feat(wm): add monitor reconciliator module

This commit adds the monitor_reconciliator module which uses a tightly
bounded channel (cap: 1) to handle monitor connection and disconnection
events, as well as resolution and work area change events.

Before, all this logic lived in a the WindowManager.reconcile_monitors
function, which ran on pretty much every process_event iteration, and
sometimes led to undesirable behaviour, but now the logic is split up to
only run when the appropriate notifications are dispatched from the
hidden window which listens for monitor and display-related events.

The monitor cache has been moved out of WindowManager and into the
monitor_reconciliator module, and in addition to the previous behaviour
of attempting to cache monitors which had been identified as
disconnected, now when the static configuration file is loaded, if the
user has set display_index_preferences, the device IDs will be used to
pre-populate the cache for the event where a known monitor is connected
later in a session.

The monitor cache itself now uses the unique device ID as a key rather
than the hmonitor which is known to be inconsistent.

This commit also delegates all display monitor-related Win32 calls to
the "win32-display-data" crate, which was extracted from the larger
"brightness" crate for its use in komorebi.

As a result of these changes, "device" and "device_id" on Monitor have
been changed from Option<String> to String types, as failures in
retrieving these values with directly attached monitors has not been
possible to reproduce. However, it remains to be seen if this will
adversely impact users who use display docks which may prevent display
monitor device IDs from being read and stored by the operating system.

WindowManagerEvent::DisplayChange has been removed in favour of
the monitor_reconciliator::Notification enum, as these events are no
longer being handled in process_events.

Attempts are now made to eagerly update hmonitors both within the
monitor_reconciliator loop on DisplayConnectionChange notifications and
when failing to find a matching hmonitor in functions like
monitor_idx_from_current_pos and monitor_idx_from_window.

Cargo.lock

@@ -833,6 +833,15 @@ version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7655c9839580ee829dfacba1d1278c2b7883e50a277ff7541299489d6bdfdc45"
 
+[[package]]
+name = "itertools"
+version = "0.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ba291022dbbd398a455acf126c1e341954079855bc60dfdda641363bd6922569"
+dependencies = [
+ "either",
+]
+
 [[package]]
 name = "itoa"
 version = "1.0.11"
@@ -882,6 +891,7 @@ dependencies = [
  "uds_windows",
  "which",
  "widestring",
+ "win32-display-data",
  "windows 0.54.0",
  "windows-implement",
  "windows-interface",
@@ -2465,6 +2475,16 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7219d36b6eac893fa81e84ebe06485e7dcbb616177469b142df14f1f4deb1311"
 
+[[package]]
+name = "win32-display-data"
+version = "0.1.0"
+source = "git+https://github.com/LGUG2Z/win32-display-data#2c47b9f1ca1f359ba2481d0b6ea8667ccd9d075c"
+dependencies = [
+ "itertools",
+ "thiserror",
+ "windows 0.54.0",
+]
+
 [[package]]
 name = "winapi"
 version = "0.3.9"

komorebi/Cargo.toml

@@ -48,5 +48,7 @@ windows-interface = { workspace = true }
 winput = "0.2"
 winreg = "0.52"
 
+win32-display-data = { git = "https://github.com/LGUG2Z/win32-display-data" }
+
 [features]
 deadlock_detection = []

komorebi/src/hidden.rs

@@ -1,75 +0,0 @@
-use std::sync::atomic::Ordering;
-
-use color_eyre::Result;
-use windows::core::PCWSTR;
-use windows::Win32::Foundation::HWND;
-use windows::Win32::UI::WindowsAndMessaging::DispatchMessageW;
-use windows::Win32::UI::WindowsAndMessaging::FindWindowW;
-use windows::Win32::UI::WindowsAndMessaging::GetMessageW;
-use windows::Win32::UI::WindowsAndMessaging::CS_HREDRAW;
-use windows::Win32::UI::WindowsAndMessaging::CS_VREDRAW;
-use windows::Win32::UI::WindowsAndMessaging::MSG;
-use windows::Win32::UI::WindowsAndMessaging::WNDCLASSW;
-
-use crate::windows_callbacks;
-use crate::WindowsApi;
-use crate::HIDDEN_HWND;
-
-#[derive(Debug, Clone, Copy)]
-pub struct Hidden {
-    pub(crate) hwnd: isize,
-}
-
-impl From<isize> for Hidden {
-    fn from(hwnd: isize) -> Self {
-        Self { hwnd }
-    }
-}
-
-impl Hidden {
-    pub const fn hwnd(self) -> HWND {
-        HWND(self.hwnd)
-    }
-
-    pub fn create(name: &str) -> Result<()> {
-        let name: Vec<u16> = format!("{name}\0").encode_utf16().collect();
-        let instance = WindowsApi::module_handle_w()?;
-        let class_name = PCWSTR(name.as_ptr());
-        let brush = WindowsApi::create_solid_brush(0);
-        let window_class = WNDCLASSW {
-            hInstance: instance.into(),
-            lpszClassName: class_name,
-            style: CS_HREDRAW | CS_VREDRAW,
-            lpfnWndProc: Some(windows_callbacks::hidden_window),
-            hbrBackground: brush,
-            ..Default::default()
-        };
-
-        let _atom = WindowsApi::register_class_w(&window_class)?;
-
-        let name_cl = name.clone();
-        std::thread::spawn(move || -> Result<()> {
-            let hwnd = WindowsApi::create_hidden_window(PCWSTR(name_cl.as_ptr()), instance)?;
-            let hidden = Self::from(hwnd);
-
-            let mut message = MSG::default();
-
-            unsafe {
-                while GetMessageW(&mut message, hidden.hwnd(), 0, 0).into() {
-                    DispatchMessageW(&message);
-                }
-            }
-
-            Ok(())
-        });
-
-        let mut hwnd = HWND(0);
-        while hwnd == HWND(0) {
-            hwnd = unsafe { FindWindowW(PCWSTR(name.as_ptr()), PCWSTR::null()) };
-        }
-
-        HIDDEN_HWND.store(hwnd.0, Ordering::SeqCst);
-
-        Ok(())
-    }
-}

komorebi/src/lib.rs

@@ -4,8 +4,8 @@ pub mod com;
 pub mod ring;
 pub mod colour;
 pub mod container;
-pub mod hidden;
 pub mod monitor;
+pub mod monitor_reconciliator;
 pub mod process_command;
 pub mod process_event;
 pub mod process_movement;
@@ -33,13 +33,11 @@ use std::path::PathBuf;
 use std::process::Command;
 use std::sync::atomic::AtomicBool;
 use std::sync::atomic::AtomicI32;
-use std::sync::atomic::AtomicIsize;
 use std::sync::atomic::AtomicU32;
 use std::sync::atomic::Ordering;
 use std::sync::Arc;
 
 pub use colour::*;
-pub use hidden::*;
 pub use process_command::*;
 pub use process_event::*;
 pub use stackbar::*;
@@ -217,8 +215,6 @@ pub static SESSION_ID: AtomicU32 = AtomicU32::new(0);
 
 pub static REMOVE_TITLEBARS: AtomicBool = AtomicBool::new(false);
 
-pub static HIDDEN_HWND: AtomicIsize = AtomicIsize::new(0);
-
 pub static STACKBAR_FOCUSED_TEXT_COLOUR: AtomicU32 = AtomicU32::new(16777215); // white
 pub static STACKBAR_UNFOCUSED_TEXT_COLOUR: AtomicU32 = AtomicU32::new(11776947); // gray text
 pub static STACKBAR_TAB_BACKGROUND_COLOUR: AtomicU32 = AtomicU32::new(3355443); // gray

komorebi/src/main.rs

@@ -24,8 +24,8 @@ use tracing_subscriber::layer::SubscriberExt;
 use tracing_subscriber::EnvFilter;
 
 use komorebi::border_manager;
-use komorebi::hidden::Hidden;
 use komorebi::load_configuration;
+use komorebi::monitor_reconciliator;
 use komorebi::process_command::listen_for_commands;
 use komorebi::process_command::listen_for_commands_tcp;
 use komorebi::process_event::listen_for_events;
@@ -188,8 +188,6 @@ fn main() -> Result<()> {
     #[cfg(feature = "deadlock_detection")]
     detect_deadlocks();
 
-    Hidden::create("komorebi-hidden")?;
-
     let static_config = opts.config.map_or_else(
         || {
             let komorebi_json = HOME_DIR.join("komorebi.json");
@@ -257,6 +255,7 @@ fn main() -> Result<()> {
 
     border_manager::listen_for_notifications(wm.clone());
     workspace_reconciliator::listen_for_notifications(wm.clone());
+    monitor_reconciliator::listen_for_notifications(wm.clone())?;
 
     let (ctrlc_sender, ctrlc_receiver) = crossbeam_channel::bounded(1);
     ctrlc::set_handler(move || {

komorebi/src/monitor.rs

@@ -27,9 +27,9 @@ pub struct Monitor {
     #[getset(get = "pub", set = "pub")]
     name: String,
     #[getset(get = "pub", set = "pub")]
-    device: Option<String>,
+    device: String,
     #[getset(get = "pub", set = "pub")]
-    device_id: Option<String>,
+    device_id: String,
     #[getset(get = "pub", set = "pub")]
     size: Rect,
     #[getset(get = "pub", set = "pub")]
@@ -50,15 +50,22 @@ pub struct Monitor {
 
 impl_ring_elements!(Monitor, Workspace);
 
-pub fn new(id: isize, size: Rect, work_area_size: Rect, name: String) -> Monitor {
+pub fn new(
+    id: isize,
+    size: Rect,
+    work_area_size: Rect,
+    name: String,
+    device: String,
+    device_id: String,
+) -> Monitor {
     let mut workspaces = Ring::default();
     workspaces.elements_mut().push_back(Workspace::default());
 
     Monitor {
         id,
         name,
-        device: None,
-        device_id: None,
+        device,
+        device_id,
         size,
         work_area_size,
         work_area_offset: None,

komorebi/src/monitor_reconciliator/hidden.rs

@@ -0,0 +1,190 @@
+use std::sync::mpsc;
+
+use windows::core::PCWSTR;
+use windows::Win32::Foundation::HWND;
+use windows::Win32::Foundation::LPARAM;
+use windows::Win32::Foundation::LRESULT;
+use windows::Win32::Foundation::WPARAM;
+use windows::Win32::UI::WindowsAndMessaging::DefWindowProcW;
+use windows::Win32::UI::WindowsAndMessaging::DispatchMessageW;
+use windows::Win32::UI::WindowsAndMessaging::GetMessageW;
+use windows::Win32::UI::WindowsAndMessaging::TranslateMessage;
+use windows::Win32::UI::WindowsAndMessaging::CS_HREDRAW;
+use windows::Win32::UI::WindowsAndMessaging::CS_VREDRAW;
+use windows::Win32::UI::WindowsAndMessaging::DBT_DEVNODES_CHANGED;
+use windows::Win32::UI::WindowsAndMessaging::MSG;
+use windows::Win32::UI::WindowsAndMessaging::PBT_APMRESUMEAUTOMATIC;
+use windows::Win32::UI::WindowsAndMessaging::PBT_APMRESUMESUSPEND;
+use windows::Win32::UI::WindowsAndMessaging::PBT_APMSUSPEND;
+use windows::Win32::UI::WindowsAndMessaging::SPI_SETWORKAREA;
+use windows::Win32::UI::WindowsAndMessaging::WM_DEVICECHANGE;
+use windows::Win32::UI::WindowsAndMessaging::WM_DISPLAYCHANGE;
+use windows::Win32::UI::WindowsAndMessaging::WM_POWERBROADCAST;
+use windows::Win32::UI::WindowsAndMessaging::WM_SETTINGCHANGE;
+use windows::Win32::UI::WindowsAndMessaging::WM_WTSSESSION_CHANGE;
+use windows::Win32::UI::WindowsAndMessaging::WNDCLASSW;
+use windows::Win32::UI::WindowsAndMessaging::WTS_SESSION_LOCK;
+use windows::Win32::UI::WindowsAndMessaging::WTS_SESSION_UNLOCK;
+
+use crate::monitor_reconciliator;
+use crate::WindowsApi;
+
+// This is a hidden window specifically spawned to listen to system-wide events related to monitors
+#[derive(Debug, Clone, Copy)]
+pub struct Hidden {
+    pub hwnd: isize,
+}
+
+impl From<isize> for Hidden {
+    fn from(hwnd: isize) -> Self {
+        Self { hwnd }
+    }
+}
+
+impl Hidden {
+    pub const fn hwnd(self) -> HWND {
+        HWND(self.hwnd)
+    }
+
+    pub fn create(name: &str) -> color_eyre::Result<Self> {
+        let name: Vec<u16> = format!("{name}\0").encode_utf16().collect();
+        let class_name = PCWSTR(name.as_ptr());
+
+        let h_module = WindowsApi::module_handle_w()?;
+        let window_class = WNDCLASSW {
+            hInstance: h_module.into(),
+            lpszClassName: class_name,
+            style: CS_HREDRAW | CS_VREDRAW,
+            lpfnWndProc: Some(Self::callback),
+            hbrBackground: WindowsApi::create_solid_brush(0),
+            ..Default::default()
+        };
+
+        let _ = WindowsApi::register_class_w(&window_class)?;
+
+        let (hwnd_sender, hwnd_receiver) = mpsc::channel();
+
+        std::thread::spawn(move || -> color_eyre::Result<()> {
+            let hwnd = WindowsApi::create_hidden_window(PCWSTR(name.as_ptr()), h_module)?;
+            hwnd_sender.send(hwnd)?;
+
+            let mut message = MSG::default();
+
+            unsafe {
+                while GetMessageW(&mut message, HWND(hwnd), 0, 0).into() {
+                    TranslateMessage(&message);
+                    DispatchMessageW(&message);
+                }
+            }
+
+            Ok(())
+        });
+
+        let hwnd = hwnd_receiver.recv()?;
+
+        WindowsApi::wts_register_session_notification(hwnd)?;
+
+        Ok(Self { hwnd })
+    }
+
+    pub extern "system" fn callback(
+        window: HWND,
+        message: u32,
+        wparam: WPARAM,
+        lparam: LPARAM,
+    ) -> LRESULT {
+        unsafe {
+            match message {
+                WM_POWERBROADCAST => {
+                    match wparam.0 as u32 {
+                        // Automatic: System resumed itself from sleep or hibernation
+                        // Suspend: User resumed system from sleep or hibernation
+                        PBT_APMRESUMEAUTOMATIC | PBT_APMRESUMESUSPEND => {
+                            tracing::debug!(
+                                "WM_POWERBROADCAST event received - resume from suspend"
+                            );
+                            let _ = monitor_reconciliator::event_tx().send(
+                                monitor_reconciliator::Notification::ResumingFromSuspendedState,
+                            );
+                            LRESULT(0)
+                        }
+                        // Computer is entering a suspended state
+                        PBT_APMSUSPEND => {
+                            tracing::debug!(
+                                "WM_POWERBROADCAST event received - entering suspended state"
+                            );
+                            let _ = monitor_reconciliator::event_tx()
+                                .send(monitor_reconciliator::Notification::EnteringSuspendedState);
+                            LRESULT(0)
+                        }
+                        _ => LRESULT(0),
+                    }
+                }
+                WM_WTSSESSION_CHANGE => {
+                    match wparam.0 as u32 {
+                        WTS_SESSION_LOCK => {
+                            tracing::debug!("WM_WTSSESSION_CHANGE event received with WTS_SESSION_LOCK - screen locked");
+
+                            let _ = monitor_reconciliator::event_tx()
+                                .send(monitor_reconciliator::Notification::SessionLocked);
+                        }
+                        WTS_SESSION_UNLOCK => {
+                            tracing::debug!("WM_WTSSESSION_CHANGE event received with WTS_SESSION_UNLOCK - screen unlocked");
+
+                            let _ = monitor_reconciliator::event_tx()
+                                .send(monitor_reconciliator::Notification::SessionUnlocked);
+                        }
+                        _ => {}
+                    }
+
+                    LRESULT(0)
+                }
+                // This event gets sent when:
+                // - The scaling factor on a display changes
+                // - The resolution on a display changes
+                // - A monitor is added
+                // - A monitor is removed
+                // Since WM_DEVICECHANGE also notifies on monitor changes, we only handle scaling
+                // and resolution changes here
+                WM_DISPLAYCHANGE => {
+                    tracing::debug!(
+                        "WM_DISPLAYCHANGE event received with wparam: {}- work area or display resolution changed", wparam.0
+                    );
+
+                    let _ = monitor_reconciliator::event_tx()
+                        .send(monitor_reconciliator::Notification::ResolutionScalingChanged);
+                    LRESULT(0)
+                }
+                // Unfortunately this is the event sent with ButteryTaskbar which I use a lot
+                // Original idea from https://stackoverflow.com/a/33762334
+                WM_SETTINGCHANGE => {
+                    #[allow(clippy::cast_possible_truncation)]
+                    if wparam.0 as u32 == SPI_SETWORKAREA.0 {
+                        tracing::debug!(
+                                "WM_SETTINGCHANGE event received with SPI_SETWORKAREA - work area changed (probably butterytaskbar or something similar)"
+                            );
+
+                        let _ = monitor_reconciliator::event_tx()
+                            .send(monitor_reconciliator::Notification::WorkAreaChanged);
+                    }
+                    LRESULT(0)
+                }
+                // This event + wparam combo is sent 4 times when a monitor is added based on my testing on win11
+                // Original idea from https://stackoverflow.com/a/33762334
+                WM_DEVICECHANGE => {
+                    #[allow(clippy::cast_possible_truncation)]
+                    if wparam.0 as u32 == DBT_DEVNODES_CHANGED {
+                        tracing::debug!(
+                                "WM_DEVICECHANGE event received with DBT_DEVNODES_CHANGED - display added or removed"
+                            );
+                        let _ = monitor_reconciliator::event_tx()
+                            .send(monitor_reconciliator::Notification::DisplayConnectionChange);
+                    }
+
+                    LRESULT(0)
+                }
+                _ => DefWindowProcW(window, message, wparam, lparam),
+            }
+        }
+    }
+}

komorebi/src/monitor_reconciliator/mod.rs

@@ -0,0 +1,404 @@
+#![deny(clippy::unwrap_used, clippy::expect_used)]
+
+use crate::border_manager;
+use crate::monitor;
+use crate::monitor::Monitor;
+use crate::monitor_reconciliator::hidden::Hidden;
+use crate::MonitorConfig;
+use crate::WindowManager;
+use crate::WindowsApi;
+use crossbeam_channel::Receiver;
+use crossbeam_channel::Sender;
+use crossbeam_utils::atomic::AtomicConsume;
+use komorebi_core::Rect;
+use parking_lot::Mutex;
+use std::collections::HashMap;
+use std::sync::atomic::AtomicBool;
+use std::sync::atomic::Ordering;
+use std::sync::Arc;
+use std::sync::OnceLock;
+
+pub mod hidden;
+
+pub enum Notification {
+    ResolutionScalingChanged,
+    WorkAreaChanged,
+    DisplayConnectionChange,
+    EnteringSuspendedState,
+    ResumingFromSuspendedState,
+    SessionLocked,
+    SessionUnlocked,
+}
+
+static ACTIVE: AtomicBool = AtomicBool::new(true);
+
+static CHANNEL: OnceLock<(Sender<Notification>, Receiver<Notification>)> = OnceLock::new();
+
+static MONITOR_CACHE: OnceLock<Mutex<HashMap<String, MonitorConfig>>> = OnceLock::new();
+
+pub fn channel() -> &'static (Sender<Notification>, Receiver<Notification>) {
+    CHANNEL.get_or_init(|| crossbeam_channel::bounded(1))
+}
+
+pub fn event_tx() -> Sender<Notification> {
+    channel().0.clone()
+}
+
+pub fn event_rx() -> Receiver<Notification> {
+    channel().1.clone()
+}
+
+pub fn insert_in_monitor_cache(device_id: &str, config: MonitorConfig) {
+    let mut monitor_cache = MONITOR_CACHE
+        .get_or_init(|| Mutex::new(HashMap::new()))
+        .lock();
+
+    monitor_cache.insert(device_id.to_string(), config);
+}
+
+pub fn attached_display_devices() -> color_eyre::Result<Vec<Monitor>> {
+    Ok(win32_display_data::connected_displays()
+        .flatten()
+        .map(|display| {
+            let path = display.device_path;
+            let mut split: Vec<_> = path.split('#').collect();
+            split.remove(0);
+            split.remove(split.len() - 1);
+            let device = split[0].to_string();
+            let device_id = split.join("-");
+
+            let name = display.device_name.trim_start_matches(r"\\.\").to_string();
+            let name = name.split('\\').collect::<Vec<_>>()[0].to_string();
+
+            monitor::new(
+                display.hmonitor,
+                display.size.into(),
+                display.work_area_size.into(),
+                name,
+                device,
+                device_id,
+            )
+        })
+        .collect::<Vec<_>>())
+}
+pub fn listen_for_notifications(wm: Arc<Mutex<WindowManager>>) -> color_eyre::Result<()> {
+    #[allow(clippy::expect_used)]
+    Hidden::create("komorebi-hidden")?;
+
+    tracing::info!("created hidden window to listen for monitor-related events");
+
+    std::thread::spawn(move || loop {
+        match handle_notifications(wm.clone()) {
+            Ok(()) => {
+                tracing::warn!("restarting finished thread");
+            }
+            Err(error) => {
+                if cfg!(debug_assertions) {
+                    tracing::error!("restarting failed thread: {:?}", error)
+                } else {
+                    tracing::error!("restarting failed thread: {}", error)
+                }
+            }
+        }
+    });
+
+    Ok(())
+}
+pub fn handle_notifications(wm: Arc<Mutex<WindowManager>>) -> color_eyre::Result<()> {
+    tracing::info!("listening");
+
+    let receiver = event_rx();
+
+    'receiver: for notification in receiver {
+        if !ACTIVE.load_consume() {
+            if matches!(
+                notification,
+                Notification::ResumingFromSuspendedState | Notification::SessionUnlocked
+            ) {
+                tracing::debug!(
+                    "reactivating reconciliator - system has resumed from suspended state or session has been unlocked"
+                );
+
+                ACTIVE.store(true, Ordering::SeqCst);
+            }
+
+            continue 'receiver;
+        }
+
+        let mut wm = wm.lock();
+
+        match notification {
+            Notification::EnteringSuspendedState | Notification::SessionLocked => {
+                tracing::debug!(
+                    "deactivating reconciliator until system resumes from suspended state or session is unlocked"
+                );
+                ACTIVE.store(false, Ordering::SeqCst);
+            }
+            Notification::ResumingFromSuspendedState | Notification::SessionUnlocked => {
+                // this is only handled above if the reconciliator is paused
+            }
+            Notification::WorkAreaChanged => {
+                tracing::debug!("handling work area changed notification");
+                let offset = wm.work_area_offset;
+                for monitor in wm.monitors_mut() {
+                    let mut should_update = false;
+
+                    // Update work areas as necessary
+                    if let Ok(reference) = WindowsApi::monitor(monitor.id()) {
+                        if reference.work_area_size() != monitor.work_area_size() {
+                            monitor.set_work_area_size(Rect {
+                                left: reference.work_area_size().left,
+                                top: reference.work_area_size().top,
+                                right: reference.work_area_size().right,
+                                bottom: reference.work_area_size().bottom,
+                            });
+
+                            should_update = true;
+                        }
+                    }
+
+                    if should_update {
+                        tracing::info!("updated work area for {}", monitor.device_id());
+                        monitor.update_focused_workspace(offset)?;
+                        border_manager::event_tx().send(border_manager::Notification)?;
+                    } else {
+                        tracing::debug!(
+                            "work areas match, reconciliation not required for {}",
+                            monitor.device_id()
+                        );
+                    }
+                }
+            }
+            Notification::ResolutionScalingChanged => {
+                tracing::debug!("handling resolution/scaling changed notification");
+                let offset = wm.work_area_offset;
+                for monitor in wm.monitors_mut() {
+                    let mut should_update = false;
+
+                    // Update sizes and work areas as necessary
+                    if let Ok(reference) = WindowsApi::monitor(monitor.id()) {
+                        if reference.work_area_size() != monitor.work_area_size() {
+                            monitor.set_work_area_size(Rect {
+                                left: reference.work_area_size().left,
+                                top: reference.work_area_size().top,
+                                right: reference.work_area_size().right,
+                                bottom: reference.work_area_size().bottom,
+                            });
+
+                            should_update = true;
+                        }
+
+                        if reference.size() != monitor.size() {
+                            monitor.set_size(Rect {
+                                left: reference.size().left,
+                                top: reference.size().top,
+                                right: reference.size().right,
+                                bottom: reference.size().bottom,
+                            });
+
+                            should_update = true;
+                        }
+                    }
+
+                    if should_update {
+                        tracing::info!(
+                            "updated monitor resolution/scaling for {}",
+                            monitor.device_id()
+                        );
+
+                        monitor.update_focused_workspace(offset)?;
+                        border_manager::event_tx().send(border_manager::Notification)?;
+                    } else {
+                        tracing::debug!(
+                            "resolutions match, reconciliation not required for {}",
+                            monitor.device_id()
+                        );
+                    }
+                }
+            }
+            Notification::DisplayConnectionChange => {
+                tracing::debug!("handling display connection change notification");
+                let mut monitor_cache = MONITOR_CACHE
+                    .get_or_init(|| Mutex::new(HashMap::new()))
+                    .lock();
+
+                let initial_monitor_count = wm.monitors().len();
+
+                // Get the currently attached display devices
+                let attached_devices = attached_display_devices()?;
+
+                // Make sure that in our state any attached displays have the latest Win32 data
+                for monitor in wm.monitors_mut() {
+                    for attached in &attached_devices {
+                        if attached.device_id().eq(monitor.device_id()) {
+                            monitor.set_id(attached.id());
+                            monitor.set_name(attached.name().clone());
+                            monitor.set_size(*attached.size());
+                            monitor.set_work_area_size(*attached.work_area_size());
+                        }
+                    }
+                }
+
+                if initial_monitor_count == attached_devices.len() {
+                    tracing::debug!("monitor counts match, reconciliation not required");
+                    continue 'receiver;
+                }
+
+                if attached_devices.is_empty() {
+                    tracing::debug!(
+                        "no devices found, skipping reconciliation to avoid breaking state"
+                    );
+                    continue 'receiver;
+                }
+
+                if initial_monitor_count > attached_devices.len() {
+                    tracing::info!(
+                        "monitor count mismatch ({initial_monitor_count} vs {}), removing disconnected monitors",
+                        attached_devices.len()
+                    );
+
+                    // Gather all the containers that will be orphaned from disconnected and invalid displays
+                    let mut orphaned_containers = vec![];
+
+                    // Collect the ids in our state which aren't in the current attached display ids
+                    // These are monitors that have been removed
+                    let mut newly_removed_displays = vec![];
+
+                    for m in wm.monitors().iter() {
+                        if !attached_devices
+                            .iter()
+                            .any(|attached| attached.device_id().eq(m.device_id()))
+                        {
+                            newly_removed_displays.push(m.device_id().clone());
+                            for workspace in m.workspaces() {
+                                for container in workspace.containers() {
+                                    // Save the orphaned containers from the removed monitor
+                                    orphaned_containers.push(container.clone());
+                                }
+                            }
+
+                            // Let's add their state to the cache for later
+                            monitor_cache.insert(m.device_id().clone(), m.into());
+                        }
+                    }
+
+                    if !orphaned_containers.is_empty() {
+                        tracing::info!(
+                            "removed orphaned containers from: {newly_removed_displays:?}"
+                        );
+                    }
+
+                    if !newly_removed_displays.is_empty() {
+                        // After we have cached them, remove them from our state
+                        wm.monitors_mut()
+                            .retain(|m| !newly_removed_displays.contains(m.device_id()));
+                    }
+
+                    let post_removal_monitor_count = wm.monitors().len();
+                    let focused_monitor_idx = wm.focused_monitor_idx();
+                    if focused_monitor_idx >= post_removal_monitor_count {
+                        wm.focus_monitor(0)?;
+                    }
+
+                    if !orphaned_containers.is_empty() {
+                        if let Some(primary) = wm.monitors_mut().front_mut() {
+                            if let Some(focused_ws) = primary.focused_workspace_mut() {
+                                let focused_container_idx = focused_ws.focused_container_idx();
+
+                                // Put the orphaned containers somewhere visible
+                                for container in orphaned_containers {
+                                    focused_ws.add_container(container);
+                                }
+
+                                // Gotta reset the focus or the movement will feel "off"
+                                if initial_monitor_count != post_removal_monitor_count {
+                                    focused_ws.focus_container(focused_container_idx);
+                                }
+                            }
+                        }
+                    }
+
+                    let offset = wm.work_area_offset;
+
+                    for monitor in wm.monitors_mut() {
+                        // If we have lost a monitor, update everything to filter out any jank
+                        if initial_monitor_count != post_removal_monitor_count {
+                            monitor.update_focused_workspace(offset)?;
+                        }
+                    }
+                }
+
+                let post_removal_monitor_count = wm.monitors().len();
+
+                // This is the list of device ids after we have removed detached displays
+                let post_removal_device_ids = wm
+                    .monitors()
+                    .iter()
+                    .map(Monitor::device_id)
+                    .cloned()
+                    .collect::<Vec<_>>();
+
+                // Check for and add any new monitors that may have been plugged in
+                // Monitor and display index preferences get applied in this function
+                WindowsApi::load_monitor_information(&mut wm.monitors)?;
+
+                let post_addition_monitor_count = wm.monitors().len();
+
+                if post_addition_monitor_count > post_removal_monitor_count {
+                    tracing::info!(
+                        "monitor count mismatch ({post_removal_monitor_count} vs {post_addition_monitor_count}), adding connected monitors",
+                    );
+
+                    // Look in the updated state for new monitors
+                    for m in wm.monitors_mut() {
+                        let device_id = m.device_id().clone();
+                        // We identify a new monitor when we encounter a new device id
+                        if !post_removal_device_ids.contains(&device_id) {
+                            let mut cache_hit = false;
+                            // Check if that device id exists in the cache for this session
+                            if let Some(cached) = monitor_cache.get(&device_id) {
+                                cache_hit = true;
+
+                                tracing::info!("found monitor and workspace configuration for {device_id} in the monitor cache, applying");
+
+                                // If it does, load all the monitor settings from the cache entry
+                                m.ensure_workspace_count(cached.workspaces.len());
+                                m.set_work_area_offset(cached.work_area_offset);
+                                m.set_window_based_work_area_offset(
+                                    cached.window_based_work_area_offset,
+                                );
+                                m.set_window_based_work_area_offset_limit(
+                                    cached.window_based_work_area_offset_limit.unwrap_or(1),
+                                );
+
+                                for (w_idx, workspace) in m.workspaces_mut().iter_mut().enumerate()
+                                {
+                                    if let Some(cached_workspace) = cached.workspaces.get(w_idx) {
+                                        workspace.load_static_config(cached_workspace)?;
+                                    }
+                                }
+                            }
+
+                            // Entries in the cache should only be used once; remove the entry there was a cache hit
+                            if cache_hit {
+                                monitor_cache.remove(&device_id);
+                            }
+                        }
+                    }
+                }
+
+                let final_count = wm.monitors().len();
+
+                if post_removal_monitor_count != final_count {
+                    wm.retile_all(true)?;
+                    // Second retile to fix DPI/resolution related jank
+                    wm.retile_all(true)?;
+                    // Border updates to fix DPI/resolution related jank
+                    border_manager::event_tx().send(border_manager::Notification)?;
+                }
+            }
+        }
+    }
+
+    Ok(())
+}

komorebi/src/process_command.rs

@@ -774,13 +774,10 @@ impl WindowManager {
             SocketMessage::VisibleWindows => {
                 let mut monitor_visible_windows = HashMap::new();
 
-                for (index, monitor) in self.monitors().iter().enumerate() {
+                for monitor in self.monitors() {
                     if let Some(ws) = monitor.focused_workspace() {
                         monitor_visible_windows.insert(
-                            monitor
-                                .device_id()
-                                .clone()
-                                .unwrap_or_else(|| format!("{index}")),
+                            monitor.device_id().clone(),
                             ws.visible_window_details().clone(),
                         );
                     }

komorebi/src/process_event.rs

@@ -74,7 +74,7 @@ impl WindowManager {
 
         // All event handlers below this point should only be processed if the event is
         // related to a window that should be managed by the WindowManager.
-        if !should_manage && !matches!(event, WindowManagerEvent::DisplayChange(_)) {
+        if !should_manage {
             return Ok(());
         }
 
@@ -94,31 +94,29 @@ impl WindowManager {
         match event {
             WindowManagerEvent::FocusChange(_, window)
             | WindowManagerEvent::Show(_, window)
-            | WindowManagerEvent::DisplayChange(window)
             | WindowManagerEvent::MoveResizeEnd(_, window) => {
-                self.reconcile_monitors()?;
-
-                let monitor_idx = self.monitor_idx_from_window(window)
-                    .ok_or_else(|| anyhow!("there is no monitor associated with this window, it may have already been destroyed"))?;
-
-                // This is a hidden window apparently associated with COM support mechanisms (based
-                // on a post from http://www.databaseteam.org/1-ms-sql-server/a5bb344836fb889c.htm)
-                //
-                // The hidden window, OLEChannelWnd, associated with this class (spawned by
-                // explorer.exe), after some debugging, is observed to always be tied to the primary
-                // display monitor, or (usually) monitor 0 in the WindowManager state.
-                //
-                // Due to this, at least one user in the Discord has witnessed behaviour where, when
-                // a MonitorPoll event is triggered by OLEChannelWnd, the focused monitor index gets
-                // set repeatedly to 0, regardless of where the current foreground window is actually
-                // located.
-                //
-                // This check ensures that we only update the focused monitor when the window
-                // triggering monitor reconciliation is known to not be tied to a specific monitor.
-                if window.class()? != "OleMainThreadWndClass"
-                    && self.focused_monitor_idx() != monitor_idx
-                {
-                    self.focus_monitor(monitor_idx)?;
+                if let Some(monitor_idx) = self.monitor_idx_from_window(window) {
+                    // This is a hidden window apparently associated with COM support mechanisms (based
+                    // on a post from http://www.databaseteam.org/1-ms-sql-server/a5bb344836fb889c.htm)
+                    //
+                    // The hidden window, OLEChannelWnd, associated with this class (spawned by
+                    // explorer.exe), after some debugging, is observed to always be tied to the primary
+                    // display monitor, or (usually) monitor 0 in the WindowManager state.
+                    //
+                    // Due to this, at least one user in the Discord has witnessed behaviour where, when
+                    // a MonitorPoll event is triggered by OLEChannelWnd, the focused monitor index gets
+                    // set repeatedly to 0, regardless of where the current foreground window is actually
+                    // located.
+                    //
+                    // This check ensures that we only update the focused monitor when the window
+                    // triggering monitor reconciliation is known to not be tied to a specific monitor.
+                    if let Ok(class) = window.class() {
+                        if class != "OleMainThreadWndClass"
+                            && self.focused_monitor_idx() != monitor_idx
+                        {
+                            self.focus_monitor(monitor_idx)?;
+                        }
+                    }
                 }
             }
             _ => {}
@@ -606,9 +604,7 @@ impl WindowManager {
             WindowManagerEvent::ForceUpdate(_) => {
                 self.update_focused_workspace(false, true)?;
             }
-            WindowManagerEvent::DisplayChange(..)
-            | WindowManagerEvent::MouseCapture(..)
-            | WindowManagerEvent::Cloak(..) => {}
+            WindowManagerEvent::MouseCapture(..) | WindowManagerEvent::Cloak(..) => {}
         };
 
         // If we unmanaged a window, it shouldn't be immediately hidden behind managed windows

komorebi/src/stackbar.rs

@@ -67,7 +67,7 @@ use crate::WINDOWS_BY_BAR_HWNDS;
 
 #[derive(Debug, Clone, Default, Serialize, Deserialize, JsonSchema)]
 pub struct Stackbar {
-    pub(crate) hwnd: isize,
+    pub hwnd: isize,
 }
 
 impl Stackbar {

komorebi/src/static_config.rs

@@ -5,6 +5,7 @@ use crate::border_manager::Z_ORDER;
 use crate::colour::Colour;
 use crate::current_virtual_desktop;
 use crate::monitor::Monitor;
+use crate::monitor_reconciliator;
 use crate::ring::Ring;
 use crate::window_manager::WindowManager;
 use crate::window_manager_event::WindowManagerEvent;
@@ -82,7 +83,7 @@ pub struct BorderColours {
     pub unfocused: Option<Colour>,
 }
 
-#[derive(Debug, Serialize, Deserialize, JsonSchema)]
+#[derive(Debug, Clone, Serialize, Deserialize, JsonSchema)]
 pub struct WorkspaceConfig {
     /// Name
     pub name: String,
@@ -196,7 +197,7 @@ impl From<&Workspace> for WorkspaceConfig {
     }
 }
 
-#[derive(Debug, Serialize, Deserialize, JsonSchema)]
+#[derive(Debug, Clone, Serialize, Deserialize, JsonSchema)]
 pub struct MonitorConfig {
     /// Workspace configurations
     pub workspaces: Vec<WorkspaceConfig>,
@@ -648,7 +649,6 @@ impl StaticConfig {
 
         let mut wm = WindowManager {
             monitors: Ring::default(),
-            monitor_cache: HashMap::new(),
             incoming_events: incoming,
             command_listener: listener,
             is_paused: false,
@@ -706,6 +706,13 @@ impl StaticConfig {
 
         if let Some(monitors) = value.monitors {
             for (i, monitor) in monitors.iter().enumerate() {
+                {
+                    let display_index_preferences = DISPLAY_INDEX_PREFERENCES.lock();
+                    if let Some(device_id) = display_index_preferences.get(&i) {
+                        monitor_reconciliator::insert_in_monitor_cache(device_id, monitor.clone());
+                    }
+                }
+
                 if let Some(m) = wm.monitors_mut().get_mut(i) {
                     m.ensure_workspace_count(monitor.workspaces.len());
                     m.set_work_area_offset(monitor.work_area_offset);

komorebi/src/window_manager.rs

@@ -81,7 +81,6 @@ use komorebi_core::StackbarMode;
 #[derive(Debug)]
 pub struct WindowManager {
     pub monitors: Ring<Monitor>,
-    pub monitor_cache: HashMap<usize, Monitor>,
     pub incoming_events: Receiver<WindowManagerEvent>,
     pub command_listener: UnixListener,
     pub is_paused: bool,
@@ -262,7 +261,6 @@ impl WindowManager {
 
         Ok(Self {
             monitors: Ring::default(),
-            monitor_cache: HashMap::new(),
             incoming_events: incoming,
             command_listener: listener,
             is_paused: false,
@@ -385,155 +383,6 @@ impl WindowManager {
         None
     }
 
-    #[tracing::instrument(skip(self))]
-    pub fn reconcile_monitors(&mut self) -> Result<()> {
-        if self.pending_move_op.is_some() {
-            return Ok(());
-        }
-
-        let valid_hmonitors = WindowsApi::valid_hmonitors()?;
-        let mut valid_names = vec![];
-        let before_count = self.monitors().len();
-
-        for monitor in self.monitors_mut() {
-            for (valid_name, valid_id) in &valid_hmonitors {
-                let actual_name = monitor.name().clone();
-                if actual_name == *valid_name {
-                    monitor.set_id(*valid_id);
-                    valid_names.push(actual_name);
-                }
-            }
-        }
-
-        let mut orphaned_containers = vec![];
-        let mut invalid_indices = vec![];
-
-        for (i, invalid) in self
-            .monitors()
-            .iter()
-            .enumerate()
-            .filter(|(_, m)| !valid_names.contains(m.name()))
-        {
-            invalid_indices.push(i);
-            for workspace in invalid.workspaces() {
-                for container in workspace.containers() {
-                    // Save the orphaned containers from an invalid monitor
-                    // (which has most likely been disconnected)
-                    orphaned_containers.push(container.clone());
-                }
-            }
-        }
-
-        for i in invalid_indices {
-            if let Some(monitor) = self.monitors().get(i) {
-                self.monitor_cache.insert(i, monitor.clone());
-            }
-        }
-
-        // Remove any invalid monitors from our state
-        self.monitors_mut()
-            .retain(|m| valid_names.contains(m.name()));
-
-        let after_count = self.monitors().len();
-
-        if let Some(primary) = self.monitors_mut().front_mut() {
-            if let Some(focused_ws) = primary.focused_workspace_mut() {
-                let focused_container_idx = focused_ws.focused_container_idx();
-
-                // Put the orphaned containers somewhere visible
-                for container in orphaned_containers {
-                    focused_ws.add_container(container);
-                }
-
-                // Gotta reset the focus or the movement will feel "off"
-                if before_count != after_count {
-                    focused_ws.focus_container(focused_container_idx);
-                }
-            }
-        }
-
-        let offset = self.work_area_offset;
-
-        for monitor in self.monitors_mut() {
-            // If we have lost a monitor, update everything to filter out any jank
-            let mut should_update = before_count != after_count;
-
-            let reference = WindowsApi::monitor(monitor.id())?;
-            if reference.work_area_size() != monitor.work_area_size() {
-                monitor.set_work_area_size(Rect {
-                    left: reference.work_area_size().left,
-                    top: reference.work_area_size().top,
-                    right: reference.work_area_size().right,
-                    bottom: reference.work_area_size().bottom,
-                });
-
-                should_update = true;
-            }
-
-            if reference.size() != monitor.size() {
-                monitor.set_size(Rect {
-                    left: reference.size().left,
-                    top: reference.size().top,
-                    right: reference.size().right,
-                    bottom: reference.size().bottom,
-                });
-
-                should_update = true;
-            }
-
-            if should_update {
-                monitor.update_focused_workspace(offset)?;
-            }
-        }
-
-        #[allow(clippy::needless_collect)]
-        let old_sizes = self
-            .monitors()
-            .iter()
-            .map(Monitor::size)
-            .copied()
-            .collect::<Vec<_>>();
-
-        // Check for and add any new monitors that may have been plugged in
-        WindowsApi::load_monitor_information(&mut self.monitors)?;
-
-        let mut check_cache = vec![];
-
-        for (i, m) in self.monitors().iter().enumerate() {
-            if !old_sizes.contains(m.size()) {
-                check_cache.push(i);
-            }
-        }
-
-        for i in check_cache {
-            if let Some(cached) = self.monitor_cache.get(&i).cloned() {
-                if let Some(monitor) = self.monitors_mut().get_mut(i) {
-                    for (w_idx, workspace) in monitor.workspaces_mut().iter_mut().enumerate() {
-                        if let Some(cached_workspace) = cached.workspaces().get(w_idx) {
-                            workspace.set_layout(cached_workspace.layout().clone());
-                            workspace.set_layout_rules(cached_workspace.layout_rules().clone());
-                            workspace.set_layout_flip(cached_workspace.layout_flip());
-                            workspace.set_workspace_padding(cached_workspace.workspace_padding());
-                            workspace.set_container_padding(cached_workspace.container_padding());
-                        }
-                    }
-                }
-            }
-        }
-
-        let final_count = self.monitors().len();
-        if after_count != final_count {
-            self.retile_all(true)?;
-            // Second retile to fix DPI/resolution related jank when a window
-            // moves between monitors with different resolutions - this doesn't
-            // really get seen by the user since the screens are flickering anyway
-            // as a result of the display connections / disconnections
-            self.retile_all(true)?;
-        }
-
-        Ok(())
-    }
-
     #[allow(clippy::too_many_arguments)]
     #[tracing::instrument(skip(self), level = "debug")]
     fn add_window_handle_to_move_based_on_workspace_rule(
@@ -2382,10 +2231,21 @@ impl WindowManager {
             }
         }
 
+        // our hmonitor might be stale, so if we didn't return above, try querying via the latest
+        // info taken from win32_display_data and update our hmonitor while we're at it
+        if let Ok(latest) = WindowsApi::monitor(hmonitor) {
+            for (i, monitor) in self.monitors_mut().iter_mut().enumerate() {
+                if monitor.device_id() == latest.device_id() {
+                    monitor.set_id(latest.id());
+                    return Option::from(i);
+                }
+            }
+        }
+
         None
     }
 
-    pub fn monitor_idx_from_current_pos(&self) -> Option<usize> {
+    pub fn monitor_idx_from_current_pos(&mut self) -> Option<usize> {
         let hmonitor = WindowsApi::monitor_from_point(WindowsApi::cursor_pos().ok()?);
 
         for (i, monitor) in self.monitors().iter().enumerate() {
@@ -2394,6 +2254,17 @@ impl WindowManager {
             }
         }
 
+        // our hmonitor might be stale, so if we didn't return above, try querying via the latest
+        // info taken from win32_display_data and update our hmonitor while we're at it
+        if let Ok(latest) = WindowsApi::monitor(hmonitor) {
+            for (i, monitor) in self.monitors_mut().iter_mut().enumerate() {
+                if monitor.device_id() == latest.device_id() {
+                    monitor.set_id(latest.id());
+                    return Option::from(i);
+                }
+            }
+        }
+
         None
     }
 

komorebi/src/window_manager_event.rs

@@ -27,7 +27,6 @@ pub enum WindowManagerEvent {
     Manage(Window),
     Unmanage(Window),
     Raise(Window),
-    DisplayChange(Window),
     ForceUpdate(Window),
 }
 
@@ -76,9 +75,6 @@ impl Display for WindowManagerEvent {
             Self::Raise(window) => {
                 write!(f, "Raise (Window: {window})")
             }
-            Self::DisplayChange(window) => {
-                write!(f, "DisplayChange (Window: {window})")
-            }
             Self::ForceUpdate(window) => {
                 write!(f, "ForceUpdate (Window: {window})")
             }
@@ -101,7 +97,6 @@ impl WindowManagerEvent {
             | Self::MouseCapture(_, window)
             | Self::Raise(window)
             | Self::Manage(window)
-            | Self::DisplayChange(window)
             | Self::Unmanage(window)
             | Self::ForceUpdate(window) => window,
         }

komorebi/src/windows_api.rs

@@ -4,9 +4,9 @@ use std::ffi::c_void;
 use std::mem::size_of;
 
 use color_eyre::eyre::anyhow;
+use color_eyre::eyre::bail;
 use color_eyre::eyre::Error;
 use color_eyre::Result;
-use widestring::U16CStr;
 use windows::core::Result as WindowsCrateResult;
 use windows::core::PCWSTR;
 use windows::core::PWSTR;
@@ -30,14 +30,12 @@ use windows::Win32::Graphics::Dwm::DWM_CLOAKED_APP;
 use windows::Win32::Graphics::Dwm::DWM_CLOAKED_INHERITED;
 use windows::Win32::Graphics::Dwm::DWM_CLOAKED_SHELL;
 use windows::Win32::Graphics::Gdi::CreateSolidBrush;
-use windows::Win32::Graphics::Gdi::EnumDisplayDevicesW;
 use windows::Win32::Graphics::Gdi::EnumDisplayMonitors;
 use windows::Win32::Graphics::Gdi::GetMonitorInfoW;
 use windows::Win32::Graphics::Gdi::MonitorFromPoint;
 use windows::Win32::Graphics::Gdi::MonitorFromWindow;
 use windows::Win32::Graphics::Gdi::Rectangle;
 use windows::Win32::Graphics::Gdi::RoundRect;
-use windows::Win32::Graphics::Gdi::DISPLAY_DEVICEW;
 use windows::Win32::Graphics::Gdi::HBRUSH;
 use windows::Win32::Graphics::Gdi::HDC;
 use windows::Win32::Graphics::Gdi::HMONITOR;
@@ -46,6 +44,7 @@ use windows::Win32::Graphics::Gdi::MONITORINFOEXW;
 use windows::Win32::Graphics::Gdi::MONITOR_DEFAULTTONEAREST;
 use windows::Win32::System::LibraryLoader::GetModuleHandleW;
 use windows::Win32::System::RemoteDesktop::ProcessIdToSessionId;
+use windows::Win32::System::RemoteDesktop::WTSRegisterSessionNotification;
 use windows::Win32::System::Threading::GetCurrentProcessId;
 use windows::Win32::System::Threading::OpenProcess;
 use windows::Win32::System::Threading::QueryFullProcessImageNameW;
@@ -95,7 +94,6 @@ use windows::Win32::UI::WindowsAndMessaging::ShowWindow;
 use windows::Win32::UI::WindowsAndMessaging::SystemParametersInfoW;
 use windows::Win32::UI::WindowsAndMessaging::WindowFromPoint;
 use windows::Win32::UI::WindowsAndMessaging::CW_USEDEFAULT;
-use windows::Win32::UI::WindowsAndMessaging::EDD_GET_DEVICE_INTERFACE_NAME;
 use windows::Win32::UI::WindowsAndMessaging::GWL_EXSTYLE;
 use windows::Win32::UI::WindowsAndMessaging::GWL_STYLE;
 use windows::Win32::UI::WindowsAndMessaging::GW_HWNDNEXT;
@@ -140,6 +138,8 @@ use crate::ring::Ring;
 use crate::set_window_position::SetWindowPosition;
 use crate::windows_callbacks;
 use crate::Window;
+use crate::DISPLAY_INDEX_PREFERENCES;
+use crate::MONITOR_INDEX_PREFERENCES;
 
 pub enum WindowsResult<T, E> {
     Err(E),
@@ -220,58 +220,74 @@ impl WindowsApi {
     }
 
     pub fn valid_hmonitors() -> Result<Vec<(String, isize)>> {
-        let mut monitors: Vec<(String, isize)> = vec![];
-        let monitors_ref: &mut Vec<(String, isize)> = monitors.as_mut();
-        Self::enum_display_monitors(
-            Some(windows_callbacks::valid_display_monitors),
-            monitors_ref as *mut Vec<(String, isize)> as isize,
-        )?;
+        Ok(win32_display_data::connected_displays()
+            .flatten()
+            .map(|d| {
+                let name = d.device_name.trim_start_matches(r"\\.\").to_string();
+                let name = name.split('\\').collect::<Vec<_>>()[0].to_string();
 
-        Ok(monitors)
+                (name, d.hmonitor)
+            })
+            .collect::<Vec<_>>())
     }
 
     pub fn load_monitor_information(monitors: &mut Ring<Monitor>) -> Result<()> {
-        Self::enum_display_monitors(
-            Some(windows_callbacks::enum_display_monitor),
-            monitors as *mut Ring<Monitor> as isize,
-        )?;
+        'read: for display in win32_display_data::connected_displays().flatten() {
+            let path = display.device_path.clone();
+            let mut split: Vec<_> = path.split('#').collect();
+            split.remove(0);
+            split.remove(split.len() - 1);
+            let device = split[0].to_string();
+            let device_id = split.join("-");
 
-        Ok(())
-    }
+            let name = display.device_name.trim_start_matches(r"\\.\").to_string();
+            let name = name.split('\\').collect::<Vec<_>>()[0].to_string();
 
-    pub fn enum_display_devices(
-        index: u32,
-        lp_device: Option<*const u16>,
-    ) -> Result<DISPLAY_DEVICEW> {
-        #[allow(clippy::option_if_let_else)]
-        let lp_device = match lp_device {
-            None => PCWSTR::null(),
-            Some(lp_device) => PCWSTR(lp_device),
-        };
+            for monitor in monitors.elements() {
+                if device_id.eq(monitor.device_id()) {
+                    continue 'read;
+                }
+            }
 
-        let mut display_device = DISPLAY_DEVICEW {
-            cb: u32::try_from(std::mem::size_of::<DISPLAY_DEVICEW>())?,
-            ..Default::default()
-        };
+            let m = monitor::new(
+                display.hmonitor,
+                display.size.into(),
+                display.work_area_size.into(),
+                name,
+                device,
+                device_id,
+            );
 
-        match unsafe {
-            EnumDisplayDevicesW(
-                lp_device,
-                index,
-                std::ptr::addr_of_mut!(display_device),
-                EDD_GET_DEVICE_INTERFACE_NAME,
-            )
-        }
-        .ok()
-        {
-            Ok(()) => {}
-            Err(error) => {
-                tracing::error!("enum_display_devices: {}", error);
-                return Err(error.into());
+            let mut index_preference = None;
+            let monitor_index_preferences = MONITOR_INDEX_PREFERENCES.lock();
+            for (index, monitor_size) in &*monitor_index_preferences {
+                if m.size() == monitor_size {
+                    index_preference = Option::from(index);
+                }
+            }
+
+            let display_index_preferences = DISPLAY_INDEX_PREFERENCES.lock();
+            for (index, id) in &*display_index_preferences {
+                if id.eq(m.device_id()) {
+                    index_preference = Option::from(index);
+                }
+            }
+
+            if monitors.elements().is_empty() {
+                monitors.elements_mut().push_back(m);
+            } else if let Some(preference) = index_preference {
+                let current_len = monitors.elements().len();
+                if *preference > current_len {
+                    monitors.elements_mut().reserve(1);
+                }
+
+                monitors.elements_mut().insert(*preference, m);
+            } else {
+                monitors.elements_mut().push_back(m);
             }
         }
 
-        Ok(display_device)
+        Ok(())
     }
 
     pub fn enum_windows(callback: WNDENUMPROC, callback_data_address: isize) -> Result<()> {
@@ -775,20 +791,32 @@ impl WindowsApi {
     }
 
     pub fn monitor(hmonitor: isize) -> Result<Monitor> {
-        let ex_info = Self::monitor_info_w(HMONITOR(hmonitor))?;
-        let name = U16CStr::from_slice_truncate(&ex_info.szDevice)
-            .expect("monitor name was not a valid u16 c string")
-            .to_ustring()
-            .to_string_lossy()
-            .trim_start_matches(r"\\.\")
-            .to_string();
+        for display in win32_display_data::connected_displays().flatten() {
+            if display.hmonitor == hmonitor {
+                let path = display.device_path;
+                let mut split: Vec<_> = path.split('#').collect();
+                split.remove(0);
+                split.remove(split.len() - 1);
+                let device = split[0].to_string();
+                let device_id = split.join("-");
 
-        Ok(monitor::new(
-            hmonitor,
-            ex_info.monitorInfo.rcMonitor.into(),
-            ex_info.monitorInfo.rcWork.into(),
-            name,
-        ))
+                let name = display.device_name.trim_start_matches(r"\\.\").to_string();
+                let name = name.split('\\').collect::<Vec<_>>()[0].to_string();
+
+                let monitor = monitor::new(
+                    hmonitor,
+                    display.size.into(),
+                    display.work_area_size.into(),
+                    name,
+                    device,
+                    device_id,
+                );
+
+                return Ok(monitor);
+            }
+        }
+
+        bail!("could not find device_id for hmonitor: {hmonitor}");
     }
 
     pub fn set_process_dpi_awareness_context() -> Result<()> {
@@ -1031,4 +1059,8 @@ impl WindowsApi {
             SendInput(&inputs, std::mem::size_of::<INPUT>() as i32)
         }
     }
+
+    pub fn wts_register_session_notification(hwnd: isize) -> Result<()> {
+        unsafe { WTSRegisterSessionNotification(HWND(hwnd), 1) }.process()
+    }
 }

komorebi/src/windows_callbacks.rs

@@ -1,129 +1,17 @@
 use std::collections::VecDeque;
-use widestring::U16CStr;
 
 use windows::Win32::Foundation::BOOL;
 use windows::Win32::Foundation::HWND;
 use windows::Win32::Foundation::LPARAM;
-use windows::Win32::Foundation::LRESULT;
-use windows::Win32::Foundation::RECT;
-use windows::Win32::Foundation::WPARAM;
-use windows::Win32::Graphics::Gdi::HDC;
-use windows::Win32::Graphics::Gdi::HMONITOR;
 use windows::Win32::UI::Accessibility::HWINEVENTHOOK;
-use windows::Win32::UI::WindowsAndMessaging::DefWindowProcW;
-use windows::Win32::UI::WindowsAndMessaging::DBT_DEVNODES_CHANGED;
-use windows::Win32::UI::WindowsAndMessaging::SPI_ICONVERTICALSPACING;
-use windows::Win32::UI::WindowsAndMessaging::SPI_SETWORKAREA;
-use windows::Win32::UI::WindowsAndMessaging::WM_DEVICECHANGE;
-use windows::Win32::UI::WindowsAndMessaging::WM_DISPLAYCHANGE;
-use windows::Win32::UI::WindowsAndMessaging::WM_SETTINGCHANGE;
 
 use crate::container::Container;
-use crate::monitor::Monitor;
-use crate::ring::Ring;
 use crate::window::RuleDebug;
 use crate::window::Window;
 use crate::window_manager_event::WindowManagerEvent;
 use crate::windows_api::WindowsApi;
 use crate::winevent::WinEvent;
 use crate::winevent_listener;
-use crate::DISPLAY_INDEX_PREFERENCES;
-use crate::MONITOR_INDEX_PREFERENCES;
-
-pub extern "system" fn valid_display_monitors(
-    hmonitor: HMONITOR,
-    _: HDC,
-    _: *mut RECT,
-    lparam: LPARAM,
-) -> BOOL {
-    let monitors = unsafe { &mut *(lparam.0 as *mut Vec<(String, isize)>) };
-    if let Ok(m) = WindowsApi::monitor(hmonitor.0) {
-        monitors.push((m.name().to_string(), hmonitor.0));
-    }
-
-    true.into()
-}
-
-pub extern "system" fn enum_display_monitor(
-    hmonitor: HMONITOR,
-    _: HDC,
-    _: *mut RECT,
-    lparam: LPARAM,
-) -> BOOL {
-    let monitors = unsafe { &mut *(lparam.0 as *mut Ring<Monitor>) };
-
-    // Don't duplicate a monitor that is already being managed
-    for monitor in monitors.elements() {
-        if monitor.id() == hmonitor.0 {
-            return true.into();
-        }
-    }
-
-    let current_index = monitors.elements().len();
-
-    if let Ok(mut m) = WindowsApi::monitor(hmonitor.0) {
-        #[allow(clippy::cast_possible_truncation)]
-        if let Ok(d) = WindowsApi::enum_display_devices(current_index as u32, None) {
-            let name = U16CStr::from_slice_truncate(d.DeviceName.as_ref())
-                .expect("display device name was not a valid u16 c string")
-                .to_ustring()
-                .to_string_lossy()
-                .trim_start_matches(r"\\.\")
-                .to_string();
-
-            if name.eq(m.name()) {
-                if let Ok(device) = WindowsApi::enum_display_devices(0, Some(d.DeviceName.as_ptr()))
-                {
-                    let id = U16CStr::from_slice_truncate(device.DeviceID.as_ref())
-                        .expect("display device id was not a valid u16 c string")
-                        .to_ustring()
-                        .to_string_lossy()
-                        .trim_start_matches(r"\\?\")
-                        .to_string();
-
-                    let mut split: Vec<_> = id.split('#').collect();
-                    split.remove(0);
-                    split.remove(split.len() - 1);
-
-                    m.set_device(Option::from(split[0].to_string()));
-                    m.set_device_id(Option::from(split.join("-")));
-                }
-            }
-        }
-
-        let monitor_index_preferences = MONITOR_INDEX_PREFERENCES.lock();
-        let mut index_preference = None;
-        for (index, monitor_size) in &*monitor_index_preferences {
-            if m.size() == monitor_size {
-                index_preference = Option::from(index);
-            }
-        }
-
-        let display_index_preferences = DISPLAY_INDEX_PREFERENCES.lock();
-        for (index, device) in &*display_index_preferences {
-            if let Some(known_device) = m.device_id() {
-                if device == known_device {
-                    index_preference = Option::from(index);
-                }
-            }
-        }
-
-        if monitors.elements().is_empty() {
-            monitors.elements_mut().push_back(m);
-        } else if let Some(preference) = index_preference {
-            let current_len = monitors.elements().len();
-            if *preference > current_len {
-                monitors.elements_mut().reserve(1);
-            }
-
-            monitors.elements_mut().insert(*preference, m);
-        } else {
-            monitors.elements_mut().push_back(m);
-        }
-    }
-
-    true.into()
-}
 
 pub extern "system" fn enum_window(hwnd: HWND, lparam: LPARAM) -> BOOL {
     let containers = unsafe { &mut *(lparam.0 as *mut VecDeque<Container>) };
@@ -201,48 +89,3 @@ pub extern "system" fn win_event_hook(
         .send(event_type)
         .expect("could not send message on winevent_listener::event_tx");
 }
-
-pub extern "system" fn hidden_window(
-    window: HWND,
-    message: u32,
-    wparam: WPARAM,
-    lparam: LPARAM,
-) -> LRESULT {
-    unsafe {
-        match message {
-            WM_DISPLAYCHANGE => {
-                let event_type = WindowManagerEvent::DisplayChange(Window { hwnd: window.0 });
-                winevent_listener::event_tx()
-                    .send(event_type)
-                    .expect("could not send message on winevent_listener::event_tx");
-
-                LRESULT(0)
-            }
-            // Added based on this https://stackoverflow.com/a/33762334
-            WM_SETTINGCHANGE => {
-                #[allow(clippy::cast_possible_truncation)]
-                if wparam.0 as u32 == SPI_SETWORKAREA.0
-                    || wparam.0 as u32 == SPI_ICONVERTICALSPACING.0
-                {
-                    let event_type = WindowManagerEvent::DisplayChange(Window { hwnd: window.0 });
-                    winevent_listener::event_tx()
-                        .send(event_type)
-                        .expect("could not send message on winevent_listener::event_tx");
-                }
-                LRESULT(0)
-            }
-            // Added based on this https://stackoverflow.com/a/33762334
-            WM_DEVICECHANGE => {
-                #[allow(clippy::cast_possible_truncation)]
-                if wparam.0 as u32 == DBT_DEVNODES_CHANGED {
-                    let event_type = WindowManagerEvent::DisplayChange(Window { hwnd: window.0 });
-                    winevent_listener::event_tx()
-                        .send(event_type)
-                        .expect("could not send message on winevent_listener::event_tx");
-                }
-                LRESULT(0)
-            }
-            _ => DefWindowProcW(window, message, wparam, lparam),
-        }
-    }
-}