CODEWITHSUNDEEP
javakeyevent
tygzy
tygzy

Reputation: 716

Java how to use KeyEvent

I am trying to make a game at the moment and I am having trouble finding out how to make the player go faster by pressing shift at the same time.

Here's some of my code:

public void keyPressed(KeyEvent e) {
    int key = e.getKeyCode();

    for(int i = 0; i < handler.object.size(); i++) {
        GameObject tempObject = handler.object.get(i);

        if(tempObject.getId() == ID.Player) {
            //key events for player 1
            if(key == KeyEvent.VK_W) tempObject.setVelY(-5);
            if(key == KeyEvent.VK_S) tempObject.setVelY(5);
            if(key == KeyEvent.VK_A) tempObject.setVelX(-5);
            if(key == KeyEvent.VK_D) tempObject.setVelX(5);
            if(key == KeyEvent.VK_W && key == KeyEvent.VK_SHIFT) tempObject.setVelY(-8);
            if(key == KeyEvent.VK_S && key == KeyEvent.VK_SHIFT) tempObject.setVelY(8);
            if(key == KeyEvent.VK_A && key == KeyEvent.VK_SHIFT) tempObject.setVelX(-8);
            if(key == KeyEvent.VK_D && key == KeyEvent.VK_SHIFT) tempObject.setVelX(8);
        }
    }
    if(key == KeyEvent.VK_ESCAPE) System.exit(1);
}

public void keyReleased(KeyEvent e) {
    int key = e.getKeyCode();

    for(int i = 0; i < handler.object.size(); i++) {
        GameObject tempObject = handler.object.get(i);

        if(tempObject.getId() == ID.Player) {
            if(key == KeyEvent.VK_W) tempObject.setVelY(-0);
            if(key == KeyEvent.VK_S) tempObject.setVelY(0);
            if(key == KeyEvent.VK_A) tempObject.setVelX(-0);
            if(key == KeyEvent.VK_D) tempObject.setVelX(0);
            if(key == KeyEvent.VK_W && key == KeyEvent.VK_SHIFT) tempObject.setVelY(-0);
            if(key == KeyEvent.VK_S && key == KeyEvent.VK_SHIFT) tempObject.setVelY(0);
            if(key == KeyEvent.VK_A && key == KeyEvent.VK_SHIFT) tempObject.setVelX(-0);
            if(key == KeyEvent.VK_D && key == KeyEvent.VK_SHIFT) tempObject.setVelX(0);
        }
    }
}

Now all this works but doesn't change the velX to 7 to 5.

Upvotes: 1

Views: 1649

Answers (1)

Cpp plus 1
Cpp plus 1

Reputation: 1010

Two keys cannot actually be pressed at the same time. The keyPressed() method is actually being called twice (once for a letter button, and once for shift). To check whether or not shift is pressed, set a global boolean value to the state of the shift press and manage the variable's state with keyPressed and keyReleased. For example:

public boolean shiftPressed;

public void keyPressed(KeyEvent e) {
    if(shiftPressed && e.getKeyCode() == VK_(a letter)) {
        //Execute some code
    }
    else if(e.getKeyCode() == VK_SHIFT) {
        shiftPressed = true;
    }
}

public void keyReleased(KeyEvent e) {
    if(e.getKeyCode() == VK_SHIFT) {
        shiftPressed = false;
    }
}

Upvotes: 4

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