- (void) panned:(UIPanGestureRecognizer *) recognizer {
    if (waitForSomething) {
        // cancel or reset the recognizer!
        // because the next event should be UIGestureRecognizerStateBegan and not UIGestureRecognizerStateChanged
        return;
    }

    switch (recognizer.state) {
        case UIGestureRecognizerStateBegan:
            // important initialisation code
            break;

        case UIGestureRecognizerStateChanged:
            // do something
            break;
    }
}

if (waitForSomething) {
    recognizer.enabled = NO;
    recognizer.enabled = YES;
    return;
}