Toogle visibility of custom title bar based on fullscreen state (#814)

src/FloatingDockContainer.cpp

@@ -850,6 +850,12 @@ void CFloatingDockContainer::changeEvent(QEvent *event)
 				this->showMaximized();
 			}
 		}
+#if defined(Q_OS_UNIX) && !defined(Q_OS_MACOS)
+        if (d->TitleBar)
+        {
+            d->TitleBar->setVisible(!(isFloating() && isFullScreen()));
+        }
+#endif
 		break;
 
 	default:

src/linux/FloatingWidgetTitleBar.cpp

@@ -238,6 +238,20 @@ void CFloatingWidgetTitleBar::mouseDoubleClickEvent(QMouseEvent *event)
     }
 }
 
+//============================================================================
+QSize CFloatingWidgetTitleBar::sizeHint() const
+{
+    if (isVisible())
+    {
+        return QFrame::sizeHint();
+    }
+    else
+    {
+        // Allow titlebar to collapse when set invisible.
+        return QSize();
+    }
+}
+
 
 //============================================================================
 void CFloatingWidgetTitleBar::setMaximizedIcon(bool maximized)

src/linux/FloatingWidgetTitleBar.h

@@ -59,6 +59,7 @@ protected:
 	virtual void mouseReleaseEvent(QMouseEvent *ev) override;
 	virtual void mouseMoveEvent(QMouseEvent *ev) override;
     virtual void mouseDoubleClickEvent(QMouseEvent *event) override;
+    virtual QSize sizeHint() const override;
 
     void setMaximizeIcon(const QIcon& Icon);
     QIcon maximizeIcon() const;