Add .jsonl syntax highlighting support to TextViewer

QuickLook.Plugin/QuickLook.Plugin.TextViewer/TextViewerPanel.cs

@@ -163,9 +163,9 @@ private void Viewer_KeyDown(object sender, KeyEventArgs e)
             // RTL: Ctrl + RShift
             // LTR: Ctrl + LShift
             if (Keyboard.IsKeyDown(Key.RightShift))
-                FlowDirection = System.Windows.FlowDirection.RightToLeft;
+                FlowDirection = FlowDirection.RightToLeft;
             else if (Keyboard.IsKeyDown(Key.LeftShift))
-                FlowDirection = System.Windows.FlowDirection.LeftToRight;
+                FlowDirection = FlowDirection.LeftToRight;
         }
         else if (Keyboard.IsKeyDown(Key.LeftAlt) || Keyboard.IsKeyDown(Key.RightAlt))
         {

QuickLook.Plugin/QuickLook.Plugin.TextViewer/Themes/HighlightingDefinitions/Dark/JSONLHighlightingDefinition.cs

@@ -0,0 +1,47 @@
+// Copyright © 2017-2026 QL-Win Contributors
+//
+// This file is part of QuickLook program.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+using ICSharpCode.AvalonEdit.Highlighting;
+using ICSharpCode.AvalonEdit.Rendering;
+using QuickLook.Plugin.TextViewer.Themes.HighlightingDefinitions.Light;
+using System.Collections.Generic;
+
+namespace QuickLook.Plugin.TextViewer.Themes.HighlightingDefinitions.Dark;
+
+public class JSONLHighlightingDefinition : DarkHighlightingDefinition
+{
+    public override string Name => "JSONL";
+
+    public override string Extension => ".jsonl";
+
+    public override HighlightingRuleSet MainRuleSet => new();
+
+    public override HighlightingColor GetNamedColor(string name) => null;
+
+    public override IEnumerable<HighlightingColor> NamedHighlightingColors => [];
+
+    public override DocumentColorizingTransformer[] LineTransformers { get; } =
+    [
+        new JsonLineHighlighter(
+            keyColor:     "#9CDCF0",   // field names  (VSCode default)
+            stringColor:  "#CE9178",   // string values (VSCode default)
+            numberColor:  "#B5CEA8",   // numbers       (VSCode default)
+            boolNullColor:"#569CD6",   // true/false/null (VSCode default)
+            braceColor:   "#DA66BE",   // { }
+            bracketColor: "#FFD710")   // [ ]
+    ];
+}

QuickLook.Plugin/QuickLook.Plugin.TextViewer/Themes/HighlightingDefinitions/Light/JSONLHighlightingDefinition.cs

@@ -0,0 +1,211 @@
+// Copyright © 2017-2026 QL-Win Contributors
+//
+// This file is part of QuickLook program.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+using ICSharpCode.AvalonEdit.Document;
+using ICSharpCode.AvalonEdit.Highlighting;
+using ICSharpCode.AvalonEdit.Rendering;
+using System.Collections.Generic;
+
+namespace QuickLook.Plugin.TextViewer.Themes.HighlightingDefinitions.Light;
+
+public class JSONLHighlightingDefinition : LightHighlightingDefinition
+{
+    public override string Name => "JSONL";
+
+    public override string Extension => ".jsonl";
+
+    public override HighlightingRuleSet MainRuleSet => new();
+
+    public override HighlightingColor GetNamedColor(string name) => null;
+
+    public override IEnumerable<HighlightingColor> NamedHighlightingColors => [];
+
+    public override DocumentColorizingTransformer[] LineTransformers { get; } =
+    [
+        new JsonLineHighlighter(
+            keyColor:     "#0451A5",   // field names  (VSCode light default)
+            stringColor:  "#A31515",   // string values (VSCode light default)
+            numberColor:  "#098658",   // numbers       (VSCode light default)
+            boolNullColor:"#0000FF",   // true/false/null (VSCode light default)
+            braceColor:   "#800000",   // { }
+            bracketColor: "#0451A5")   // [ ]
+    ];
+}
+
+/// <summary>
+/// Per-line JSON tokenizer for JSONL (JSON Lines) files.
+/// Each call to ColorizeLine processes one independent JSON object/array.
+/// </summary>
+public class JsonLineHighlighter(
+    string keyColor,
+    string stringColor,
+    string numberColor,
+    string boolNullColor,
+    string braceColor,
+    string bracketColor) : DocumentColorizingTransformer
+{
+    protected override void ColorizeLine(DocumentLine line)
+    {
+        var text = CurrentContext.Document.GetText(line);
+        if (string.IsNullOrWhiteSpace(text))
+            return;
+
+        ColorizeJsonLine(line, text);
+    }
+
+    private void ColorizeJsonLine(DocumentLine line, string text)
+    {
+        // Stack: true = currently inside an object (next unquoted string is a key),
+        //        false = currently inside an array (all strings are values).
+        var contextStack = new Stack<bool>();
+        bool expectKey = false;
+
+        int i = 0;
+        while (i < text.Length)
+        {
+            char c = text[i];
+
+            if (char.IsWhiteSpace(c)) { i++; continue; }
+
+            switch (c)
+            {
+                case '{':
+                    Colorize(line, i, i + 1, braceColor);
+                    contextStack.Push(true);
+                    expectKey = true;
+                    i++;
+                    break;
+
+                case '}':
+                    Colorize(line, i, i + 1, braceColor);
+                    if (contextStack.Count > 0) contextStack.Pop();
+                    expectKey = false;
+                    i++;
+                    break;
+
+                case '[':
+                    Colorize(line, i, i + 1, bracketColor);
+                    contextStack.Push(false);
+                    expectKey = false;
+                    i++;
+                    break;
+
+                case ']':
+                    Colorize(line, i, i + 1, bracketColor);
+                    if (contextStack.Count > 0) contextStack.Pop();
+                    expectKey = false;
+                    i++;
+                    break;
+
+                case ':':
+                    // Colon separates key from value; next token is a value.
+                    expectKey = false;
+                    i++;
+                    break;
+
+                case ',':
+                    // In object context the next string is a key; in array it is a value.
+                    expectKey = contextStack.Count > 0 && contextStack.Peek();
+                    i++;
+                    break;
+
+                case '"':
+                case '\'':
+                    i = TokenizeString(line, text, i, c, expectKey);
+                    if (expectKey)
+                        expectKey = false; // key consumed, colon follows next
+                    break;
+
+                default:
+                    if (c == '-' || char.IsDigit(c))
+                    {
+                        i = TokenizeNumber(line, text, i);
+                        expectKey = false;
+                    }
+                    else if (char.IsLetter(c))
+                    {
+                        i = TokenizeKeyword(line, text, i);
+                        expectKey = false;
+                    }
+                    else
+                    {
+                        i++;
+                    }
+                    break;
+            }
+        }
+    }
+
+    private int TokenizeString(DocumentLine line, string text, int start, char quote, bool isKey)
+    {
+        int i = start + 1; // skip opening quote
+        while (i < text.Length)
+        {
+            if (text[i] == '\\')
+            {
+                i += 2; // skip escape sequence
+                continue;
+            }
+            if (text[i] == quote)
+            {
+                i++; // include closing quote
+                break;
+            }
+            i++;
+        }
+        Colorize(line, start, i, isKey ? keyColor : stringColor);
+        return i;
+    }
+
+    private int TokenizeNumber(DocumentLine line, string text, int start)
+    {
+        int i = start;
+        if (i < text.Length && text[i] == '-') i++; // optional leading minus
+        while (i < text.Length && char.IsDigit(text[i])) i++;
+        if (i < text.Length && text[i] == '.')
+        {
+            i++;
+            while (i < text.Length && char.IsDigit(text[i])) i++;
+        }
+        if (i < text.Length && (text[i] == 'e' || text[i] == 'E'))
+        {
+            i++;
+            if (i < text.Length && (text[i] == '+' || text[i] == '-')) i++;
+            while (i < text.Length && char.IsDigit(text[i])) i++;
+        }
+        Colorize(line, start, i, numberColor);
+        return i;
+    }
+
+    private int TokenizeKeyword(DocumentLine line, string text, int start)
+    {
+        int i = start;
+        while (i < text.Length && char.IsLetter(text[i])) i++;
+        string keyword = text.Substring(start, i - start);
+        if (keyword is "true" or "false" or "null")
+            Colorize(line, start, i, boolNullColor);
+        return i;
+    }
+
+    private void Colorize(DocumentLine line, int from, int to, string hexColor)
+    {
+        ChangeLinePart(line.Offset + from, line.Offset + to, el =>
+        {
+            el.TextRunProperties.SetForegroundBrush(hexColor.ToBrush());
+        });
+    }
+}

SUPPORTED_FORMATS.md

@@ -7,7 +7,7 @@ Update not completed yet...
 - `.rtf` (Rich Text Format)
 - `.log` (Log file)
 - `.ini` (Initialization/config file)
-- `.json` (JavaScript Object Notation)
+- `.json`, `.jsonl` (JavaScript Object Notation / JSON Lines)
 - `.xml` (Extensible Markup Language)
 - `.yaml`, `.yml` (YAML Ain't Markup Language)
 - `.md`, `.markdown`, `.mdx`, `.mmd`, `.mkd`, `.mdwn`, `.mdown`, `.mdc`, `.qmd`, `.rmd`, `.rmarkdown`, `.apib`, `.mdtxt`, `.mdtext` (Markdown and variants)