Add configurable hot-corner actions

docs/wiki/Configuration:-Gestures.md

@@ -27,6 +27,11 @@ gestures {
         // top-right
         // bottom-left
         // bottom-right
+
+        // You can also run a custom action instead of toggling the overview.
+        // top-right {
+        //     power-off-monitors
+        // }
     }
 }
 ```
@@ -85,8 +90,9 @@ gestures {
 
 <sup>Since: 25.05</sup>
 
-Put your mouse at the very top-left corner of a monitor to toggle the overview.
+Put your mouse at a hot corner of a monitor to run an action.
 Also works during drag-and-dropping something.
+By default, the top-left hot corner toggles the overview.
 
 `off` disables the hot corners.
 
@@ -101,6 +107,7 @@ gestures {
 
 <sup>Since: 25.11</sup> You can choose specific hot corners by name: `top-left`, `top-right`, `bottom-left`, `bottom-right`.
 If no corners are explicitly set, the top-left corner will be active by default.
+Bare corner names toggle the overview for compatibility with previous versions.
 
 ```kdl
 // Enable the top-right and bottom-right hot corners.
@@ -112,4 +119,17 @@ gestures {
 }
 ```
 
+You can set a hot corner to run any bind action by putting exactly one action inside its block.
+
+```kdl
+// Power off monitors when the pointer enters the top-right hot corner.
+gestures {
+    hot-corners {
+        top-right {
+            power-off-monitors
+        }
+    }
+}
+```
+
 You can also customize hot corners per-output [in the output config](./Configuration:-Outputs.md#hot-corners).

docs/wiki/Configuration:-Outputs.md

@@ -22,6 +22,11 @@ output "eDP-1" {
         // top-right
         // bottom-left
         // bottom-right
+
+        // You can also run a custom action instead of toggling the overview.
+        // top-right {
+        //     power-off-monitors
+        // }
     }
 
     layout {
@@ -286,7 +291,9 @@ output "HDMI-A-1" {
 Customize the hot corners for this output.
 By default, hot corners [in the gestures settings](./Configuration:-Gestures.md#hot-corners) are used for all outputs.
 
-Hot corners toggle the overview when you put your mouse at the very corner of a monitor.
+Hot corners run an action when you put your mouse at the very corner of a monitor.
+Bare corner names toggle the overview for compatibility with previous versions.
+A corner block with exactly one action runs that action instead.
 
 `off` will disable the hot corners on this output, and writing specific corners will enable only those hot corners on this output.
 
@@ -305,6 +312,15 @@ output "DP-2" {
         off
     }
 }
+
+// Power off monitors from the top-right hot corner on eDP-1.
+output "eDP-1" {
+    hot-corners {
+        top-right {
+            power-off-monitors
+        }
+    }
+}
 ```
 
 ### Layout config overrides

docs/wiki/Gestures.md

@@ -91,9 +91,10 @@ This will bring a floating window to the top for example.
 
 In the overview, you can also hold the mouse over a workspace to switch to it.
 
-#### Hot Corner to Toggle the Overview
+#### Hot Corners
 
 <sup>Since: 25.05</sup>
 
-Put your mouse at the very top-left corner of a monitor to toggle the overview.
+Put your mouse at a hot corner of a monitor to run its configured action.
+By default, the top-left hot corner toggles the overview.
 Also works during drag-and-dropping something.

docs/wiki/Overview.md

@@ -11,7 +11,7 @@ https://github.com/user-attachments/assets/379a5d1f-acdb-4c11-b36c-e85fd91f0995
 
 </video>
 
-Open it with the `toggle-overview` bind, via the top-left hot corner, or using a touchpad four-finger swipe up.
+Open it with the `toggle-overview` bind, via the default top-left hot corner, or using a touchpad four-finger swipe up.
 While in the overview, all keyboard shortcuts keep working, while pointing devices get easier:
 
 - Mouse: left click and drag windows to move them, right click and drag to scroll workspaces left/right, scroll to switch workspaces (no holding Mod required).
@@ -25,7 +25,7 @@ While in the overview, all keyboard shortcuts keep working, while pointing devic
 > Put your bar on the *top* layer.
 
 Drag-and-drop will scroll the workspaces up/down in the overview, and will activate a workspace when holding it for a moment.
-Combined with the hot corner, this lets you do a mouse-only DnD across workspaces.
+Combined with the default hot corner, this lets you do a mouse-only DnD across workspaces.
 
 <video controls src="https://github.com/user-attachments/assets/5f09c5b7-ff40-462b-8b9c-f1b8073a2cbb">
 

niri-config/src/gestures.rs

@@ -1,14 +1,20 @@
+use knuffel::ast::SpannedNode;
+use knuffel::decode::Context;
+use knuffel::errors::DecodeError;
+use knuffel::traits::ErrorSpan;
+
+use crate::binds::Action;
 use crate::utils::MergeWith;
 use crate::FloatOrInt;
 
-#[derive(Debug, Default, Clone, Copy, PartialEq)]
+#[derive(Debug, Default, Clone, PartialEq)]
 pub struct Gestures {
     pub dnd_edge_view_scroll: DndEdgeViewScroll,
     pub dnd_edge_workspace_switch: DndEdgeWorkspaceSwitch,
     pub hot_corners: HotCorners,
 }
 
-#[derive(knuffel::Decode, Debug, Default, Clone, Copy, PartialEq)]
+#[derive(knuffel::Decode, Debug, Default, Clone, PartialEq)]
 pub struct GesturesPart {
     #[knuffel(child)]
     pub dnd_edge_view_scroll: Option<DndEdgeViewScrollPart>,
@@ -97,16 +103,127 @@ impl MergeWith<DndEdgeWorkspaceSwitchPart> for DndEdgeWorkspaceSwitch {
     }
 }
 
-#[derive(knuffel::Decode, Debug, Default, Clone, Copy, PartialEq)]
+#[derive(knuffel::Decode, Debug, Default, Clone, PartialEq)]
 pub struct HotCorners {
     #[knuffel(child)]
     pub off: bool,
     #[knuffel(child)]
-    pub top_left: bool,
+    pub top_left: Option<HotCorner>,
     #[knuffel(child)]
-    pub top_right: bool,
+    pub top_right: Option<HotCorner>,
     #[knuffel(child)]
-    pub bottom_left: bool,
+    pub bottom_left: Option<HotCorner>,
     #[knuffel(child)]
-    pub bottom_right: bool,
+    pub bottom_right: Option<HotCorner>,
+}
+
+#[derive(Debug, Default, Clone, PartialEq)]
+pub struct HotCorner {
+    pub action: Option<Action>,
+}
+
+impl HotCorners {
+
+    pub fn has_any_explicit_corner(&self) -> bool {
+        self.top_left.is_some()
+            || self.top_right.is_some()
+            || self.bottom_left.is_some()
+            || self.bottom_right.is_some()
+    }
+
+    pub fn action_top_left(&self) -> Option<Action> {
+        if self.off {
+            return None;
+        }
+
+        if let Some(corner) = &self.top_left {
+            return Some(corner.action.clone().unwrap_or(Action::ToggleOverview));
+        }
+
+        if !self.has_any_explicit_corner() {
+            return Some(Action::ToggleOverview);
+        }
+
+        None
+    }
+
+    pub fn action_top_right(&self) -> Option<Action> {
+        if self.off {
+            return None;
+        }
+
+        self.top_right
+            .as_ref()
+            .map(|corner| corner.action.clone().unwrap_or(Action::ToggleOverview))
+    }
+
+    pub fn action_bottom_left(&self) -> Option<Action> {
+        if self.off {
+            return None;
+        }
+
+        self.bottom_left
+            .as_ref()
+            .map(|corner| corner.action.clone().unwrap_or(Action::ToggleOverview))
+    }
+
+    pub fn action_bottom_right(&self) -> Option<Action> {
+        if self.off {
+            return None;
+        }
+
+        self.bottom_right
+            .as_ref()
+            .map(|corner| corner.action.clone().unwrap_or(Action::ToggleOverview))
+    }
+}
+
+impl<S: ErrorSpan> knuffel::Decode<S> for HotCorner {
+    fn decode_node(node: &SpannedNode<S>, ctx: &mut Context<S>) -> Result<Self, DecodeError<S>> {
+        if let Some(type_name) = &node.type_name {
+            ctx.emit_error(DecodeError::unexpected(
+                type_name,
+                "type name",
+                "no type name expected for this node",
+            ));
+        }
+
+        for val in node.arguments.iter() {
+            ctx.emit_error(DecodeError::unexpected(
+                &val.literal,
+                "argument",
+                "no arguments expected for this node",
+            ));
+        }
+
+        for (name, _) in &node.properties {
+            ctx.emit_error(DecodeError::unexpected(
+                name,
+                "property",
+                format!("unexpected property `{}`", name.escape_default()),
+            ));
+        }
+
+        let mut children = node.children();
+        let action = if let Some(child) = children.next() {
+            for unwanted_child in children {
+                ctx.emit_error(DecodeError::unexpected(
+                    unwanted_child,
+                    "node",
+                    "only one action is allowed per hot corner",
+                ));
+            }
+            match <Action as knuffel::Decode<S>>::decode_node(child, ctx) {
+                Ok(action) => Some(action),
+                Err(e) => {
+                    ctx.emit_error(e);
+                    None
+                }
+            }
+        } else {
+            None
+        };
+
+        Ok(Self { action })
+    }
 }

niri-config/src/lib.rs

@@ -870,6 +870,13 @@ mod tests {
                     trigger-width 10
                     max-speed 50
                 }
+
+                hot-corners {
+                    top-left
+                    top-right {
+                        power-off-monitors
+                    }
+                }
             }
 
             environment {
@@ -1191,10 +1198,26 @@ mod tests {
                         hot_corners: Some(
                             HotCorners {
                                 off: true,
-                                top_left: true,
-                                top_right: true,
-                                bottom_left: true,
-                                bottom_right: true,
+                                top_left: Some(
+                                    HotCorner {
+                                        action: None,
+                                    },
+                                ),
+                                top_right: Some(
+                                    HotCorner {
+                                        action: None,
+                                    },
+                                ),
+                                bottom_left: Some(
+                                    HotCorner {
+                                        action: None,
+                                    },
+                                ),
+                                bottom_right: Some(
+                                    HotCorner {
+                                        action: None,
+                                    },
+                                ),
                             },
                         ),
                         layout: None,
@@ -1658,10 +1681,20 @@ mod tests {
                 },
                 hot_corners: HotCorners {
                     off: false,
-                    top_left: false,
-                    top_right: false,
-                    bottom_left: false,
-                    bottom_right: false,
+                    top_left: Some(
+                        HotCorner {
+                            action: None,
+                        },
+                    ),
+                    top_right: Some(
+                        HotCorner {
+                            action: Some(
+                                PowerOffMonitors,
+                            ),
+                        },
+                    ),
+                    bottom_left: None,
+                    bottom_right: None,
                 },
             },
             overview: Overview {

resources/default-config.kdl

@@ -346,6 +346,15 @@ window-rule {
     clip-to-geometry true
 }
 
+// Hot corners can trigger actions when you move the mouse into a monitor corner.
+// Bare corner names toggle the overview. Corner blocks can run any bind action.
+// gestures {
+//     hot-corners {
+//         top-left
+//         // top-right { power-off-monitors; }
+//     }
+// }
+
 binds {
     // Keys consist of modifiers separated by + signs, followed by an XKB key name
     // in the end. To find an XKB name for a particular key, you may use a program
@@ -394,7 +403,7 @@ binds {
     XF86MonBrightnessDown allow-when-locked=true { spawn "brightnessctl" "--class=backlight" "set" "10%-"; }
 
     // Open/close the Overview: a zoomed-out view of workspaces and windows.
-    // You can also move the mouse into the top-left hot corner,
+    // You can also move the mouse into the default top-left hot corner,
     // or do a four-finger swipe up on a touchpad.
     Mod+O repeat=false { toggle-overview; }
 

src/input/mod.rs

@@ -2631,7 +2631,11 @@ impl State {
                     .with_grab(|_, grab| grab_allows_hot_corner(grab))
                     .unwrap_or(true)
             {
-                self.niri.layout.toggle_overview();
+                if let Some((output, pos_within_output)) = self.niri.output_under(new_pos) {
+                    if let Some(action) = self.niri.hot_corner_action(output, pos_within_output) {
+                        self.do_action(action, false);
+                    }
+                }
             }
             self.niri.pointer_inside_hot_corner = true;
         }
@@ -2718,7 +2722,11 @@ impl State {
                     .with_grab(|_, grab| grab_allows_hot_corner(grab))
                     .unwrap_or(true)
             {
-                self.niri.layout.toggle_overview();
+                if let Some((output, pos_within_output)) = self.niri.output_under(pos) {
+                    if let Some(action) = self.niri.hot_corner_action(output, pos_within_output) {
+                        self.do_action(action, false);
+                    }
+                }
             }
             self.niri.pointer_inside_hot_corner = true;
         }