Add monet theme engine to WebAPI

app/src/main/java/com/fox2code/mmm/androidacy/AndroidacyWebAPI.java

@@ -11,6 +11,7 @@ import android.widget.Button;
 import android.widget.Toast;
 
 import androidx.annotation.Keep;
+import androidx.annotation.RequiresApi;
 import androidx.appcompat.app.AlertDialog;
 import androidx.core.graphics.ColorUtils;
 
@@ -479,6 +480,26 @@ public class AndroidacyWebAPI {
         return typedValue.data;
     }
 
+    /**
+     * Return current hex string of monet theme
+     */
+    @RequiresApi(api = Build.VERSION_CODES.M)
+    @JavascriptInterface
+    public String getMonetColor(String id) {
+        int nameResourceID = this.activity.getResources().getIdentifier("@android:color/" + id,
+                "color", this.activity.getApplicationInfo().packageName);
+        if (nameResourceID == 0) {
+            throw new IllegalArgumentException(
+                    "No resource string found with name " + id);
+        } else {
+            int color = this.activity.getColor(nameResourceID);
+            int red = Color.red(color);
+            int blue = Color.blue(color);
+            int green = Color.green(color);
+            return String.format("#%02x%02x%02x", red, green, blue);
+        }
+    }
+
     // Androidacy feature level declaration method
 
     @JavascriptInterface