/**
* Update the lastState property. Should ideally be called on each World.act(), or at least before
* getState() in a frame where mouse info is wanted.
*/
public void act() {
MouseInfo mouseinfo = Greenfoot.getMouseInfo();
/* To-be properties of MouseState */
boolean held = lastState.held;
boolean down = false;
boolean up = false;
boolean moved;
Vector position;
if (mouseinfo != null) {
/* Get the new mouse position */
position = new Vector(mouseinfo.getX(), mouseinfo.getY());
/* We have moved if there is a difference between this mouse position and
* the previous mouse position. */
moved = lastState.position == null || position.subtract(lastState.position).length() > 0.5;
} else {
/* mouseinfo == null */
/* Use the previous mouse position */
position = lastState.position;
/* We haven't moved the mouse pointer. */
moved = false;
}
if (lastState.held) {
/* Figure out if the mouse has been released. This has to be done
* differently on Mac OS X, as MouseInfo contains different info in case
* of mouse release on that platform. */
if (System.getProperty("os.name").equals("Mac OS X")) {
if (Greenfoot.mouseClicked(null)
|| mouseinfo != null
&& (mouseinfo.getActor() != concerning || mouseinfo.getButton() != 1)) {
up = true;
held = false;
}
} else {
/* TODO: Check if this behaves correctly in Windows */
if (Greenfoot.mouseClicked(concerning)
|| mouseinfo != null
&& (mouseinfo.getActor() != concerning || mouseinfo.getButton() != 0)) {
up = true;
held = false;
}
}
} else {
/* !lastState.held */
/* Figure out if mouse has been pressed. This is thankfully
* cross-platform consistent. */
if (Greenfoot.mousePressed(concerning)) {
down = true;
held = true;
}
}
/* Store the state in the lastState property. */
lastState = new MouseState(held, down, up, moved, position);
}
