[android] Minimal Android support for 'format' expression

- No dedicated support for creating format expressions
- Java accessors for 'text-field' flatten back to String
- 'text-field' setter implicitly creates a 'format' expression. For tests, use JsonArray to build an equivalent format expression by hand.

2 files changed, 11 insertions, 0 deletions

diff --git a/platform/android/src/conversion/constant.cpp b/platform/android/src/conversion/constant.cpp
index 804d5fd146..eaff434dbc 100644
--- a/platform/android/src/conversion/constant.cpp
+++ b/platform/android/src/conversion/constant.cpp
@@ -29,6 +29,10 @@ Result<jni::Local<jni::Object<>>> Converter<jni::Local<jni::Object<>>, Color>::o
     return jni::Make<jni::String>(env, sstream.str());
 }
 
+Result<jni::Local<jni::Object<>>> Converter<jni::Local<jni::Object<>>, style::expression::Formatted>::operator()(jni::JNIEnv& env, const style::expression::Formatted& value) const {
+    return jni::Make<jni::String>(env, value.toString());
+}
+
 Result<jni::Local<jni::Object<>>> Converter<jni::Local<jni::Object<>>, std::vector<std::string>>::operator()(jni::JNIEnv& env, const std::vector<std::string>& value) const {
     auto result = jni::Array<jni::String>::New(env, value.size());
 
diff --git a/platform/android/src/conversion/constant.hpp b/platform/android/src/conversion/constant.hpp
index c6dafe1174..4def670f3c 100644
--- a/platform/android/src/conversion/constant.hpp
+++ b/platform/android/src/conversion/constant.hpp
@@ -5,6 +5,8 @@
 #include <mbgl/util/color.hpp>
 #include <mbgl/util/enum.hpp>
 
+#include <mbgl/style/expression/formatted.hpp>
+
 #include <jni/jni.hpp>
 
 #include <string>
@@ -53,6 +55,11 @@ struct Converter<jni::Local<jni::Object<>>, Color> {
     Result<jni::Local<jni::Object<>>> operator()(jni::JNIEnv& env, const Color& value) const;
 };
 
+template <>
+struct Converter<jni::Local<jni::Object<>>, style::expression::Formatted> {
+    Result<jni::Local<jni::Object<>>> operator()(jni::JNIEnv& env, const style::expression::Formatted& value) const;
+};
+
 template <std::size_t N>
 struct Converter<jni::Local<jni::Object<>>, std::array<float, N>> {
     Result<jni::Local<jni::Object<>>> operator()(jni::JNIEnv& env, const std::array<float, N>& value) const {