Utils: Add simple text highlight function

Change-Id: I0eb740214c975da9f6bea87cef2aee23a63d6125
Reviewed-by: hjk <hjk@qt.io>

src/libs/utils/stringutils.cpp

@@ -678,4 +678,25 @@ QString ansiColoredText(const QString &text, const QColor &color)
     return formatString.arg(color.red()).arg(color.green()).arg(color.blue()).arg(text);
 }
 
+static HighlightCallback &codeHighlighter()
+{
+    static HighlightCallback s_highlighter;
+    return s_highlighter;
+}
+
+QTextDocument *highlightCode(const QString &code, const QString &mimeType)
+{
+    if (const auto highlighter = codeHighlighter())
+        return highlighter(code, mimeType);
+
+    QTextDocument *doc = new QTextDocument;
+    doc->setPlainText(code);
+    return doc;
+}
+
+void setCodeHighlighter(const HighlightCallback &highlighter)
+{
+    codeHighlighter() = highlighter;
+}
+
 } // namespace Utils

src/libs/utils/stringutils.h

@@ -9,6 +9,7 @@
 #include <QList>
 #include <QString>
 #include <QSyntaxHighlighter>
+#include <QTextDocument>
 
 #include <functional>
 
@@ -140,4 +141,8 @@ private:
 
 QTCREATOR_UTILS_EXPORT QString ansiColoredText(const QString &text, const QColor &color);
 
+using HighlightCallback = std::function<QTextDocument *(const QString &, const QString &)>;
+QTCREATOR_UTILS_EXPORT QTextDocument *highlightCode(const QString &code, const QString &mimeType);
+QTCREATOR_UTILS_EXPORT void setCodeHighlighter(const HighlightCallback &highlighter);
+
 } // namespace Utils