Tripwire Hook

A tripwire hook is a block that can be used to detect entities (players, mobs, items, etc.) when part of a tripwire circuit.

Phases
Tripwire hook has three phases. They are:
 * Folded Phase: This phase is the initial phase of a Tripwire Hook when it is placed at the beginning.
 * Straight Phase: This phase appears when two tripwires are connected in a horizontal line with a tripwire (placeable string).
 * Downward Phase: This phase appears when an object (mobs like hostile mobs and non-hostile mobs) touch the tripwire that is connected between two tripwire hooks connected in a horizontal line with a tripwire (placeable string). A charged or '1' signal is generated when it is in this downward phase.

Breaking
To remove a tripwire hook, it. Tripwire hooks can be broken instantly using any tool, or without a tool.

A tripwire hook will also be removed and drop itself as an item if:
 * its attachment block is moved, removed, or destroyed
 * water flows into its space
 * a piston tries to push it or moves a block into its space

A tripwire hook will be destroyed without dropping itself as an item if lava flows into its space.

Fishing
Tripwire hooks can be obtained as a "junk" item from fishing.

Natural generation
Four tripwire hooks are generated naturally in each jungle temple.

Usage
Tripwire hooks can be used as crafting ingredients or as redstone components.

Crafting ingredient
Tripwire hooks can be used to craft trapped chests.

Redstone component
A tripwire hook can be used to detect mobs, items, and other entities over a large area.


 * Placement


 * To place a tripwire hook, use the control.


 * A tripwire hook can be attached to the side of any full solid opaque block.


 * In order to function correctly, a tripwire hook must be part of a "tripwire circuit": a straight line of blocks consisting of a block with a tripwire hook attached to it, a "tripwire line" (1 to 40 blocks of tripwire), and a second tripwire hook attached to another block.


 * To place tripwire, right-click on an adjacent block with a string. Until 1.9, tripwire can be placed "on the ground" or "in the air", and will only form a valid tripwire line if all the tripwire is of the same type. Tripwire is considered on the ground if placed on any opaque block, or on a block of redstone, a hopper, an upside-down slab, or an upside-down stairs. Tripwire is considered in the air if placed on any other block, or above air. Valid tripwire lines will not form directly over flowing water.


 * Tripwire on the ground has a short hitbox (0.125 blocks high), while tripwire in the air has a taller hitbox (0.5 blocks high).


 * If the attachment block under ground tripwire is removed, the tripwire will be destroyed and drop itself as string.


 * A tripwire circuit is placed correctly when the tripwire hooks are fully extended and the tripwire line runs continuously between the tripwire hooks. Tripwire lines from separate tripwire circuits can be placed next to each other (in parallel), above each other, and can even intersect each other.


 * Activation


 * A tripwire hook in a valid tripwire circuit activates when certain entities (players, mobs, items, etc.) intersect the tripwire hook's tripwire line "hit box" (but not the tripwire hook itself), and deactivates when all entities leave or are removed from the tripwire line.


 * Entities which will not activate a tripwire circuit include: thrown potions, some arrows, thrown ender pearls, and thrown eyes of ender.


 * A tripwire hook also activates for 5 redstone ticks (0.5 seconds, barring lag) when any of its tripwires are destroyed, except when shears are used to destroy the tripwire.


 * Breaking the tripwire hook, or the block it is attached to, does not generate a pulse.


 * Behavior


 * While active, a tripwire hook:
 * powers any adjacent redstone dust to power level 15, including beneath the tripwire hook
 * powers any adjacent redstone comparators or redstone repeaters facing away from the tripwire hook to power level 15
 * strongly powers its attachment block to power level 15
 * activates any adjacent mechanism components, including above or below, such as pistons, redstone lamps, etc.


 * Tripwire produces no power itself.


 * Although destroying tripwire with shears will not activate a tripwire hook, it will change the tripwire hook's block data (from "connected" to not "connected") which can be detected with a block update detector (BUD). In addition, every time a tripwire hook receives a block tick (a random update that occurs in up to three block in each chunk section every game tick, and on average affects any particular block every 47 seconds), the tripwire hook and its attachment block will produce a redstone update which can also be detected with a BUD.

Data values
A tripwire hook has an ID name of  and is further defined by its block data. A tripwire hook also has a block state which is expected to replace the functionality of block data in a future version.

Block data
A tripwire hook's block data stores its orientation, connection status, and activation status: