[1.8.9] Whenever a book is opened, read the contents on the page

[Fifti]

So i have a pretty basic request for my firstever forgemod. I want to have an event handler which is called whenever a book is opened on the client (as in the gui is brought up). Whenever this happens, I want to find the contents of the opened page (there will only be 1 page). Coming from a bukkit background, my first instinct was to take a GuiOpenEvent and cast the gui passed through as a BookGui, but the IDE seems to not be too enthusiastic about that.

 

I expect this is a pretty basic question so apologies for seeming a bit stupid :(

[Mista Helper]

1.8.9 is no longer supported.

Update to a modern version to receive support

[Fifti]

47 minutes ago, Mista Helper said:

1.8.9 is no longer supported.

Update to a modern version to receive support

Hey, thanks for this reply

 

How should I go about doing this in 1.16?