Mouse input help

Newbie & Debugging Questions
#1

Hi all, im new to java programming and creating 2d games.
i am currently trying to make a space invaders game, i have it working as i intended it to.
Only prob i have now is how do i use the mouse in the game.

i want to have the mouse cursor as my aim/cross hair but i have no idea how i would do this.
my plan is to have the users use the mouse to target their enemies and then click to fire at the enemy.

i have searched for 2 days now trying to look for simple examples that explain how i could implement this in my game but i have had no luck so far. If this has been discussed already i am really sorry, i did search on the forum several times and cant find anything that helps me.

Thank you in advance for any help or advice you may have to assist me

Bongklerz

#2

One method (possibly not the best) would be to enable mouse events in your contructor

		enableEvents(AWTEvent.MOUSE_EVENT_MASK);
		enableEvents(AWTEvent.MOUSE_MOTION_EVENT_MASK);

And then override the processEvent method. My method is geared towards a tile-based board game, but it should give you a place to start.

	protected void processEvent(AWTEvent evt) {
		MouseEvent mevt = (MouseEvent)evt;
		int y = mevt.getY();
		int x = mevt.getX();
		if (x < leftBorder || y < topBorder || x >= rightBorder || y >= bottomBorder) {
			return;
		}
		switch (evt.getID()) {
			case MouseEvent.MOUSE_PRESSED:
				pressedX = x;
				pressedY = y;
				break;
			case MouseEvent.MOUSE_RELEASED:
				if (pressedX == x && pressedY == y) {
					if (splash) {
					} else {
						if (board[x][y].owner() == Tile.EMPTY) {
							placeTile(x,y);
							repaint();
						}
					}
				}
				break;
			case MouseEvent.MOUSE_CLICKED:
				if (splash) {
				} else {
					if (board[x][y].owner() == Tile.EMPTY) {
						placeTile(x,y);
						repaint();
					}
				}
				break;
			case MouseEvent.MOUSE_MOVED:
			case MouseEvent.MOUSE_DRAGGED:
				if (mevt.getX() <= leftBorder || x >= rightBorder) {
					x = -1;
				}
				if (mevt.getY() <= topBorder || y >= bottomBorder) {
					y = -1;
				}
				if (x != highlightX || y != highlightY) {
					highlightX = x;
					highlightY = y;
					repaint();
				}
				break;
			default:
				super.processEvent(evt);
		}
	}
#3

I wouldn’t recommend doing that except for 4k competitions. The “correct” way to do it is to add a MouseListener and a MouseMotionListener to the relevant component. This is covered in Sun’s Java Tutorial as part of the section on event listeners in Swing:
http://java.sun.com/docs/books/tutorial/uiswing/events/index.html
http://java.sun.com/docs/books/tutorial/uiswing/events/mouselistener.html
http://java.sun.com/docs/books/tutorial/uiswing/events/mousemotionlistener.html