gistfile1.m

- (void) handlePan:(UIPanGestureRecognizer *) gesture {
    if ((gesture.state == UIGestureRecognizerStateChanged) ||
        (gesture.state == UIGestureRecognizerStateEnded)) {
        
        CGPoint location = [gesture locationInView:[self.tableView superview]];
        
        if (location.x <= (_tableView.frame.size.width / 2) + 40) {
            if (location.x < _tableView.frame.size.width / 2-70 && isFilterViewShowing)
                [self.tableView setFrame:CGRectMake(location.x, 0, _tableView.frame.size.width, _tableView.frame.size.height)];
            else if (location.x < _tableView.frame.size.width / 2 + 40) 
                [self.tableView setFrame:CGRectMake(location.x, 0, _tableView.frame.size.width, _tableView.frame.size.height)];
            if (location.x > 0) {
                [self.navigationItem.leftBarButtonItem setAction:@selector(hideFilterMenu)];
            }
            else if (location.x == 0) {
                [self.navigationItem.leftBarButtonItem setAction:@selector(showFilterMenu)];
            }
        }
        isFilterViewShowing = location.x > 0;
    }
}