Added piston retract event listener (#32)

* Check all blocks moved by piston instead of only one.

* Added retract event listener

src/main/java/com/derongan/minecraft/deeperworld/synchronization/SectionSyncListener.kt

@@ -57,15 +57,21 @@ object SectionSyncListener : Listener {
  updateCorrespondingBlock(location, updateBlockData)
  }
 
-
- /** Disables pistons if they are in the overlap of two sections */
+ /** Disables pistons extending if they are in the overlap of two sections */
  @EventHandler
- fun onPistonEvent(event: BlockPistonExtendEvent) {
+ fun onPistonExtendEvent(event: BlockPistonExtendEvent) {
  //TODO handle pistons properly instead of just cancelling the event
  if (event.blocks.any { it.location.correspondingSection != null })
  event.isCancelled = true
  }
 
+ /** Disables pistons retracting if they are in the overlap of two sections */
+ @EventHandler
+ fun onPistonRetractEvent(event: BlockPistonRetractEvent) {
+ if (event.blocks.any { it.location.correspondingSection != null })
+ event.isCancelled = true
+ }
+
  @EventHandler
  fun onWaterEmptyEvent(event: PlayerBucketEmptyEvent) =
  updateCorrespondingBlock(event.block.location) { orig, corr ->