fix struct style

Samples/UIWidgetsSamples_2019_4/Assets/TextTest.cs

 using System;
+using System.Collections.Generic;
 using System.IO;
 using Unity.UIWidgets.async2;
 using Unity.UIWidgets.engine2;
             check = false;
         }
 
-        var style = new ParagraphStyle(fontFamily: "Arial", height: 4);
+        var style = new ParagraphStyle(
+            fontFamily: "Arial",
+            height: 4,
+            strutStyle: new StrutStyle(fontFamily: "ranchers",
+                fontFamilyFallback: new List<string>() {"Roboto-RegularB"}, 
+                fontSize: 30),
+            ellipsis: "and so on..."
+        );
+
+        pb.addText("just for testxxx\n");
+            fontFamilyFallback: new List<string>() {"ranchers"},
             fontSize: 30,
             height: 1.5f
         );

com.unity.uiwidgets/Runtime/ui2/painting.cs

             this.blurRadius = blurRadius;
         }
 
-        public static readonly uint _kColorDefault = 0xFF000000;
+        static readonly uint _kColorDefault = 0xFF000000;
 
         // Constants for shadow encoding.
         static readonly int _kBytesPerShadow = 16;

com.unity.uiwidgets/Runtime/ui2/text.cs

 using System.Collections.Generic;
 using System.Linq;
 using System.Runtime.InteropServices;
-using System.Text;
-using Unity.UIWidgets.external.simplejson;
 using Unity.UIWidgets.services;
 using Rect = Unity.UIWidgets.ui.Rect;
 
 
         public override string ToString() {
             return "TextHeightBehavior(\n" +
-                   " applyHeightToFirstAscent: $applyHeightToFirstAscent, \n" +
-                   " applyHeightToLastDescent: $applyHeightToLastDescent \n" +
+                   $" applyHeightToFirstAscent: {applyHeightToFirstAscent}, \n" +
+                   $" applyHeightToLastDescent: {applyHeightToLastDescent} \n" +
                    ")";
         }
 
         }
     }
 
-    public partial class ui_ {
+    public struct Float32List {
+        public IntPtr data;
+        public int length;
+    }
+    
+    public static partial class ui_ {
+        static readonly object VoidObject = new object();
+        
         internal static int[] _encodeTextStyle(
             Color color,
             TextDecoration decoration,
             return result;
         }
 
+        internal static unsafe void setFloat(this byte[] bytes, int byteOffset, float value) {
+            D.assert(byteOffset >= 0 && byteOffset + 4 < bytes.Length);
+            fixed (byte* b = &bytes[byteOffset]) {
+                *(float*) b = value;
+            }
+        }
+
         internal static byte[] _encodeStrut(
             string fontFamily,
             List<string> fontFamilyFallback,
 
             if (fontSize != null) {
                 bitmask |= 1 << 3;
-                data.setFloat32(byteCount, (float) fontSize);
+                data.setFloat(byteCount, (float) fontSize);
-                data.setFloat32(byteCount, (float) height);
+                data.setFloat(byteCount, (float) height);
-                data.setFloat32(byteCount, (float) leading);
+                data.setFloat(byteCount, (float) leading);
                 byteCount += 4;
             }
 
             completerHandle.Free();
             _sendFontChangeMessage();
             try {
-                callback(new object());
+                callback(VoidObject);
             }
             catch (Exception ex) {
                 Debug.LogException(ex);
             IntPtr callbackHandle,
             string fontFamily);
 
-        public struct Float32List {
-            public IntPtr data;
-            public int length;
-        }
-
+        
-            ui_.Lists_Free(data.data);
+            Lists_Free(data.data);
-        public static unsafe extern void Lists_Free(IntPtr data);
+        public static extern void Lists_Free(IntPtr data);
     }
 
     public class TextStyle : IEquatable<TextStyle> {
 
     public class StrutStyle : IEquatable<StrutStyle> {
         public StrutStyle(
-            string fontFamily,
-            List<string> fontFamilyFallback,
-            float? fontSize,
-            float? height,
-            float? leading,
-            FontWeight fontWeight,
-            FontStyle? fontStyle,
-            bool? forceStrutHeight
+            string fontFamily = null,
+            List<string> fontFamilyFallback = null,
+            float? fontSize = null,
+            float? height = null,
+            float? leading = null,
+            FontWeight fontWeight = null,
+            FontStyle? fontStyle = null,
+            bool? forceStrutHeight = null
         ) {
             _encoded = ui_._encodeStrut(
                 fontFamily,
     }
 
     public class TextBox : IEquatable<TextBox> {
-        public TextBox(
+        TextBox(
             float left,
             float top,
             float right,
         static extern void Paragraph_layout(IntPtr ptr, float width);
 
         [DllImport(NativeBindings.dllName)]
-        static extern ui_.Float32List Paragraph_getRectsForRange(IntPtr ptr, int start, int end,
+        static extern Float32List Paragraph_getRectsForRange(IntPtr ptr, int start, int end,
-        static extern ui_.Float32List Paragraph_getRectsForPlaceholders(IntPtr ptr);
+        static extern Float32List Paragraph_getRectsForPlaceholders(IntPtr ptr);
 
         [DllImport(NativeBindings.dllName)]
         static extern unsafe void Paragraph_getPositionForOffset(IntPtr ptr, float dx, float dy, int* encodedPtr);
         static extern void Paragraph_paint(IntPtr ptr, IntPtr canvas, float x, float y);
 
         [DllImport(NativeBindings.dllName)]
-        static extern ui_.Float32List Paragraph_computeLineMetrics(IntPtr ptr);
+        static extern Float32List Paragraph_computeLineMetrics(IntPtr ptr);
 
         [DllImport(NativeBindings.dllName)]
         static extern void Paragraph_dispose(IntPtr ptr);
         }
 
         // See paragraph.cc for the layout of this return value.
-        ui_.Float32List _getBoxesForRange(int start, int end, int boxHeightStyle, int boxWidthStyle) =>
+        Float32List _getBoxesForRange(int start, int end, int boxHeightStyle, int boxWidthStyle) =>
             Paragraph_getRectsForRange(_ptr, start, end, boxHeightStyle, boxWidthStyle);
 
 
         }
 
-        ui_.Float32List _getBoxesForPlaceholders() => Paragraph_getRectsForPlaceholders(_ptr);
+        Float32List _getBoxesForPlaceholders() => Paragraph_getRectsForPlaceholders(_ptr);
 
         public unsafe TextPosition getPositionForOffset(Offset offset) {
             int[] encoded = new int[2];
             return metrics;
         }
 
-        ui_.Float32List _computeLineMetrics() => Paragraph_computeLineMetrics(_ptr);
+        Float32List _computeLineMetrics() => Paragraph_computeLineMetrics(_ptr);
-        [DllImport(NativeBindings.dllName, CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(NativeBindings.dllName)]
         static extern IntPtr ParagraphBuilder_constructor(
             int[] encoded,
             int encodeSize,
-            [In] string[] structFontFamily,
+            string[] structFontFamily,
             int structFontFamilySize,
             float fontSize,
             float height,
-        [DllImport(NativeBindings.dllName, CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(NativeBindings.dllName)]
-            [In] string[] fontFamilies,
+            string[] fontFamilies,
             int fontFamiliesSize,
             float fontSize,
             float letterSpacing,
         [DllImport(NativeBindings.dllName)]
         static extern void ParagraphBuilder_pop(IntPtr ptr);
 
-        [DllImport(NativeBindings.dllName, CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(NativeBindings.dllName)]
         static extern IntPtr ParagraphBuilder_addText(IntPtr ptr, [MarshalAs(UnmanagedType.LPWStr)] string text);
 
         [DllImport(NativeBindings.dllName)]

engine/README.md

 
 convert icudtl.dat to object file in skia
 ```
-cd SkiaRoot/third_party/externals/icu/flutter/icudtl.dat
+cd SkiaRoot/third_party/externals/icu/flutter/
 ld -r -b binary -o icudtl.o icudtl.dat
 ```
 ### Build flutter fml

engine/src/lib/ui/text/paragraph_builder.cc

 #include "paragraph_builder.h"
 
 #include "lib/ui/ui_mono_state.h"
-#include "third_party/icu/source/common/unicode/ustring.h"
+#include "unicode/ustring.h"
 
 namespace uiwidgets {
 namespace {

engine/src/shell/platform/unity/uiwidgets_panel.cc

   // args.icu_data_path = icu_path.c_str();
 
   args.icu_mapper = GetICUStaticMapping;
+
+  // Used for IOS build
   // std::string icu_symbol_prefix = "_binary_icudtl_dat_start";
   // std::string native_lib_path =
   // "pathtodll/Plugins/x86_64/libUIWidgets_d.dll"; args.icu_mapper =