From ce9638d64cfe80ddf61b214d2ad4480f8a2f034b Mon Sep 17 00:00:00 2001
From: Marcus Tillmanns <marcus.tillmanns@qt.io>
Date: Thu, 10 Oct 2024 11:05:10 +0200
Subject: [PATCH] Utils: Allow highlighting to be done asynchronously

Change-Id: Ief0e1ba2e2c32b6ad112f4adc9b582b03a521fad
Reviewed-by: hjk <hjk@qt.io>
---
 src/libs/utils/textutils.cpp | 11 +++++++++--
 src/libs/utils/textutils.h   |  6 ++++--
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/src/libs/utils/textutils.cpp b/src/libs/utils/textutils.cpp
index c3b2822ae3e..9840e653561 100644
--- a/src/libs/utils/textutils.cpp
+++ b/src/libs/utils/textutils.cpp
@@ -4,6 +4,7 @@
 #include "textutils.h"
 #include "qtcassert.h"
 
+#include <QPromise>
 #include <QRegularExpression>
 #include <QTextBlock>
 #include <QTextDocument>
@@ -299,14 +300,20 @@ static HighlightCallback &codeHighlighter()
     return s_highlighter;
 }
 
-QTextDocument *highlightCode(const QString &code, const QString &mimeType)
+QFuture<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;
+
+    QPromise<QTextDocument *> promise;
+    promise.start();
+    promise.addResult(doc);
+    promise.finish();
+
+    return promise.future();
 }
 
 void setCodeHighlighter(const HighlightCallback &highlighter)
diff --git a/src/libs/utils/textutils.h b/src/libs/utils/textutils.h
index a900cb6e9d4..3d6d8cb5efe 100644
--- a/src/libs/utils/textutils.h
+++ b/src/libs/utils/textutils.h
@@ -5,6 +5,7 @@
 
 #include "utils_global.h"
 
+#include <QFuture>
 #include <QMetaType>
 #include <QString>
 
@@ -84,8 +85,9 @@ QTCREATOR_UTILS_EXPORT QString utf16LineTextInUtf8Buffer(const QByteArray &utf8B
 
 QTCREATOR_UTILS_EXPORT QDebug &operator<<(QDebug &stream, const Position &pos);
 
-using HighlightCallback = std::function<QTextDocument *(const QString &, const QString &)>;
-QTCREATOR_UTILS_EXPORT QTextDocument *highlightCode(const QString &code, const QString &mimeType);
+using HighlightCallback = std::function<QFuture<QTextDocument *>(const QString &, const QString &)>;
+QTCREATOR_UTILS_EXPORT QFuture<QTextDocument *> highlightCode(
+    const QString &code, const QString &mimeType);
 QTCREATOR_UTILS_EXPORT void setCodeHighlighter(const HighlightCallback &highlighter);
 
 } // Text