refactor: major client code changes

This does away with `lazy_static` singletons for all the clients, instead putting them all inside a `Clients` struct on the `Ironbar` struct.

Client code has been refactored in places to accommodate this, and module code has been updated to get the clients the new way.

The Wayland client has been re-written from the ground up to remove a lot of the needless complications, provide a nicer interface and reduce some duplicate data.

The MPD music client has been overhauled to use the `mpd_utils` crate, which simplifies the code within Ironbar and should offer more robustness and better recovery when connection is lost to the server.

The launcher module in particular has been affected by the refactor.

src/clients/wayland/wlr_data_control/mod.rs

@@ -6,8 +6,8 @@ pub mod source;
 use self::device::{DataControlDeviceDataExt, DataControlDeviceHandler};
 use self::offer::{DataControlDeviceOffer, DataControlOfferHandler, SelectionOffer};
 use self::source::DataControlSourceHandler;
-use crate::clients::wayland::Environment;
-use crate::{lock, send, Ironbar};
+use super::{Client, Environment, Event, Request, Response};
+use crate::{lock, try_send, Ironbar};
 use device::DataControlDevice;
 use glib::Bytes;
 use nix::fcntl::{fcntl, F_GETPIPE_SZ, F_SETPIPE_SZ};
@@ -21,22 +21,28 @@ use std::io::{ErrorKind, Read, Write};
 use std::os::fd::{AsRawFd, OwnedFd, RawFd};
 use std::sync::Arc;
 use std::{fs, io};
+use tokio::sync::broadcast;
 use tracing::{debug, error, trace};
 use wayland_client::{Connection, QueueHandle};
 use wayland_protocols_wlr::data_control::v1::client::zwlr_data_control_source_v1::ZwlrDataControlSourceV1;
 
 const INTERNAL_MIME_TYPE: &str = "x-ironbar-internal";
 
+#[derive(Debug)]
 pub struct SelectionOfferItem {
     offer: SelectionOffer,
     token: Option<RegistrationToken>,
 }
 
+/// Represents a value which can be read/written
+/// to/from the system clipboard and surrounding metadata.
+///
+/// Can be cheaply cloned.
 #[derive(Debug, Clone, Eq)]
 pub struct ClipboardItem {
     pub id: usize,
-    pub value: ClipboardValue,
-    pub mime_type: String,
+    pub value: Arc<ClipboardValue>,
+    pub mime_type: Arc<str>,
 }
 
 impl PartialEq<Self> for ClipboardItem {
@@ -108,24 +114,60 @@ impl MimeType {
     }
 }
 
-impl Environment {
-    pub fn copy_to_clipboard(&mut self, item: Arc<ClipboardItem>, qh: &QueueHandle<Self>) {
-        debug!("Copying item to clipboard: {item:?}");
-
-        // TODO: Proper device tracking
-        let device = self.data_control_devices.first();
-        if let Some(device) = device {
-            let source = self
-                .data_control_device_manager_state
-                .create_copy_paste_source(qh, [INTERNAL_MIME_TYPE, item.mime_type.as_str()]);
-
-            source.set_selection(&device.device);
-            self.copy_paste_sources.push(source);
-
-            lock!(self.clipboard).replace(item);
+impl Client {
+    /// Gets the current clipboard item,
+    /// if this exists and Ironbar has record of it.
+    pub fn clipboard_item(&self) -> Option<ClipboardItem> {
+        match self.send_request(Request::ClipboardItem) {
+            Response::ClipboardItem(item) => item,
+            _ => unreachable!(),
         }
     }
 
+    /// Copies the provided value to the system clipboard.
+    pub fn copy_to_clipboard(&self, item: ClipboardItem) {
+        match self.send_request(Request::CopyToClipboard(item)) {
+            Response::Ok => (),
+            _ => unreachable!(),
+        }
+    }
+
+    /// Subscribes to the system clipboard,
+    /// receiving all new copied items.
+    pub fn subscribe_clipboard(&self) -> broadcast::Receiver<ClipboardItem> {
+        self.clipboard_channel.0.subscribe()
+    }
+}
+
+impl Environment {
+    /// Creates a new copy/paste source on the
+    /// seat's data control device.
+    ///
+    /// This provides it as an offer,
+    /// which the compositor will then treat as the current copied value.
+    pub fn copy_to_clipboard(&mut self, item: ClipboardItem) {
+        debug!("Copying item to clipboard: {item:?}");
+
+        let seat = self.default_seat();
+        let Some(device) = self
+            .data_control_devices
+            .iter()
+            .find(|entry| entry.seat == seat)
+        else {
+            return;
+        };
+
+        let source = self
+            .data_control_device_manager_state
+            .create_copy_paste_source(&self.queue_handle, [INTERNAL_MIME_TYPE, &item.mime_type]);
+
+        source.set_selection(&device.device);
+        self.copy_paste_sources.push(source);
+
+        lock!(self.clipboard).replace(item);
+    }
+
+    /// Reads an offer file handle into a new `ClipboardItem`.
     fn read_file(mime_type: &MimeType, file: &mut File) -> io::Result<ClipboardItem> {
         let value = match mime_type.category {
             MimeTypeCategory::Text => {
@@ -145,13 +187,15 @@ impl Environment {
 
         Ok(ClipboardItem {
             id: Ironbar::unique_id(),
-            value,
-            mime_type: mime_type.value.clone(),
+            value: Arc::new(value),
+            mime_type: mime_type.value.clone().into(),
         })
     }
 }
 
 impl DataControlDeviceHandler for Environment {
+    /// Called when an offer for a new value is received
+    /// (ie something has copied to the clipboard)
     fn selection(
         &mut self,
         _conn: &Connection,
@@ -175,15 +219,16 @@ impl DataControlDeviceHandler for Environment {
                 .last_mut()
                 .expect("Failed to get current offer");
 
+            // clear prev
             let Some(mime_type) = MimeType::parse_multiple(&mime_types) else {
                 lock!(self.clipboard).take();
                 // send an event so the clipboard module is aware it's changed
-                send!(
-                    self.clipboard_tx,
-                    Arc::new(ClipboardItem {
+                try_send!(
+                    self.event_tx,
+                    Event::Clipboard(ClipboardItem {
                         id: usize::MAX,
-                        mime_type: String::new(),
-                        value: ClipboardValue::Other
+                        mime_type: String::new().into(),
+                        value: Arc::new(ClipboardValue::Other)
                     })
                 );
                 return;
@@ -192,7 +237,7 @@ impl DataControlDeviceHandler for Environment {
             if let Ok(read_pipe) = cur_offer.offer.receive(mime_type.value.clone()) {
                 let offer_clone = cur_offer.offer.clone();
 
-                let tx = self.clipboard_tx.clone();
+                let tx = self.event_tx.clone();
                 let clipboard = self.clipboard.clone();
 
                 let token =
@@ -207,9 +252,8 @@ impl DataControlDeviceHandler for Environment {
 
                             match Self::read_file(&mime_type, file.get_mut()) {
                                 Ok(item) => {
-                                    let item = Arc::new(item);
                                     lock!(clipboard).replace(item.clone());
-                                    send!(tx, item);
+                                    try_send!(tx, Event::Clipboard(item));
                                 }
                                 Err(err) => error!("{err:?}"),
                             }
@@ -255,6 +299,8 @@ impl DataControlSourceHandler for Environment {
         debug!("Accepted mime type: {mime:?}");
     }
 
+    /// Writes the current clipboard item to 'paste' it
+    /// upon request from a compositor client.
     fn send_request(
         &mut self,
         _conn: &Connection,
@@ -274,12 +320,12 @@ impl DataControlSourceHandler for Environment {
             {
                 trace!("Source found, writing to file");
 
-                let mut bytes = match &item.value {
+                let mut bytes = match item.value.as_ref() {
                     ClipboardValue::Text(text) => text.as_bytes(),
                     ClipboardValue::Image(bytes) => bytes.as_ref(),
                     ClipboardValue::Other => panic!(
                         "{:?}",
-                        io::Error::new(ErrorKind::Other, "Attempted to copy unsupported mime type",)
+                        io::Error::new(ErrorKind::Other, "Attempted to copy unsupported mime type")
                     ),
                 };