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Thread: key input handler

  1. #1
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    Default key input handler

    import java.awt.Canvas;
    import java.awt.Color;
    import java.awt.Dimension;
    import java.awt.Graphics;
    import java.awt.event.KeyEvent;
    import java.awt.image.BufferStrategy;
     
    import javax.swing.JFrame;
     
    public class Main extends Canvas implements Runnable {
     
    	private static final long serialVersionUID = 1L;
    	public boolean running = false;
    	public int width;
    	public int height;
    	public Thread thread;
        inputHandler input;
     
    	public Main(int width, int height) {
     
    		this.width = width;
    		this.height = height;
     
    		Dimension size = new Dimension(width, height);
    		setPreferredSize(size);
    		setMinimumSize(size);
    		setMaximumSize(size);
     
    		input = new inputHandler();
    		addKeyListener(input);
     
    	}
     
    	private void init() {
     
     
    	}
     
    	public synchronized void start() {
    		thread = new Thread(this, "main thread");
    		running = true;
    		thread.start();
    	}
     
    	public void run() {
    		while (running) {
    			render();
    			update();
    		}
    	}
     
    	public void render() {
    		BufferStrategy bs = this.getBufferStrategy();
    		if (bs == null) {
    			createBufferStrategy(2);
    			return;
    		}
    		Graphics g = bs.getDrawGraphics();
    		g.setColor(Color.black);
    		g.fillRect(0, 0, getWidth(), getHeight());
    		g.dispose();
    		bs.show();
    	}
     
    	public void update() {
    		System.out.println(input.keys[KeyEvent.VK_UP]);
    	}
     
    	public static void main(String[] args) {
    		Main main = new Main(640, 480);
    		JFrame window = new JFrame();
    		window.add(main);
    		window.pack();
    		window.setVisible(true);
    		window.setResizable(false);
    		window.setTitle("buffer Strategy test");
    		window.setLocationRelativeTo(null);
    		window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
     
    		main.start();
    	}
    }

    import java.awt.event.KeyEvent;
    import java.awt.event.KeyListener;
     
     
    public class inputHandler implements KeyListener {
     
    	public boolean keys[] = new boolean[65536];
     
    	public void keyPressed(KeyEvent e) {
    		int keycode = e.getKeyCode();
    		keys[keycode] = true;
    	}
     
    	public void keyReleased(KeyEvent e) {
    		int keycode = e.getKeyCode();
    		keys[keycode] = false;
    	}
     
    	public void keyTyped(KeyEvent e) {
     
    	}
    }

    please note this is not my code i am following a youtube tutorial. so basicaly im trying to use booleans to save the key strokes as true using the key event method getKeyCode() rather than using many if statements to what key has been pressed. when i put a system println in my update method telling it to print the boolean value of the key up it is constantly false even if i press it. thanks


  2. #2
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    Default Re: key input handler

    please note this is not my code i am following a youtube tutorial
    My first thought is to ditch the code as well as the tutorial. There is a lot that is incorrect - mixing Swing and AWT, not following the Single threaded model of Swing/AWT, naming conventions are incorrect (and very close to clashing with the naming of the API methods)...all this being said, I do not see where the listener is ever created/instantiated

  3. The Following User Says Thank You to copeg For This Useful Post:

    DanielJamesCollier (May 2nd, 2012)

  4. #3
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    Default Re: key input handler

    how would you recomend i learn, by reading the oracle tutorials ? thanks

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    Default Re: key input handler

    Quote Originally Posted by DanielJamesCollier View Post
    how would you recomend i learn, by reading the oracle tutorials ? thanks
    Yes. They can seem overwhelming, so here's my advice for a beginner - read through them at a high level. Get an idea of the different GUI components available, the different types of listeners you can use to interact with those components (ActionListener, MouseListener, etc...), and options available for customization (Layouts, Borders, etc...). You do not need to know how to code them at that point - just what you could do. Then when it comes down to writing code for a specific project, break the problem down and get into the specifics of the tutorials for each problem.
    Trail: Creating a GUI With JFC/Swing: Table of Contents (The Java™ Tutorials)

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