Markdown: Reuse Markdown highlighter from change log viewer

Change-Id: Ief1b0c135a34bfd5e9b5220e9fbf93f281d8e95a
Reviewed-by: David Schulz <david.schulz@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

share/qtcreator/templates/wizards/files/markdown/file.md

@@ -11,8 +11,6 @@ Paragraph.
 * another bullet
     * child bullet
 
----
-
 1. ordered
 2. next ordered
 
@@ -25,6 +23,10 @@ An empty line starts a new paragraph.
 Use two spaces at the end  
 to force a line break.
 
+A horizontal ruler follows:
+
+---
+
 Add links inline like [this link to the Qt homepage](https://www.qt.io),
 or with a reference like [this other link to the Qt homepage][1].
 

src/libs/utils/stringutils.cpp

@@ -3,10 +3,9 @@
 
 #include "stringutils.h"
 
-#include "algorithm.h"
-#include "hostosinfo.h"
-#include "qtcassert.h"
 #include "filepath.h"
+#include "qtcassert.h"
+#include "theme/theme.h"
 #include "utilstr.h"
 
 #ifdef QT_WIDGETS_LIB
@@ -15,11 +14,13 @@
 #endif
 
 #include <QDir>
+#include <QFontMetrics>
 #include <QJsonArray>
 #include <QJsonValue>
 #include <QLocale>
 #include <QRegularExpression>
 #include <QSet>
+#include <QTextList>
 #include <QTime>
 
 #include <limits.h>
@@ -568,4 +569,60 @@ QTCREATOR_UTILS_EXPORT int endOfNextWord(const QString &string, int position)
     return std::distance(string.begin(), it);
 }
 
+MarkdownHighlighter::MarkdownHighlighter(QTextDocument *parent)
+    : QSyntaxHighlighter(parent)
+    , h2Brush(Qt::NoBrush)
+{
+    parent->setIndentWidth(30); // default value is 40
+}
+
+void MarkdownHighlighter::highlightBlock(const QString &text)
+{
+    if (text.isEmpty())
+        return;
+
+    QTextBlockFormat fmt = currentBlock().blockFormat();
+    QTextCursor cur(currentBlock());
+    if (fmt.hasProperty(QTextFormat::HeadingLevel)) {
+        fmt.setTopMargin(10);
+        fmt.setBottomMargin(10);
+
+        // Draw an underline for Heading 2, by creating a texture brush
+        // with the last pixel visible
+        if (fmt.property(QTextFormat::HeadingLevel) == 2) {
+            QTextCharFormat charFmt = currentBlock().charFormat();
+            charFmt.setBaselineOffset(15);
+            setFormat(0, text.length(), charFmt);
+
+            if (h2Brush.style() == Qt::NoBrush) {
+                const int height = QFontMetrics(charFmt.font()).height();
+                QImage image(1, height, QImage::Format_ARGB32);
+
+                image.fill(QColor(0, 0, 0, 0).rgba());
+                image.setPixel(0,
+                               height - 1,
+                               Utils::creatorTheme()->color(Theme::TextColorDisabled).rgba());
+
+                h2Brush = QBrush(image);
+            }
+            fmt.setBackground(h2Brush);
+        }
+        cur.setBlockFormat(fmt);
+    } else if (fmt.hasProperty(QTextFormat::BlockCodeLanguage) && fmt.indent() == 0) {
+        // set identation for code blocks
+        fmt.setIndent(1);
+        cur.setBlockFormat(fmt);
+    }
+
+    // Show the bulet points as filled circles
+    QTextList *list = cur.currentList();
+    if (list) {
+        QTextListFormat listFmt = list->format();
+        if (listFmt.indent() == 1 && listFmt.style() == QTextListFormat::ListCircle) {
+            listFmt.setStyle(QTextListFormat::ListDisc);
+            list->setFormat(listFmt);
+        }
+    }
+}
+
 } // namespace Utils

src/libs/utils/stringutils.h

@@ -5,8 +5,10 @@
 
 #include "utils_global.h"
 
+#include <QBrush>
 #include <QList>
 #include <QString>
+#include <QSyntaxHighlighter>
 
 #include <functional>
 
@@ -121,4 +123,14 @@ QTCREATOR_UTILS_EXPORT QPair<QStringView, QStringView> splitAtFirst(const QStrin
 
 QTCREATOR_UTILS_EXPORT int endOfNextWord(const QString &string, int position = 0);
 
+class QTCREATOR_UTILS_EXPORT MarkdownHighlighter : public QSyntaxHighlighter
+{
+public:
+    MarkdownHighlighter(QTextDocument *parent);
+    void highlightBlock(const QString &text);
+
+private:
+    QBrush h2Brush;
+};
+
 } // namespace Utils

src/plugins/coreplugin/mainwindow.cpp

@@ -1384,67 +1384,6 @@ public:
     }
 };
 
-class MarkdownHighlighter : public QSyntaxHighlighter
-{
-    QBrush h2Brush;
-public:
-    MarkdownHighlighter(QTextDocument *parent)
-        : QSyntaxHighlighter(parent)
-        , h2Brush(Qt::NoBrush)
-    {
-        parent->setIndentWidth(30); // default value is 40
-    }
-
-    void highlightBlock(const QString &text)
-    {
-        if (text.isEmpty())
-            return;
-
-        QTextBlockFormat fmt = currentBlock().blockFormat();
-        QTextCursor cur(currentBlock());
-        if (fmt.hasProperty(QTextFormat::HeadingLevel)) {
-            fmt.setTopMargin(10);
-            fmt.setBottomMargin(10);
-
-            // Draw an underline for Heading 2, by creating a texture brush
-            // with the last pixel visible
-            if (fmt.property(QTextFormat::HeadingLevel) == 2) {
-                QTextCharFormat charFmt = currentBlock().charFormat();
-                charFmt.setBaselineOffset(15);
-                setFormat(0, text.length(), charFmt);
-
-                if (h2Brush.style() == Qt::NoBrush) {
-                    const int height = QFontMetrics(charFmt.font()).height();
-                    QImage image(1, height, QImage::Format_ARGB32);
-
-                    image.fill(QColor(0, 0, 0, 0).rgba());
-                    image.setPixel(0,
-                                   height - 1,
-                                   Utils::creatorTheme()->color(Theme::TextColorDisabled).rgba());
-
-                    h2Brush = QBrush(image);
-                }
-                fmt.setBackground(h2Brush);
-            }
-            cur.setBlockFormat(fmt);
-        } else if (fmt.hasProperty(QTextFormat::BlockCodeLanguage) && fmt.indent() == 0) {
-            // set identation for code blocks
-            fmt.setIndent(1);
-            cur.setBlockFormat(fmt);
-        }
-
-        // Show the bulet points as filled circles
-        QTextList *list = cur.currentList();
-        if (list) {
-            QTextListFormat listFmt = list->format();
-            if (listFmt.indent() == 1 && listFmt.style() == QTextListFormat::ListCircle) {
-                listFmt.setStyle(QTextListFormat::ListDisc);
-                list->setFormat(listFmt);
-            }
-        }
-    }
-};
-
 void MainWindow::changeLog()
 {
     static QPointer<LogDialog> dialog;
@@ -1484,8 +1423,7 @@ void MainWindow::changeLog()
     aggregate->add(textEdit);
     aggregate->add(new Core::BaseTextFind(textEdit));
 
-    auto highlighter = new MarkdownHighlighter(textEdit->document());
-    (void)highlighter;
+    new MarkdownHighlighter(textEdit->document());
 
     auto textEditWidget = new QFrame;
     textEditWidget->setFrameStyle(QFrame::NoFrame);

src/plugins/texteditor/markdowneditor.cpp

@@ -7,10 +7,11 @@
 #include "texteditor.h"
 #include "texteditortr.h"
 
-#include <coreplugin/icore.h>
 #include <coreplugin/coreconstants.h>
 #include <coreplugin/coreplugintr.h>
+#include <coreplugin/icore.h>
 #include <coreplugin/minisplitter.h>
+#include <utils/stringutils.h>
 
 #include <QHBoxLayout>
 #include <QScrollBar>
@@ -34,6 +35,7 @@ public:
         auto browser = new QTextBrowser(&m_widget);
         browser->setOpenExternalLinks(true);
         browser->setFrameShape(QFrame::NoFrame);
+        new Utils::MarkdownHighlighter(browser->document());
 
         // Right side (hidable)
         auto editor = new TextEditorWidget(&m_widget);