when someone said :"That does it!" What did he meant?
It can be used when the person is about to get angry, can't tolerate something any more, is going to give up trying, etc. It's a way of saying that a limit has been reached or something has gone wrong, failed and so on.
NOT A TEACHER
May I just add something to the Editor's answer?
In English, we have the saying: That's the straw that breaks the camel's back.
In other words, you might put 99 straws on the camel's back, and it can still walk.
But if you add the 100th straw, you have broken the poor camel's back.
So let's say that Tommy had been a very bad boy on Monday, Tuesday, Wednesday,
and Thursday. On those days, his mother had told him not to be bad again.
But on Friday he was bad again, so his mother yelled: That does it! /
That's it! = I have lost my patience. You are now going to be punished: No television
for a week; no use of the computer for two weeks; no use of your cellphone for three
weeks. I have had it with you! Your horrible conduct on Friday was the straw that
broke the camel's back!
Thank you.