[Win] another solution,`isChangingTab()` removed from last commit.

src/lib/app/qupzilla.cpp

@@ -774,6 +774,7 @@ void QupZilla::loadSettings()
         m_navigationBar->installEventFilter(this);
         m_bookmarksToolbar->installEventFilter(this);
         statusBar()->installEventFilter(this);
+        m_navigationContainer->installEventFilter(this);
     }
 #endif
 }
@@ -2345,9 +2346,7 @@ bool QupZilla::nativeEvent(const QByteArray &eventType, void* _message, long* re
 
 void QupZilla::applyBlurToMainWindow(bool force)
 {
-    if (!force && (m_actionShowFullScreen->isChecked()
-                   || !m_usingTransparentBackground
-                   || m_tabWidget->getTabBar()->isChangingTab())) {
+    if (!force && (m_actionShowFullScreen->isChecked() || !m_usingTransparentBackground)) {
         return;
     }
     int topMargin = 0;
@@ -2389,10 +2388,23 @@ void QupZilla::applyBlurToMainWindow(bool force)
 bool QupZilla::eventFilter(QObject* object, QEvent* event)
 {
     switch (event->type()) {
-    case QEvent::DeferredDelete:
-    case QEvent::Show:
     case QEvent::Hide:
+        if (object == m_navigationContainer) {
+            m_navigationBar->removeEventFilter(this);
+            m_bookmarksToolbar->removeEventFilter(this);
+            break;
+        }
+    case QEvent::Show:
+        if (object == m_navigationContainer) {
+            m_navigationBar->installEventFilter(this);
+            m_bookmarksToolbar->installEventFilter(this);
+            break;
+        }
     case QEvent::Resize:
+    case QEvent::DeferredDelete:
+        if (object == m_navigationContainer) {
+            break;
+        }
         applyBlurToMainWindow();
         break;
     default:

src/lib/webview/tabbar.cpp

@@ -44,7 +44,6 @@ TabBar::TabBar(QupZilla* mainClass, TabWidget* tabWidget)
     , m_tabWidget(tabWidget)
     , m_tabPreview(new TabPreview(mainClass, tabWidget))
     , m_showTabPreviews(false)
-    , m_isChangingTab(false)
     , m_clickedTab(0)
     , m_pinnedTabsCount(0)
     , m_normalTabWidth(0)
@@ -400,14 +399,13 @@ void TabBar::currentTabChanged(int index)
     if (!validIndex(index)) {
         return;
     }
-    m_isChangingTab = true;
+
     hideTabPreview(false);
 
     showCloseButton(index);
     hideCloseButton(m_tabWidget->lastTabIndex());
 
     m_tabWidget->currentTabChanged(index);
-    m_isChangingTab = false;
 }
 
 void TabBar::bookmarkTab()

src/lib/webview/tabbar.h

@@ -42,7 +42,6 @@ public:
     int pinnedTabsCount();
     int normalTabsCount();
 
-    bool isChangingTab() { return m_isChangingTab; }
     void updatePinnedTabCloseButton(int index);
 
     void disconnectObjects();
@@ -106,7 +105,6 @@ private:
     QTimer* m_tabPreviewTimer;
 
     bool m_showTabPreviews;
-    bool m_isChangingTab;
 
     int m_clickedTab;
     int m_pinnedTabsCount;