don't reset KSyntaxhigHlighter state every line

If the state is reset every line KSyntaxHighlighter will be unable to
highlight multi line comments (for example). This patch changes that by
highlighting everyting at once.

src/models/highlightedtext.cpp

@@ -27,6 +27,8 @@
 
 #include "formattingutils.h"
 
+using LineFormat = QVector<QTextLayout::FormatRange>;
+
 #if KFSyntaxHighlighting_FOUND
 // highlighter using KSyntaxHighlighting
 class HighlightingImplementation : public KSyntaxHighlighting::AbstractHighlighter
@@ -38,13 +40,23 @@ class HighlightingImplementation : public KSyntaxHighlighting::AbstractHighlight
     }
     ~HighlightingImplementation() override = default;
 
-    virtual QVector<QTextLayout::FormatRange> format(const QString& text)
+    void formatText(const QStringList& text)
     {
+        if (m_lines != text) {
+            m_lines = text;
+        }
+
         m_formats.clear();
+        m_state = {};
 
-        highlightLine(text, {});
+        for (const auto& line : text) {
+            m_formats.push_back(formatLine(line));
+        }
+    }
 
-        return m_formats;
+    virtual LineFormat format(int lineIndex) const
+    {
+        return m_formats.at(lineIndex);
     }
 
     virtual void themeChanged()
@@ -66,37 +78,57 @@ class HighlightingImplementation : public KSyntaxHighlighting::AbstractHighlight
     virtual void setHighlightingDefinition(const KSyntaxHighlighting::Definition& definition)
     {
         setDefinition(definition);
+        formatText(m_lines);
     }
 
     virtual QString definitionName() const
     {
         return definition().name();
     }
 
+    virtual LineFormat formatLine(const QString& line)
+    {
+        m_lineFormat.clear();
+        m_state = highlightLine(line, m_state);
+        return m_lineFormat;
+    }
+
 protected:
     void applyFormat(int offset, int length, const KSyntaxHighlighting::Format& format) override
     {
         QTextCharFormat textCharFormat;
         textCharFormat.setForeground(format.textColor(theme()));
         textCharFormat.setFontWeight(format.isBold(theme()) ? QFont::Bold : QFont::Normal);
-        m_formats.push_back({offset, length, textCharFormat});
+        m_lineFormat.push_back({offset, length, textCharFormat});
     }
 
 private:
     KSyntaxHighlighting::Repository* m_repository;
-    QVector<QTextLayout::FormatRange> m_formats;
+    KSyntaxHighlighting::State m_state;
+    QStringList m_lines; // for reformatting if definition changes
+    LineFormat m_lineFormat;
+    QVector<LineFormat> m_formats;
 };
 #else
-// stub incase KSyntaxHighlighting is not available
+// stub in case KSyntaxHighlighting is not available
 class HighlightingImplementation
 {
 public:
     HighlightingImplementation(KSyntaxHighlighting::Repository* /*repository*/) { }
     virtual ~HighlightingImplementation() = default;
 
-    virtual QVector<QTextLayout::FormatRange> format(const QString& /*text*/)
+    void formatText(const QStringList& text)
     {
-        return {};
+        m_formats.clear();
+
+        for (const auto& line : text) {
+            m_formats.push_back(formatLine(line));
+        }
+    }
+
+    LineFormat format(int lineIndex) const
+    {
+        return m_formats.at(lineIndex);
     }
 
     virtual void themeChanged() { }
@@ -105,7 +137,17 @@ class HighlightingImplementation
     virtual QString definitionName() const
     {
         return {};
+    };
+
+private:
+    // stub implementation necessary for testing
+    virtual LineFormat formatLine(const QString& line)
+    {
+        return {{QTextLayout::FormatRange {0, line.length(), {}}}};
     }
+
+    Q_DISABLE_COPY(HighlightingImplementation)
+    QVector<LineFormat> m_formats;
 };
 #endif
 
@@ -118,7 +160,19 @@ class AnsiHighlightingImplementation : public HighlightingImplementation
     }
     ~AnsiHighlightingImplementation() override = default;
 
-    QVector<QTextLayout::FormatRange> format(const QString& text) final
+    void themeChanged() override
+    {
+        m_colorScheme = KColorScheme(QPalette::Normal, KColorScheme::Complementary);
+    }
+
+    void setHighlightingDefinition(const KSyntaxHighlighting::Definition& /*definition*/) override { }
+    QString definitionName() const override
+    {
+        return {};
+    }
+
+private:
+    LineFormat formatLine(const QString& text) override
     {
         QVector<QTextLayout::FormatRange> formats;
 
@@ -167,28 +221,17 @@ class AnsiHighlightingImplementation : public HighlightingImplementation
         return formats;
     }
 
-    void themeChanged() override
-    {
-        m_colorScheme = KColorScheme(QPalette::Normal, KColorScheme::Complementary);
-    }
-
-    void setHighlightingDefinition(const KSyntaxHighlighting::Definition& /*definition*/) override { }
-    QString definitionName() const override
-    {
-        return {};
-    }
-
-private:
     KColorScheme m_colorScheme;
 };
 
 // QTextLayout is slow, this class acts as a cache that only creates and fills the QTextLayout on demand
 class HighlightedLine
 {
 public:
-    HighlightedLine(HighlightingImplementation* highlighter, QString text)
+    HighlightedLine(HighlightingImplementation* highlighter, const QString& text, int index)
         : m_highlighter(highlighter)
-        , m_text(std::move(text))
+        , m_text(Util::removeAnsi(text))
+        , m_index(index)
         , m_layout(nullptr)
     {
     }
@@ -216,12 +259,10 @@ class HighlightedLine
         if (!m_layout) {
             m_layout = std::make_unique<QTextLayout>();
             m_layout->setFont(QFontDatabase::systemFont(QFontDatabase::FixedFont));
-            const auto& ansiFreeLine = Util::removeAnsi(m_text);
-            m_layout->setText(ansiFreeLine);
+            m_layout->setText(m_text);
         }
 
-        m_layout->setFormats(m_highlighter->format(m_text));
-
+        m_layout->setFormats(m_highlighter->format(m_index));
         m_layout->beginLayout();
 
         // there is at most one line, so we don't need to check this multiple times
@@ -234,13 +275,15 @@ class HighlightedLine
 
     HighlightingImplementation* m_highlighter;
     QString m_text;
+    int m_index;
     std::unique_ptr<QTextLayout> m_layout;
 };
 
 HighlightedText::HighlightedText(KSyntaxHighlighting::Repository* repository, QObject* parent)
     : QObject(parent)
     , m_repository(repository)
 {
+    Q_UNUSED(repository);
 }
 
 HighlightedText::~HighlightedText() = default;
@@ -262,9 +305,12 @@ void HighlightedText::setText(const QStringList& text)
     }
 
     m_highlightedLines.reserve(text.size());
-    std::transform(text.cbegin(), text.cend(), std::back_inserter(m_highlightedLines), [this](const QString& text) {
-        return HighlightedLine {m_highlighter.get(), text};
-    });
+    m_highlighter->formatText(text);
+    int index = 0;
+    std::transform(text.cbegin(), text.cend(), std::back_inserter(m_highlightedLines),
+                   [this, &index](const QString& text) {
+                       return HighlightedLine {m_highlighter.get(), text, index++};
+                   });
 
     connect(this, &HighlightedText::definitionChanged, this, &HighlightedText::updateHighlighting);