refactor: opacity helper

navigatorview.cpp

@@ -1,6 +1,7 @@
 #include "navigatorview.h"
 
 #include "graphicsview.h"
+#include "opacityhelper.h"
 
 #include <QMouseEvent>
 #include <QDebug>
@@ -8,6 +9,7 @@
 NavigatorView::NavigatorView(QWidget *parent)
     : QGraphicsView (parent)
     , m_viewportRegion(this->rect())
+    , m_opacityHelper(new OpacityHelper(this))
 {
     setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
     setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
@@ -21,6 +23,11 @@ void NavigatorView::setMainView(GraphicsView *mainView)
     m_mainView = mainView;
 }
 
+void NavigatorView::setOpacity(qreal opacity, bool animated)
+{
+    m_opacityHelper->setOpacity(opacity, animated);
+}
+
 void NavigatorView::updateMainViewportRegion()
 {
     if (m_mainView != nullptr) {