Add an event for shard updates

Add an event in the EventHandler to be called when a shard updates its
Connection Stage.

3 files changed, 43 insertions, 3 deletions

diff --git a/src/client/bridge/gateway/event.rs b/src/client/bridge/gateway/event.rs
new file mode 100644
index 0000000..a967ab5
--- /dev/null
+++ b/src/client/bridge/gateway/event.rs
@@ -0,0 +1,29 @@
+//! A collection of events created by the client, not a part of the Discord API
+//! itself.
+
+use super::ShardId;
+use ::gateway::ConnectionStage;
+
+#[derive(Clone, Debug)]
+pub(crate) enum ClientEvent {
+    ShardStageUpdate(ShardStageUpdateEvent),
+}
+
+/// An event denoting that a shard's connection stage was changed.
+///
+/// # Examples
+///
+/// This might happen when a shard changes from [`ConnectionStage::Identifying`]
+/// to [`ConnectionStage::Connected`].
+///
+/// [`ConnectionStage::Connected`]: ../../../../gateway/enum.ConnectionStage.html#variant.Connected
+/// [`ConnectionStage::Identifying`]: ../../../../gateway/enum.ConnectionStage.html#variant.Identifying
+#[derive(Clone, Debug)]
+pub struct ShardStageUpdateEvent {
+    /// The new connection stage.
+    pub new: ConnectionStage,
+    /// The old connection stage.
+    pub old: ConnectionStage,
+    /// The ID of the shard that had its connection stage change.
+    pub shard_id: ShardId,
+}
diff --git a/src/client/bridge/gateway/mod.rs b/src/client/bridge/gateway/mod.rs
index 5c9ec69..23d2864 100644
--- a/src/client/bridge/gateway/mod.rs
+++ b/src/client/bridge/gateway/mod.rs
@@ -47,6 +47,8 @@
 //! [`ShardQueuer`]: struct.ShardQueuer.html
 //! [`ShardRunner`]: struct.ShardRunner.html
 
+pub mod event;
+
 mod shard_manager;
 mod shard_manager_monitor;
 mod shard_messenger;
diff --git a/src/client/bridge/gateway/shard_runner.rs b/src/client/bridge/gateway/shard_runner.rs
index 7c6cf83..8781149 100644
--- a/src/client/bridge/gateway/shard_runner.rs
+++ b/src/client/bridge/gateway/shard_runner.rs
@@ -6,7 +6,9 @@ use parking_lot::Mutex;
 use serde::Deserialize;
 use std::sync::mpsc::{self, Receiver, Sender, TryRecvError};
 use std::sync::Arc;
-use super::super::super::{EventHandler, dispatch};
+use super::super::super::dispatch::{DispatchEvent, dispatch};
+use super::super::super::EventHandler;
+use super::event::{ClientEvent, ShardStageUpdateEvent};
 use super::{ShardClientMessage, ShardId, ShardManagerMessage, ShardRunnerMessage};
 use threadpool::ThreadPool;
 use typemap::ShareMap;
@@ -149,6 +151,13 @@ impl<H: EventHandler + Send + Sync + 'static> ShardRunner<H> {
 
             if post != pre {
                 self.update_manager();
+
+                let e = ClientEvent::ShardStageUpdate(ShardStageUpdateEvent {
+                    new: post,
+                    old: pre,
+                    shard_id: ShardId(self.shard.shard_info()[0]),
+                });
+                self.dispatch(DispatchEvent::Client(e));
             }
 
             match action {
@@ -162,7 +171,7 @@ impl<H: EventHandler + Send + Sync + 'static> ShardRunner<H> {
             }
 
             if let Some(event) = event {
-                self.dispatch(event);
+                self.dispatch(DispatchEvent::Model(event));
             }
 
             if !successful && !self.shard.stage().is_connecting() {
@@ -222,7 +231,7 @@ impl<H: EventHandler + Send + Sync + 'static> ShardRunner<H> {
     }
 
     #[inline]
-    fn dispatch(&self, event: Event) {
+    fn dispatch(&self, event: DispatchEvent) {
         dispatch(
             event,
             #[cfg(feature = "framework")]