From d9b7c25a4b7e8cc151e8c200b07d4eabbcf63a97 Mon Sep 17 00:00:00 2001
From: Rene Damm <rene@unity3d.com>
Date: Tue, 2 Oct 2018 17:51:20 -0700
Subject: [PATCH] NEW: Support full UTF-32 text input.

---
 .../InputSystem/Devices/ITextInputReceiver.cs |  4 ++--
 .../InputSystem/Events/TextEvent.cs           | 19 ++++++++++++++---
 .../InputSystem/InputManager.cs               | 20 ++++++++++++------
 .../Tests/InputSystem/CoreTests_Devices.cs    | 21 +++++++++++++++++++
 4 files changed, 53 insertions(+), 11 deletions(-)

diff --git a/Packages/com.unity.inputsystem/InputSystem/Devices/ITextInputReceiver.cs b/Packages/com.unity.inputsystem/InputSystem/Devices/ITextInputReceiver.cs
index 3b560d230a..6eba0300a3 100644
--- a/Packages/com.unity.inputsystem/InputSystem/Devices/ITextInputReceiver.cs
+++ b/Packages/com.unity.inputsystem/InputSystem/Devices/ITextInputReceiver.cs
@@ -13,8 +13,8 @@ public interface ITextInputReceiver
         /// A single, fully-formed Unicode character has been typed on the device.
         /// </summary>
         /// <param name="character">Character that was typed. Note that in case the character is part of
-        /// a surrogate pair, this method is called first with the low surrogate and then with the
-        /// high surrogate character.</param>
+        /// a surrogate pair, this method is called first with the high surrogate and then with the
+        /// low surrogate character.</param>
         void OnTextInput(char character);
 
         /// <summary>
diff --git a/Packages/com.unity.inputsystem/InputSystem/Events/TextEvent.cs b/Packages/com.unity.inputsystem/InputSystem/Events/TextEvent.cs
index a21182d25d..3a6aee81fd 100644
--- a/Packages/com.unity.inputsystem/InputSystem/Events/TextEvent.cs
+++ b/Packages/com.unity.inputsystem/InputSystem/Events/TextEvent.cs
@@ -39,9 +39,22 @@ public FourCC GetTypeStatic()
 
         public static TextEvent Create(int deviceId, char character, double time)
         {
-            var inputEvent = new TextEvent();
-            inputEvent.baseEvent = new InputEvent(Type, InputEvent.kBaseEventSize + 4, deviceId, time);
-            inputEvent.character = character;
+            ////TODO: detect and throw when if character is surrogate
+            var inputEvent = new TextEvent
+            {
+                baseEvent = new InputEvent(Type, InputEvent.kBaseEventSize + 4, deviceId, time),
+                character = character
+            };
+            return inputEvent;
+        }
+
+        public static TextEvent Create(int deviceId, int character, double time)
+        {
+            var inputEvent = new TextEvent
+            {
+                baseEvent = new InputEvent(Type, InputEvent.kBaseEventSize + 4, deviceId, time),
+                character = character
+            };
             return inputEvent;
         }
     }
diff --git a/Packages/com.unity.inputsystem/InputSystem/InputManager.cs b/Packages/com.unity.inputsystem/InputSystem/InputManager.cs
index eab795d648..d0c62276e6 100644
--- a/Packages/com.unity.inputsystem/InputSystem/InputManager.cs
+++ b/Packages/com.unity.inputsystem/InputSystem/InputManager.cs
@@ -2216,13 +2216,21 @@ internal unsafe void OnUpdate(InputUpdateType updateType, int eventCount, IntPtr
                         var textInputReceiver = device as ITextInputReceiver;
                         if (textInputReceiver != null)
                         {
-                            var ch = (char)textEventPtr->character;
-                            textInputReceiver.OnTextInput(ch);
-                            if (char.IsSurrogate(ch))
+                            var utf32Char = textEventPtr->character;
+                            if (utf32Char >= 0x10000)
                             {
-                                // Get high-surrogate char of pair.
-                                ch = (char)(textEventPtr->character >> 16);
-                                textInputReceiver.OnTextInput(ch);
+                                // Send surrogate pair.
+                                utf32Char -= 0x10000;
+                                var highSurrogate = 0xD800 + ((utf32Char >> 10) & 0x3FF);
+                                var lowSurrogate = 0xDC00 + (utf32Char & 0x3FF);
+
+                                textInputReceiver.OnTextInput((char)highSurrogate);
+                                textInputReceiver.OnTextInput((char)lowSurrogate);
+                            }
+                            else
+                            {
+                                // Send single, plain character.
+                                textInputReceiver.OnTextInput((char)utf32Char);
                             }
                         }
                         break;
diff --git a/Packages/com.unity.inputsystem/Tests/InputSystem/CoreTests_Devices.cs b/Packages/com.unity.inputsystem/Tests/InputSystem/CoreTests_Devices.cs
index 050d98a8a1..49f102885a 100644
--- a/Packages/com.unity.inputsystem/Tests/InputSystem/CoreTests_Devices.cs
+++ b/Packages/com.unity.inputsystem/Tests/InputSystem/CoreTests_Devices.cs
@@ -1790,6 +1790,27 @@ public void Devices_CanGetTextInputFromKeyboard()
         Assert.That(textReceived, Is.EqualTo("abc"));
     }
 
+    [Test]
+    [Category("Devices")]
+    public void Devices_CanHandleUTF32CharactersInTextInputOnKeyboard()
+    {
+        var keyboard = InputSystem.AddDevice<Keyboard>();
+
+        var charsReceived = new List<char>();
+        keyboard.onTextInput += ch => charsReceived.Add(ch);
+
+        const int highBits = 0x12;
+        const int lowBits = 0x21;
+
+        var inputEvent = TextEvent.Create(keyboard.id, 0x10000 + (highBits << 10 | lowBits), 123);
+        InputSystem.QueueEvent(ref inputEvent);
+        InputSystem.Update();
+
+        Assert.That(charsReceived, Has.Count.EqualTo(2));
+        Assert.That(charsReceived[0], Is.EqualTo(0xD800 + highBits));
+        Assert.That(charsReceived[1], Is.EqualTo(0xDC00 + lowBits));
+    }
+
     [Test]
     [Category("Devices")]
     public void Devices_CanGetDisplayNameFromKeyboardKey()