Merge pull request #9 from albyoo/features/net60

Add image generator

Author: mstancombe

Source/Demos/HtmlRenderer.Demo.Common/SampleConverterBase.cs

@@ -55,11 +55,11 @@ public SampleConverterFileBase(string sampleRunIdentifier, string basePath) : ba
             _thisTypeName = this.GetType().Name;
         }
 
-        protected string GetSamplePath(HtmlSample sample)
+        protected string GetSamplePath(HtmlSample sample, string extension = ".pdf")
         {
             var path = Path.Combine(_basePath, _sampleRunIdentifier);
             Directory.CreateDirectory(path);
-            return Path.Combine(path, sample.FullName + _thisTypeName + "_" + ".pdf");
+            return Path.Combine(path, sample.FullName + _thisTypeName + "_" + extension);
         }
     }
 }

Source/Demos/HtmlRenderer.Demo.Console/Program.cs

@@ -13,7 +13,8 @@
 //Probably won't be running a suite of tests more than once a second, so this will do.
 var runIdentifier = DateTime.Now.ToString("yyyyMMdd-hhmmss");
 
-var skia = new SkiaConverter(runIdentifier, basePath);
+var skia = new SkiaPdfConverter(runIdentifier, basePath);
+var svgSkia = new SkiaSvgConverter(runIdentifier, basePath);
 var pdfSharp = new PdfSharpCoreConverter(runIdentifier, basePath);
 
 SamplesLoader.Init("Console", typeof(Program).Assembly.GetName().Version.ToString());
@@ -23,10 +24,11 @@
 foreach (var htmlSample in samples)
 {
     ////Just doing one test here.  Comment this for all of them.
-    //if (!htmlSample.FullName.Contains("16", StringComparison.OrdinalIgnoreCase)) continue;
+    if (!htmlSample.FullName.Contains("16", StringComparison.OrdinalIgnoreCase)) continue;
 
     await skia.GenerateSampleAsync(htmlSample);
-    await pdfSharp.GenerateSampleAsync(htmlSample);
+    await svgSkia.GenerateSampleAsync(htmlSample);
+    //await pdfSharp.GenerateSampleAsync(htmlSample);
 }
 
 

…mlRenderer.Demo.Console/SkiaConverter.cs …enderer.Demo.Console/SkiaPdfConverter.csSource/Demos/HtmlRenderer.Demo.Console/SkiaConverter.cs renamed to Source/Demos/HtmlRenderer.Demo.Console/SkiaPdfConverter.cs Source/Demos/HtmlRenderer.Demo.Console/SkiaConverter.cs renamed to Source/Demos/HtmlRenderer.Demo.Console/SkiaPdfConverter.cs

@@ -9,9 +9,9 @@
 
 namespace HtmlRenderer.Demo.Console
 {
-    public class SkiaConverter : SampleConverterFileBase
+    public class SkiaPdfConverter : SampleConverterFileBase
     {
-        public SkiaConverter(string sampleRunIdentifier, string basePath) : base(sampleRunIdentifier, basePath)
+        public SkiaPdfConverter(string sampleRunIdentifier, string basePath) : base(sampleRunIdentifier, basePath)
         {
         }
 

Source/Demos/HtmlRenderer.Demo.Console/SkiaSvgConverter.cs

@@ -0,0 +1,36 @@
+using HtmlRenderer.Demo.Common;
+using SkiaSharp;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using TheArtOfDev.HtmlRenderer.Demo.Common;
+using TheArtOfDev.HtmlRenderer.SkiaSharp;
+
+namespace HtmlRenderer.Demo.Console
+{
+    public class SkiaSvgConverter : SampleConverterFileBase
+    {
+        public SkiaSvgConverter(string sampleRunIdentifier, string basePath) : base(sampleRunIdentifier, basePath)
+        {
+        }
+
+        public async Task GenerateSampleAsync(HtmlSample sample)
+        {
+            var size = new SKSize(500, 1000);
+
+            using (var fileStream = File.Open(GetSamplePath(sample, ".svg"), FileMode.CreateNew))
+            {
+                await ImageGenerator.GenerateSvgAsync(sample.Html, fileStream, size, imageLoad: OnImageLoaded);
+                fileStream.Flush();
+            }
+
+            using (var fileStream = File.Open(GetSamplePath(sample, ".png"), FileMode.CreateNew))
+            {
+                await ImageGenerator.GenerateBitmapAsync(sample.Html, fileStream, size, SKEncodedImageFormat.Png, 100, imageLoad: OnImageLoaded);
+                fileStream.Flush();
+            }
+        }
+    }
+}

Source/HtmlRenderer.SkiaSharp/ImageGenerator.cs

@@ -0,0 +1,160 @@
+// "Therefore those skilled at the unorthodox
+// are infinite as heaven and earth,
+// inexhaustible as the great rivers.
+// When they come to an end,
+// they begin again,
+// like the days and months;
+// they die and are reborn,
+// like the four seasons."
+// 
+// - Sun Tsu,
+// "The Art of War"
+
+using HtmlRenderer.Core.Dom;
+using SkiaSharp;
+using Svg.Skia;
+using System;
+using TheArtOfDev.HtmlRenderer.Core;
+using TheArtOfDev.HtmlRenderer.Core.Entities;
+using TheArtOfDev.HtmlRenderer.Core.Utils;
+using TheArtOfDev.HtmlRenderer.SkiaSharp.Adapters;
+using TheArtOfDev.HtmlRenderer.SkiaSharp.Utilities;
+
+namespace TheArtOfDev.HtmlRenderer.SkiaSharp
+{
+    /// <summary>
+    /// TODO:a add doc
+    /// </summary>
+    public static class ImageGenerator
+    {
+        /// <summary>
+        /// Adds a font mapping from <paramref name="fromFamily"/> to <paramref name="toFamily"/> iff the <paramref name="fromFamily"/> is not found.<br/>
+        /// When the <paramref name="fromFamily"/> font is used in rendered html and is not found in existing 
+        /// fonts (installed or added) it will be replaced by <paramref name="toFamily"/>.<br/>
+        /// </summary>
+        /// <remarks>
+        /// This fonts mapping can be used as a fallback in case the requested font is not installed in the client system.
+        /// </remarks>
+        /// <param name="fromFamily">the font family to replace</param>
+        /// <param name="toFamily">the font family to replace with</param>
+        public static void AddFontFamilyMapping(string fromFamily, string toFamily)
+        {
+            ArgChecker.AssertArgNotNullOrEmpty(fromFamily, "fromFamily");
+            ArgChecker.AssertArgNotNullOrEmpty(toFamily, "toFamily");
+
+            SkiaSharpAdapter.Instance.AddFontFamilyMapping(fromFamily, toFamily);
+        }
+
+        /// <summary>
+        /// Parse the given stylesheet to <see cref="CssData"/> object.<br/>
+        /// If <paramref name="combineWithDefault"/> is true the parsed css blocks are added to the 
+        /// default css data (as defined by W3), merged if class name already exists. If false only the data in the given stylesheet is returned.
+        /// </summary>
+        /// <seealso cref="http://www.w3.org/TR/CSS21/sample.html"/>
+        /// <param name="stylesheet">the stylesheet source to parse</param>
+        /// <param name="combineWithDefault">true - combine the parsed css data with default css data, false - return only the parsed css data</param>
+        /// <returns>the parsed css data</returns>
+        public static CssData ParseStyleSheet(string stylesheet, bool combineWithDefault = true)
+        {
+            return CssData.Parse(SkiaSharpAdapter.Instance, stylesheet, combineWithDefault);
+        }
+
+        /// <summary>
+        /// Create Svg document from given HTML.<br/>
+        /// </summary>
+        /// <param name="html">HTML source to create image from</param>
+        /// <param name="cssData">optional: the style to use for html rendering (default - use W3 default style)</param>
+        /// <param name="stylesheetLoad">optional: can be used to overwrite stylesheet resolution logic</param>
+        /// <param name="imageLoad">optional: can be used to overwrite image resolution logic</param>
+        /// <returns>the generated image of the html</returns>
+        public static async Task<SKCanvas> GenerateSvgAsync(
+            string html,
+            Stream outputStream,
+            SKSize size,
+            CssData cssData = null,
+            EventHandler<HtmlStylesheetLoadEventArgs> stylesheetLoad = null,
+            EventHandler<HtmlImageLoadEventArgs> imageLoad = null)
+        {
+            // create svg document to render the HTML into
+            var canvas = SKSvgCanvas.Create(new SKRect(0, 0, size.Width, size.Height), outputStream);
+
+            // add rendered image
+            await DrawSvgAsync(canvas, html, size, cssData, stylesheetLoad, imageLoad);
+            canvas.Dispose();
+
+            return canvas;
+        }
+
+        /// <summary>
+        /// Writes html to a bitmap image
+        /// </summary>
+        /// <param name="html">HTML source to create image from</param>
+        /// <param name="size">The size of the image</param>
+        /// <param name="imageFormat">The file format used to encode the image.</param>
+        /// <param name="quality">The quality level to use for the image. Quality range from 0-100. Higher values correspond to improved visual quality, but less compression.</param>
+        /// <param name="cssData">optional: the style to use for html rendering (default - use W3 default style)</param>
+        /// <param name="stylesheetLoad">optional: can be used to overwrite stylesheet resolution logic</param>
+        /// <param name="imageLoad">optional: can be used to overwrite image resolution logic</param>
+        /// <returns></returns>
+        public static async Task<SKCanvas> GenerateBitmapAsync(
+            string html,
+            Stream outputStream,
+            SKSize size,
+            SKEncodedImageFormat imageFormat,
+            int quality,
+            CssData cssData = null,
+            EventHandler<HtmlStylesheetLoadEventArgs> stylesheetLoad = null,
+            EventHandler<HtmlImageLoadEventArgs> imageLoad = null)
+        {
+
+            var bitmap = new SKBitmap((int)size.Width, (int)size.Height);
+            var canvas = new SKCanvas(bitmap);
+
+            // add rendered image
+            await DrawSvgAsync(canvas, html, size, cssData, stylesheetLoad, imageLoad);
+            bitmap.Encode(outputStream, imageFormat, quality);
+
+            return canvas;
+        }
+
+        /// <summary>
+        /// Create image pages from given HTML and appends them to the provided image document.<br/>
+        /// </summary>
+        /// <param name="canvas">canvas to draw to</param>
+        /// <param name="html">HTML source to create image from</param>
+        /// <param name="cssData">optional: the style to use for html rendering (default - use W3 default style)</param>
+        /// <param name="stylesheetLoad">optional: can be used to overwrite stylesheet resolution logic</param>
+        /// <param name="imageLoad">optional: can be used to overwrite image resolution logic</param>
+        /// <returns>the generated image of the html</returns>
+        public static async Task DrawSvgAsync(
+            SKCanvas canvas,
+            string html,
+            SKSize size,
+            CssData cssData = null,
+            EventHandler<HtmlStylesheetLoadEventArgs> stylesheetLoad = null,
+            EventHandler<HtmlImageLoadEventArgs> imageLoad = null)
+        {
+            using var container = new HtmlContainer();
+            if (stylesheetLoad != null)
+                container.StylesheetLoad += stylesheetLoad;
+            if (imageLoad != null)
+                container.ImageLoad += imageLoad;
+
+            container.Location = new SKPoint(0, 0);
+            //container.MaxSize = size;
+            container.MaxSize = new SKSize(size.Width, 0);
+            container.PageSize = size;
+            container.MarginBottom = 0;
+            container.MarginLeft = 0;
+            container.MarginRight = 0;
+            container.MarginTop = 0;
+            container.ScrollOffset = new SKPoint(0, 0);
+
+            await container.SetHtml(html, cssData);
+
+            // layout the HTML with the page width restriction to know how many pages are required
+            await container.PerformLayout(canvas);
+            await container.PerformPaint(canvas);
+        }
+    }
+}