add macos titlebar

Zhao Yuhang

2023-12-14 2452f5958272d50981ab89ff843d2fa715d33957

 src/widgets/widgetwindowagent.cpp

@@ -57,6 +57,9 @@
        if (!d->context->setTitleBar(w)) {
            return;
        }
#ifdef Q_OS_MACOS
        d->setupMacOSTitleBar(w);
#endif
        Q_EMIT titleBarWidgetChanged(w);
    }