add ios build support

Samples/UIWidgetsSamples_2019_4/Assets/Editor/EditorWindowSample/UIWidgetsEditorWindowSample.asmdef

         "UIWidgetsGallery"
     ],
     "optionalUnityReferences": [],
-    "includePlatforms": [],
+    "includePlatforms": [
+        "Editor"
+    ],
     "excludePlatforms": [],
     "allowUnsafeCode": false,
     "overrideReferences": false,

Samples/UIWidgetsSamples_2019_4/Assets/Scene/TextTest.unity

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-    fonts:
-    - asset: CupertinoIcons.ttf
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+  fonts: []
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Samples/UIWidgetsSamples_2019_4/Assets/UIWidgetsGallery/demo/material/backdrop_demo.cs

                     {
                         new IconButton(
                             onPressed: this._toggleBackdropPanelVisibility,
-                            icon: new AnimatedIcon(
-                                icon: AnimatedIcons.close_menu,
-                                progress: this._controller.view
+                            icon: new Icon(
+                                icon: Icons.close
                             )
                         )
                     }

Samples/UIWidgetsSamples_2019_4/Assets/UIWidgetsGallery/demo/material/search_demo.cs

                 appBar: new AppBar(
                     leading: new IconButton(
                         tooltip: "Navigation menu",
-                        icon: new AnimatedIcon(
-                            icon: AnimatedIcons.arrow_menu,
-                            color: Colors.white,
-                            progress: this._delegate.transitionAnimation
+                        icon: new Icon(
+                            icon: Icons.menu,
+                            color: Colors.white
                         ),
                         onPressed: () => { this._scaffoldKey.currentState.openDrawer(); }
                     ),
         public override Widget buildLeading(BuildContext context) {
             return new IconButton(
                 tooltip: "Back",
-                icon: new AnimatedIcon(
-                    icon: AnimatedIcons.arrow_menu,
-                    progress: this.transitionAnimation
+                icon: new Icon(
+                    icon: Icons.menu
                 ),
                 onPressed: () => { this.close(context, null); }
             );

Samples/UIWidgetsSamples_2019_4/Assets/UIWidgetsGallery/gallery/backdrop.cs

                             trailing: new IconButton(
                                 onPressed: this._toggleFrontLayer,
                                 tooltip: "Toggle options page",
-                                icon: new AnimatedIcon(
-                                    icon: AnimatedIcons.close_menu,
-                                    progress: this._controller
+                                icon: new Icon(
+                                    icon: Icons.close
                                 )
                             )
                         ),

com.unity.uiwidgets/Runtime/engine/DisplayMetrics.cs

 #endif
 
 #if UNITY_IOS
-                this._devicePixelRatio = IOSDeviceScaleFactor();
+                //this._devicePixelRatio = IOSDeviceScaleFactor();
 #endif
 
                 if (_devicePixelRatio <= 0) {
                     padding_bottom = 0
                 };
 #elif UNITY_IOS
-                viewMetrics metrics = IOSGetViewportPadding();
-                this._viewMetrics = metrics;
+                //viewMetrics metrics = IOSGetViewportPadding();
+                //this._viewMetrics = metrics;
 #else
                 _viewMetrics = new viewMetrics {
                     insets_bottom = 0,
 #endif
 
 #if UNITY_IOS
-        [DllImport("__Internal")]
-        static extern float IOSDeviceScaleFactor();
+        //[DllImport("__Internal")]
+        //static extern float IOSDeviceScaleFactor();
-		[DllImport("__Internal")]
-		static extern viewMetrics IOSGetViewportPadding();
+		//[DllImport("__Internal")]
+		//static extern viewMetrics IOSGetViewportPadding();
 #endif
     }
 }

com.unity.uiwidgets/Runtime/engine/UIWidgetsMessageManager.cs

 
         void UpdateNameIfNeed() {
 #if UNITY_IOS || UNITY_ANDROID || UNITY_WEBGL
-            var name = gameObject.name;
+            /*var name = gameObject.name;
             if (name != _lastObjectName) {
 
                 if (!Application.isEditor) {
-            }
+            }*/
 #endif
         }
 
         }
 
 #if UNITY_IOS || UNITY_WEBGL        
-        [DllImport("__Internal")]
-        static extern void UIWidgetsMessageSetObjectName(string objectName);
+        //[DllImport("__Internal")]
+        //static extern void UIWidgetsMessageSetObjectName(string objectName);
 #elif UNITY_ANDROID
         
         static void UIWidgetsMessageSetObjectName(string objectName) {

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

 
         protected void OnEnable() {
             base.OnEnable();
+#if UNITY_IOS
+            //the hook API cannot be automatically called on IOS, so we need try hook it here
+            Hooks.tryHook();
+#endif
             D.assert(_wrapper == null);
             _configurations = new Configurations();
             _wrapper = new UIWidgetsPanelWrapper();

com.unity.uiwidgets/Runtime/material/animated_icons/animated_icons_data.cs

 
 namespace Unity.UIWidgets.material {
     public abstract class AnimatedIcons {
-        public static readonly AnimatedIconData add_event = AnimatedIconsData._add_event;
+        //public static readonly AnimatedIconData add_event = AnimatedIconsData._add_event;
-        public static readonly AnimatedIconData arrow_menu = AnimatedIconsData._arrow_menu;
+        //public static readonly AnimatedIconData arrow_menu = AnimatedIconsData._arrow_menu;
-        public static readonly AnimatedIconData close_menu = AnimatedIconsData._close_menu;
+        //public static readonly AnimatedIconData close_menu = AnimatedIconsData._close_menu;
 
         // public readonly AnimatedIconData ellipsis_search = AnimatedIconsData._ellipsis_search;
 

com.unity.uiwidgets/Runtime/material/animated_icons/data/add_event.g.cs

-using System.Collections.Generic;
+/*using System.Collections.Generic;
 using Unity.UIWidgets.ui;
 using UnityEngine;
 
         );
 
     }
-}
+}*/

com.unity.uiwidgets/Runtime/material/animated_icons/data/arrow_menu.g.cs

-using System.Collections.Generic;
+/*using System.Collections.Generic;
 using Unity.UIWidgets.ui;
 using UnityEngine;
 
         );
       }
 
-}
+}*/

com.unity.uiwidgets/Runtime/material/animated_icons/data/close_menu.g.cs

-using System.Collections.Generic;
+/*using System.Collections.Generic;
 using Unity.UIWidgets.ui;
 using UnityEngine;
 
         );
 
     }
-}
+}*/

com.unity.uiwidgets/Runtime/material/animated_icons/data/ellipsis_search.g.cs

-using Unity.UIWidgets.ui;
+/*using Unity.UIWidgets.ui;
 using System.Collections.Generic;
 
 namespace Unity.UIWidgets.material
           }
         );
     }
-}
+}*/

com.unity.uiwidgets/Runtime/material/animated_icons/data/event_add.g.cs

-using Unity.UIWidgets.ui;
+/*using Unity.UIWidgets.ui;
 using System.Collections.Generic;
 
 namespace Unity.UIWidgets.material {
   }
 );
     }
-}
+}*/

com.unity.uiwidgets/Runtime/services/keyboard.cs

 #endif
 
 #if UNITY_IOS || UNITY_ANDROID
-    class UIWidgetsTouchScreenKeyboardDelegate : AbstractUIWidgetsKeyboardDelegate {
+    /*class UIWidgetsTouchScreenKeyboardDelegate : AbstractUIWidgetsKeyboardDelegate {
 
         public override void show() {
             UIWidgetsTextInputShow();
 
         public override void clearClient() {
             UIWidgetsTextInputClearTextInputClient();
-        }
+        }*/
+    /*
         [DllImport ("__Internal")]
         internal static extern void UIWidgetsTextInputShow();
         
         internal static extern void UIWidgetsTextInputSetTextInputEditingState(string jsonText);
         
         [DllImport ("__Internal")]
-        internal static extern void UIWidgetsTextInputClearTextInputClient();
+        internal static extern void UIWidgetsTextInputClearTextInputClient();*/
 #elif UNITY_ANDROID
         internal static void UIWidgetsTextInputShow() {
             using (
             }
         }
 #endif
-    }
+    //}
 #endif
 }

com.unity.uiwidgets/Runtime/services/text_input.cs

             }
             else {
 #if UNITY_IOS || UNITY_ANDROID
-                if (configuration.unityTouchKeyboard) {
+                /*if (configuration.unityTouchKeyboard) {
-                }
+                }*/
 #elif UNITY_WEBGL
                 keyboardDelegate = new UIWidgetsWebGLKeyboardDelegate();
 #else

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

 
 namespace Unity.UIWidgets.ui {
     public static class Hooks {
+        
+        static bool hooked = false;
 #if UNITY_EDITOR
         [UnityEditor.InitializeOnLoadMethod]
 #else
+            D.assert(!hooked);
+
+            hooked = true;
             Mono_hook(
                 Mono_throwException,
                 Mono_shutdown);
                 Window_drawFrame,
                 ui_._dispatchPlatformMessage,
                 ui_._dispatchPointerDataPacket);
+        }
+        
+        public static void tryHook() {
+            if (hooked) {
+                return;
+            }
+            hook();
         }
 
         delegate void Mono_ThrowExceptionCallback(IntPtr exception);

engine/src/lib/ui/painting/color_filter.cc

 #include "color_filter.h"
+#include "runtime/mono_api.h"
 
 namespace uiwidgets {
 
 
 ColorFilter::~ColorFilter() = default;
 
-}  // namespace uiwidgets
+UIWIDGETS_API(ColorFilter*)
+ColorFilter_constructor() {
+  const auto colorFilter = ColorFilter::Create();
+  colorFilter->AddRef();
+  return colorFilter.get();
+}
+
+UIWIDGETS_API(void)
+ColorFilter_dispose(ColorFilter* ptr) {
+  ptr->Release();
+}
+
+UIWIDGETS_API(void)
+ColorFilter_initMode(ColorFilter* ptr, int color, int blend_mode) {
+  ptr->initMode(color, blend_mode);
+}
+
+UIWIDGETS_API(void)
+ColorFilter_initMatrix(ColorFilter* ptr, const float* color_matrix) {
+  ptr->initMatrix(color_matrix);
+}
+
+UIWIDGETS_API(void)
+ColorFilter_initLinearToSrgbGamma(ColorFilter* ptr) {
+  ptr->initLinearToSrgbGamma();
+}
+
+UIWIDGETS_API(void)
+ColorFilter_initSrgbToLinearGamma(ColorFilter* ptr) {
+  ptr->initSrgbToLinearGamma();
+}
+
+}  // namespace uiwidgets

com.unity.uiwidgets/Runtime/service.meta

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