Key Detection not working on laptop

Newbie & Debugging Questions
#1

I followed the tutorial on http://zetcode.com/tutorials/javagamestutorial/movingsprites/ pretty much line for line but I have this weird bug I just can’t fix.
My little program runs fine on my computer and I can move things around on the screen, but when I move to my laptop with the same program - everything works fine except the key detection.

I’ve tried debugging it like so and nothing happens at all.


	public void keyPressed(KeyEvent e) {
		System.out.println(1);
		player.keyPressed(e);
	}

This problem only exists on my laptop and works fine on other computers.
My laptop has JDK/JRE up to date and now I have no other solutions to try but to post here.

#2

If I am correct then only if your program has focus then it can catch events.
By the way does your laptop has Linux OS ? It can sometimes be pain in ass to find and fix what’s work for windows but don’t work for Linux :smiley:

#3

Yup, my canvas is definitely focused.
I mean it works fine on my desktop and for everybody else, so why only does it not work on my laptop? :confused:

Both on Windows btw.
I originally started with Linux but that just had a complete mind of its own in terms of Java so I moved back to Windows.

I’m going to try out some small Java games around here and see if it happens with them too.

Edit:
Okay, I pretty much give up. Java has annoyed me constantly on how a simple program can act completely different on other OSs and computers.
I just started looking into libgdx and I’m fairly impressed by it, so I think I’ll be sticking with it. Was a little scary at first making the jump but it’s easier than I thought! :stuck_out_tongue:

#4

I have experienced that problem with my JDoodle Jump, several people told me they can’t control with the keyboard. The solution: requestFocusInWindow() :slight_smile:

EDIT: LibGDX is an OpenGL library. You were using AWT. Two completely different graphics systems. It is best to learn the low levels of OpenGL instead of jumping to a really high level library like LibGDX that does everything for you behind the scenes :wink:

#5

Honestly I have to say - I love you.
It worked. lol
Thanks a bunch :slight_smile:

Now I can finally continue programming games in work when I have nothing else better to do.
I’m still looking into LibGDX but I think I’ll learn better where I can actually play around with things and relate to. I didn’t go straight for OpenGL because I thought that it only deals with 3D stuff? (Feel free to put me straight)

#6

@ra4king:

does your solution also solve key listening problems on linux?

#7

@Hazzy
OpenGL is 2D and 3D.

@h3ckboy
I do believe so but I have not tested it on Linux :frowning:

#8

@ra4king, In Linux, I tried your jdoodle jump thing and get a java message saying “Error extracting sounds!”, If I click OK the message comes right back up, over and over. The only way to stop it is to close the tab the applet is in. So, yea that’s as far as I can get.

@h3ckboy, if you’re looking for a linux fix for the keyboard you can find the RepeatingReleasedEventsFixer class here: http://tech.stolsvik.com/2010/05/linux-java-repeats-released-keyevents.html The only alteration you need to do to your existing code is add:

new RepeatingReleasedEventsFixer().install();

in the init() or main().

I actually found it last night (read: early this morning) after 3 hours of trying to figure out why my character was firing off shots at random while I was holding down the space bar to select the velocity. Thinking my code was wrong somewhere and creating premature release events, I was trying stupid things to try and fix the issue before realizing that the pressed and released events were in a different order than what I had thought. For a change, this bug wasn’t my fault! ;D

#9

@gbeebe
That message will pop up for each sound file that cannot be loaded. The error that you showed me means that either your Linux OS or the JRE for that Linux OS don’t support little-endian sounds. The only way to fix this would be to make big-endian sounds but that would take up too much space. For now, I’ll make it so it tells you sounds are not supported on your machine and continue to play the game without sounds.

#10

I knew the difference between big and little-endian, as a Linux developer you’re kinda forced to. But i never realized that sound files were that way too. I wonder if a fix would be as simple as allocating memory the same size as the sound data and copy it over backwards and use it instead of the origional.