added a new text input system

Demos.Android/Activity1.cs

@@ -2,6 +2,7 @@ using Android.App;
 using Android.Content.PM;
 using Android.OS;
 using Android.Views;
+using MLEM.Misc;
 
 namespace Demos.Android {
     [Activity(Label = "Demos.Android"
@@ -16,6 +17,7 @@ namespace Demos.Android {
 
         protected override void OnCreate(Bundle bundle) {
             base.OnCreate(bundle);
+            TextInputWrapper.Current = new TextInputWrapper.Mobile();
             var g = new GameImpl();
             // disable mouse handling for android to make emulator behavior more coherent
             g.OnLoadContent += game => game.InputHandler.HandleMouse = false;

Demos.DesktopGL/Program.cs

@@ -1,9 +1,11 @@
-using System;
+using Microsoft.Xna.Framework;
+using MLEM.Misc;
 
 namespace Demos.DesktopGL {
     public static class Program {
 
         public static void Main() {
+            TextInputWrapper.Current = new TextInputWrapper.DesktopGl<TextInputEventArgs>((w, c) => w.TextInput += c);
             using (var game = new GameImpl())
                 game.Run();
         }

MLEM.Ui/Elements/TextField.cs

@@ -7,6 +7,7 @@ using Microsoft.Xna.Framework.Input;
 using MLEM.Extensions;
 using MLEM.Font;
 using MLEM.Input;
+using MLEM.Misc;
 using MLEM.Textures;
 using MLEM.Ui.Style;
 
@@ -53,22 +54,7 @@ namespace MLEM.Ui.Elements {
             if (font != null)
                 this.Font.Set(font);
 
-            if (WindowExtensions.SupportsTextInput()) {
+            if (TextInputWrapper.Current.RequiresOnScreenKeyboard()) {
-                this.OnTextInput += (element, key, character) => {
-                    if (!this.IsSelected || this.IsHidden)
-                        return;
-                    if (key == Keys.Back) {
-                        if (this.CaretPos > 0) {
-                            this.CaretPos--;
-                            this.RemoveText(this.CaretPos, 1);
-                        }
-                    } else if (key == Keys.Delete) {
-                        this.RemoveText(this.CaretPos, 1);
-                    } else {
-                        this.InsertText(character);
-                    }
-                };
-            } else {
                 this.OnPressed += async e => {
                     if (!KeyboardInput.IsVisible) {
                         var title = this.MobileTitle ?? this.PlaceholderText;
@@ -78,6 +64,20 @@ namespace MLEM.Ui.Elements {
                     }
                 };
             }
+            this.OnTextInput += (element, key, character) => {
+                if (!this.IsSelected || this.IsHidden)
+                    return;
+                if (key == Keys.Back) {
+                    if (this.CaretPos > 0) {
+                        this.CaretPos--;
+                        this.RemoveText(this.CaretPos, 1);
+                    }
+                } else if (key == Keys.Delete) {
+                    this.RemoveText(this.CaretPos, 1);
+                } else {
+                    this.InsertText(character);
+                }
+            };
             this.OnDeselected += e => this.CaretPos = 0;
             this.OnSelected += e => this.CaretPos = this.text.Length;
         }

MLEM.Ui/UiSystem.cs

@@ -81,7 +81,7 @@ namespace MLEM.Ui {
                     root.Element.ForceUpdateArea();
             };
 
-            window.AddTextInputListener((sender, key, character) => this.ApplyToAll(e => e.OnTextInput?.Invoke(e, key, character)));
+            TextInputWrapper.Current.AddListener(window, (sender, key, character) => this.ApplyToAll(e => e.OnTextInput?.Invoke(e, key, character)));
             this.OnMousedElementChanged = e => this.ApplyToAll(t => t.OnMousedElementChanged?.Invoke(t, e));
             this.OnSelectedElementChanged = e => this.ApplyToAll(t => t.OnSelectedElementChanged?.Invoke(t, e));
             this.OnSelectedElementDrawn = (element, time, batch, alpha) => {

MLEM/Extensions/WindowExtensions.cs

@@ -1,59 +0,0 @@
-using System;
-using System.Linq;
-using System.Reflection;
-using Microsoft.Xna.Framework;
-using Microsoft.Xna.Framework.Input;
-
-namespace MLEM.Extensions {
-    public static class WindowExtensions {
-
-        private static readonly EventInfo TextInput = typeof(GameWindow).GetEvent("TextInput");
-
-        public static bool AddTextInputListener(this GameWindow window, TextInputCallback callback) {
-            return new TextInputReflector(callback).AddToWindow(window);
-        }
-
-        public static bool SupportsTextInput() {
-            if (TextInput == null)
-                return false;
-            // The newest version of DesktopGL.Core made a change where TextInputEventArgs doesn't extend EventArgs
-            // anymore, making this reflection system incompatible with it. For now, this just disables text input
-            // meaning that MLEM.Ui text boxes won't work, but at least it won't crash either.
-            // Let's hope there'll be one last update to DesktopGL that also introduces this change so we can fix this.
-            if (!typeof(EventArgs).IsAssignableFrom(TextInput.EventHandlerType.GenericTypeArguments.FirstOrDefault()))
-                return false;
-            return true;
-        }
-
-        public delegate void TextInputCallback(object sender, Keys key, char character);
-
-        private class TextInputReflector {
-
-            private static readonly MethodInfo Callback = typeof(TextInputReflector).GetMethod(nameof(OnTextInput), BindingFlags.Instance | BindingFlags.NonPublic);
-            private static PropertyInfo key;
-            private static PropertyInfo character;
-            private readonly TextInputCallback callback;
-
-            public TextInputReflector(TextInputCallback callback) {
-                this.callback = callback;
-            }
-
-            public bool AddToWindow(GameWindow window) {
-                if (!SupportsTextInput())
-                    return false;
-                TextInput.AddEventHandler(window, Delegate.CreateDelegate(TextInput.EventHandlerType, this, Callback));
-                return true;
-            }
-
-            private void OnTextInput(object sender, object args) {
-                if (key == null)
-                    key = args.GetType().GetProperty("Key");
-                if (character == null)
-                    character = args.GetType().GetProperty("Character");
-                this.callback.Invoke(sender, (Keys) key.GetValue(args), (char) character.GetValue(args));
-            }
-
-        }
-
-    }
-}

MLEM/Misc/TextInputWrapper.cs

@@ -0,0 +1,173 @@
+using System;
+using System.Linq;
+using System.Reflection;
+using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Input;
+using MLEM.Input;
+
+namespace MLEM.Misc {
+    public abstract class TextInputWrapper {
+
+        private static TextInputWrapper current;
+        public static TextInputWrapper Current {
+            get {
+                if (current == null)
+                    throw new InvalidOperationException("The TextInputWrapper was not initialized yet. Please do so before running your game like so:\n" +
+                                                        "DesktopGL: TextInputWrapper.Current = new TextInputWrapper.DesktopGl<TextInputEventArgs>((w, c) => w.TextInput += c);\n" +
+                                                        "Mobile and Consoles: TextInputWrapper.Current = new TextInputWrapper.Mobile();\n" +
+                                                        "Other Systems: TextInputWrapper.Current = new TextInputWrapper.Primitive();\n" +
+                                                        "Note that the primitive wrapper needs to have its Update() method called.");
+                return current;
+            }
+            set => current = value;
+        }
+
+        public abstract bool RequiresOnScreenKeyboard();
+
+        public abstract void AddListener(GameWindow window, TextInputCallback callback);
+
+        public delegate void TextInputCallback(object sender, Keys key, char character);
+
+        public class DesktopGl<T> : TextInputWrapper where T : EventArgs {
+
+            private PropertyInfo key;
+            private PropertyInfo character;
+            private readonly Action<GameWindow, EventHandler<T>> addListener;
+
+            public DesktopGl(Action<GameWindow, EventHandler<T>> addListener) {
+                this.addListener = addListener;
+            }
+
+            public override bool RequiresOnScreenKeyboard() {
+                return false;
+            }
+
+            public override void AddListener(GameWindow window, TextInputCallback callback) {
+                this.addListener(window, (sender, args) => {
+                    if (this.key == null)
+                        this.key = args.GetType().GetProperty("Key");
+                    if (this.character == null)
+                        this.character = args.GetType().GetProperty("Character");
+                    callback.Invoke(sender, (Keys) this.key.GetValue(args), (char) this.character.GetValue(args));
+                });
+            }
+
+        }
+
+        public class Mobile : TextInputWrapper {
+
+            public override bool RequiresOnScreenKeyboard() {
+                return true;
+            }
+
+            public override void AddListener(GameWindow window, TextInputCallback callback) {
+            }
+
+        }
+
+        public class Primitive : TextInputWrapper {
+
+            private TextInputCallback callback;
+
+            public void Update(InputHandler handler) {
+                var pressed = handler.KeyboardState.GetPressedKeys().Except(handler.LastKeyboardState.GetPressedKeys());
+                var shift = handler.IsModifierKeyDown(ModifierKey.Shift);
+                foreach (var key in pressed) {
+                    var c = GetChar(key, shift);
+                    if (c.HasValue)
+                        this.callback?.Invoke(this, key, c.Value);
+                }
+            }
+
+            public override bool RequiresOnScreenKeyboard() {
+                return false;
+            }
+
+            public override void AddListener(GameWindow window, TextInputCallback callback) {
+                this.callback += callback;
+            }
+
+            private static char? GetChar(Keys key, bool shift) {
+                if (key == Keys.A) return shift ? 'A' : 'a';
+                if (key == Keys.B) return shift ? 'B' : 'b';
+                if (key == Keys.C) return shift ? 'C' : 'c';
+                if (key == Keys.D) return shift ? 'D' : 'd';
+                if (key == Keys.E) return shift ? 'E' : 'e';
+                if (key == Keys.F) return shift ? 'F' : 'f';
+                if (key == Keys.G) return shift ? 'G' : 'g';
+                if (key == Keys.H) return shift ? 'H' : 'h';
+                if (key == Keys.I) return shift ? 'I' : 'i';
+                if (key == Keys.J) return shift ? 'J' : 'j';
+                if (key == Keys.K) return shift ? 'K' : 'k';
+                if (key == Keys.L) return shift ? 'L' : 'l';
+                if (key == Keys.M) return shift ? 'M' : 'm';
+                if (key == Keys.N) return shift ? 'N' : 'n';
+                if (key == Keys.O) return shift ? 'O' : 'o';
+                if (key == Keys.P) return shift ? 'P' : 'p';
+                if (key == Keys.Q) return shift ? 'Q' : 'q';
+                if (key == Keys.R) return shift ? 'R' : 'r';
+                if (key == Keys.S) return shift ? 'S' : 's';
+                if (key == Keys.T) return shift ? 'T' : 't';
+                if (key == Keys.U) return shift ? 'U' : 'u';
+                if (key == Keys.V) return shift ? 'V' : 'v';
+                if (key == Keys.W) return shift ? 'W' : 'w';
+                if (key == Keys.X) return shift ? 'X' : 'x';
+                if (key == Keys.Y) return shift ? 'Y' : 'y';
+                if (key == Keys.Z) return shift ? 'Z' : 'z';
+                if (key == Keys.D0 && !shift || key == Keys.NumPad0) return '0';
+                if (key == Keys.D1 && !shift || key == Keys.NumPad1) return '1';
+                if (key == Keys.D2 && !shift || key == Keys.NumPad2) return '2';
+                if (key == Keys.D3 && !shift || key == Keys.NumPad3) return '3';
+                if (key == Keys.D4 && !shift || key == Keys.NumPad4) return '4';
+                if (key == Keys.D5 && !shift || key == Keys.NumPad5) return '5';
+                if (key == Keys.D6 && !shift || key == Keys.NumPad6) return '6';
+                if (key == Keys.D7 && !shift || key == Keys.NumPad7) return '7';
+                if (key == Keys.D8 && !shift || key == Keys.NumPad8) return '8';
+                if (key == Keys.D9 && !shift || key == Keys.NumPad9) return '9';
+                if (key == Keys.D0 && shift) return ')';
+                if (key == Keys.D1 && shift) return '!';
+                if (key == Keys.D2 && shift) return '@';
+                if (key == Keys.D3 && shift) return '#';
+                if (key == Keys.D4 && shift) return '$';
+                if (key == Keys.D5 && shift) return '%';
+                if (key == Keys.D6 && shift) return '^';
+                if (key == Keys.D7 && shift) return '&';
+                if (key == Keys.D8 && shift) return '*';
+                if (key == Keys.D9 && shift) return '(';
+                if (key == Keys.Space) return ' ';
+                if (key == Keys.Tab) return '\t';
+                if (key == Keys.Add) return '+';
+                if (key == Keys.Decimal) return '.';
+                if (key == Keys.Divide) return '/';
+                if (key == Keys.Multiply) return '*';
+                if (key == Keys.OemBackslash) return '\\';
+                if (key == Keys.OemComma && !shift) return ',';
+                if (key == Keys.OemComma && shift) return '<';
+                if (key == Keys.OemOpenBrackets && !shift) return '[';
+                if (key == Keys.OemOpenBrackets && shift) return '{';
+                if (key == Keys.OemCloseBrackets && !shift) return ']';
+                if (key == Keys.OemCloseBrackets && shift) return '}';
+                if (key == Keys.OemPeriod && !shift) return '.';
+                if (key == Keys.OemPeriod && shift) return '>';
+                if (key == Keys.OemPipe && !shift) return '\\';
+                if (key == Keys.OemPipe && shift) return '|';
+                if (key == Keys.OemPlus && !shift) return '=';
+                if (key == Keys.OemPlus && shift) return '+';
+                if (key == Keys.OemMinus && !shift) return '-';
+                if (key == Keys.OemMinus && shift) return '_';
+                if (key == Keys.OemQuestion && !shift) return '/';
+                if (key == Keys.OemQuestion && shift) return '?';
+                if (key == Keys.OemQuotes && !shift) return '\'';
+                if (key == Keys.OemQuotes && shift) return '"';
+                if (key == Keys.OemSemicolon && !shift) return ';';
+                if (key == Keys.OemSemicolon && shift) return ':';
+                if (key == Keys.OemTilde && !shift) return '`';
+                if (key == Keys.OemTilde && shift) return '~';
+                if (key == Keys.Subtract) return '-';
+                return null;
+            }
+
+        }
+
+    }
+}

Sandbox/Program.cs

@@ -1,7 +1,11 @@
-namespace Sandbox {
+using Microsoft.Xna.Framework;
+using MLEM.Misc;
+
+namespace Sandbox {
     internal static class Program {
 
         private static void Main() {
+            TextInputWrapper.Current = new TextInputWrapper.DesktopGl<TextInputEventArgs>((w, c) => w.TextInput += c);
             using (var game = new GameImpl())
                 game.Run();
         }