nobreakdelay

// We're inside the PlayerInteractEvent, make sure to check if event.getAction() is LEFT_CLICK_BLOCK or whatever it's called

/*
 * NoBreakDelay
 */

if (!player.getGameMode().equals(GameMode.CREATIVE)) {

    // Make sure that the currently clicked block and the last destroyed block aren't blocks that you can destroy instantly or almost instantly
    if (event.getClickedBlock() != null && stats.getLastBlock() != null && Useful.isSemiSolid(event.getClickedBlock()) && Useful.isSolid(stats.getLastBlock())) {

        // Get the difference of now and the last broken block time
        // Pretty much results in the time from breaking the last block and clicking a new block
        double diff = System.currentTimeMillis() - stats.getBlockDestroyHook();

        DelayCheck:
        if (diff <= 50) {

            // Make sure his item doesn't have efficiency
            // I believe the Haste Potion effect alone does not create false positives, but you might want to double check that
            ItemStack hand = player.getItemInHand();
            if (hand != null) {
                if (hand.containsEnchantment(Enchantment.DIG_SPEED) && hand.getEnchantmentLevel(Enchantment.DIG_SPEED) >= 3) {
                    break DelayCheck;
                }
            }

            // Threshold stuff
            stats.setClickDelayLevel(stats.getClickDelayLevel() + 5);
            if (stats.getClickDelayLevel() > 10) {

                // DangerLevel stuff
                stats.setBuildDangerLevel(stats.getBuildDangerLevel() + 50);
                if (stats.getBuildDangerLevel() > 200) {
                    stats.setBlockDestroying(1000);
                }
                getOwner().alert(player, player.getName() + ": Tried to click block too quickly after breaking another one (" + diff + ")", null, AlertPriority.LOW, stats.getBuildDangerLevel(), DetectionType.CLICK_DELAY);
                event.setCancelled(true);
                stats.setClickDelayLevel(10);
            }
        }
    }
}