1 files changed, 85 insertions, 0 deletions
diff --git a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/layers/Function.java b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/layers/Function.java
new file mode 100644
index 0000000000..c776f9ff23
--- /dev/null
+++ b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/layers/Function.java
@@ -0,0 +1,85 @@
+package com.mapbox.mapboxsdk.style.layers;
+
+import android.support.annotation.FloatRange;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.annotation.Size;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Representation of <a href="https://www.mapbox.com/mapbox-gl-style-spec/#types-function">Function</a> in the Mapbox style specification
+ *
+ * @param <T> the target property's value type. Make sure it matches.
+ */
+public class Function<T> {
+
+    public static class Stop<I, O> {
+        public final I in;
+        public final O out;
+
+        Stop(I in, O out) {
+            this.in = in;
+            this.out = out;
+        }
+
+        Object[] toValueObject() {
+            return new Object[]{in, out};
+        }
+    }
+
+    @SafeVarargs
+    public static <T> Function<T> zoom(@NonNull @Size(min = 1) Stop<Float, T>... stops) {
+        return new Function<T>(stops);
+    }
+
+    @SafeVarargs
+    public static <T> Function<T> zoom(
+            @FloatRange(from = 0, to = 1, fromInclusive = false, toInclusive = false) float base,
+            @NonNull @Size(min = 1) Stop<Float, T>... stops) {
+        return new Function<T>(stops)
+                .withBase(base);
+    }
+
+    public static <T> Stop<Float, T> stop(float in, Property<T> output) {
+        return new Stop<>(in, output.value);
+    }
+
+    private final Stop<Float, T>[] stops;
+    private Float base;
+
+    Function(@NonNull @Size(min = 1) Stop<Float, T>[] stops) {
+        this.stops = stops;
+    }
+
+    Function<T> withBase(float base) {
+        this.base = base;
+        return this;
+    }
+
+    @Nullable
+    public Float getBase() {
+        return base;
+    }
+
+    public Stop<Float, T>[] getStops() {
+        return stops;
+    }
+
+    Map<String, Object> toValueObject() {
+        Object[] stopsValue = new Object[stops.length];
+
+        for (int i = 0; i < stopsValue.length; i++) {
+            Stop stop = stops[i];
+            stopsValue[i] = stop.toValueObject();
+        }
+
+        Map<String, Object> value = new HashMap<>();
+        if (base != null) {
+            value.put("base", base);
+        }
+        value.put("stops", stopsValue);
+        return value;
+    }
+}