add ability to inject custom typefaces into TextRendererUtil.java (#3137)

Author: patgoley

source/android/adaptivecards/src/main/java/io/adaptivecards/renderer/readonly/TextRendererUtil.java

@@ -5,6 +5,9 @@
 import android.graphics.Typeface;
 import android.view.Gravity;
 
+import java.util.HashMap;
+import java.util.Map;
+
 import io.adaptivecards.objectmodel.ContainerStyle;
 import io.adaptivecards.objectmodel.FontType;
 import io.adaptivecards.objectmodel.ForegroundColor;
@@ -15,6 +18,12 @@
 
 public class TextRendererUtil
 {
+    private static Map<String, Typeface> customTypefaces = new HashMap<>();
+
+    public static void registerCustomTypeface(String name, Typeface typeface) {
+
+        customTypefaces.put(name, typeface);
+    }
 
     static int getTextAlignment(HorizontalAlignment textAlignment)
     {
@@ -53,8 +62,12 @@ static Typeface getTextFormat(HostConfig hostConfig, FontType type)
         {
             typeface = Typeface.MONOSPACE;
         }
+        else if (customTypefaces.containsKey(fontFamily)) {
+            typeface = customTypefaces.get(fontFamily);
+        }
         else
         {
+
             typeface = Typeface.create(fontFamily, Typeface.NORMAL);
         }