add font load

Samples/UIWidgetsSamples_2019_4/Assets/TextTest.cs

 using ParagraphBuilder = Unity.UIWidgets.ui2.ParagraphBuilder;
 using ParagraphConstraints = Unity.UIWidgets.ui2.ParagraphConstraints;
 using ParagraphStyle = Unity.UIWidgets.ui2.ParagraphStyle;
+using Path = System.IO.Path;
 using Picture = Unity.UIWidgets.ui2.Picture;
 using PictureRecorder = Unity.UIWidgets.ui2.PictureRecorder;
 using Rect = Unity.UIWidgets.ui.Rect;
     {
         if (check)
         {
-            var robot_regular_bold = File.ReadAllBytes("./Assets/StreamingAssets/Roboto-BlackItalic.ttf");
-            ui_.loadFontFromList(robot_regular_bold, "Roboto-RegularB").then(value =>
+            foreach (var font in fonts)
-                Debug.Log("finish loading");
-                return FutureOr.nil;
-            });
-            var robot_regular = File.ReadAllBytes("./Assets/StreamingAssets/Roboto-Italic.ttf");
-            ui_.loadFontFromList(robot_regular, "Roboto-Regular");
-            var ranchers = File.ReadAllBytes("./Assets/StreamingAssets/Ranchers-Regular.ttf");
-            ui_.loadFontFromList(ranchers, "ranchers");
+                var path = Path.Combine(Application.streamingAssetsPath, font.path);
+                var fontFile = File.ReadAllBytes(path);
+                ui_.loadFontFromList(fontFile, font.name).then(value =>
+                {
+                    Debug.Log("finish loading");
+                    return FutureOr.nil;
+                });
+            }
             check = false;
         }
 

Samples/UIWidgetsSamples_2019_4/Assets/TextTest.unity

   m_Script: {fileID: 11500000, guid: db61290d6ca38264995f5749021d562c, type: 3}
   m_Name: 
   m_EditorClassIdentifier: 
-  m_Material: {fileID: 0}
-  m_Color: {r: 1, g: 1, b: 1, a: 1}
-  m_RaycastTarget: 1
-  m_Maskable: 1
-  m_OnCullStateChanged:
-    m_PersistentCalls:
-      m_Calls: []
-  m_Texture: {fileID: 0}
-  m_UVRect:
-    serializedVersion: 2
-    x: 0
-    y: 0
-    width: 1
-    height: 1
+  fonts:
+  - path: Roboto-BlackItalic.ttf
+    name: Roboto-RegularB
+  - path: Roboto-Italic.ttf
+    name: Roboto-Regular
+  - path: Ranchers-Regular.ttf
+    name: ranchers
 --- !u!222 &847097471
 CanvasRenderer:
   m_ObjectHideFlags: 0

com.unity.uiwidgets/Runtime/engine2/UIWidgetsPanel.cs

 using System;
+using System.Collections.Generic;
 using System.Runtime.InteropServices;
 using AOT;
 using Unity.UIWidgets.foundation;
 
 namespace Unity.UIWidgets.engine2 {
     public partial class UIWidgetsPanel : MonoBehaviour {
+        [Serializable]
+        public class TextFont {
+            public string path;
+            public string name;
+        }
+        
+        public List<TextFont> fonts;
+
         public class UIWidgetRawImage : RawImage {
             UIWidgetsPanel _uiWidgetsPanel;