inventory client events (#66)

* finish packet definition for ClickContainer

* add CloseScreen client event

* add DropItem client event

* add SetSlotCreative client event

* implement ClientEvent::CloseScreen

* ClientEvent::DropItem

* implement ClientEvent::SetSlotCreative

* cargo fmt

* add inventory_piano example to demo inventory slot click events

* lints

* implement ClickContainer event

* inventory_piano: deduplicate note playing logic

* add DropItemStack client event

* implement ClientEvent::DropItemStack

* adjust logging

* tweak inventory_piano example, send text to chat instead of stdout

* fix lint

* move Slot outside of protocol module

* avoid cloning slot in ClickContainer packet handler

* fix inventory_piano example

examples/inventory_piano.rs

@@ -0,0 +1,249 @@
+use std::net::SocketAddr;
+use std::sync::atomic::{AtomicUsize, Ordering};
+
+use log::LevelFilter;
+use num::Integer;
+use valence::block::BlockState;
+use valence::chunk::{Chunk, UnloadedChunk};
+use valence::client::{handle_event_default, Client, ClientEvent, GameMode};
+use valence::config::{Config, ServerListPing};
+use valence::dimension::{Dimension, DimensionId};
+use valence::entity::{Entity, EntityId, EntityKind};
+use valence::player_list::PlayerListId;
+use valence::protocol::packets::c2s::play::ClickContainerMode;
+use valence::protocol::packets::s2c::play::SoundCategory;
+use valence::server::{Server, SharedServer, ShutdownResult};
+use valence::slot::SlotId;
+use valence::text::{Color, TextFormat};
+use valence::{async_trait, ident};
+
+pub fn main() -> ShutdownResult {
+    env_logger::Builder::new()
+        .filter_module("valence", LevelFilter::Trace)
+        .parse_default_env()
+        .init();
+
+    valence::start_server(
+        Game {
+            player_count: AtomicUsize::new(0),
+        },
+        ServerState { player_list: None },
+    )
+}
+
+struct Game {
+    player_count: AtomicUsize,
+}
+
+struct ServerState {
+    player_list: Option<PlayerListId>,
+}
+
+#[derive(Default)]
+struct ClientState {
+    entity_id: EntityId,
+}
+
+const MAX_PLAYERS: usize = 10;
+
+const SIZE_X: usize = 100;
+const SIZE_Z: usize = 100;
+
+const SLOT_MIN: SlotId = 36;
+const SLOT_MAX: SlotId = 43;
+const PITCH_MIN: f32 = 0.5;
+const PITCH_MAX: f32 = 1.0;
+
+#[async_trait]
+impl Config for Game {
+    type ServerState = ServerState;
+    type ClientState = ClientState;
+    type EntityState = ();
+    type WorldState = ();
+    type ChunkState = ();
+    type PlayerListState = ();
+
+    fn max_connections(&self) -> usize {
+        // We want status pings to be successful even if the server is full.
+        MAX_PLAYERS + 64
+    }
+
+    fn dimensions(&self) -> Vec<Dimension> {
+        vec![Dimension {
+            fixed_time: Some(6000),
+            ..Dimension::default()
+        }]
+    }
+
+    async fn server_list_ping(
+        &self,
+        _server: &SharedServer<Self>,
+        _remote_addr: SocketAddr,
+        _protocol_version: i32,
+    ) -> ServerListPing {
+        ServerListPing::Respond {
+            online_players: self.player_count.load(Ordering::SeqCst) as i32,
+            max_players: MAX_PLAYERS as i32,
+            player_sample: Default::default(),
+            description: "Hello Valence!".color(Color::AQUA),
+            favicon_png: Some(include_bytes!("../assets/logo-64x64.png").as_slice().into()),
+        }
+    }
+
+    fn init(&self, server: &mut Server<Self>) {
+        let world = server.worlds.insert(DimensionId::default(), ()).1;
+        server.state.player_list = Some(server.player_lists.insert(()).0);
+
+        // initialize chunks
+        for chunk_z in -2..Integer::div_ceil(&(SIZE_Z as i32), &16) + 2 {
+            for chunk_x in -2..Integer::div_ceil(&(SIZE_X as i32), &16) + 2 {
+                world.chunks.insert(
+                    [chunk_x as i32, chunk_z as i32],
+                    UnloadedChunk::default(),
+                    (),
+                );
+            }
+        }
+
+        // initialize blocks in the chunks
+        for chunk_x in 0..Integer::div_ceil(&SIZE_X, &16) {
+            for chunk_z in 0..Integer::div_ceil(&SIZE_Z, &16) {
+                let chunk = world
+                    .chunks
+                    .get_mut((chunk_x as i32, chunk_z as i32))
+                    .unwrap();
+                for x in 0..16 {
+                    for z in 0..16 {
+                        let cell_x = chunk_x * 16 + x;
+                        let cell_z = chunk_z * 16 + z;
+
+                        if cell_x < SIZE_X && cell_z < SIZE_Z {
+                            chunk.set_block_state(x, 63, z, BlockState::GRASS_BLOCK);
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    fn update(&self, server: &mut Server<Self>) {
+        let (world_id, _) = server.worlds.iter_mut().next().unwrap();
+
+        let spawn_pos = [SIZE_X as f64 / 2.0, 1.0, SIZE_Z as f64 / 2.0];
+
+        server.clients.retain(|_, client| {
+            if client.created_this_tick() {
+                if self
+                    .player_count
+                    .fetch_update(Ordering::SeqCst, Ordering::SeqCst, |count| {
+                        (count < MAX_PLAYERS).then_some(count + 1)
+                    })
+                    .is_err()
+                {
+                    client.disconnect("The server is full!".color(Color::RED));
+                    return false;
+                }
+
+                match server
+                    .entities
+                    .insert_with_uuid(EntityKind::Player, client.uuid(), ())
+                {
+                    Some((id, _)) => client.state.entity_id = id,
+                    None => {
+                        client.disconnect("Conflicting UUID");
+                        return false;
+                    }
+                }
+
+                client.spawn(world_id);
+                client.set_flat(true);
+                client.teleport(spawn_pos, 0.0, 0.0);
+                client.set_player_list(server.state.player_list.clone());
+
+                if let Some(id) = &server.state.player_list {
+                    server.player_lists.get_mut(id).insert(
+                        client.uuid(),
+                        client.username(),
+                        client.textures().cloned(),
+                        client.game_mode(),
+                        0,
+                        None,
+                    );
+                }
+
+                client.set_game_mode(GameMode::Creative);
+                client.send_message(
+                    "Welcome to Valence! Open your inventory, and click on your hotbar to play \
+                     the piano."
+                        .italic(),
+                );
+                client.send_message(
+                    "Click the rightmost hotbar slot to toggle between creative and survival."
+                        .italic(),
+                );
+            }
+
+            if client.is_disconnected() {
+                self.player_count.fetch_sub(1, Ordering::SeqCst);
+                server.entities.remove(client.state.entity_id);
+                if let Some(id) = &server.state.player_list {
+                    server.player_lists.get_mut(id).remove(client.uuid());
+                }
+                return false;
+            }
+
+            let player = server.entities.get_mut(client.state.entity_id).unwrap();
+
+            if client.position().y <= -20.0 {
+                client.teleport(spawn_pos, client.yaw(), client.pitch());
+            }
+
+            while let Some(event) = handle_event_default(client, player) {
+                match event {
+                    ClientEvent::CloseScreen { .. } => {
+                        client.send_message("Done already?");
+                    }
+                    ClientEvent::SetSlotCreative { slot_id, .. } => {
+                        client.send_message(format!("{:#?}", event));
+                        // If the user does a double click, 3 notes will be played.
+                        // This is not possible to fix :(
+                        play_note(client, player, slot_id);
+                    }
+                    ClientEvent::ClickContainer { slot_id, mode, .. } => {
+                        client.send_message(format!("{:#?}", event));
+                        if mode != ClickContainerMode::Click {
+                            // Prevent notes from being played twice if the user clicks quickly
+                            continue;
+                        }
+                        play_note(client, player, slot_id);
+                    }
+                    _ => {}
+                }
+            }
+
+            true
+        });
+    }
+}
+
+fn play_note(client: &mut Client<Game>, player: &mut Entity<Game>, clicked_slot: SlotId) {
+    if (SLOT_MIN..=SLOT_MAX).contains(&clicked_slot) {
+        let pitch = (clicked_slot - SLOT_MIN) as f32 * (PITCH_MAX - PITCH_MIN)
+            / (SLOT_MAX - SLOT_MIN) as f32
+            + PITCH_MIN;
+        client.send_message(format!("playing note with pitch: {}", pitch));
+        client.play_sound(
+            ident!("block.note_block.harp"),
+            SoundCategory::Block,
+            player.position(),
+            10.0,
+            pitch,
+        );
+    } else if clicked_slot == 44 {
+        client.set_game_mode(match client.game_mode() {
+            GameMode::Survival => GameMode::Creative,
+            GameMode::Creative => GameMode::Survival,
+            _ => GameMode::Creative,
+        });
+    }
+}

src/client.rs

@@ -40,6 +40,7 @@ use crate::protocol::packets::s2c::play::{
 use crate::protocol::{BoundedInt, BoundedString, ByteAngle, NbtBridge, RawBytes, VarInt};
 use crate::server::{C2sPacketChannels, NewClientData, S2cPlayMessage, SharedServer};
 use crate::slab_versioned::{Key, VersionedSlab};
+use crate::slot::Slot;
 use crate::text::Text;
 use crate::util::{chunks_in_view_distance, is_chunk_in_view_distance};
 use crate::world::{WorldId, Worlds};
@@ -232,6 +233,9 @@ pub struct Client<C: Config> {
     /// The data for the client's own player entity.
     player_data: Player,
     entity_events: Vec<entity::EntityEvent>,
+    /// The item currently being held by the client's cursor in an inventory
+    /// screen. Does not work for creative mode.
+    cursor_held_item: Slot,
 }
 
 #[bitfield(u16)]
@@ -301,6 +305,7 @@ impl<C: Config> Client<C> {
                 .with_created_this_tick(true),
             player_data: Player::new(),
             entity_events: Vec::new(),
+            cursor_held_item: Slot::Empty,
         }
     }
 
@@ -769,8 +774,39 @@ impl<C: Config> Client<C> {
             }
             C2sPlayPacket::CommandSuggestionsRequest(_) => {}
             C2sPlayPacket::ClickContainerButton(_) => {}
-            C2sPlayPacket::ClickContainer(_) => {}
+            C2sPlayPacket::ClickContainer(p) => {
-            C2sPlayPacket::CloseContainerC2s(_) => {}
+                if p.slot_idx == -999 {
+                    // client is trying to drop the currently held stack
+                    let held = std::mem::replace(&mut self.cursor_held_item, Slot::Empty);
+                    match held {
+                        Slot::Empty => {}
+                        Slot::Present {
+                            item_id,
+                            item_count,
+                            nbt,
+                        } => self.events.push_back(ClientEvent::DropItemStack {
+                            item_id,
+                            item_count,
+                            nbt,
+                        }),
+                    }
+                } else {
+                    self.cursor_held_item = p.carried_item.clone();
+                    self.events.push_back(ClientEvent::ClickContainer {
+                        window_id: p.window_id,
+                        state_id: p.state_id,
+                        slot_id: p.slot_idx,
+                        mode: p.mode,
+                        slot_changes: p.slots,
+                        carried_item: p.carried_item,
+                    });
+                }
+            }
+            C2sPlayPacket::CloseContainerC2s(c) => {
+                self.events.push_back(ClientEvent::CloseScreen {
+                    window_id: c.window_id,
+                })
+            }
             C2sPlayPacket::PluginMessageC2s(_) => {}
             C2sPlayPacket::EditBook(_) => {}
             C2sPlayPacket::QueryEntityTag(_) => {}
@@ -895,7 +931,7 @@ impl<C: Config> Client<C> {
                         face: p.face,
                     },
                     play::DiggingStatus::DropItemStack => return,
-                    play::DiggingStatus::DropItem => return,
+                    play::DiggingStatus::DropItem => ClientEvent::DropItem,
                     play::DiggingStatus::ShootArrowOrFinishEating => return,
                     play::DiggingStatus::SwapItemInHand => return,
                 });
@@ -929,7 +965,30 @@ impl<C: Config> Client<C> {
             C2sPlayPacket::SetHeldItemS2c(_) => {}
             C2sPlayPacket::ProgramCommandBlock(_) => {}
             C2sPlayPacket::ProgramCommandBlockMinecart(_) => {}
-            C2sPlayPacket::SetCreativeModeSlot(_) => {}
+            C2sPlayPacket::SetCreativeModeSlot(e) => {
+                if e.slot == -1 {
+                    // The client is trying to drop a stack of items
+                    match e.clicked_item {
+                        Slot::Empty => log::warn!(
+                            "Invalid packet, creative client tried to drop a stack of nothing."
+                        ),
+                        Slot::Present {
+                            item_id,
+                            item_count,
+                            nbt,
+                        } => self.events.push_back(ClientEvent::DropItemStack {
+                            item_id,
+                            item_count,
+                            nbt,
+                        }),
+                    }
+                } else {
+                    self.events.push_back(ClientEvent::SetSlotCreative {
+                        slot_id: e.slot,
+                        slot: e.clicked_item,
+                    })
+                }
+            }
             C2sPlayPacket::ProgramJigsawBlock(_) => {}
             C2sPlayPacket::ProgramStructureBlock(_) => {}
             C2sPlayPacket::UpdateSign(_) => {}

src/client/event.rs

@@ -1,5 +1,6 @@
 use std::time::Duration;
 
+use serde_nbt::Compound;
 use vek::Vec3;
 
 use super::Client;
@@ -7,11 +8,13 @@ use crate::block_pos::BlockPos;
 use crate::config::Config;
 use crate::entity::types::Pose;
 use crate::entity::{Entity, EntityEvent, EntityId, TrackedData};
+use crate::protocol::packets::c2s::play::ClickContainerMode;
 pub use crate::protocol::packets::c2s::play::{
     BlockFace, ChatMode, DisplayedSkinParts, Hand, MainHand, ResourcePackC2s as ResourcePackStatus,
 };
 pub use crate::protocol::packets::s2c::play::GameMode;
 use crate::protocol::VarInt;
+use crate::slot::{Slot, SlotId};
 
 /// Represents an action performed by a client.
 ///
@@ -129,6 +132,49 @@ pub enum ClientEvent {
         sequence: VarInt,
     },
     ResourcePackStatusChanged(ResourcePackStatus),
+    /// The client closed a screen. This occurs when the client closes their
+    /// inventory, closes a chest inventory, etc.
+    CloseScreen {
+        window_id: u8,
+    },
+    /// The client is attempting to drop 1 of the currently held item.
+    DropItem,
+    /// The client is attempting to drop a stack of items.
+    ///
+    /// If the client is in creative mode, the items come from the void, so it
+    /// is safe to trust the contents of this event. Otherwise, you may need to
+    /// do some validation to make sure items are actually coming from the
+    /// user's inventory.
+    DropItemStack {
+        // TODO: maybe we could add `from_slot_id` to make validation easier
+        item_id: VarInt,
+        item_count: u8,
+        nbt: Option<Compound>,
+    },
+    /// The client is in creative mode, and is trying to set it's inventory slot
+    /// to a value.
+    SetSlotCreative {
+        /// The slot number that the client is trying to set.
+        slot_id: SlotId,
+        /// The contents of the slot.
+        slot: Slot,
+    },
+    /// The client is in survival mode, and is trying to modify an inventory.
+    ClickContainer {
+        window_id: u8,
+        state_id: VarInt,
+        /// The slot that was clicked
+        slot_id: SlotId,
+        /// The type of click that the user performed
+        mode: ClickContainerMode,
+        /// A list of slot ids and what their contents should be set to.
+        ///
+        /// It's not safe to blindly trust the contents of this. Servers need to
+        /// validate it if they want to prevent item duping.
+        slot_changes: Vec<(SlotId, Slot)>,
+        /// The item that is now being carried by the user's cursor
+        carried_item: Slot,
+    },
 }
 
 #[derive(Clone, PartialEq, Debug)]
@@ -287,6 +333,11 @@ pub fn handle_event_default<C: Config>(
         ClientEvent::Digging { .. } => {}
         ClientEvent::InteractWithBlock { .. } => {}
         ClientEvent::ResourcePackStatusChanged(_) => {}
+        ClientEvent::CloseScreen { .. } => {}
+        ClientEvent::DropItem => {}
+        ClientEvent::DropItemStack { .. } => {}
+        ClientEvent::SetSlotCreative { .. } => {}
+        ClientEvent::ClickContainer { .. } => {}
     }
 
     entity.set_world(client.world());

src/lib.rs

@@ -109,6 +109,7 @@ pub mod server;
 mod slab;
 mod slab_rc;
 mod slab_versioned;
+pub mod slot;
 pub mod spatial_index;
 pub mod text;
 pub mod util;

src/protocol.rs

@@ -12,7 +12,6 @@ pub use byte_angle::ByteAngle;
 use byteorder::{BigEndian, ReadBytesExt, WriteBytesExt};
 use serde::de::DeserializeOwned;
 use serde::Serialize;
-pub use slot::Slot;
 use uuid::Uuid;
 pub use var_int::VarInt;
 pub use var_long::VarLong;
@@ -24,7 +23,6 @@ use crate::nbt;
 mod byte_angle;
 pub mod codec;
 pub mod packets;
-mod slot;
 mod var_int;
 mod var_long;
 

src/protocol/packets.rs

@@ -20,9 +20,10 @@ use crate::block_pos::BlockPos;
 use crate::ident::Ident;
 use crate::nbt::Compound;
 use crate::protocol::{
-    BoundedArray, BoundedInt, BoundedString, ByteAngle, Decode, Encode, NbtBridge, RawBytes, Slot,
+    BoundedArray, BoundedInt, BoundedString, ByteAngle, Decode, Encode, NbtBridge, RawBytes,
     VarInt, VarLong,
 };
+use crate::slot::Slot;
 use crate::text::Text;
 
 /// Provides the name of a packet for debugging purposes.

src/protocol/packets/c2s.rs

@@ -255,10 +255,13 @@ pub mod play {
             slot_idx: i16,
             button: i8,
             mode: ClickContainerMode,
+            slots: Vec<(i16, Slot)>,
+            carried_item: Slot,
         }
     }
 
     def_enum! {
+        #[derive(Copy, PartialEq, Eq)]
         ClickContainerMode: VarInt {
             Click = 0,
             ShiftClick = 1,

src/slot.rs

@@ -5,6 +5,8 @@ use byteorder::ReadBytesExt;
 use crate::nbt::Compound;
 use crate::protocol::{Decode, Encode, VarInt};
 
+pub type SlotId = i16;
+
 /// Represents a slot in an inventory.
 #[derive(Clone, Default, Debug)]
 pub enum Slot {