CodeEditor improvements

- Block (un)indent (works for tabs and or spaces)
- Block indent inserts spaces when m_useTabs == false
- Tabsize based on number of chars (instead of pixels) default size is now 4 chars
- Change fontsize with Ctrl + [-|+|=] (= is same key as +)

pglab/CodeEditor.h

@@ -18,8 +18,11 @@ public:
 
 	void addErrorMarker(int position, int length);
 	void clearErrorMarkers();
+	void setFont(const QFont &);
+	void setTabSize(int chars);
 protected:
 	void resizeEvent(QResizeEvent *event) override;
+	void keyPressEvent(QKeyEvent *e) override;
 
 signals:
 
@@ -31,6 +34,7 @@ private slots:
 	void updateGutterArea(const QRect &, int);
 	void onTextChanged();
 
+
 private:
 	QWidget *gutterArea;
 
@@ -39,7 +43,13 @@ private:
 
 	std::set<int> errorLines;
 
+	// Settings
+	int m_tabSize = 0;  // tabSize in characters
+	bool m_useTab = false;
+
 	void updateExtraSelections();
+	bool indentSelection(bool indent);
+
 };
 
 #endif // CODEEDITOR_H