Improve performance of expand / collapse all

src/headers/macro-segment.hpp

@@ -30,6 +30,7 @@ public:
 	// Use this function to avoid accidental edits when scrolling through
 	// list of actions and conditions
 	void SetFocusPolicyOfWidgets();
+	void SetCollapsed(bool collapsed);
 
 protected slots:
 	void HeaderInfoChanged(const QString &);

src/headers/section.hpp

@@ -16,6 +16,7 @@ public:
 
 	void SetContent(QWidget *w, bool collapsed = true);
 	void AddHeaderWidget(QWidget *);
+	void SetCollapsed(bool);
 
 protected:
 	bool eventFilter(QObject *obj, QEvent *event) override;