This site requires JavaScript, please enable it in your browser!
Greenfoot back
Twitter Twitter.hover
Minion1
Minion1 wrote ...

2012/12/24

Is there a "keyPressed" method in Greenfoot?

1
2
Minion1 Minion1

2012/12/24

#
I've been looking through the API, and I can't seem to find a method that checks to see if a key has been pressed. Sure there's the obvious "isKeyDown" method, but that doesn't serve. I just need the computer to register the press of a particular key one time, not check to see if it's down. This seems like a silly thing to bring up here, but I can't seem to find anything in the API (by the way, my search skills suck).
actinium actinium

2012/12/24

#
Your looking for the getKey() method in the Greenfoot class i think.
Minion1 Minion1

2012/12/24

#
getKey checks the last key that was pressed. Not sure If I can use that the way I want to. It doesn't take any parameters, it merely returns the last key pressed, so... Let's see.. getKey will return "M" if that was the last key I pressed, then I have to set up a boolean to check if "M" was pressed, and if true then implement the statement.. nope. Didn't work..
Minion1 Minion1

2012/12/24

#
Here is the code. I'm trying to make it so that the user can turn the music in the game on or off by pressing the "M" key. if(Greenfoot.getKey() == "M" && music.isPlaying()) { music.pause(); } else if(Greenfoot.getKey() == "M" && !music.isPlaying()) { music.playLoop(); }
actinium actinium

2012/12/24

#
if you want any key check if its not null
Minion1 Minion1

2012/12/24

#
I'm looking for a way to have the program check for the pressing of the "M" key specifically. It kind of blows my mind that a way to check if a single key has been pressed doesn't already exist in Greenfoot.
nooby123 nooby123

2012/12/24

#
This is a function that returns a true or false if a specific key has been pressed or not.
?
1
Greenfoot.isKeyDown("m");
You can replace "m" with any other letter or action key such as "up", "space", "down", "right", "left".
Minion1 Minion1

2012/12/24

#
Dang it, this is the problem with programming. Lol. Everything is moving along swimmingly and then "BAM!" ..some miniscule problem halts everything. It's frustrating as all heck. So why am I still having fun?
nooby123 nooby123

2012/12/24

#
If you want to put it in to use :
?
1
2
if(Greenfoot.isKeyDown("m")) //what ever code you want to put in here
;
Minion1 Minion1

2012/12/24

#
nooby123. Thanks, but the "isKeyDown" method only checks to see if the key is currently down. It doesn't do anything else. I want my music to stop and start at the touch of a key, not continue playing only if the "M" key is still down.
nooby123 nooby123

2012/12/24

#
Oh then here. Make a boolean that shows if the music is playing or not.
?
1
2
3
4
5
6
7
boolean music_playing = true;
GreenfootSound music = new GreenfootSound("what ever sound you're playing");
 
if(Greenfoot.isKeyDown("m")) music_playing = false;
 
if(music_playing) music.play();
else music.stop();
Minion1 Minion1

2012/12/24

#
Well, thanks again, but it doesn't seem to be working. Truth is, I can solve this problem easily by just using two different keys instead of one. I guess for the time being I'll use that route. I googled the problem,and for the most part the results were somewhat difficult to understand, and they all used methods I'm unfamiliar with. I really need to take some time to work out how to go "cold turkey" without Greenfoot. Thanks everyone.
actinium actinium

2012/12/24

#
Your using the getKey() method wrong, getKey() returns a string therefore you should do,
?
1
2
3
4
String key = Greenfoot.getKey()
 
if (key == "m")
ect
actinium actinium

2012/12/24

#
?
1
2
3
4
5
6
7
8
9
10
11
12
13
public void checkKey()
   {
       String key = Greenfoot.getKey();
        
       if (key != null)
       {
           if (key.equals("m"))
           {
               System.out.println("here");
               sound.stop();
           }
       }
   }
This seems to work
danpost danpost

2012/12/25

#
This will also work:
?
1
2
3
4
5
6
7
8
9
public void checkKey()
{
    String key = Greenfoot.getKey();
    if ("m".equals(key))
    {
        System.out.println("here");
        sound.stop();
    }
}
As long you are not calling 'equals' on a null, you will not get an error. It matters not what is returned from inside the parenthesis '( )'. In other words, no error will ensue with
?
1
"any valid string".equals(null)
There are more replies on the next page.
1
2