pocketmine\entity\Item::onUpdate PHP Method

    public function onUpdate($currentTick)
    {
        if ($this->closed) {
            return false;
        }
        $this->age++;
        $tickDiff = $currentTick - $this->lastUpdate;
        if ($tickDiff <= 0 and !$this->justCreated) {
            return true;
        }
        $this->lastUpdate = $currentTick;
        $this->timings->startTiming();
        $hasUpdate = $this->entityBaseTick($tickDiff);
        if ($this->isAlive()) {
            if ($this->pickupDelay > 0 and $this->pickupDelay < 32767) {
                //Infinite delay
                $this->pickupDelay -= $tickDiff;
                if ($this->pickupDelay < 0) {
                    $this->pickupDelay = 0;
                }
            }
            $this->motionY -= $this->gravity;
            if ($this->checkObstruction($this->x, $this->y, $this->z)) {
                $hasUpdate = true;
            }
            $this->move($this->motionX, $this->motionY, $this->motionZ);
            $friction = 1 - $this->drag;
            if ($this->onGround and (abs($this->motionX) > 1.0E-5 or abs($this->motionZ) > 1.0E-5)) {
                $friction = $this->getLevel()->getBlock($this->temporalVector->setComponents((int) floor($this->x), (int) floor($this->y - 1), (int) floor($this->z) - 1))->getFrictionFactor() * $friction;
            }
            $this->motionX *= $friction;
            $this->motionY *= 1 - $this->drag;
            $this->motionZ *= $friction;
            if ($this->onGround) {
                $this->motionY *= -0.5;
            }
            if ($currentTick % 5 == 0) {
                $this->updateMovement();
            }
            if ($this->age > 2000) {
                $this->server->getPluginManager()->callEvent($ev = new ItemDespawnEvent($this));
                if ($ev->isCancelled()) {
                    $this->age = 0;
                } else {
                    $this->kill();
                    $hasUpdate = true;
                }
            }
        }
        $this->timings->stopTiming();
        return $hasUpdate or !$this->onGround or abs($this->motionX) > 1.0E-5 or abs($this->motionY) > 1.0E-5 or abs($this->motionZ) > 1.0E-5;
    }