feature: document template QR Code image extensions

2023-10-12 15:51:33 +11:00
parent 7353405b16
commit a3fb09440d
17 changed files with 299 additions and 65 deletions
@@ -0,0 +1,122 @@
+using Disco.Models.Services.Expressions.Extensions;
+using Disco.Services.Documents;
+using System;
+using System.Drawing;
+using System.Drawing.Imaging;
+using System.IO;
+using System.Runtime.InteropServices;
+using ZXing.QrCode.Internal;
+
+namespace Disco.Services.Expressions.Extensions.ImageResultImplementations
+{
+    public class QrCodeImageExpressionResult : BaseImageExpressionResult
+    {
+        public static Func<byte[], int, int, byte[]> CCITTG4EncoderCompressDelegate;
+        public string Data { get; }
+        public char ErrorCorrectionLevel { get; }
+        private readonly ErrorCorrectionLevel ecLevel;
+
+        public QrCodeImageExpressionResult(string data, char errorCorrectionLevel)
+        {
+            Data = data;
+            ErrorCorrectionLevel = errorCorrectionLevel;
+
+            switch (errorCorrectionLevel)
+            {
+                case 'l':
+                case 'L':
+                    ecLevel = ZXing.QrCode.Internal.ErrorCorrectionLevel.L;
+                    break;
+                case 'm':
+                case 'M':
+                    ecLevel = ZXing.QrCode.Internal.ErrorCorrectionLevel.M;
+                    break;
+                case 'q':
+                case 'Q':
+                    ecLevel = ZXing.QrCode.Internal.ErrorCorrectionLevel.Q;
+                    break;
+                case 'h':
+                case 'H':
+                    ecLevel = ZXing.QrCode.Internal.ErrorCorrectionLevel.H;
+                    break;
+                default:
+                    throw new ArgumentException("Error correction level must be L, M, Q or H");
+            }
+
+            Format = ImageExpressionFormat.CcittG4;
+            Quality = 90;
+            ShowField = false;
+            BackgroundPreferTransparent = true;
+        }
+
+        public override MemoryStream GetImage(int width, int height)
+        {
+            var rawImage = QRCodeBinaryEncoder.Encode(Data, ecLevel, width, height);
+            return RenderStream(rawImage, width, height);
+        }
+
+        public override MemoryStream GetImage(out int width, out int height)
+        {
+            var rawImage = QRCodeBinaryEncoder.Encode(Data, ecLevel, out width, out height);
+            return RenderStream(rawImage, width, height);
+        }
+
+        private MemoryStream RenderStream(byte[] data, int width, int height)
+        {
+            if (Format == ImageExpressionFormat.CcittG4)
+            {
+                if (CCITTG4EncoderCompressDelegate == null)
+                    throw new InvalidOperationException($"The {CCITTG4EncoderCompressDelegate} delegate has not been initialized");
+
+                var result = CCITTG4EncoderCompressDelegate(data, width, height);
+                return new MemoryStream(result, 0, result.Length, false, true);
+            }
+            else
+            {
+                using (var bitmap = RenderBitmap(data, width, height))
+                {
+                    return OutputBitmapImage(bitmap);
+                }
+            }
+        }
+
+        private Image RenderBitmap(byte[] data, int width, int height)
+        {
+            var bitmap = new Bitmap(width, height, PixelFormat.Format1bppIndexed);
+            bitmap.Palette.Entries[0] = Color.Black;
+            bitmap.Palette.Entries[0] = Color.White;
+
+            var pixelData = bitmap.LockBits(new Rectangle(Point.Empty, bitmap.Size), ImageLockMode.WriteOnly, PixelFormat.Format1bppIndexed);
+            try
+            {
+                for (int y = 0; y < height; y++)
+                {
+                    var offset = y * width;
+                    var buffer = new byte[(width + 7) / 8];
+                    var bufferOffset = 0;
+                    var bitOffset = 0;
+                    for (int x = 0; x < width; x++)
+                    {
+                        var pixel = data[offset + x];
+                        if (pixel != 0)
+                        {
+                            buffer[bufferOffset] = (byte)(buffer[bufferOffset] | (byte)((128) >> bitOffset));
+                        }
+                        if (bitOffset == 8)
+                        {
+                            bufferOffset++;
+                            bitOffset = 0;
+                        }
+                    }
+                    Marshal.Copy(buffer, 0, pixelData.Scan0, buffer.Length);
+                }
+            }
+            finally
+            {
+                bitmap.UnlockBits(pixelData);
+            }
+
+            return bitmap;
+        }
+    }
+}