Simple plugin that applies gravity to blocks when they are placed or update. A example of a block update could be a Leaf decaying, an explosion or when you place or break an adjacent block. Use the Whitelist or blacklist to control what blocks are affected and choose how much clearance is required before gravity is applied.

Features:

Apply gravity to blocks when they update or just when they are placed.
Blacklist a block type or list of block types to avoid gravity.
Whitelist a block type or list of block types to ONLY apply gravity to.
Control who gravity applies to with permissions. (When "only-on-place" = true)
Choose how much clearance is required before a block can fall.
Choose which Worlds gravity will be applied to.

Commands:

None

Permissions:

gravity.apply - (Only required when config option "only-on-place" is set to true. v0.6+)

Configurations:

drop-item: true/false - Allow items to drop if a block falls to an invalid location. For example onto a torch.
clearance: 1 to 256 - The number of air blocks below the block before gravity is applied. v0.6+
only-on-place: true/false - If true gravity will only apply to the block that was placed. v0.6+
blacklist: true/false - Enable this to list block types you DO NOT want gravity to apply.
blacklist-blocks: If blacklist is set to true the Material names in this list will avoid gravity.
whitelist: true/false - Enable this to list block types you want gravity to apply.
whitelist-blocks: If whitelist is set to true only the Material names on this list will have gravity.
enabled-worlds: A list of World names that you want gravity to apply.

Default config.yml

drop-item: true
only-on-place: false
clearance: 1
blacklist: false
blacklist-blocks:
- STONE
- NETHERRACK
- NETHER_BRICK
- ENDER_STONE
- LEAVES
- LEAVES_2
- BEDROCK
- JUKEBOX
- CAULDRON
- ENDER_PORTAL  (IMPORTANT)
- ENDER_PORTAL_FRAME  (IMPORTANT)
whitelist: true
whitelist-blocks:
- LOG
- GOLD_BLOCK
enabled-worlds:
- world
- world_nether
- world_the_end

Disabled blocks:

Blocks which already have gravity like sand gravel and Dragon Eggs.
Any Block with a stored inventory like a Chest, Furnace or Brewing Stand.
Blocks with stored data like a Sign.

Compatibility:

Minecraft Versions 1.3.* to 1.7.* and possibly future Versions.

TODO:

~~Add permissions.~~ v0.2
~~Add a config blacklist to list the blocks NOT to apply gravity to.~~ v0.4
~~Add a config whitelist to list the blocks to apply gravity to.~~ v0.5
~~Add a config option to allow items to not drop if they land on a transparent block.~~ v0.3
~~Apply gravity to all blocks, not just the block placed.~~ v0.6
~~Apply gravity to only Worlds listed in config option "enabled-worlds".~~ v0.7
~~Remove the use of block ID's and instead use the~~ Material names.v0.6
Limit the number of blocks falling at once, to prevent possible client or server crashes due to common blocks.

Notes:

For logging plugins such as LogBlock, the event is not cancelled but will be recorded as if the player placed an air block.

WARNING! Applying gravity to common blocks can cause client lag or World corruption. For example Bedrock or Stone could cause the world to collapse causing a huge number of block updates. Some blocks can cause unexpected behavior, for example ENDER_PORTAL and ENDER_PORTAL_FRAME blocks can cause server crashes so please exclude this block.

Bold text = New feature or change

Video Showcase:

Gravity