仿真平台内核初版 -tlib库 包含<sparc arm riscv powerPC>

lib/termsharp/Vt100/Vt100ITermFileEscapeCodeHandler.cs

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+//
+// Copyright (c) Antmicro
+//
+// Full license details are defined in the 'LICENSE' file.
+//
+using System;
+using System.IO;
+using System.Collections.Generic;
+using Xwt.Drawing;
+
+namespace TermSharp.Vt100
+{
+    public class Vt100ITermFileEscapeCodeHandler
+    {
+        public static bool TryParse(string encodedCommand, out Vt100ITermFileEscapeCodeHandler handler)
+        {
+            handler = new Vt100ITermFileEscapeCodeHandler();
+
+            if(!encodedCommand.StartsWith(FileCommandHeader))
+            {
+                handler.Error = $"Unexpected command type: {encodedCommand}";
+                return false;
+            }
+
+            // no, this is not a typo - we are splittin on `:` because the full command looks like:
+            // ESC ] 1337 ; File = [arguments] : base-64 encoded file contents ^G
+            // for details see: https://iterm2.com/documentation-images.html
+            var split = encodedCommand.Split(new [] { ':' }, 2);
+            if(split.Length != 2)
+            {
+                handler.Error = $"Unexpected command format: {encodedCommand}";
+                return false;
+            }
+
+            if(!handler.TryParseArguments(split[0].Substring(FileCommandHeader.Length)))
+            {
+                return false;
+            }
+
+            if(!handler.TryParseImage(split[1]))
+            {
+                return false;
+            }
+
+            return true;
+        }
+
+        public string Error { get; private set; }
+        public Image Image { get; private set; }
+
+        private const string FileCommandHeader = "File=";
+
+        private static bool InlineHandler(Vt100ITermFileEscapeCodeHandler handler, string argument)
+        {
+            if(argument == "0")
+            {
+                handler.Error = $"Only inline images are supported";
+                return false;
+            }
+
+            return true;
+        }
+
+        private static bool Noop(Vt100ITermFileEscapeCodeHandler handler, string argument)
+        {
+            return true;
+        }
+
+        private bool TryParseArguments(string arguments)
+        {
+            if(arguments.Length == 0)
+            {
+                // nothing to parse
+                return true;
+            }
+
+            var tags = arguments.Split(new [] { ';' });
+            foreach(var tag in tags)
+            {
+                // name is base64 encoded and can contain the `=` character
+                var splittedTag = tag.Split(new [] { '=' }, 2);
+                if(splittedTag.Length != 2)
+                {
+                    Error = $"Unexpected tag format: {tag}";
+                    return false;
+                }
+
+                if(!tagHandlers.TryGetValue(splittedTag[0], out var handler))
+                {
+                    Error = $"Unsupported tag: {(splittedTag[0])}";
+                    return false;
+                }
+
+                if(!handler(this, splittedTag[1]))
+                {
+                    return false;
+                }
+            }
+
+            return true;
+        }
+
+        private bool TryParseImage(string encodedImage)
+        {
+            byte[] imageBytes = null;
+
+            try
+            {
+                imageBytes = Convert.FromBase64String(encodedImage);
+            }
+            catch(FormatException e)
+            {
+                Error = $"Base64-encoded image format error: {(e.Message)}";
+                return false;
+            }
+
+            try
+            {
+                using(var stream = new MemoryStream(imageBytes))
+                {
+                    Image = Image.FromStream(stream);
+                }
+            }
+            catch(Exception e)
+            {
+                Error = $"Unsupported image format error: {(e.Message)}";
+                return false;
+            }
+
+            return true;
+        }
+
+        private readonly Dictionary<string, Func<Vt100ITermFileEscapeCodeHandler, string, bool>> tagHandlers = new Dictionary<string, Func< Vt100ITermFileEscapeCodeHandler, string, bool>>
+        {
+            { "name", Noop },
+            { "size", Noop },
+            { "width", Noop },
+            { "height", Noop },
+            { "preserveAspectRatio", Noop },
+            { "inline", InlineHandler }
+        };
+    }
+}
+