/* The list of transparent blocks, put this in a constructor somewhere... */

private HashSet<Material> transparentBlocks = new HashSet<Material>();

transparentBlocks.add(Material.AIR);
/* Misc */
transparentBlocks.add(Material.CAKE_BLOCK);

/* Redstone Material */
transparentBlocks.add(Material.REDSTONE);
transparentBlocks.add(Material.REDSTONE_WIRE);

/* Redstone Torches */
transparentBlocks.add(Material.REDSTONE_TORCH_OFF);
transparentBlocks.add(Material.REDSTONE_TORCH_ON);

/* Diodes (Repeaters) */
transparentBlocks.add(Material.DIODE_BLOCK_OFF);
transparentBlocks.add(Material.DIODE_BLOCK_ON);

/* Power Sources */
transparentBlocks.add(Material.DETECTOR_RAIL);
transparentBlocks.add(Material.LEVER);
transparentBlocks.add(Material.STONE_BUTTON);
transparentBlocks.add(Material.WOOD_BUTTON);
transparentBlocks.add(Material.STONE_PLATE);
transparentBlocks.add(Material.WOOD_PLATE);

/* Nature Material */
transparentBlocks.add(Material.RED_MUSHROOM);
transparentBlocks.add(Material.BROWN_MUSHROOM);

transparentBlocks.add(Material.RED_ROSE);
transparentBlocks.add(Material.YELLOW_FLOWER);

transparentBlocks.add(Material.FLOWER_POT);

/* Greens */
transparentBlocks.add(Material.LONG_GRASS);
transparentBlocks.add(Material.VINE);
transparentBlocks.add(Material.WATER_LILY);

/* Seedy things */
transparentBlocks.add(Material.MELON_STEM);
transparentBlocks.add(Material.PUMPKIN_STEM);
transparentBlocks.add(Material.CROPS);
transparentBlocks.add(Material.NETHER_WARTS);

/* Semi-nature */
transparentBlocks.add(Material.SNOW);
transparentBlocks.add(Material.FIRE);
transparentBlocks.add(Material.WEB);
transparentBlocks.add(Material.TRIPWIRE);
transparentBlocks.add(Material.TRIPWIRE_HOOK);

/* Stairs */
transparentBlocks.add(Material.COBBLESTONE_STAIRS);
transparentBlocks.add(Material.BRICK_STAIRS);
transparentBlocks.add(Material.SANDSTONE_STAIRS);
transparentBlocks.add(Material.NETHER_BRICK_STAIRS);
transparentBlocks.add(Material.SMOOTH_STAIRS);

/* Wood Stairs */
transparentBlocks.add(Material.BIRCH_WOOD_STAIRS);
transparentBlocks.add(Material.WOOD_STAIRS);
transparentBlocks.add(Material.JUNGLE_WOOD_STAIRS);
transparentBlocks.add(Material.SPRUCE_WOOD_STAIRS);

/* Lava & Water */
transparentBlocks.add(Material.LAVA);
transparentBlocks.add(Material.STATIONARY_LAVA);
transparentBlocks.add(Material.WATER);
transparentBlocks.add(Material.STATIONARY_WATER);

/* Saplings and bushes */
transparentBlocks.add(Material.SAPLING);
transparentBlocks.add(Material.DEAD_BUSH);

/* Construction Material */
/* Fences */
transparentBlocks.add(Material.FENCE);
transparentBlocks.add(Material.FENCE_GATE);
transparentBlocks.add(Material.IRON_FENCE);
transparentBlocks.add(Material.NETHER_FENCE);

/* Ladders, Signs */
transparentBlocks.add(Material.LADDER);
transparentBlocks.add(Material.SIGN);
transparentBlocks.add(Material.SIGN_POST);
transparentBlocks.add(Material.WALL_SIGN);

/* Bed */
transparentBlocks.add(Material.BED_BLOCK);
transparentBlocks.add(Material.BED);

/* Pistons */
transparentBlocks.add(Material.PISTON_EXTENSION);
transparentBlocks.add(Material.PISTON_MOVING_PIECE);
transparentBlocks.add(Material.RAILS);

/* Torch & Trapdoor */
transparentBlocks.add(Material.TORCH);
transparentBlocks.add(Material.TRAP_DOOR);



/* The method to check for transparent blocks */
/**
 * @param playerLoc The location of the player's eye (Eg. Player.getEyeLocation() or Player.getLocation().add(0,1.62,0))
 * @return The dispenser they're looking at, or null if they aren't looking at one.
 */
public Block getDispenser(Location playerLoc){
    Block c;
    BlockIterator bIt = new BlockIterator(loc, 0, 5); //'5' is the distance to search for in blocks.  Apparently this gets pretty inaccurate after a lot of blocks.
    while(bIt.hasNext()){
        c = bIt.next();
        if(c.getType() == Material.DISPENSER){
            return c; //Success
        }
        if(plugin.getTransparentBlocks().contains(c.getType())){
            continue;
        }
        else{
            return null; //They're not looking at a dispenser block!
        }
    }

    return null; //There's no dispenser
}