I’m looking at how I would tell my plugin that, when I place a wall sign with the words ‘Game Room’ on the first line, to set lines 3 and 4 of the sign to say stuff that I need them to say.
(Line 1 of sign says Game Room, I close out of the sign’s window, it auto-changes to say stuff)
Would this be a ChangeBlockEvent.Modify thing, or…? I don’t think it would, as the sign is not actually changing, as it is still a sign.
The event you are looking for is ChangeSignEvent which is fired when a sign changes text. When a sign gets placed it is placed with no text on it and the player gets the interface to write the text. When the player writes the text and is ok with it, minecraft changes the blank text on the sign to what they normally put it. Sponge fires this event at that point in time.
https://github.com/SpongePowered/SpongeAPI/blob/bleeding/src/main/java/org/spongepowered/api/event/block/tileentity/ChangeSignEvent.java