revert: remove OpacityHelper

- remove OpacityHelper
- remove all related animation
- now bottom toolbar and navigation view are always visible

app/bottombuttongroup.cpp

@@ -4,15 +4,12 @@
 
 #include "bottombuttongroup.h"
 
-#include "opacityhelper.h"
-
 #include <QToolButton>
 #include <QVBoxLayout>
 #include <QDebug>
 
 BottomButtonGroup::BottomButtonGroup(const std::vector<QAction *> &actionList, QWidget *parent)
     : QGroupBox (parent)
-    , m_opacityHelper(new OpacityHelper(this))
 {
     QHBoxLayout * mainLayout = new QHBoxLayout(this);
     mainLayout->setSizeConstraint(QLayout::SetFixedSize);
@@ -45,11 +42,6 @@ BottomButtonGroup::BottomButtonGroup(const std::vector<QAction *> &actionList, Q
     }
 }
 
-void BottomButtonGroup::setOpacity(qreal opacity, bool animated)
-{
-    m_opacityHelper->setOpacity(opacity, animated);
-}
-
 void BottomButtonGroup::addButton(QAbstractButton *button)
 {
     layout()->addWidget(button);