How can I check keyboard for a single press?

Question

I can't figure how to get the condition to work. Is there something like Keyboard.isKeyDown(//anykey) for the condition?

import org.lwjgl.input.Keyboard;
import org.lwjgl.input.Mouse;

public class InputHandler {

    public static boolean currentKeyState, previousKeyState;

    public static void update() {
        previousKeyState = currentKeyState;

        if (//condition for keydown) {
            currentKeyState = true;
         } else {
            currentKeyState = false;
        }
    }

    public static boolean keyReleased() {
       if (currentKeyState == true && previousKeyState == false) {
            return true;
       } else {
            return false;
        }
   }
}

Here's the C# version of what I'm trying to accomplish. Is there a method similar to Keyboard.GetState() in Java?

using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Input;

namespace Game.Controls
{
    public class InputHandler
    {
    public KeyboardState currentKeyState;
    public KeyboardState previousKeyState;

    public InputHandler()
    {
        currentKeyState = new KeyboardState();
        previousKeyState = new KeyboardState();
    }

    public void Update()
    {
        previousKeyState = currentKeyState;
        currentKeyState = Keyboard.GetState();
    }

    public bool IsHeld(Keys key)
    {
        if (currentKeyState.IsKeyDown(key))
        {
            return true;
        }
        else
        {
            return false;
        }
    }

    public bool IsReleased(Keys key)
    {
        if (currentKeyState.IsKeyUp(key) && previousKeyState.IsKeyDown(key))
        {
            return true;
        }
        else
        {
            return false;
        }
    }

    public bool IsPressed(Keys key)
    {
        if (currentKeyState.IsKeyDown(key) && previousKeyState.IsKeyUp(key))
        {
            return true;
        }
        else
        {
            return false;
        }
    }
}

}

No idea about the answer to this one, but I still think I have something to offer! Your C# `IsPressed()` method can be written just as `return (currentKeyState.IsKeyDown(key) && previousKeyState.IsKeyUp(key));`. Same with all the other methods, in Java, too. Saves a lot of typing and space ;) — Petr Janeček, Jun 08 '12 at 21:09

AurA · Answer 1 · 2012-06-09T08:46:27.337

2

if (Keyboard.getEventKey() == Keyboard.KEY_A) {
    if (Keyboard.getEventKeyState()) {
        System.out.println("A Key Pressed");
    }
    else {
        System.out.println("A Key Released");
    }
}

You can refer this document

for getting all the input methods.

For all the keys supported refer http://www.lwjgl.org/javadoc/org/lwjgl/input/Keyboard.html

edited Jun 09 '12 at 08:46

answered Jun 08 '12 at 09:54

AurA

12,135
7
46
63

But can I replace Keyboard.KEY_A to get any keyboard input? – KeyHeart Jun 08 '12 at 19:26
I have edited my answer, I have added http://www.lwjgl.org/javadoc/org/lwjgl/input/Keyboard.html – AurA Jun 09 '12 at 09:06

score 2 · Answer 2 · edited Jun 29 '12 at 15:36

2

I find this to be the easiest method of checking for event-driven input:

while (Keyboard.next()) {
    if (Keyboard.getEventKeyState()) {
        switch (Keyboard.getEventKey()) {
            // case Keyboard.KEY_UP: /** do something here **/ break;
        }
    }
}

edited Jun 29 '12 at 15:36

James Webster

31,873
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answered Jun 29 '12 at 15:28

Oskar

1,321
9
19

KeyHeart · Answer 3 · 2012-06-08T21:03:12.403

import org.lwjgl.input.Keyboard;

public class InputHandler {

public static boolean currentKeyState = true, previousKeyState;

public static void update() {
    previousKeyState = currentKeyState;

    if (Keyboard.getEventKeyState()) {
        currentKeyState = true;
    } else {
        previousKeyState = false;
    }
}

public static boolean keyPressed() {
    if (currentKeyState == true && previousKeyState == true) {
        return true;
    } else {
        return false;
    }
}

}

score -1 · Answer 4 · answered Jun 08 '12 at 09:40

-1

You can use java KeyEvent Class for this

answered Jun 08 '12 at 09:40

Pramod Kumar

7,914
5
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he is asking for LWJGL... where I doubt java KeyEvent will have a key role to play... they must be having their own api better suited for their needs(gaming). – AurA Jun 08 '12 at 09:42

How can I check keyboard for a single press?

4 Answers4