line number, symtax highlight, initial dark theme

sciedit.h

@@ -3,6 +3,9 @@
 #include <ScintillaEdit.h>
 #include <ILexer.h>
 
+#include <QFont>
+#include <QString>
+
 class SciEdit : public ScintillaEdit
 {
     Q_OBJECT
@@ -18,6 +21,9 @@ public:
     void setStyleFont(const QFont & font, int style = STYLE_DEFAULT);
     void setFolding(FoldType foldType, int margin = 2);
     void setLexer(Scintilla::ILexer5 * lexer);
+    void setLineNumbersEnabled(bool enabled);
+    void setEditorFont(const QFont &font);
+    void applyTheme(bool dark);
     void sendColor(unsigned int iMessage, uptr_t wParam, const QColor &col) const;
 
 signals:
@@ -26,4 +32,12 @@ signals:
 
 private:
     void setMarkerDefine(int markerNumber, int markerSymbol);
+    void updateLineNumberMarginWidth();
+    void applyLexerStyles();
+
+    bool m_lineNumbersEnabled = false;
+    int m_lastLineNumberDigits = 0;
+    bool m_isDarkTheme = false;
+    QFont m_editorFont;
+    QString m_lexerName;
 };