Can I open an explorer file automatically after initializing my widget?

Every time the user starts Theia, the Explorer is folded in the left side, and there is no file openning in the middle area. So i want to open an explorer file automatically while Theia is started. Can i do that?

[original thread by AlwaysMing]

https://spectrum.chat/theia/dev/how-to-let-widget-open-automatically~56a843e1-b174-4894-b9db-eab425b38aed?m=MTU4NDYwNDAyNzQ2MA==https://spectrum.chat/theia/dev/how-to-let-widget-open-automatically~56a843e1-b174-4894-b9db-eab425b38aed

You need a custom extension implementing thing hook, then you inject FileNavigatorContirubution and call contribution.openView from this hook.