feat(wm): move/focus across monitor edges

This commit introduces the ability to operate across monitor boundaries
with the 'move' and 'focus' commands.

When operating down or to the right, the target index of the monitor in
that direction will be 0. When operating up or to the left, the target
index will either be len() - 1 if focusing, or len() if moving.

re #145

komorebi/src/window_manager.rs

@@ -264,6 +264,39 @@ impl WindowManager {
         Ok(())
     }
 
+    pub fn monitor_index_in_direction(&self, direction: OperationDirection) -> Option<usize> {
+        let current_monitor_size = self.focused_monitor_size().ok()?;
+
+        for (idx, monitor) in self.monitors.elements().iter().enumerate() {
+            match direction {
+                OperationDirection::Left => {
+                    if monitor.size().left + monitor.size().right == current_monitor_size.left {
+                        return Option::from(idx);
+                    }
+                }
+                OperationDirection::Right => {
+                    if current_monitor_size.right + current_monitor_size.left == monitor.size().left
+                    {
+                        return Option::from(idx);
+                    }
+                }
+                OperationDirection::Up => {
+                    if monitor.size().top + monitor.size().bottom == current_monitor_size.top {
+                        return Option::from(idx);
+                    }
+                }
+                OperationDirection::Down => {
+                    if current_monitor_size.top + current_monitor_size.bottom == monitor.size().top
+                    {
+                        return Option::from(idx);
+                    }
+                }
+            }
+        }
+
+        None
+    }
+
     #[tracing::instrument(skip(self))]
     pub fn reconcile_monitors(&mut self) -> Result<()> {
         let valid_hmonitors = WindowsApi::valid_hmonitors()?;
@@ -903,13 +936,24 @@ impl WindowManager {
 
         tracing::info!("focusing container");
 
-        let workspace = self.focused_workspace_mut()?;
+        let workspace = self.focused_workspace()?;
+        let new_idx = workspace.new_idx_for_direction(direction);
 
-        let new_idx = workspace
-            .new_idx_for_direction(direction)
-            .ok_or_else(|| anyhow!("this is not a valid direction from the current position"))?;
+        // if there is no container in that direction for this workspace
+        if new_idx.is_none() {
+            // check if there is a monitor in that direction
+            let monitor_idx = self
+                .monitor_index_in_direction(direction)
+                .ok_or_else(|| anyhow!("there is no container or monitor in this direction"))?;
+            self.focus_monitor(monitor_idx)?;
+        }
+
+        let workspace = self.focused_workspace_mut()?;
+        workspace.focus_container(new_idx.unwrap_or_else(|| match direction {
+            OperationDirection::Right | OperationDirection::Down => 0,
+            OperationDirection::Left | OperationDirection::Up => workspace.containers().len() - 1,
+        }));
 
-        workspace.focus_container(new_idx);
         self.focused_window_mut()?.focus(self.mouse_follows_focus)?;
 
         Ok(())
@@ -921,15 +965,48 @@ impl WindowManager {
 
         tracing::info!("moving container");
 
-        let workspace = self.focused_workspace_mut()?;
+        let workspace = self.focused_workspace()?;
 
         let current_idx = workspace.focused_container_idx();
-        let new_idx = workspace
-            .new_idx_for_direction(direction)
-            .ok_or_else(|| anyhow!("this is not a valid direction from the current position"))?;
+        let new_idx = workspace.new_idx_for_direction(direction);
+
+        match new_idx {
+            // If there is nowhere to move on the current workspace, try to move it onto the monitor
+            // in that direction if there is one
+            None => {
+                let monitor_idx = self
+                    .monitor_index_in_direction(direction)
+                    .ok_or_else(|| anyhow!("there is no container or monitor in this direction"))?;
+
+                // move to the target monitor
+                self.move_container_to_monitor(monitor_idx, None, true)?;
+                let workspace = self.focused_workspace_mut()?;
+
+                // by default move_container_to_monitor appends to the end, so remove it
+                let container = workspace
+                    .remove_container(workspace.containers().len() - 1)
+                    .ok_or_else(|| {
+                        anyhow!("the container was not found to have been moved to monitor in the desired direction")
+                    })?;
+
+                // decide where to reinsert it before redrawing
+                let final_idx = match direction {
+                    OperationDirection::Right | OperationDirection::Down => 0,
+                    OperationDirection::Left | OperationDirection::Up => {
+                        workspace.containers().len()
+                    }
+                };
+
+                // insert it in the right place on the target monitor's workspace
+                workspace.insert_container(container, final_idx);
+            }
+            Some(new_idx) => {
+                let workspace = self.focused_workspace_mut()?;
+                workspace.swap_containers(current_idx, new_idx);
+                workspace.focus_container(new_idx);
+            }
+        }
 
-        workspace.swap_containers(current_idx, new_idx);
-        workspace.focus_container(new_idx);
         self.update_focused_workspace(self.mouse_follows_focus)
     }
 
@@ -1627,6 +1704,13 @@ impl WindowManager {
         self.update_focused_workspace(false)
     }
 
+    pub fn focused_monitor_size(&self) -> Result<Rect> {
+        Ok(*self
+            .focused_monitor()
+            .ok_or_else(|| anyhow!("there is no monitor"))?
+            .size())
+    }
+
     pub fn focused_monitor_work_area(&self) -> Result<Rect> {
         Ok(*self
             .focused_monitor()
@@ -1659,7 +1743,7 @@ impl WindowManager {
         None
     }
 
-    pub fn monitor_idx_from_current_pos(&mut self) -> Option<usize> {
+    pub fn monitor_idx_from_current_pos(&self) -> Option<usize> {
         let hmonitor = WindowsApi::monitor_from_point(WindowsApi::cursor_pos().ok()?);
 
         for (i, monitor) in self.monitors().iter().enumerate() {

komorebi/src/workspace.rs

@@ -412,6 +412,11 @@ impl Workspace {
         self.focus_last_container();
     }
 
+    pub fn insert_container(&mut self, container: Container, idx: usize) {
+        self.containers_mut().insert(idx, container);
+        self.focus_container(idx);
+    }
+
     fn remove_container_by_idx(&mut self, idx: usize) -> Option<Container> {
         if idx < self.resize_dimensions().len() {
             self.resize_dimensions_mut().remove(idx);