Huge cleanups and added open gl window

src/editor/widgets/codeeditorwidget.h

@@ -0,0 +1,41 @@
+#pragma once
+
+#include <QPlainTextEdit>
+
+class CodeEditorWidget : public QPlainTextEdit
+{
+    Q_OBJECT
+
+public:
+    explicit CodeEditorWidget(QWidget *parent = nullptr);
+
+    void lineNumberAreaPaintEvent(QPaintEvent *event);
+    int lineNumberAreaWidth();
+
+protected:
+    void resizeEvent(QResizeEvent *event) override;
+
+private slots:
+    void updateLineNumberAreaWidth(int newBlockCount);
+    void highlightCurrentLine();
+    void updateLineNumberArea(const QRect &rect, int dy);
+
+private:
+    QWidget *lineNumberArea;
+};
+
+class LineNumberArea : public QWidget
+{
+    Q_OBJECT
+
+public:
+    LineNumberArea(CodeEditorWidget *editor);
+
+    QSize sizeHint() const override;
+
+protected:
+    void paintEvent(QPaintEvent *event) override;
+
+private:
+    CodeEditorWidget *codeEditor;
+};