fixed the splitoverlay not disappearing when the window is not selected

src/widgets/helper/splitoverlay.cpp

@@ -81,6 +81,8 @@ SplitOverlay::SplitOverlay(Split *parent)
         up->setIconSize(size);
         down->setIconSize(size);
     });
+
+    this->setMouseTracking(true);
 }
 
 void SplitOverlay::paintEvent(QPaintEvent *event)
@@ -122,6 +124,13 @@ void SplitOverlay::resizeEvent(QResizeEvent *event)
     this->_down->setVisible(highEnough);
 }
 
+void SplitOverlay::mouseMoveEvent(QMouseEvent *event)
+{
+    if ((event->modifiers() & Qt::AltModifier) == 0) {
+        this->hide();
+    }
+}
+
 SplitOverlay::ButtonEventFilter::ButtonEventFilter(SplitOverlay *_parent, HoveredElement _element)
     : QObject(_parent)
     , parent(_parent)

src/widgets/helper/splitoverlay.hpp

@@ -19,6 +19,7 @@ public:
 protected:
     void paintEvent(QPaintEvent *event) override;
     void resizeEvent(QResizeEvent *event) override;
+    void mouseMoveEvent(QMouseEvent *event) override;
 
 private:
     // fourtf: !!! preserve the order of left, up, right and down