Add Gemini media handler

Media/GeminiMediaHandler.cs

@@ -0,0 +1,80 @@
+using System.Numerics;
+using ImGuiNET;
+
+namespace Shoko;
+
+[MediaType("text/gemini")]
+class GeminiMediaHandler : MediaHandler
+{
+    List<string> lines;
+    public GeminiMediaHandler(ProtoHandler content)
+    {
+        Content = content;
+        lines = new List<string>();
+    }
+
+    public override void Load()
+    {
+        Title = new UriBuilder(Content.URL).Path;
+        var reader = new StreamReader(Content.Content);
+        string line;
+        while((line = reader.ReadLine()) is not null)
+        {
+            lines.Add(line);
+        }
+    }
+
+    public override void Render()
+    {
+        var formatting = true;
+        foreach(var line in lines)
+        {
+            if(line.StartsWith("```"))
+            {
+                formatting = !formatting;
+            }
+            else if(formatting)
+            {
+                if(line.StartsWith("=>"))
+                {
+                    var parts = line[2..].Trim().Split(new char[]{' ', '\t'}, 2, StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+                    var title = parts[parts.Length > 1 ? 1 : 0];
+                    var linkurl = new Uri(Content.URL, parts[0]).ToString();
+                    ImGui.TextColored(new Vector4(0,0,255,255), title.Trim());
+                    ImGui.SetItemTooltip(linkurl);
+                    if(ImGui.IsItemClicked(ImGuiMouseButton.Left))
+                        Content.CurrentTab.Load(linkurl);
+                }
+                else if(line.StartsWith("#"))
+                {
+                    var scale = 2f;
+                    var heading = 1;
+                    if(line.StartsWith("##")) (scale, heading) = (1.5f, 2);
+                    if(line.StartsWith("###")) (scale, heading) = (1.25f, 3);
+
+                    var font = ImGui.GetFont();
+                    float oldScale = font.Scale;
+                    font.Scale *= scale;
+                    ImGui.PushFont(font);
+
+                    ImGui.TextUnformatted(line[heading..].Trim());
+
+                    font.Scale = oldScale;
+                    ImGui.PopFont();
+                }
+                else if(line.StartsWith("* "))
+                {
+                    ImGui.BulletText(line[2..].Trim());
+                }
+                else if(line.StartsWith(">"))
+                {
+                    ImGui.TextDisabled("    "+line.Trim());
+                }
+                else
+                    ImGui.TextWrapped(line.Trim());
+            }
+            else
+                ImGui.TextUnformatted(line);
+        }
+    }
+}

Protocols/GeminiProtoHandler.cs

@@ -44,7 +44,14 @@ class GeminiProtoHandler : ProtoHandler
         {
             byte[] content = new byte[]{};
             if(meta.Length > 1)
+            {
+                if(Status.StartsWith('3'))
+                {
+                    meta[1] = "=> "+meta[1];
+                    MediaType = "text/gemini";
+                }
                 content = Encoding.UTF8.GetBytes(meta[1]);
+            }
             Content = new MemoryStream(content);
         }