message: Add middle-click-to-close for tabs in ToolWindowManager
diff: @@ -128,7 +128,18 @@ bool ToolWindowManagerArea::eventFilter(QObject *object, QEvent *event) {
  } else {
  m_dragCanStart = true;
  }
  + } else if (event->type() == QEvent::MouseButtonPress &&
  + qApp->mouseButtons() == Qt::MiddleButton) {
  + int tabIndex = tabBar()->tabAt(static_cast<QMouseEvent*>(event)->pos());
  +
  + if(tabIndex >= 0) {
  + QWidget *w = widget(tabIndex);
  +
  + if(!(m_manager->toolWindowProperties(w) & ToolWindowManager::HideCloseButton)) {
  + m_manager->removeToolWindow(w);
  + }
  + }
  } else if (event->type() == QEvent::MouseButtonRelease) {
  m_tabDragCanStart = false;
  m_dragCanStart = false;
  