function eventFilter($target, $event) { if ($target == $this->display) { if ($event->type() == QEvent::MouseButtonPress || $event->type() == QEvent::MouseButtonDblClick || $event->type() == QEvent::MouseButtonRelease || $event->type() == QEvent::ContextMenu) { qstatic_cast($event, "QMouseEvent"); if ($event->buttons() & Qt::LeftButton) { $newPalette = $this->palette(); $newPalette->setColor(QPalette::Base, $this->display->palette()->color(QPalette::Text)); $newPalette->setColor(QPalette::Text, $this->display->palette()->color(QPalette::Base)); $this->display->setPalette($newPalette); } else { $this->display->setPalette($this->palette()); } return true; } } return parent::eventFilter($target, $event); }