I am currently trying to implement a keylistener in my program so that it does an action when I pressed an arrow key, the object in my program either moves left or right.
Here is the moving method in my program
public void moveDirection(KeyEvent e)
{
int move = 0;
int r = K.getRow();
int c = K.getCol();
if (e.getKeyCode() == 39) move = 1; //KeyEvent.VK_RIGHT
if (e.getKeyCode() == 37) move = 2; //KeyEvent.VK_LEFT
//if (e.getKeyCode() == KeyEvent.VK_DOWN) move = 3;
switch (move)
{
case 1: if (inBound(r, c+1))
K.setLocation(r ,c+1);
if (inBound(r, c-1) && frame2[r][c-1] == K)
frame2[K.getRow()][K.getCol()-1] = null;
break; //move right 39
case 2: K.setLocation(K.getRow(), K.getCol()-1); break; //move left 37
//case 3: b.setLocation(b.getRow()+1, b.getCol()); break; //move down
default: return;
}
processBlockList();
}
I am wondering how the program is supposed to read in (KeyEvent) e. I cannot really type in an arrowkey....
Please help!
edit: I also need to know what I need to add to my code so that my program waits about 700 milliseconds for a keyinput before moving on to another method
A Simple KeyListener Java ClassCreate a new KeyListener object. Override the methods that correspond to the key events you want to monitor e.g keyPressed , keyReleased , keyTyped . Create a JTextField component. Use it's addKeyListener method to add to it the KeyListener you've created.
Interface KeyListenerThe listener interface for receiving keyboard events (keystrokes). The class that is interested in processing a keyboard event either implements this interface (and all the methods it contains) or extends the abstract KeyAdapter class (overriding only the methods of interest).
The KeyListener interface is found in java. awt. event package, and it has three methods.
Methods of Java KeyListener The following are the commonly used methods: KeyPresses(KeyEventev): This method will be invoked when Key is pressed. KeyReleased(KeyEventev): This method will be invoked when a key is released. KeyTyped(KeyEventev): This method will be invoked when Key is typed.
http://docs.oracle.com/javase/tutorial/uiswing/events/keylistener.html Check this tutorial
If it's a UI based application , then " I also need to know what I need to add to my code so that my program waits about 700 milliseconds for a keyinput before moving on to another method" you can use GlassPane or Timer class to fulfill the requirement.
For key Event:
public void keyPressed(KeyEvent e) {
int key = e.getKeyCode();
if (key == KeyEvent.VK_LEFT) {
dx = -1;
}
if (key == KeyEvent.VK_RIGHT) {
dx = 1;
}
if (key == KeyEvent.VK_UP) {
dy = -1;
}
if (key == KeyEvent.VK_DOWN) {
dy = 1;
}
}
check this game example http://zetcode.com/tutorials/javagamestutorial/movingsprites/
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