#include "Bullet.h"

#include <QTimer>

#include <QGraphicsScene>

#include <QList>

#include "Enemy.h"

#include "Game.h"

extern Game * game; // there is an external global object called game

Bullet::Bullet(QGraphicsItem *parent): QObject(), QGraphicsPixmapItem(parent){

// draw graphics

setPixmap(QPixmap(":/images/bullet.png"));

// make/connect a timer to move() the bullet every so often

QTimer * timer = new QTimer(this);

connect(timer,SIGNAL(timeout()),this,SLOT(move()));

// start the timer

timer->start(50);

}

void Bullet::move(){

// get a list of all the items currently colliding with this bullet

QList<QGraphicsItem *> colliding_items = collidingItems();

// if one of the colliding items is an Enemy, destroy both the bullet and the enemy

for (int i = 0, n = colliding_items.size(); i < n; ++i){

if (typeid(*(colliding_items[i])) == typeid(Enemy)){

// increase the score

game->score->increase();

// remove them from the scene (still on the heap)

scene()->removeItem(colliding_items[i]);

scene()->removeItem(this);

// delete them from the heap to save memory

delete colliding_items[i];

delete this;

// return (all code below refers to a non existint bullet)

return;

}

}

// if there was no collision with an Enemy, move the bullet forward

setPos(x(),y()-10);

// if the bullet is off the screen, destroy it

if (pos().y() < 0){

scene()->removeItem(this);

delete this;

}

}