Multiple Key Press

[rob starteren]

Trying to figure out the animation framework in Java and i managed to get a box to move around a JFrame.

I can move up down left and right using the arrow keys. How can i tell the box to move diagonally up without using a new key.

So how do i know if the user pressed the up and right key at the same time to make the box move diagonally up to the right?

if(evt.getKeyCode()==39)
{
posX ++;
direction="right";
}
else if((evt.getKeyCode()==38))
{
posY --;
direction="down";
}


else if((evt.getKeyCode()==40))
{
posY ++;
direction="up";
}
else if((evt.getKeyCode()==37))
{
posX --;
direction="left";
}

System.out.println(evt.getKeyCode());

Because if i hold up and right at the same time it just registers that as 2 single events. Any ideas?

[Rob Spoor]

You already found out that it is two events. So in between those two events, you should keep track of all relevant key presses.

In this case:

private int horizontal; // -1 for left, 0 for nothing, 1 for right
private int vertical; // -1 for up, 0 for nothing, 1 for down

public void keyPressed(KeyEvent e)
{
    switch (e.getKeyCode())
    {
        case KeyEvent.VK_LEFT:
            horizontal--; // will make horizontal == 0 if RIGHT was already pressed
            break;
        case KeyEvent.VK_RIGHT:
            horizontal++;
            break;
        case KeyEvent.VK_UP:
            vertical--;
            break;
        case KeyEvent.VK_DOWN:
            vertical++;
            break;
    }
}

public void keyReleased(KeyEvent e)
{
    switch (e.getKeyCode())
    {
        case KeyEvent.VK_LEFT:
            horizontal++; // will make horizontal == 1 if RIGHT was already pressed
            break;
        case KeyEvent.VK_RIGHT:
            horizontal--;
            break;
        case KeyEvent.VK_UP:
            vertical++;
            break;
        case KeyEvent.VK_DOWN:
            vertical--;
            break;
    }
}

if (horizontal < 0 && vertical && 0) // up and left
// etc