1 files changed, 64 insertions, 0 deletions
diff --git a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/utils/FontUtils.java b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/utils/FontUtils.java
new file mode 100644
index 0000000000..09064ee168
--- /dev/null
+++ b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/utils/FontUtils.java
@@ -0,0 +1,64 @@
+package com.mapbox.mapboxsdk.utils;
+
+import android.graphics.Typeface;
+
+import com.mapbox.mapboxsdk.MapStrictMode;
+import com.mapbox.mapboxsdk.log.Logger;
+
+import java.lang.reflect.Field;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+import static com.mapbox.mapboxsdk.constants.MapboxConstants.DEFAULT_FONT;
+
+/**
+ * Utility class to select a font from a range of font names based on the availability of fonts on the device.
+ */
+public class FontUtils {
+
+  private static final String TAG = "Mbgl-FontUtils";
+
+  private FontUtils() {
+    // no instance
+  }
+
+  /**
+   * Select a font from a range of font names to match the availability of fonts on the device.
+   *
+   * @param fontNames the range of font names to select from
+   * @return the selected fon
+   */
+  public static String extractValidFont(String... fontNames) {
+    if (fontNames == null) {
+      return null;
+    }
+
+    List<String> validFonts = getAvailableFonts();
+    for (String fontName : fontNames) {
+      if (validFonts.contains(fontName)) {
+        return fontName;
+      }
+    }
+
+    Logger.i(TAG, String.format(
+      "Couldn't map font family for local ideograph, using %s instead", DEFAULT_FONT)
+    );
+    return DEFAULT_FONT;
+  }
+
+  private static List<String> getAvailableFonts() {
+    List<String> fonts = new ArrayList<>();
+    try {
+      Typeface typeface = Typeface.create(Typeface.DEFAULT, Typeface.NORMAL);
+      Field f = Typeface.class.getDeclaredField("sSystemFontMap");
+      f.setAccessible(true);
+      Map<String, Typeface> fontMap = (Map<String, Typeface>) f.get(typeface);
+      fonts.addAll(fontMap.keySet());
+    } catch (Exception exception) {
+      Logger.e(TAG,"Couldn't load fonts from Typeface", exception);
+      MapStrictMode.strictModeViolation("Couldn't load fonts from Typeface", exception);
+    }
+    return fonts;
+  }
+}
+\ No newline at end of file