bundledStyleURLs __attribute__((deprecated("Call the relevant class method of MGLStyle for the URL of a particular default style.")));
 
 /** URL of the style currently displayed in the receiver.
 *

include/mbgl/ios/MGLStyle.h

@@ -0,0 +1,36 @@
+#import "Mapbox.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+/** A collection of convenience methods for creating style URLs of default styles provided by Mapbox. These instances of NSURL are cached. */
+@interface MGLStyle : NSObject
+
+/** Returns the Streets style URL.
+*   Mapbox Streets is a complete base map, perfect for incorporating your own data. */
++ (NSURL *)streetsStyleURL;
+
+/** Returns the Emerald style URL.
+*   Emerald is a versatile style with emphasis on road networks and public transportation. */
++ (NSURL *)emeraldStyleURL;
+
+/** Returns the Light style URL.
+*   Light is a subtle, light-colored backdrop for data visualizations. */
++ (NSURL *)lightStyleURL;
+
+/** Returns the Dark style URL.
+*   Dark is a subtle, dark-colored backdrop for data visualizations. */
++ (NSURL *)darkStyleURL;
+
+/** Returns the Satellite style URL.
+*   Mapbox Satellite is a beautiful global satellite and aerial imagery layer. */
++ (NSURL *)satelliteStyleURL;
+
+/** Returns the Hybrid style URL.
+*   Hybrid combines the global satellite and aerial imagery of Mapbox Satellite with unobtrusive labels. */
++ (NSURL *)hybridStyleURL;
+
+- (instancetype)init NS_UNAVAILABLE;
+
+@end
+
+NS_ASSUME_NONNULL_END

include/mbgl/ios/Mapbox.h

@@ -10,5 +10,6 @@
 #import "MGLPolygon.h"
 #import "MGLPolyline.h"
 #import "MGLShape.h"
+#import "MGLStyle.h"
 #import "MGLTypes.h"
 #import "MGLUserLocation.h"

include/mbgl/util/default_styles.hpp

@@ -0,0 +1,32 @@
+#ifndef MBGL_PLATFORM_DEFAULT_STYLES
+#define MBGL_PLATFORM_DEFAULT_STYLES
+
+#include <vector>
+#include <string>
+
+namespace mbgl {
+namespace util {
+namespace default_styles {
+
+struct DefaultStyle {
+    const char* url;
+    const char* name;
+};
+
+extern const DefaultStyle streets;
+extern const DefaultStyle emerald;
+extern const DefaultStyle light;
+extern const DefaultStyle dark;
+extern const DefaultStyle satellite;
+extern const DefaultStyle hybrid;
+
+const DefaultStyle orderedStyles[] = {
+    streets, emerald, light, dark, satellite, hybrid,
+};
+const size_t numOrderedStyles = sizeof(orderedStyles) / sizeof(DefaultStyle);
+
+} // end namespace default_styles
+} // end namespace util
+} // end namespace mbgl
+
+#endif

ios/app/MBXViewController.mm

@@ -1,25 +1,12 @@
 #import "MBXViewController.h"
 
 #import <mbgl/ios/Mapbox.h>
+#import <mbgl/util/default_styles.hpp>
 
 #import <CoreLocation/CoreLocation.h>
 
 static UIColor *const kTintColor = [UIColor colorWithRed:0.120 green:0.550 blue:0.670 alpha:1.000];
 
-static struct MBXStyle {
-    NSString *name;
-    NSString *displayName;
-} MBXAvailableStyles[] = {
-    {@"streets",            @"Streets"},
-    {@"emerald",            @"Emerald"},
-    {@"light",              @"Light"},
-    {@"dark",               @"Dark"},
-    {@"satellite",          @"Satellite"},
-    {@"satellite-hybrid",   @"Hybrid"},
-};
-
-static NSUInteger const kStyleVersion = 8;
-
 @interface MBXViewController () <UIActionSheetDelegate, MGLMapViewDelegate>
 
 @property (nonatomic) MGLMapView *mapView;
@@ -79,7 +66,7 @@ - (void)viewDidLoad
 
     UIButton *titleButton = [UIButton buttonWithType:UIButtonTypeCustom];
     [titleButton setFrame:CGRectMake(0, 0, 150, 40)];
-    [titleButton setTitle:MBXAvailableStyles[self.styleIndex].displayName forState:UIControlStateNormal];
+    [titleButton setTitle:@(mbgl::util::default_styles::orderedStyles[self.styleIndex].name) forState:UIControlStateNormal];
     [titleButton setTitleColor:kTintColor forState:UIControlStateNormal];
     [titleButton addTarget:self action:@selector(cycleStyles) forControlEvents:UIControlEventTouchUpInside];
     self.navigationItem.titleView = titleButton;
@@ -323,14 +310,11 @@ - (void)cycleStyles
 {
     UIButton *titleButton = (UIButton *)self.navigationItem.titleView;
 
-    self.styleIndex = (self.styleIndex + 1) % (sizeof(MBXAvailableStyles) / sizeof(MBXAvailableStyles[0]));
+    self.styleIndex = (self.styleIndex + 1) % mbgl::util::default_styles::numOrderedStyles;
 
-    self.mapView.styleURL = [NSURL URLWithString:
-        [NSString stringWithFormat:@"mapbox://styles/mapbox/%@-v%lu",
-            MBXAvailableStyles[self.styleIndex].name,
-            (unsigned long)kStyleVersion]];
+    self.mapView.styleURL = [NSURL URLWithString:@(mbgl::util::default_styles::orderedStyles[self.styleIndex].url)];
 
-    [titleButton setTitle:MBXAvailableStyles[self.styleIndex].displayName forState:UIControlStateNormal];
+    [titleButton setTitle:@(mbgl::util::default_styles::orderedStyles[self.styleIndex].name) forState:UIControlStateNormal];
 }
 
 - (void)locateUser

linux/main.cpp

@@ -1,5 +1,5 @@
 #include <mbgl/mbgl.hpp>
-#include "../platform/default/default_styles.hpp"
+#include <mbgl/util/default_styles.hpp>
 #include <mbgl/util/uv.hpp>
 #include <mbgl/platform/log.hpp>
 #include <mbgl/platform/platform.hpp>
@@ -131,22 +131,22 @@ int main(int argc, char *argv[]) {
     view->setChangeStyleCallback([&map] () {
         static uint8_t currentStyleIndex;
 
-        if (++currentStyleIndex == mbgl::util::defaultStyles.size()) {
+        if (++currentStyleIndex == mbgl::util::default_styles::numOrderedStyles) {
             currentStyleIndex = 0;
         }
 
-        const auto& newStyle = mbgl::util::defaultStyles[currentStyleIndex];
-        map.setStyleURL(newStyle.first);
-        view->setWindowTitle(newStyle.second);
+        mbgl::util::default_styles::DefaultStyle newStyle = mbgl::util::default_styles::orderedStyles[currentStyleIndex];
+        map.setStyleURL(newStyle.url);
+        view->setWindowTitle(newStyle.name);
 
-        mbgl::Log::Info(mbgl::Event::Setup, std::string("Changed style to: ") + newStyle.first);
+        mbgl::Log::Info(mbgl::Event::Setup, std::string("Changed style to: ") + newStyle.name);
     });
 
     // Load style
     if (style.empty()) {
-        const auto& newStyle = mbgl::util::defaultStyles.front();
-        style = newStyle.first;
-        view->setWindowTitle(newStyle.second);
+        mbgl::util::default_styles::DefaultStyle newStyle = mbgl::util::default_styles::orderedStyles[0];
+        style = newStyle.url;
+        view->setWindowTitle(newStyle.name);
     }
 
     map.setStyleURL(style);

linux/mapboxgl-app.gypi

@@ -22,8 +22,6 @@
         '../platform/default/glfw_view.hpp',
         '../platform/default/glfw_view.cpp',
         '../platform/default/log_stderr.cpp',
-        '../platform/default/default_styles.hpp',
-        '../platform/default/default_styles.cpp',
       ],
 
       'variables' : {

macosx/main.mm

@@ -1,5 +1,4 @@
 #include <mbgl/platform/log.hpp>
-#include "../platform/default/default_styles.hpp"
 #include <mbgl/platform/platform.hpp>
 #include <mbgl/platform/darwin/settings_nsuserdefaults.hpp>
 #include <mbgl/platform/darwin/reachability.h>
@@ -9,6 +8,7 @@
 #include <mbgl/storage/network_status.hpp>
 
 #include <mbgl/util/geo.hpp>
+#include <mbgl/util/default_styles.hpp>
 
 #import <Foundation/Foundation.h>
 
@@ -172,23 +172,23 @@ int main(int argc, char* argv[]) {
     view.setChangeStyleCallback([&map, &view] () {
         static uint8_t currentStyleIndex;
 
-        if (++currentStyleIndex == mbgl::util::defaultStyles.size()) {
+        if (++currentStyleIndex == mbgl::util::default_styles::numOrderedStyles) {
             currentStyleIndex = 0;
         }
 
-        const auto& newStyle = mbgl::util::defaultStyles[currentStyleIndex];
-        map.setStyleURL(newStyle.first);
-        view.setWindowTitle(newStyle.second);
+        mbgl::util::default_styles::DefaultStyle newStyle = mbgl::util::default_styles::orderedStyles[currentStyleIndex];
+        map.setStyleURL(newStyle.url);
+        view.setWindowTitle(newStyle.name);
 
-        mbgl::Log::Info(mbgl::Event::Setup, std::string("Changed style to: ") + newStyle.first);
+        mbgl::Log::Info(mbgl::Event::Setup, std::string("Changed style to: ") + newStyle.name);
     });
 
 
     // Load style
     if (style.empty()) {
-        const auto& newStyle = mbgl::util::defaultStyles.front();
-        style = newStyle.first;
-        view.setWindowTitle(newStyle.second);
+        mbgl::util::default_styles::DefaultStyle newStyle = mbgl::util::default_styles::orderedStyles[0];
+        style = newStyle.url;
+        view.setWindowTitle(newStyle.name);
     }
 
     map.setStyleURL(style);

macosx/mapboxgl-app.gypi

@@ -27,8 +27,6 @@
         '../platform/darwin/reachability.m',
         '../platform/default/glfw_view.hpp',
         '../platform/default/glfw_view.cpp',
-        '../platform/default/default_styles.hpp',
-        '../platform/default/default_styles.cpp',
       ],
 
       'variables' : {

platform/ios/MGLMapView.mm

@@ -22,6 +22,7 @@
 #include <mbgl/util/constants.hpp>
 #include <mbgl/util/image.hpp>
 #include <mbgl/util/std.hpp>
+#include <mbgl/util/default_styles.hpp>
 
 #import "Mapbox.h"
 
@@ -42,12 +43,9 @@
 
 class MBGLView;
 
-NSString *const MGLDefaultStyleName = @"streets";
 NSString *const MGLDefaultStyleMarkerSymbolName = @"default_marker";
 NSString *const MGLMapboxSetupDocumentationURLDisplayString = @"mapbox.com/guides/first-steps-ios-sdk";
 
-NSUInteger const MGLStyleVersion = 8;
-
 const NSTimeInterval MGLAnimationDuration = 0.3;
 const CGSize MGLAnnotationUpdateViewportOutset = {150, 150};
 const CGFloat MGLMinimumZoom = 3;
@@ -60,11 +58,6 @@
 NSString *const MGLAnnotationSymbolKey = @"MGLAnnotationSymbolKey";
 NSString *const MGLAnnotationSpritePrefix = @"com.mapbox.sprites.";
 
-static NSURL *MGLURLForBundledStyleNamed(NSString *styleName)
-{
-    return [NSURL URLWithString:[NSString stringWithFormat:@"mapbox://styles/mapbox/%@", styleName]];
-}
-
 mbgl::util::UnitBezier MGLUnitBezierForMediaTimingFunction(CAMediaTimingFunction *function)
 {
     if ( ! function)
@@ -190,9 +183,7 @@ - (void)setStyleURL:(nullable NSURL *)styleURL
 
     if ( ! styleURL)
     {
-        styleURL = MGLURLForBundledStyleNamed([NSString stringWithFormat:@"%@-v%lu",
-                                               MGLDefaultStyleName.lowercaseString,
-                                               (unsigned long)MGLStyleVersion]);
+        styleURL = [MGLStyle streetsStyleURL];
     }
 
     if ( ! [styleURL scheme])
@@ -1980,14 +1971,11 @@ CLLocationCoordinate2D MGLLocationCoordinate2DFromLatLng(mbgl::LatLng latLng)
 {
     if ( ! _bundledStyleURLs)
     {
-        NSString *stylesPath = [[NSBundle mgl_resourceBundlePath] stringByAppendingPathComponent:@"styles"];
-
         _bundledStyleURLs = [NSMutableArray array];
-
-        NSArray *bundledStyleNamesWithExtensions = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:stylesPath error:nil];
-        for (NSString *fileName in bundledStyleNamesWithExtensions)
+        for (NSUInteger i = 0; i < mbgl::util::default_styles::numOrderedStyles; i++)
         {
-            [_bundledStyleURLs addObject:MGLURLForBundledStyleNamed([fileName stringByDeletingPathExtension])];
+            NSURL *styleURL = [NSURL URLWithString:@(mbgl::util::default_styles::orderedStyles[i].url)];
+            [_bundledStyleURLs addObject:styleURL];
         }
     }
 

platform/ios/MGLStyle.mm

@@ -0,0 +1,30 @@
+#import "MGLStyle.h"
+
+#import <mbgl/util/default_styles.hpp>
+
+@implementation MGLStyle
+
+// name is lowercase
+#define MGL_DEFINE_STYLE(name) \
+    static NSURL *MGLStyleURL_##name; \
+    + (NSURL *)name##StyleURL { \
+        static dispatch_once_t onceToken; \
+        dispatch_once(&onceToken, ^{ \
+            MGLStyleURL_##name = [NSURL URLWithString:@(mbgl::util::default_styles::name.url)]; \
+        }); \
+        return MGLStyleURL_##name; \
+    }
+
+MGL_DEFINE_STYLE(streets)
+MGL_DEFINE_STYLE(emerald)
+MGL_DEFINE_STYLE(light)
+MGL_DEFINE_STYLE(dark)
+MGL_DEFINE_STYLE(satellite)
+MGL_DEFINE_STYLE(hybrid)
+
+// Make sure all the styles listed in mbgl::util::default_styles::orderedStyles
+// are defined above and also declared in MGLStyle.h.
+static_assert(6 == mbgl::util::default_styles::numOrderedStyles,
+              "mbgl::util::default_styles::orderedStyles and MGLStyle have different numbers of styles.");
+
+@end