How to implement the keyboard change event in javaFx

I have to implement a event that when my mouse click into a PasswordField, the keyborad input method needs to switch to english state ,then the mouse is left , the keyborad input method need to switch to the input method before,for example, change to Chinese state.

Now I hava tried java.awt.im.InputContext, but it doesn’t work in javaFX.
See detail here: https://forums.oracle.com/message/10918889

Thany you!