TextEditor: Register as code highlighter

Change-Id: Ie79cf3805d81f6fef240e88b51569ebc12e1c012
Reviewed-by: hjk <hjk@qt.io>

src/plugins/texteditor/highlighterhelper.cpp

@@ -222,4 +222,49 @@ void handleShutdown()
     delete highlightRepository();
 }
 
+QFuture<QTextDocument *> highlightCode(const QString &code, const QString &mimeType)
+{
+    QTextDocument *document = new QTextDocument;
+    document->setPlainText(code);
+
+    const HighlighterHelper::Definitions definitions = HighlighterHelper::definitionsForMimeType(
+        mimeType);
+
+    std::shared_ptr<QPromise<QTextDocument *>> promise
+        = std::make_shared<QPromise<QTextDocument *>>();
+
+    promise->start();
+
+    if (definitions.isEmpty()) {
+        promise->addResult(document);
+        promise->finish();
+        return promise->future();
+    }
+
+    auto definition = definitions.first();
+
+    const QString definitionFilesPath
+        = TextEditorSettings::highlighterSettings().definitionFilesPath().toString();
+
+    Highlighter *highlighter = new Highlighter(definitionFilesPath);
+    QObject::connect(highlighter, &Highlighter::finished, document, [document, promise]() {
+        promise->addResult(document);
+        promise->finish();
+    });
+
+    QFutureWatcher<QTextDocument *> *watcher = new QFutureWatcher<QTextDocument *>(document);
+    QObject::connect(watcher, &QFutureWatcher<QTextDocument *>::canceled, document, [document]() {
+        document->deleteLater();
+    });
+    watcher->setFuture(promise->future());
+
+    highlighter->setDefinition(definition);
+    highlighter->setParent(document);
+    highlighter->setFontSettings(TextEditorSettings::fontSettings());
+    highlighter->setMimeType(mimeType);
+    highlighter->setDocument(document);
+
+    return promise->future();
+}
+
 } // namespace TextEditor::HighlighterHelper

src/plugins/texteditor/highlighterhelper.h

@@ -3,8 +3,13 @@
 
 #pragma once
 
+#include "texteditor_global.h"
+
 #include <KSyntaxHighlighting/Definition>
 
+#include <QFuture>
+#include <QTextDocument>
+
 namespace Utils { class FilePath; }
 
 namespace TextEditor {
@@ -30,6 +35,8 @@ void reload();
 
 void handleShutdown();
 
+QFuture<QTextDocument *> highlightCode(const QString &code, const QString &mimeType);
+
 } // namespace HighlighterHelper
 
 } // namespace TextEditor

src/plugins/texteditor/texteditorplugin.cpp

@@ -49,8 +49,9 @@
 #include <extensionsystem/iplugin.h>
 
 #include <utils/fancylineedit.h>
-#include <utils/qtcassert.h>
 #include <utils/macroexpander.h>
+#include <utils/qtcassert.h>
+#include <utils/textutils.h>
 #include <utils/utilsicons.h>
 
 #include <QMenu>
@@ -137,6 +138,8 @@ void TextEditorPlugin::initialize()
     addTestCreator(createCodeAssistTests);
     addTestCreator(createGenericHighlighterTests);
 #endif
+
+    Utils::Text::setCodeHighlighter(HighlighterHelper::highlightCode);
 }
 
 void TextEditorPlugin::extensionsInitialized()