Programming Forums > Application Development > Java

sibelius7 · Dec 25th, 2007, 2:23 PM

Hi there...

I believe that my question is somewhat simple, but as my thread title suggests, I'm a little new at Java programming.

My problem is that I need to know how register keypresses somehow with Java. I plan to use this as a component of part of a senior project (which is basically a very simple music composition program which saves files in .mid format) for my computer science class which. This is the only component of the program so far that I havent had any progress in, and seeing as it's winter break now... I might as well use this time wisely.

All I need is to figure out how to do the following... in code of course:

If the a-key is pressed, perform action x.

I have read a little and heard about keypress listening, and code that sits in an seemingly-infinite loop that only terminates upon the press of a certain key, but I just don't know how to implement it.

Any help at all would be appreciated

Thanks

andro · Dec 25th, 2007, 2:54 PM

This should help

http://java.sun.com/j2se/1.5.0/docs/...yListener.html

http://java.sun.com/docs/books/tutor...ylistener.html

sibelius7 · Dec 25th, 2007, 5:11 PM

Well that's helpful... I swear I looked in .awt.

Thanks a lot andro, now I have something to go with!

(that doesnt mean I dont need any more advice haha)

Jimbo · Dec 25th, 2007, 7:04 PM

Some people also prefer to use the KeyAdaptor class as it doesn't require you to implement all the methods in the KeyListener interface.

null_ptr0 · Dec 26th, 2007, 9:58 AM

Here's some pseudocode I whipped up:

(Toggle Plain Text)

import java.io.InputStream;

public class Test {
   private InputStream stdin = System.in;

   public char get() {
      return (char) stdin.read();
   }

   public void loop() {
      while(true)
         if(get() == 'a')
            launchEvents();
   }

   /* Implement your code here */
   protected void launchEvents() { }

   public static void main(String[] argv) {
      loop();
   }
}

That is, if your using the console.
If you are using a GUI, then search KeyListener, addKeyListener, and KeyEvent.

Dec 25th, 2007, 2:23 PM	#1
sibelius7 Newbie Join Date: Dec 2007 Location: Oregon, United States Posts: 4 Rep Power: 0	Keypress question from a somewhat new Java programmer Hi there... I believe that my question is somewhat simple, but as my thread title suggests, I'm a little new at Java programming. My problem is that I need to know how register keypresses somehow with Java. I plan to use this as a component of part of a senior project (which is basically a very simple music composition program which saves files in .mid format) for my computer science class which. This is the only component of the program so far that I havent had any progress in, and seeing as it's winter break now... I might as well use this time wisely. All I need is to figure out how to do the following... in code of course: If the a-key is pressed, perform action x. I have read a little and heard about keypress listening, and code that sits in an seemingly-infinite loop that only terminates upon the press of a certain key, but I just don't know how to implement it. Any help at all would be appreciated Thanks

Dec 25th, 2007, 2:54 PM	#2
andro Professional Programmer Join Date: Oct 2005 Location: California Posts: 290 Rep Power: 3	Re: Keypress question from a somewhat new Java programmer This should help http://java.sun.com/j2se/1.5.0/docs/...yListener.html http://java.sun.com/docs/books/tutor...ylistener.html __________________ http://www.kevinherron.com/

Dec 25th, 2007, 5:11 PM	#3
sibelius7 Newbie Join Date: Dec 2007 Location: Oregon, United States Posts: 4 Rep Power: 0	Re: Keypress question from a somewhat new Java programmer Well that's helpful... I swear I looked in .awt. Thanks a lot andro, now I have something to go with! (that doesnt mean I dont need any more advice haha)

Dec 25th, 2007, 7:04 PM	#4
Jimbo Battle Programmer Join Date: Feb 2006 Location: Bellevue, WA, USA Posts: 748 Rep Power: 3	Re: Keypress question from a somewhat new Java programmer Some people also prefer to use the KeyAdaptor class as it doesn't require you to implement all the methods in the KeyListener interface. __________________ <insert disclaimer here> <insert shameless plug for Visual Studio here>

Dec 26th, 2007, 9:58 AM	#5
null_ptr0 11 years old Join Date: Nov 2007 Posts: 79 Rep Power: 1	Re: Keypress question from a somewhat new Java programmer Here's some pseudocode I whipped up: (Toggle Plain Text) import java.io.InputStream; public class Test { private InputStream stdin = System.in; public char get() { return (char) stdin.read(); } public void loop() { while(true) if(get() == 'a') launchEvents(); } /* Implement your code here / protected void launchEvents() { } public static void main(String[] argv) { loop(); } } import java.io.InputStream; public class Test { private InputStream stdin = System.in; public char get() { return (char) stdin.read(); } public void loop() { while(true) if(get() == 'a') launchEvents(); } / Implement your code here */ protected void launchEvents() { } public static void main(String[] argv) { loop(); } } That is, if your using the console. If you are using a GUI, then search KeyListener, addKeyListener, and KeyEvent. __________________ iload_0 iconst_1 ishl or iload_0 iconst_2 idiv or iload_0 iconst_2 iconst_1 imul idiv [1] & [2] use the smallest stack size

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Programming Forums > Application Development > Java

Keypress question from a somewhat new Java programmer