Add a UIToolkit control for displaying QR codes

QRCoder.Unity/QRCodeDisplay.cs

@@ -0,0 +1,113 @@
+using System.Collections.Generic;
+using UnityEngine;
+using UnityEngine.UIElements;
+
+namespace QRCoder.Unity
+{
+    public class QRCodeDisplay : VisualElement
+    {
+        public QRCodeDisplay()
+        {
+            value = null;
+            style.unityBackgroundScaleMode = ScaleMode.ScaleToFit;
+        }
+
+        public void Update(string value, QRCodeGenerator.ECCLevel eccLevel, int pixelsPerModule)
+        {
+            _value = value;
+            _eccLevel = eccLevel;
+            _pixelsPerModule = pixelsPerModule;
+            RegenerateImage();
+        }
+
+        public QRCodeGenerator.ECCLevel eccLevel
+        {
+            get => _eccLevel;
+            set
+            {
+                if (_eccLevel == value)
+                    return;
+                _eccLevel = value;
+                RegenerateImage();
+            }
+        }
+
+        public int pixelsPerModule
+        {
+            get => _pixelsPerModule;
+            set
+            {
+                if (_pixelsPerModule == value)
+                    return;
+                _pixelsPerModule = value;
+                RegenerateImage();
+            }
+        }
+
+        private string _value;
+        private Texture2D _image;
+        private QRCodeGenerator.ECCLevel _eccLevel = QRCodeGenerator.ECCLevel.Q;
+        private int _pixelsPerModule = 8;
+
+        public string value
+        {
+            get => _value;
+            set
+            {
+                if (_value == value)
+                    return;
+                _value = value;
+                RegenerateImage();
+            }
+        }
+
+        private void RegenerateImage()
+        {
+            if (_image != null)
+                Object.DestroyImmediate(_image, true);
+
+            _image = null;
+
+            if (value == null)
+                return;
+
+            using var generator = new QRCodeGenerator();
+            using var data = generator.CreateQrCode(value, eccLevel);
+            var unityCode = new UnityQRCode(data);
+            _image = unityCode.GetGraphic(pixelsPerModule);
+            _image.name = "Generated QR code";
+
+            style.backgroundImage = _image;
+        }
+
+        public new class UxmlFactory : UxmlFactory<QRCodeDisplay, UxmlTraits>
+        {
+        }
+
+        public new class UxmlTraits : VisualElement.UxmlTraits
+        {
+            private UxmlStringAttributeDescription m_Value = new() { name = "value" };
+
+            private UxmlEnumAttributeDescription<QRCodeGenerator.ECCLevel> m_ECCLevel = new()
+                { name = "ecc-level", defaultValue = QRCodeGenerator.ECCLevel.Q };
+
+            private UxmlIntAttributeDescription m_PixelsPerModule = new()
+                { name = "pixels-per-module", defaultValue = 8 };
+
+            public override IEnumerable<UxmlChildElementDescription> uxmlChildElementsDescription
+            {
+                get { yield break; }
+            }
+
+            public override void Init(VisualElement ve, IUxmlAttributes bag, CreationContext cc)
+            {
+                base.Init(ve, bag, cc);
+
+                var qr = (QRCodeDisplay)ve;
+                qr.Update(m_Value.GetValueFromBag(bag, cc),
+                    m_ECCLevel.GetValueFromBag(bag, cc),
+                    m_PixelsPerModule.GetValueFromBag(bag, cc));
+            }
+        }
+    }
+}