[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

1 files changed, 16 insertions, 0 deletions

diff --git a/src/mbgl/util/default_styles.cpp b/src/mbgl/util/default_styles.cpp
new file mode 100644
index 0000000000..d1fc199b64
--- /dev/null
+++ b/src/mbgl/util/default_styles.cpp
@@ -0,0 +1,16 @@
+#include <mbgl/util/default_styles.hpp>
+
+namespace mbgl {
+namespace util {
+namespace default_styles {
+
+const DefaultStyle streets   = { "mapbox://styles/mapbox/streets-v8",          "Streets" };
+const DefaultStyle emerald   = { "mapbox://styles/mapbox/emerald-v8",          "Emerald" };
+const DefaultStyle light     = { "mapbox://styles/mapbox/light-v8",            "Light" };
+const DefaultStyle dark      = { "mapbox://styles/mapbox/dark-v8",             "Dark" };
+const DefaultStyle satellite = { "mapbox://styles/mapbox/satellite-v8",        "Satellite" };
+const DefaultStyle hybrid    = { "mapbox://styles/mapbox/satellite-hybrid-v8", "Hybrid" };
+
+}
+} // end namespace util
+} // end namespace mbgl