can i listen to variable change in diffrent class

[gloomy1991]

well as the title states: is it possible for me to listen to a variable change in a diffrent class?

im making a game in wich the GUI.java ( within the view package) has to change the labels of a number of buttons if the gameStatus variable in spel.java( in the model package) changes to false.

i want the model package to be able to run even if the view package aint there. This for Junit testing later on ( its for school btw).

however. i cant find a way to do this. at the moment i made a really ugly solution. whenever i change the variable's value i set a timer to timer.start this timer has set its repeat to false. and im listening to it from the GUI.java.

is there a way if a variable is changed just like the way you listen if the timer is firing?

like spel.timer.addActionListener();

but then spel.spelStatus.addCheckIfChangedThingyListener();

i spent 1 hour on google finding something like this but no results ( maybe google and i were better friends if he actually knew what i was looking for in this case).

hope if you guys can help me :D thanks in advance

[doWhile]

If I understand correctly, just write your own Listener interface. This is in my opinion one of the more important design patterns (see Observer pattern - Wikipedia, the free encyclopedia). Java provides a bare-bones way you can implement using pattern using a Property Change Listener

[Singing Boyo]

Note that property change listeners are probably more complex than is really necessary. Just write an entirely new interface, similar to the ActionListener interface.